Last updated on March 22nd, 2023 at 12:10 am
Title 40 – Protection of Environment–Volume 9
CHAPTER I – ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
SUBCHAPTER C – AIR PROGRAMS (CONTINUED)
PART 60 – STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES (CONTINUED)
Appendix A-1 to Part 60 – Test Methods 1 through 2F
The test methods in this appendix are referred to in § 60.8 (Performance Tests) and § 60.11 (Compliance With Standards and Maintenance Requirements) of 40 CFR part 60, subpart A (General Provisions). Specific uses of these test methods are described in the standards of performance contained in the subparts, beginning with Subpart D.
Within each standard of performance, a section title “Test Methods and Procedures” is provided to: (1) Identify the test methods to be used as reference methods to the facility subject to the respective standard and (2) identify any special instructions or conditions to be followed when applying a method to the respective facility. Such instructions (for example, establish sampling rates, volumes, or temperatures) are to be used either in addition to, or as a substitute for procedures in a test method. Similarly, for sources subject to emission monitoring requirements, specific instructions pertaining to any use of a test method as a reference method are provided in the subpart or in appendix B.
Inclusion of methods in this appendix is not intended as an endorsement or denial of their applicability to sources that are not subject to standards of performance. The methods are potentially applicable to other sources; however, applicability should be confirmed by careful and appropriate evaluation of the conditions prevalent at such sources.
The approach followed in the formulation of the test methods involves specifications for equipment, procedures, and performance. In concept, a performance specification approach would be preferable in all methods because this allows the greatest flexibility to the user. In practice, however, this approach is impractical in most cases because performance specifications cannot be established. Most of the methods described herein, therefore, involve specific equipment specifications and procedures, and only a few methods in this appendix rely on performance criteria.
Minor changes in the test methods should not necessarily affect the validity of the results and it is recognized that alternative and equivalent methods exist. section 60.8 provides authority for the Administrator to specify or approve (1) equivalent methods, (2) alternative methods, and (3) minor changes in the methodology of the test methods. It should be clearly understood that unless otherwise identified all such methods and changes must have prior approval of the Administrator. An owner employing such methods or deviations from the test methods without obtaining prior approval does so at the risk of subsequent disapproval and retesting with approved methods.
Within the test methods, certain specific equipment or procedures are recognized as being acceptable or potentially acceptable and are specifically identified in the methods. The items identified as acceptable options may be used without approval but must be identified in the test report. The potentially approvable options are cited as “subject to the approval of the Administrator” or as “or equivalent.” Such potentially approvable techniques or alternatives may be used at the discretion of the owner without prior approval. However, detailed descriptions for applying these potentially approvable techniques or alternatives are not provided in the test methods. Also, the potentially approvable options are not necessarily acceptable in all applications. Therefore, an owner electing to use such potentially approvable techniques or alternatives is responsible for: (1) assuring that the techniques or alternatives are in fact applicable and are properly executed; (2) including a written description of the alternative method in the test report (the written method must be clear and must be capable of being performed without additional instruction, and the degree of detail should be similar to the detail contained in the test methods); and (3) providing any rationale or supporting data necessary to show the validity of the alternative in the particular application. Failure to meet these requirements can result in the Administrator’s disapproval of the alternative.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test method: Method 2.
1.1 Measured Parameters. The purpose of the method is to provide guidance for the selection of sampling ports and traverse points at which sampling for air pollutants will be performed pursuant to regulations set forth in this part. Two procedures are presented: a simplified procedure, and an alternative procedure (see section 11.5). The magnitude of cyclonic flow of effluent gas in a stack or duct is the only parameter quantitatively measured in the simplified procedure.
1.2 Applicability. This method is applicable to gas streams flowing in ducts, stacks, and flues. This method cannot be used when: (1) the flow is cyclonic or swirling; or (2) a stack is smaller than 0.30 meter (12 in.) in diameter, or 0.071 m
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
The requirements of this method must be considered before construction of a new facility from which emissions are to be measured; failure to do so may require subsequent alterations to the stack or deviation from the standard procedure. Cases involving variants are subject to approval by the Administrator.
2.1 This method is designed to aid in the representative measurement of pollutant emissions and/or total volumetric flow rate from a stationary source. A measurement site where the effluent stream is flowing in a known direction is selected, and the cross-section of the stack is divided into a number of equal areas. Traverse points are then located within each of these equal areas.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method.
6.1 Apparatus. The apparatus described below is required only when utilizing the alternative site selection procedure described in section 11.5 of this method.
6.1.1 Directional Probe. Any directional probe, such as United Sensor Type DA Three-Dimensional Directional Probe, capable of measuring both the pitch and yaw angles of gas flows is acceptable. Before using the probe, assign an identification number to the directional probe, and permanently mark or engrave the number on the body of the probe. The pressure holes of directional probes are susceptible to plugging when used in particulate-laden gas streams. Therefore, a procedure for cleaning the pressure holes by “back-purging” with pressurized air is required.
6.1.2 Differential Pressure Gauges. Inclined manometers, U-tube manometers, or other differential pressure gauges (e.g., magnehelic gauges) that meet the specifications described in Method 2, section 6.2.
If the differential pressure gauge produces both negative and positive readings, then both negative and positive pressure readings shall be calibrated at a minimum of three points as specified in Method 2, section 6.2.
11.1 Selection of Measurement Site.
11.1.1 Sampling and/or velocity measurements are performed at a site located at least eight stack or duct diameters downstream and two diameters upstream from any flow disturbance such as a bend, expansion, or contraction in the stack, or from a visible flame. If necessary, an alternative location may be selected, at a position at least two stack or duct diameters downstream and a half diameter upstream from any flow disturbance.
11.1.2 An alternative procedure is available for determining the acceptability of a measurement location not meeting the criteria above. This procedure described in section 11.5 allows for the determination of gas flow angles at the sampling points and comparison of the measured results with acceptability criteria.
11.2 Determining the Number of Traverse Points.
11.2.1 Particulate Traverses.
11.2.1.1 When the eight- and two-diameter criterion can be met, the minimum number of traverse points shall be: (1) twelve, for circular or rectangular stacks with diameters (or equivalent diameters) greater than 0.61 meter (24 in.); (2) eight, for circular stacks with diameters between 0.30 and 0.61 meter (12 and 24 in.); and (3) nine, for rectangular stacks with equivalent diameters between 0.30 and 0.61 meter (12 and 24 in.).
11.2.1.2 When the eight- and two-diameter criterion cannot be met, the minimum number of traverse points is determined from Figure 1-1. Before referring to the figure, however, determine the distances from the measurement site to the nearest upstream and downstream disturbances, and divide each distance by the stack diameter or equivalent diameter, to determine the distance in terms of the number of duct diameters. Then, determine from Figure 1-1 the minimum number of traverse points that corresponds:
(1) To the number of duct diameters upstream; and
(2) To the number of diameters downstream. Select the higher of the two minimum numbers of traverse points, or a greater value, so that for circular stacks, the number is a multiple of 4, and for rectangular stacks, the number is one of those shown in Table 1-1.
11.2.2 Velocity (Non-Particulate) Traverses. When velocity or volumetric flow rate is to be determined (but not particulate matter), the same procedure as that used for particulate traverses (Section 11.2.1) is followed, except that Figure 1-2 may be used instead of Figure 1-1.
11.3 Cross-Sectional Layout and Location of Traverse Points.
11.3.1 Circular Stacks.
11.3.1.1 Locate the traverse points on two perpendicular diameters according to Table 1-2 and the example shown in Figure 1-3. Any equation (see examples in References 2 and 3 in section 16.0) that gives the same values as those in Table 1-2 may be used in lieu of Table 1-2.
11.3.1.2 For particulate traverses, one of the diameters must coincide with the plane containing the greatest expected concentration variation (e.g., after bends); one diameter shall be congruent to the direction of the bend. This requirement becomes less critical as the distance from the disturbance increases; therefore, other diameter locations may be used, subject to the approval of the Administrator.
11.3.1.3 In addition, for elliptical stacks having unequal perpendicular diameters, separate traverse points shall be calculated and located along each diameter. To determine the cross-sectional area of the elliptical stack, use the following equation:
11.3.1.4 In addition, for stacks having diameters greater than 0.61 m (24 in.), no traverse points shall be within 2.5 centimeters (1.00 in.) of the stack walls; and for stack diameters equal to or less than 0.61 m (24 in.), no traverse points shall be located within 1.3 cm (0.50 in.) of the stack walls. To meet these criteria, observe the procedures given below.
11.3.2 Stacks With Diameters Greater Than 0.61 m (24 in.).
11.3.2.1 When any of the traverse points as located in section 11.3.1 fall within 2.5 cm (1.0 in.) of the stack walls, relocate them away from the stack walls to: (1) a distance of 2.5 cm (1.0 in.); or (2) a distance equal to the nozzle inside diameter, whichever is larger. These relocated traverse points (on each end of a diameter) shall be the “adjusted” traverse points.
11.3.2.2 Whenever two successive traverse points are combined to form a single adjusted traverse point, treat the adjusted point as two separate traverse points, both in the sampling and/or velocity measurement procedure, and in recording of the data.
11.3.3 Stacks With Diameters Equal To or Less Than 0.61 m (24 in.). Follow the procedure in section 11.3.1.1, noting only that any “adjusted” points should be relocated away from the stack walls to: (1) a distance of 1.3 cm (0.50 in.); or (2) a distance equal to the nozzle inside diameter, whichever is larger.
11.3.4 Rectangular Stacks.
11.3.4.1 Determine the number of traverse points as explained in sections 11.1 and 11.2 of this method. From Table 1-1, determine the grid configuration. Divide the stack cross-section into as many equal rectangular elemental areas as traverse points, and then locate a traverse point at the centroid of each equal area according to the example in Figure 1-4.
11.3.4.2 To use more than the minimum number of traverse points, expand the “minimum number of traverse points” matrix (see Table 1-1) by adding the extra traverse points along one or the other or both legs of the matrix; the final matrix need not be balanced. For example, if a 4 × 3 “minimum number of points” matrix were expanded to 36 points, the final matrix could be 9 × 4 or 12 × 3, and would not necessarily have to be 6 × 6. After constructing the final matrix, divide the stack cross-section into as many equal rectangular, elemental areas as traverse points, and locate a traverse point at the centroid of each equal area.
11.3.4.3 The situation of traverse points being too close to the stack walls is not expected to arise with rectangular stacks. If this problem should ever arise, the Administrator must be contacted for resolution of the matter.
11.4 Verification of Absence of Cyclonic Flow.
11.4.1 In most stationary sources, the direction of stack gas flow is essentially parallel to the stack walls. However, cyclonic flow may exist (1) after such devices as cyclones and inertial demisters following venturi scrubbers, or (2) in stacks having tangential inlets or other duct configurations which tend to induce swirling; in these instances, the presence or absence of cyclonic flow at the sampling location must be determined. The following techniques are acceptable for this determination.
11.4.2 Level and zero the manometer. Connect a Type S pitot tube to the manometer and leak-check system. Position the Type S pitot tube at each traverse point, in succession, so that the planes of the face openings of the pitot tube are perpendicular to the stack cross-sectional plane; when the Type S pitot tube is in this position, it is at “0° reference.” Note the differential pressure (Δp) reading at each traverse point. If a null (zero) pitot reading is obtained at 0° reference at a given traverse point, an acceptable flow condition exists at that point. If the pitot reading is not zero at 0° reference, rotate the pitot tube (up to ±90° yaw angle), until a null reading is obtained. Carefully determine and record the value of the rotation angle (α) to the nearest degree. After the null technique has been applied at each traverse point, calculate the average of the absolute values of α; assign α values of 0° to those points for which no rotation was required, and include these in the overall average. If the average value of α is greater than 20°, the overall flow condition in the stack is unacceptable, and alternative methodology, subject to the approval of the Administrator, must be used to perform accurate sample and velocity traverses.
11.5 The alternative site selection procedure may be used to determine the rotation angles in lieu of the procedure outlined in section 11.4.
11.5.1 Alternative Measurement Site Selection Procedure. This alternative applies to sources where measurement locations are less than 2 equivalent or duct diameters downstream or less than one-half duct diameter upstream from a flow disturbance. The alternative should be limited to ducts larger than 24 in. in diameter where blockage and wall effects are minimal. A directional flow-sensing probe is used to measure pitch and yaw angles of the gas flow at 40 or more traverse points; the resultant angle is calculated and compared with acceptable criteria for mean and standard deviation.
Both the pitch and yaw angles are measured from a line passing through the traverse point and parallel to the stack axis. The pitch angle is the angle of the gas flow component in the plane that INCLUDES the traverse line and is parallel to the stack axis. The yaw angle is the angle of the gas flow component in the plane PERPENDICULAR to the traverse line at the traverse point and is measured from the line passing through the traverse point and parallel to the stack axis.
11.5.2 Traverse Points. Use a minimum of 40 traverse points for circular ducts and 42 points for rectangular ducts for the gas flow angle determinations. Follow the procedure outlined in section 11.3 and Table 1-1 or 1-2 for the location and layout of the traverse points. If the measurement location is determined to be acceptable according to the criteria in this alternative procedure, use the same traverse point number and locations for sampling and velocity measurements.
11.5.3 Measurement Procedure.
11.5.3.1 Prepare the directional probe and differential pressure gauges as recommended by the manufacturer. Capillary tubing or surge tanks may be used to dampen pressure fluctuations. It is recommended, but not required, that a pretest leak check be conducted. To perform a leak check, pressurize or use suction on the impact opening until a reading of at least 7.6 cm (3 in.) H
11.5.3.2 Level and zero the manometers. Since the manometer level and zero may drift because of vibrations and temperature changes, periodically check the level and zero during the traverse.
11.5.3.3 Position the probe at the appropriate locations in the gas stream, and rotate until zero deflection is indicated for the yaw angle pressure gauge. Determine and record the yaw angle. Record the pressure gauge readings for the pitch angle, and determine the pitch angle from the calibration curve. Repeat this procedure for each traverse point. Complete a “back-purge” of the pressure lines and the impact openings prior to measurements of each traverse point.
11.5.3.4 A post-test check as described in section 11.5.3.1 is required. If the criteria for a leak-free system are not met, repair the equipment, and repeat the flow angle measurements.
11.5.4 Calibration. Use a flow system as described in sections 10.1.2.1 and 10.1.2.2 of Method 2. In addition, the flow system shall have the capacity to generate two test-section velocities: one between 365 and 730 m/min (1,200 and 2,400 ft/min) and one between 730 and 1,100 m/min (2,400 and 3,600 ft/min).
11.5.4.1 Cut two entry ports in the test section. The axes through the entry ports shall be perpendicular to each other and intersect in the centroid of the test section. The ports should be elongated slots parallel to the axis of the test section and of sufficient length to allow measurement of pitch angles while maintaining the pitot head position at the test-section centroid. To facilitate alignment of the directional probe during calibration, the test section should be constructed of plexiglass or some other transparent material. All calibration measurements should be made at the same point in the test section, preferably at the centroid of the test section.
11.5.4.2 To ensure that the gas flow is parallel to the central axis of the test section, follow the procedure outlined in section 11.4 for cyclonic flow determination to measure the gas flow angles at the centroid of the test section from two test ports located 90° apart. The gas flow angle measured in each port must be ±2° of 0°. Straightening vanes should be installed, if necessary, to meet this criterion.
11.5.4.3 Pitch Angle Calibration. Perform a calibration traverse according to the manufacturer’s recommended protocol in 5° increments for angles from −60° to + 60° at one velocity in each of the two ranges specified above. Average the pressure ratio values obtained for each angle in the two flow ranges, and plot a calibration curve with the average values of the pressure ratio (or other suitable measurement factor as recommended by the manufacturer) versus the pitch angle. Draw a smooth line through the data points. Plot also the data values for each traverse point. Determine the differences between the measured data values and the angle from the calibration curve at the same pressure ratio. The difference at each comparison must be within 2° for angles between 0° and 40° and within 3° for angles between 40° and 60°.
11.5.4.4 Yaw Angle Calibration. Mark the three-dimensional probe to allow the determination of the yaw position of the probe. This is usually a line extending the length of the probe and aligned with the impact opening. To determine the accuracy of measurements of the yaw angle, only the zero or null position need be calibrated as follows: Place the directional probe in the test section, and rotate the probe until the zero position is found. With a protractor or other angle measuring device, measure the angle indicated by the yaw angle indicator on the three-dimensional probe. This should be within 2° of 0°. Repeat this measurement for any other points along the length of the pitot where yaw angle measurements could be read in order to account for variations in the pitot markings used to indicate pitot head positions.
12.1 Nomenclature.
12.2 For a rectangular cross section, an equivalent diameter (D
12.3 If use of the alternative site selection procedure (Section 11.5 of this method) is required, perform the following calculations using the equations below: the resultant angle at each traverse point, the average resultant angle, and the standard deviation. Complete the calculations retaining at least one extra significant figure beyond that of the acquired data. Round the values after the final calculations.
12.3.1 Calculate the resultant angle at each traverse point:
12.3.2 Calculate the average resultant for the measurements:
12.3.3 Calculate the standard deviations:
12.3.4 Acceptability Criteria. The measurement location is acceptable if R
1. Determining Dust Concentration in a Gas Stream, ASME Performance Test Code No. 27. New York. 1957.
2. DeVorkin, Howard, et al. Air Pollution Source Testing Manual. Air Pollution Control District. Los Angeles, CA. November 1963.
3. Methods for Determining of Velocity, Volume, Dust and Mist Content of Gases. Western Precipitation Division of Joy Manufacturing Co. Los Angeles, CA. Bulletin WP-50. 1968.
4. Standard Method for Sampling Stacks for Particulate Matter. In: 1971 Book of ASTM Standards, Part 23. ASTM Designation D 2928-71. Philadelphia, PA. 1971.
5. Hanson, H.A., et al. Particulate Sampling Strategies for Large Power Plants Including Nonuniform Flow. USEPA, ORD, ESRL, Research Triangle Park, NC. EPA-600/2-76-170. June 1976.
6. Entropy Environmentalists, Inc. Determination of the Optimum Number of Sampling Points: An Analysis of Method 1 Criteria. Environmental Protection Agency. Research Triangle Park, NC. EPA Contract No. 68-01-3172, Task 7.
7. Hanson, H.A., R.J. Davini, J.K. Morgan, and A.A. Iversen. Particulate Sampling Strategies for Large Power Plants Including Nonuniform Flow. USEPA, Research Triangle Park, NC. Publication No. EPA-600/2-76-170. June 1976. 350 pp.
8. Brooks, E.F., and R.L. Williams. Flow and Gas Sampling Manual. U.S. Environmental Protection Agency. Research Triangle Park, NC. Publication No. EPA-600/2-76-203. July 1976. 93 pp.
9. Entropy Environmentalists, Inc. Traverse Point Study. EPA Contract No. 68-02-3172. June 1977. 19 pp.
10. Brown, J. and K. Yu. Test Report: Particulate Sampling Strategy in Circular Ducts. Emission Measurement Branch. U.S. Environmental Protection Agency, Research Triangle Park, NC 27711. July 31, 1980. 12 pp.
11. Hawksley, P.G.W., S. Badzioch, and J.H. Blackett. Measurement of Solids in Flue Gases. Leatherhead, England, The British Coal Utilisation Research Association. 1961. pp. 129-133.
12. Knapp, K.T. The Number of Sampling Points Needed for Representative Source Sampling. In: Proceedings of the Fourth National Conference on Energy and Environment. Theodore, L. et al. (ed). Dayton, Dayton section of the American Institute of Chemical Engineers. October 3-7, 1976. pp. 563-568.
13. Smith, W.S. and D.J. Grove. A Proposed Extension of EPA Method 1 Criteria. Pollution Engineering. XV (8):36-37. August 1983.
14. Gerhart, P.M. and M.J. Dorsey. Investigation of Field Test Procedures for Large Fans. University of Akron. Akron, OH. (EPRI Contract CS-1651). Final Report (RP-1649-5). December 1980.
15. Smith, W.S. and D.J. Grove. A New Look at Isokinetic Sampling – Theory and Applications. Source Evaluation Society Newsletter. VIII (3):19-24. August 1983.
Table 1-1 Cross-Section Layout for Rectangular Stacks
| Number of tranverse points layout | Matrix |
|---|---|
| 9 | 3 × 3 |
| 12 | 4 × 3 |
| 16 | 4 × 4 |
| 20 | 5 × 4 |
| 25 | 5 × 5 |
| 30 | 6 × 5 |
| 36 | 6 × 6 |
| 42 | 7 × 6 |
| 49 | 7 × 7 |
Table 1-2 – Location of Traverse Points in Circular Stacks
[Percent of stack diameter from inside wall to tranverse point]
| Traverse point number on a diameter | Number of traverse points on a diameter | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2 | 4 | 6 | 8 | 10 | 12 | 14 | 16 | 18 | 20 | 22 | 24 | |
| 1 | 14.6 | 6.7 | 4.4 | 3.2 | 2.6 | 2.1 | 1.8 | 1.6 | 1.4 | 1.3 | 1.1 | 1.1 |
| 2 | 85.4 | 25.0 | 14.6 | 10.5 | 8.2 | 6.7 | 5.7 | 4.9 | 4.4 | 3.9 | 3.5 | 3.2 |
| 3 | 75.0 | 29.6 | 19.4 | 14.6 | 11.8 | 9.9 | 8.5 | 7.5 | 6.7 | 6.0 | 5.5 | |
| 4 | 93.3 | 70.4 | 32.3 | 22.6 | 17.7 | 14.6 | 12.5 | 10.9 | 9.7 | 8.7 | 7.9 | |
| 5 | 85.4 | 67.7 | 34.2 | 25.0 | 20.1 | 16.9 | 14.6 | 12.9 | 11.6 | 10.5 | ||
| 6 | 95.6 | 80.6 | 65.8 | 35.6 | 26.9 | 22.0 | 18.8 | 16.5 | 14.6 | 13.2 | ||
| 7 | 89.5 | 77.4 | 64.4 | 36.6 | 28.3 | 23.6 | 20.4 | 18.0 | 16.1 | |||
| 8 | 96.8 | 85.4 | 75.0 | 63.4 | 37.5 | 29.6 | 25.0 | 21.8 | 19.4 | |||
| 9 | 91.8 | 82.3 | 73.1 | 62.5 | 38.2 | 30.6 | 26.2 | 23.0 | ||||
| 10 | 97.4 | 88.2 | 79.9 | 71.7 | 61.8 | 38.8 | 31.5 | 27.2 | ||||
| 11 | 93.3 | 85.4 | 78.0 | 70.4 | 61.2 | 39.3 | 32.3 | |||||
| 12 | 97.9 | 90.1 | 83.1 | 76.4 | 69.4 | 60.7 | 39.8 | |||||
| 13 | 94.3 | 87.5 | 81.2 | 75.0 | 68.5 | 60.2 | ||||||
| 14 | 98.2 | 91.5 | 85.4 | 79.6 | 73.8 | 67.7 | ||||||
| 15 | 95.1 | 89.1 | 83.5 | 78.2 | 72.8 | |||||||
| 16 | 98.4 | 92.5 | 87.1 | 82.0 | 77.0 | |||||||
| 17 | 95.6 | 90.3 | 85.4 | 80.6 | ||||||||
| 18 | 98.6 | 93.3 | 88.4 | 83.9 | ||||||||
| 19 | 96.1 | 91.3 | 86.8 | |||||||||
| 20 | 98.7 | 94.0 | 89.5 | |||||||||
| 21 | 96.5 | 92.1 | ||||||||||
| 22 | 98.9 | 94.5 | ||||||||||
| 23 | 96.8 | |||||||||||
| 24 | 99.9 | |||||||||||
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test method: Method 1.
1.1 Measured Parameters. The purpose of the method is to provide guidance for the selection of sampling ports and traverse points at which sampling for air pollutants will be performed pursuant to regulations set forth in this part.
1.2 Applicability. The applicability and principle of this method are identical to Method 1, except its applicability is limited to stacks or ducts. This method is applicable to flowing gas streams in ducts, stacks, and flues of less than about 0.30 meter (12 in.) in diameter, or 0.071 m
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 The method is designed to aid in the representative measurement of pollutant emissions and/or total volumetric flow rate from a stationary source. A measurement site or a pair of measurement sites where the effluent stream is flowing in a known direction is (are) selected. The cross-section of the stack is divided into a number of equal areas. Traverse points are then located within each of these equal areas.
2.2 In these small diameter stacks or ducts, the conventional Method 5 stack assembly (consisting of a Type S pitot tube attached to a sampling probe, equipped with a nozzle and thermocouple) blocks a significant portion of the cross-section of the duct and causes inaccurate measurements. Therefore, for particulate matter (PM) sampling in small stacks or ducts, the gas velocity is measured using a standard pitot tube downstream of the actual emission sampling site. The straight run of duct between the PM sampling and velocity measurement sites allows the flow profile, temporarily disturbed by the presence of the sampling probe, to redevelop and stabilize.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method.
11.1 Selection of Measurement Site.
11.1.1 Particulate Measurements – Steady or Unsteady Flow. Select a particulate measurement site located preferably at least eight equivalent stack or duct diameters downstream and 10 equivalent diameters upstream from any flow disturbances such as bends, expansions, or contractions in the stack, or from a visible flame. Next, locate the velocity measurement site eight equivalent diameters downstream of the particulate measurement site (see Figure 1A-1). If such locations are not available, select an alternative particulate measurement location at least two equivalent stack or duct diameters downstream and two and one-half diameters upstream from any flow disturbance. Then, locate the velocity measurement site two equivalent diameters downstream from the particulate measurement site. (See section 12.2 of Method 1 for calculating equivalent diameters for a rectangular cross-section.)
11.1.2 PM Sampling (Steady Flow) or Velocity (Steady or Unsteady Flow) Measurements. For PM sampling when the volumetric flow rate in a duct is constant with respect to time, section 11.1.1 of Method 1 may be followed, with the PM sampling and velocity measurement performed at one location. To demonstrate that the flow rate is constant (within 10 percent) when PM measurements are made, perform complete velocity traverses before and after the PM sampling run, and calculate the deviation of the flow rate derived after the PM sampling run from the one derived before the PM sampling run. The PM sampling run is acceptable if the deviation does not exceed 10 percent.
11.2 Determining the Number of Traverse Points.
11.2.1 Particulate Measurements (Steady or Unsteady Flow). Use Figure 1-1 of Method 1 to determine the number of traverse points to use at both the velocity measurement and PM sampling locations. Before referring to the figure, however, determine the distances between both the velocity measurement and PM sampling sites to the nearest upstream and downstream disturbances. Then divide each distance by the stack diameter or equivalent diameter to express the distances in terms of the number of duct diameters. Then, determine the number of traverse points from Figure 1-1 of Method 1 corresponding to each of these four distances. Choose the highest of the four numbers of traverse points (or a greater number) so that, for circular ducts the number is a multiple of four; and for rectangular ducts, the number is one of those shown in Table 1-1 of Method 1. When the optimum duct diameter location criteria can be satisfied, the minimum number of traverse points required is eight for circular ducts and nine for rectangular ducts.
11.2.2 PM Sampling (Steady Flow) or only Velocity (Non-Particulate) Measurements. Use Figure 1-2 of Method 1 to determine number of traverse points, following the same procedure used for PM sampling as described in section 11.2.1 of Method 1. When the optimum duct diameter location criteria can be satisfied, the minimum number of traverse points required is eight for circular ducts and nine for rectangular ducts.
11.3 Cross-sectional Layout, Location of Traverse Points, and Verification of the Absence of Cyclonic Flow. Same as Method 1, sections 11.3 and 11.4, respectively.
Same as Method 1, section 16.0, References 1 through 6, with the addition of the following:
1. Vollaro, Robert F. Recommended Procedure for Sample Traverses in Ducts Smaller Than 12 Inches in Diameter. U.S. Environmental Protection Agency, Emission Measurement Branch, Research Triangle Park, North Carolina. January 1977.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test method: Method 1.
1.1 This method is applicable for the determination of the average velocity and the volumetric flow rate of a gas stream.
1.2 This method is not applicable at measurement sites that fail to meet the criteria of Method 1, section 11.1. Also, the method cannot be used for direct measurement in cyclonic or swirling gas streams; section 11.4 of Method 1 shows how to determine cyclonic or swirling flow conditions. When unacceptable conditions exist, alternative procedures, subject to the approval of the Administrator, must be employed to produce accurate flow rate determinations. Examples of such alternative procedures are: (1) to install straightening vanes; (2) to calculate the total volumetric flow rate stoichiometrically, or (3) to move to another measurement site at which the flow is acceptable.
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 The average gas velocity in a stack is determined from the gas density and from measurement of the average velocity head with a Type S (Stausscheibe or reverse type) pitot tube.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method.
Specifications for the apparatus are given below. Any other apparatus that has been demonstrated (subject to approval of the Administrator) to be capable of meeting the specifications will be considered acceptable.
6.1 Type S Pitot Tube.
6.1.1 Pitot tube made of metal tubing (e.g., stainless steel) as shown in Figure 2-1. It is recommended that the external tubing diameter (dimension D
6.1.2 The Type S pitot tube shall have a known coefficient, determined as outlined in section 10.0. An identification number shall be assigned to the pitot tube; this number shall be permanently marked or engraved on the body of the tube. A standard pitot tube may be used instead of a Type S, provided that it meets the specifications of sections 6.7 and 10.2. Note, however, that the static and impact pressure holes of standard pitot tubes are susceptible to plugging in particulate-laden gas streams. Therefore, whenever a standard pitot tube is used to perform a traverse, adequate proof must be furnished that the openings of the pitot tube have not plugged up during the traverse period. This can be accomplished by comparing the velocity head (Δp) measurement recorded at a selected traverse point (readable Δp value) with a second Δp measurement recorded after “back purging” with pressurized air to clean the impact and static holes of the standard pitot tube. If the before and after Δp measurements are within 5 percent, then the traverse data are acceptable. Otherwise, the data should be rejected and the traverse measurements redone. Note that the selected traverse point should be one that demonstrates a readable Δp value. If “back purging” at regular intervals is part of a routine procedure, then comparative Δp measurements shall be conducted as above for the last two traverse points that exhibit suitable Δp measurements.
6.2 Differential Pressure Gauge. An inclined manometer or equivalent device. Most sampling trains are equipped with a 10 in. (water column) inclined-vertical manometer, having 0.01 in. H
6.2.1 As an alternative to criteria (1) through (3) above, Equation 2-1 (Section 12.2) may be used to determine the necessity of using a more sensitive differential pressure gauge. If T is greater than 1.05, the velocity head data are unacceptable and a more sensitive differential pressure gauge must be used.
If differential pressure gauges other than inclined manometers are used (e.g., magnehelic gauges), their calibration must be checked after each test series. To check the calibration of a differential pressure gauge, compare Δp readings of the gauge with those of a gauge-oil manometer at a minimum of three points, approximately representing the range of Δp values in the stack. If, at each point, the values of Δp as read by the differential pressure gauge and gauge-oil manometer agree to within 5 percent, the differential pressure gauge shall be considered to be in proper calibration. Otherwise, the test series shall either be voided, or procedures to adjust the measured Δp values and final results shall be used, subject to the approval of the Administrator.
6.3 Temperature Sensor. A thermocouple, liquid-filled bulb thermometer, bimetallic thermometer, mercury-in-glass thermometer, or other gauge capable of measuring temperatures to within 1.5 percent of the minimum absolute stack temperature. The temperature sensor shall be attached to the pitot tube such that the sensor tip does not touch any metal; the gauge shall be in an interference-free arrangement with respect to the pitot tube face openings (see Figure 2-1 and Figure 2-4). Alternative positions may be used if the pitot tube-temperature gauge system is calibrated according to the procedure of section 10.0. Provided that a difference of not more than 1 percent in the average velocity measurement is introduced, the temperature gauge need not be attached to the pitot tube. This alternative is subject to the approval of the Administrator.
6.4 Pressure Probe and Gauge. A piezometer tube and mercury- or water-filled U-tube manometer capable of measuring stack pressure to within 2.5 mm (0.1 in.) Hg. The static tap of a standard type pitot tube or one leg of a Type S pitot tube with the face opening planes positioned parallel to the gas flow may also be used as the pressure probe.
6.5 Barometer. A mercury, aneroid, or other barometer capable of measuring atmospheric pressure to within 2.54 mm (0.1 in.) Hg.
The barometric pressure reading may be obtained from a nearby National Weather Service station. In this case, the station value (which is the absolute barometric pressure) shall be requested and an adjustment for elevation differences between the weather station and sampling point shall be made at a rate of minus 2.5 mm (0.1 in.) Hg per 30 m (100 ft) elevation increase or plus 2.5 mm (0.1 in.) Hg per 30 m (100 ft.) for elevation decrease.
6.6 Gas Density Determination Equipment. Method 3 equipment, if needed (see section 8.6), to determine the stack gas dry molecular weight, and Method 4 (reference method) or Method 5 equipment for moisture content determination. Other methods may be used subject to approval of the Administrator.
6.7 Calibration Pitot Tube. Calibration of the Type S pitot tube requires a standard pitot tube for a reference. When calibration of the Type S pitot tube is necessary (see Section 10.1), a standard pitot tube shall be used for a reference. The standard pitot tube shall, preferably, have a known coefficient, obtained directly from the National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, (301) 975-2002; or by calibration against another standard pitot tube with a NIST-traceable coefficient. Alternatively, a standard pitot tube designed according to the criteria given in sections 6.7.1 through 6.7.5 below and illustrated in Figure 2-5 (see also References 7, 8, and 17 in section 17.0) may be used. Pitot tubes designed according to these specifications will have baseline coefficients of 0.99 ±0.01.
6.7.1 Standard Pitot Design.
6.7.1.1 Hemispherical (shown in Figure 2-5), ellipsoidal, or conical tip.
6.7.1.2 A minimum of six diameters straight run (based upon D, the external diameter of the tube) between the tip and the static pressure holes.
6.7.1.3 A minimum of eight diameters straight run between the static pressure holes and the centerline of the external tube, following the 90° bend.
6.7.1.4 Static pressure holes of equal size (approximately 0.1 D), equally spaced in a piezometer ring configuration.
6.7.1.5 90° bend, with curved or mitered junction.
6.8 Differential Pressure Gauge for Type S Pitot Tube Calibration. An inclined manometer or equivalent. If the single-velocity calibration technique is employed (see section 10.1.2.3), the calibration differential pressure gauge shall be readable to the nearest 0.127 mm (0.005 in.) H
8.1 Set up the apparatus as shown in Figure 2-1. Capillary tubing or surge tanks installed between the manometer and pitot tube may be used to dampen ΔP fluctuations. It is recommended, but not required, that a pretest leak-check be conducted as follows: (1) blow through the pitot impact opening until at least 7.6 cm (3.0 in.) H
8.2 Level and zero the manometer. Because the manometer level and zero may drift due to vibrations and temperature changes, make periodic checks during the traverse (at least once per hour). Record all necessary data on a form similar to that shown in Figure 2-6.
8.3 Measure the velocity head and temperature at the traverse points specified by Method 1. Ensure that the proper differential pressure gauge is being used for the range of Δp values encountered (see section 6.2). If it is necessary to change to a more sensitive gauge, do so, and remeasure the Δp and temperature readings at each traverse point. Conduct a post-test leak-check (mandatory), as described in section 8.1 above, to validate the traverse run.
8.4 Measure the static pressure in the stack. One reading is usually adequate.
8.5 Determine the atmospheric pressure.
8.6 Determine the stack gas dry molecular weight. For combustion processes or processes that emit essentially CO
8.7 Obtain the moisture content from Method 4 (reference method, or equivalent) or from Method 5.
8.8 Determine the cross-sectional area of the stack or duct at the sampling location. Whenever possible, physically measure the stack dimensions rather than using blueprints. Do not assume that stack diameters are equal. Measure each diameter distance to verify its dimensions.
| Section | Quality control measure | Effect |
|---|---|---|
| 10.1-10.4 | Sampling equipment calibration | Ensure accurate measurement of stack gas flow rate, sample volume. |
10.1 Type S Pitot Tube. Before its initial use, carefully examine the Type S pitot tube top, side, and end views to verify that the face openings of the tube are aligned within the specifications illustrated in Figures 2-2 and 2-3. The pitot tube shall not be used if it fails to meet these alignment specifications. After verifying the face opening alignment, measure and record the following dimensions of the pitot tube: (a) the external tubing diameter (dimension D
10.1.1 Type S Pitot Tube Assemblies. During sample and velocity traverses, the isolated Type S pitot tube is not always used; in many instances, the pitot tube is used in combination with other source-sampling components (e.g., thermocouple, sampling probe, nozzle) as part of an “assembly.” The presence of other sampling components can sometimes affect the baseline value of the Type S pitot tube coefficient (Reference 9 in section 17.0); therefore, an assigned (or otherwise known) baseline coefficient value may or may not be valid for a given assembly. The baseline and assembly coefficient values will be identical only when the relative placement of the components in the assembly is such that aerodynamic interference effects are eliminated. Figures 2-4, 2-7, and 2-8 illustrate interference-free component arrangements for Type S pitot tubes having external tubing diameters between 0.48 and 0.95 cm (
Do not use a Type S pitot tube assembly that is constructed such that the impact pressure opening plane of the pitot tube is below the entry plane of the nozzle (see Figure 2-7B).
10.1.2 Calibration Setup. If the Type S pitot tube is to be calibrated, one leg of the tube shall be permanently marked A, and the other, B. Calibration shall be performed in a flow system having the following essential design features:
10.1.2.1 The flowing gas stream must be confined to a duct of definite cross-sectional area, either circular or rectangular. For circular cross sections, the minimum duct diameter shall be 30.48 cm (12 in.); for rectangular cross sections, the width (shorter side) shall be at least 25.4 cm (10 in.).
10.1.2.2 The cross-sectional area of the calibration duct must be constant over a distance of 10 or more duct diameters. For a rectangular cross section, use an equivalent diameter, calculated according to Equation 2-2 (see section 12.3), to determine the number of duct diameters. To ensure the presence of stable, fully developed flow patterns at the calibration site, or “test section,” the site must be located at least eight diameters downstream and two diameters upstream from the nearest disturbances.
The eight- and two-diameter criteria are not absolute; other test section locations may be used (subject to approval of the Administrator), provided that the flow at the test site has been demonstrated to be or found stable and parallel to the duct axis.
10.1.2.3 The flow system shall have the capacity to generate a test-section velocity around 910 m/min (3,000 ft/min). This velocity must be constant with time to guarantee constant and steady flow during the entire period of calibration. A centrifugal fan is recommended for this purpose, as no flow rate adjustment for back pressure of the fan is allowed during the calibration process. Note that Type S pitot tube coefficients obtained by single-velocity calibration at 910 m/min (3,000 ft/min) will generally be valid to ±3 percent for the measurement of velocities above 300 m/min (1,000 ft/min) and to ±6 percent for the measurement of velocities between 180 and 300 m/min (600 and 1,000 ft/min). If a more precise correlation between the pitot tube coefficient (Cp) and velocity is desired, the flow system should have the capacity to generate at least four distinct, time-invariant test-section velocities covering the velocity range from 180 to 1,500 m/min (600 to 5,000 ft/min), and calibration data shall be taken at regular velocity intervals over this range (see References 9 and 14 in section 17.0 for details).
10.1.2.4 Two entry ports, one for each of the standard and Type S pitot tubes, shall be cut in the test section. The standard pitot entry port shall be located slightly downstream of the Type S port, so that the standard and Type S impact openings will lie in the same cross-sectional plane during calibration. To facilitate alignment of the pitot tubes during calibration, it is advisable that the test section be constructed of Plexiglas
10.1.3 Calibration Procedure. Note that this procedure is a general one and must not be used without first referring to the special considerations presented in section 10.1.5. Note also that this procedure applies only to single-velocity calibration. To obtain calibration data for the A and B sides of the Type S pitot tube, proceed as follows:
10.1.3.1 Make sure that the manometer is properly filled and that the oil is free from contamination and is of the proper density. Inspect and leak-check all pitot lines; repair or replace if necessary.
10.1.3.2 Level and zero the manometer. Switch on the fan, and allow the flow to stabilize. Seal the Type S pitot tube entry port.
10.1.3.3 Ensure that the manometer is level and zeroed. Position the standard pitot tube at the calibration point (determined as outlined in section 10.1.5.1), and align the tube so that its tip is pointed directly into the flow. Particular care should be taken in aligning the tube to avoid yaw and pitch angles. Make sure that the entry port surrounding the tube is properly sealed.
10.1.3.4 Read Δp
10.1.3.5 Connect the Type S pitot tube to the manometer and leak-check. Open the Type S tube entry port. Check the manometer level and zero. Insert and align the Type S pitot tube so that its A side impact opening is at the same point as was the standard pitot tube and is pointed directly into the flow. Make sure that the entry port surrounding the tube is properly sealed.
10.1.3.6 Read Δp
10.1.3.7 Repeat Steps 10.1.3.3 through 10.1.3.6 until three pairs of Δp readings have been obtained for the A side of the Type S pitot tube, with all the paired observations conducted at a constant fan speed (no changes to fan velocity between observed readings).
10.1.3.8 Repeat Steps 10.1.3.3 through 10.1.3.7 for the B side of the Type S pitot tube.
10.1.3.9 Perform calculations as described in section 12.4. Use the Type S pitot tube only if the values of σ
10.1.4 Special Considerations.
10.1.4.1 Selection of Calibration Point.
10.1.4.1.1 When an isolated Type S pitot tube is calibrated, select a calibration point at or near the center of the duct, and follow the procedures outlined in section 10.1.3. The Type S pitot coefficients measured or calculated, (i.e., C
10.1.4.1.2 For Type S pitot tube-thermocouple combinations (without probe assembly), select a calibration point at or near the center of the duct, and follow the procedures outlined in section 10.1.3. The coefficients so obtained will be valid so long as the pitot tube-thermocouple combination is used by itself or with other components in an interference-free arrangement (Figures 2-4, 2-7, and 2-8).
10.1.4.1.3 For Type S pitot tube combinations with complete probe assemblies, the calibration point should be located at or near the center of the duct; however, insertion of a probe sheath into a small duct may cause significant cross-sectional area interference and blockage and yield incorrect coefficient values (Reference 9 in section 17.0). Therefore, to minimize the blockage effect, the calibration point may be a few inches off-center if necessary, but no closer to the outer wall of the wind tunnel than 4 inches. The maximum allowable blockage, as determined by a projected-area model of the probe sheath, is 2 percent or less of the duct cross-sectional area (Figure 2-10a). If the pitot and/or probe assembly blocks more than 2 percent of the cross-sectional area at an insertion point only 4 inches inside the wind tunnel, the diameter of the wind tunnel must be increased.
10.1.4.2 For those probe assemblies in which pitot tube-nozzle interference is a factor (i.e., those in which the pitot-nozzle separation distance fails to meet the specifications illustrated in Figure 2-7A), the value of C
10.1.4.3 For a probe assembly constructed such that its pitot tube is always used in the same orientation, only one side of the pitot tube needs to be calibrated (the side which will face the flow). The pitot tube must still meet the alignment specifications of Figure 2-2 or 2-3, however, and must have an average deviation (σ) value of 0.01 or less (see section 12.4.4).
10.1.5 Field Use and Recalibration.
10.1.5.1 Field Use.
10.1.5.1.1 When a Type S pitot tube (isolated or in an assembly) is used in the field, the appropriate coefficient value (whether assigned or obtained by calibration) shall be used to perform velocity calculations. For calibrated Type S pitot tubes, the A side coefficient shall be used when the A side of the tube faces the flow, and the B side coefficient shall be used when the B side faces the flow. Alternatively, the arithmetic average of the A and B side coefficient values may be used, irrespective of which side faces the flow.
10.1.5.1.2 When a probe assembly is used to sample a small duct, 30.5 to 91.4 cm (12 to 36 in.) in diameter, the probe sheath sometimes blocks a significant part of the duct cross-section, causing a reduction in the effective value of C
10.1.5.2 Recalibration.
10.1.5.2.1 Isolated Pitot Tubes. After each field use, the pitot tube shall be carefully reexamined in top, side, and end views. If the pitot face openings are still aligned within the specifications illustrated in Figure 2-2 and Figure 2-3, it can be assumed that the baseline coefficient of the pitot tube has not changed. If, however, the tube has been damaged to the extent that it no longer meets the specifications of Figure 2-2 and Figure 2-3, the damage shall either be repaired to restore proper alignment of the face openings, or the tube shall be discarded.
10.1.5.2.2 Pitot Tube Assemblies. After each field use, check the face opening alignment of the pitot tube, as in section 10.1.5.2.1. Also, remeasure the intercomponent spacings of the assembly. If the intercomponent spacings have not changed and the face opening alignment is acceptable, it can be assumed that the coefficient of the assembly has not changed. If the face opening alignment is no longer within the specifications of Figure 2-2 and Figure 2-3, either repair the damage or replace the pitot tube (calibrating the new assembly, if necessary). If the intercomponent spacings have changed, restore the original spacings, or recalibrate the assembly.
10.2 Standard Pitot Tube (if applicable). If a standard pitot tube is used for the velocity traverse, the tube shall be constructed according to the criteria of section 6.7 and shall be assigned a baseline coefficient value of 0.99. If the standard pitot tube is used as part of an assembly, the tube shall be in an interference-free arrangement (subject to the approval of the Administrator).
10.3 Temperature Sensors.
10.3.1 After each field use, calibrate dial thermometers, liquid-filled bulb thermometers, thermocouple-potentiometer systems, and other sensors at a temperature within 10 percent of the average absolute stack temperature. For temperatures up to 405 °C (761 °F), use an ASTM mercury-in-glass reference thermometer, or equivalent, as a reference. Alternatively, either a reference thermocouple and potentiometer (calibrated against NIST standards) or thermometric fixed points (e.g., ice bath and boiling water, corrected for barometric pressure) may be used. For temperatures above 405 °C (761 °F), use a reference thermocouple-potentiometer system calibrated against NIST standards or an alternative reference, subject to the approval of the Administrator.
10.3.2 The temperature data recorded in the field shall be considered valid. If, during calibration, the absolute temperature measured with the sensor being calibrated and the reference sensor agree within 1.5 percent, the temperature data taken in the field shall be considered valid. Otherwise, the pollutant emission test shall either be considered invalid or adjustments (if appropriate) of the test results shall be made, subject to the approval of the Administrator.
10.4 Barometer. Calibrate the barometer used against a mercury barometer or NIST-traceable barometer prior to each field test.
Sample collection and analysis are concurrent for this method (see section 8.0).
Carry out calculations, retaining at least one extra significant figure beyond that of the acquired data. Round off figures after final calculation.
12.1 Nomenclature.
12.2 Calculate T as follows:
12.3 Calculate D
12.4 Calibration of Type S Pitot Tube.
12.4.1 For each of the six pairs of Δp readings (i.e., three from side A and three from side B) obtained in section 10.1.3, calculate the value of the Type S pitot tube coefficient according to Equation 2-3:
12.4.2 Calculate C
12.4.3 Calculate the deviation of each of the three A-side values of C
12.4.4 Calculate σ the average deviation from the mean, for both the A and B sides of the pitot tube. Use Equation 2-5:
12.5 Molecular Weight of Stack Gas.
12.6 Average Stack Gas Velocity.
12.7 Average Stack Gas Dry Volumetric Flow Rate.
1. Mark, L.S. Mechanical Engineers’ Handbook. New York. McGraw-Hill Book Co., Inc. 1951.
2. Perry, J.H., ed. Chemical Engineers’ Handbook. New York. McGraw-Hill Book Co., Inc. 1960.
3. Shigehara, R.T., W.F. Todd, and W.S. Smith. Significance of Errors in Stack Sampling Measurements. U.S. Environmental Protection Agency, Research Triangle Park, N.C. (Presented at the Annual Meeting of the Air Pollution Control Association, St. Louis, MO., June 14-19, 1970).
4. Standard Method for Sampling Stacks for Particulate Matter. In: 1971 Book of ASTM Standards, Part 23. Philadelphia, PA. 1971. ASTM Designation D 2928-71.
5. Vennard, J.K. Elementary Fluid Mechanics. New York. John Wiley and Sons, Inc. 1947.
6. Fluid Meters – Their Theory and Application. American Society of Mechanical Engineers, New York, N.Y. 1959.
7. ASHRAE Handbook of Fundamentals. 1972. p. 208.
8. Annual Book of ASTM Standards, Part 26. 1974. p. 648.
9. Vollaro, R.F. Guidelines for Type S Pitot Tube Calibration. U.S. Environmental Protection Agency, Research Triangle Park, N.C. (Presented at 1st Annual Meeting, Source Evaluation Society, Dayton, OH, September 18, 1975.)
10. Vollaro, R.F. A Type S Pitot Tube Calibration Study. U.S. Environmental Protection Agency, Emission Measurement Branch, Research Triangle Park, N.C. July 1974.
11. Vollaro, R.F. The Effects of Impact Opening Misalignment on the Value of the Type S Pitot Tube Coefficient. U.S. Environmental Protection Agency, Emission Measurement Branch, Research Triangle Park, NC. October 1976.
12. Vollaro, R.F. Establishment of a Baseline Coefficient Value for Properly Constructed Type S Pitot Tubes. U.S. Environmental Protection Agency, Emission Measurement Branch, Research Triangle Park, NC. November 1976.
13. Vollaro, R.F. An Evaluation of Single-Velocity Calibration Technique as a Means of Determining Type S Pitot Tube Coefficients. U.S. Environmental Protection Agency, Emission Measurement Branch, Research Triangle Park, NC. August 1975.
14. Vollaro, R.F. The Use of Type S Pitot Tubes for the Measurement of Low Velocities. U.S. Environmental Protection Agency, Emission Measurement Branch, Research Triangle Park, NC. November 1976.
15. Smith, Marvin L. Velocity Calibration of EPA Type Source Sampling Probe. United Technologies Corporation, Pratt and Whitney Aircraft Division, East Hartford, CT. 1975.
16. Vollaro, R.F. Recommended Procedure for Sample Traverses in Ducts Smaller than 12 Inches in Diameter. U.S. Environmental Protection Agency, Emission Measurement Branch, Research Triangle Park, NC. November 1976.
17. Ower, E. and R.C. Pankhurst. The Measurement of Air Flow, 4th Ed. London, Pergamon Press. 1966.
18. Vollaro, R.F. A Survey of Commercially Available Instrumentation for the Measurement of Low-Range Gas Velocities. U.S. Environmental Protection Agency, Emission Measurement Branch, Research Triangle Park, NC. November 1976. (Unpublished Paper).
19. Gnyp, A.W., et al. An Experimental Investigation of the Effect of Pitot Tube-Sampling Probe Configurations on the Magnitude of the S Type Pitot Tube Coefficient for Commercially Available Source Sampling Probes. Prepared by the University of Windsor for the Ministry of the Environment, Toronto, Canada. February 1975.
| Traverse Pt. No. | Vel. Hd., Δp mm (in.) H | Stack temperature | P mm Hg (in. Hg) | (Δp) | |
|---|---|---|---|---|---|
| T °C ( °F) | T °K (°R) | ||||
| Average(1) | |||||
“A” Side Calibration
| Run No. | ΔP cm H (in H | ΔP( cm H (in H | C | Deviation C |
|---|---|---|---|---|
| 1 | ||||
| 2 | ||||
| 3 | ||||
| C (SIDE A) |
“B” Side Calibration
| Run No. | ΔP cm H (in H | ΔP cm H (in H | C | Deviation C |
|---|---|---|---|---|
| 1 | ||||
| 2 | ||||
| 3 | ||||
| C (SIDE B) |
*Must be less than or equal to 0.01
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 2.
1.1 This method is applicable for the determination of gas flow rates in pipes and small ducts, either in-line or at exhaust positions, within the temperature range of 0 to 50 °C (32 to 122 °F).
1.2 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 A gas volume meter is used to measure gas volume directly. Temperature and pressure measurements are made to allow correction of the volume to standard conditions.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method.
Specifications for the apparatus are given below. Any other apparatus that has been demonstrated (subject to approval of the Administrator) to be capable of meeting the specifications will be considered acceptable.
6.1 Gas Volume Meter. A positive displacement meter, turbine meter, or other direct measuring device capable of measuring volume to within 2 percent. The meter shall be equipped with a temperature sensor (accurate to within ±2 percent of the minimum absolute temperature) and a pressure gauge (accurate to within ±2.5 mm Hg). The manufacturer’s recommended capacity of the meter shall be sufficient for the expected maximum and minimum flow rates for the sampling conditions. Temperature, pressure, corrosive characteristics, and pipe size are factors necessary to consider in selecting a suitable gas meter.
6.2 Barometer. A mercury, aneroid, or other barometer capable of measuring atmospheric pressure to within ±2.5 mm Hg.
In many cases, the barometric reading may be obtained from a nearby National Weather Service station, in which case the station value (which is the absolute barometric pressure) shall be requested and an adjustment for elevation differences between the weather station and sampling point shall be applied at a rate of minus 2.5 mm (0.1 in.) Hg per 30 m (100 ft) elevation increase or vice versa for elevation decrease.
6.3 Stopwatch. Capable of measurement to within 1 second.
8.1 Installation. As there are numerous types of pipes and small ducts that may be subject to volume measurement, it would be difficult to describe all possible installation schemes. In general, flange fittings should be used for all connections wherever possible. Gaskets or other seal materials should be used to assure leak-tight connections. The volume meter should be located so as to avoid severe vibrations and other factors that may affect the meter calibration.
8.2 Leak Test.
8.2.1 A volume meter installed at a location under positive pressure may be leak-checked at the meter connections by using a liquid leak detector solution containing a surfactant. Apply a small amount of the solution to the connections. If a leak exists, bubbles will form, and the leak must be corrected.
8.2.2 A volume meter installed at a location under negative pressure is very difficult to test for leaks without blocking flow at the inlet of the line and watching for meter movement. If this procedure is not possible, visually check all connections to assure leak-tight seals.
8.3 Volume Measurement.
8.3.1 For sources with continuous, steady emission flow rates, record the initial meter volume reading, meter temperature(s), meter pressure, and start the stopwatch. Throughout the test period, record the meter temperatures and pressures so that average values can be determined. At the end of the test, stop the timer, and record the elapsed time, the final volume reading, meter temperature, and pressure. Record the barometric pressure at the beginning and end of the test run. Record the data on a table similar to that shown in Figure 2A-1.
8.3.2 For sources with noncontinuous, non-steady emission flow rates, use the procedure in section 8.3.1 with the addition of the following: Record all the meter parameters and the start and stop times corresponding to each process cyclical or noncontinuous event.
| Section | Quality control measure | Effect |
|---|---|---|
| 10.1-10.4 | Sampling equipment calibration | Ensure accurate measurement of stack gas flow rate, sample volume. |
10.1 Volume Meter.
10.1.1 The volume meter is calibrated against a standard reference meter prior to its initial use in the field. The reference meter is a spirometer or liquid displacement meter with a capacity consistent with that of the test meter.
10.1.2 Alternatively, a calibrated, standard pitot may be used as the reference meter in conjunction with a wind tunnel assembly. Attach the test meter to the wind tunnel so that the total flow passes through the test meter. For each calibration run, conduct a 4-point traverse along one stack diameter at a position at least eight diameters of straight tunnel downstream and two diameters upstream of any bend, inlet, or air mover. Determine the traverse point locations as specified in Method 1. Calculate the reference volume using the velocity values following the procedure in Method 2, the wind tunnel cross-sectional area, and the run time.
10.1.3 Set up the test meter in a configuration similar to that used in the field installation (i.e., in relation to the flow moving device). Connect the temperature sensor and pressure gauge as they are to be used in the field. Connect the reference meter at the inlet of the flow line, if appropriate for the meter, and begin gas flow through the system to condition the meters. During this conditioning operation, check the system for leaks.
10.1.4 The calibration shall be performed during at least three different flow rates. The calibration flow rates shall be about 0.3, 0.6, and 0.9 times the rated maximum flow rate of the test meter.
10.1.5 For each calibration run, the data to be collected include: reference meter initial and final volume readings, the test meter initial and final volume reading, meter average temperature and pressure, barometric pressure, and run time. Repeat the runs at each flow rate at least three times.
10.1.6 Calculate the test meter calibration coefficient as indicated in section 12.2.
10.1.7 Compare the three Y
10.1.8 The procedure above shall be performed at least once for each volume meter. Thereafter, an abbreviated calibration check shall be completed following each field test. The calibration of the volume meter shall be checked with the meter pressure set at the average value encountered during the field test. Three calibration checks (runs) shall be performed using this average flow rate value. Calculate the average value of the calibration factor. If the calibration has changed by more than 5 percent, recalibrate the meter over the full range of flow as described above.
If the volume meter calibration coefficient values obtained before and after a test series differ by more than 5 percent, the test series shall either be voided, or calculations for the test series shall be performed using whichever meter coefficient value (i.e., before or after) gives the greater value of pollutant emission rate.
10.2 Temperature Sensor. After each test series, check the temperature sensor at ambient temperature. Use an American Society for Testing and Materials (ASTM) mercury-in-glass reference thermometer, or equivalent, as a reference. If the sensor being checked agrees within 2 percent (absolute temperature) of the reference, the temperature data collected in the field shall be considered valid. Otherwise, the test data shall be considered invalid or adjustments of the results shall be made, subject to the approval of the Administrator.
10.3 Barometer. Calibrate the barometer used against a mercury barometer or NIST-traceable barometer prior to the field test.
Sample collection and analysis are concurrent for this method (see section 8.0).
Carry out calculations, retaining at least one extra decimal figure beyond that of the acquired data. Round off figures after final calculation.
12.1 Nomenclature.
12.2 Test Meter Calibration Coefficient.
12.3 Volume.
12.4 Gas Flow Rate.
1. Rom, Jerome J. Maintenance, Calibration, and Operation of Isokinetic Source Sampling Equipment. U.S. Environmental Protection Agency, Research Triangle Park, NC. Publication No. APTD-0576. March 1972.
2. Wortman, Martin, R. Vollaro, and P.R. Westlin. Dry Gas Volume Meter Calibrations. Source Evaluation Society Newsletter. Vol. 2, No. 2. May 1977.
3. Westlin, P.R., and R.T. Shigehara. Procedure for Calibrating and Using Dry Gas Volume Meters as Calibration Standards. Source Evaluation Society Newsletter. Vol. 3, No. 1. February 1978.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should also have a thorough knowledge of at least the following additional test methods: Method 1, Method 2, Method 2A, Method 10, Method 25A, Method 25B.
1.1 This method is applicable for the determination of exhaust volume flow rate from incinerators that process gasoline vapors consisting primarily of alkanes, alkenes, and/or arenes (aromatic hydrocarbons). It is assumed that the amount of auxiliary fuel is negligible.
1.2 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 Organic carbon concentration and volume flow rate are measured at the incinerator inlet using either Method 25A or Method 25B and Method 2A, respectively. Organic carbon, carbon dioxide (CO
Same as section 3.0 of Method 10 and Method 25A.
Same as section 4.0 of Method 10.
5.1 This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method.
Same as section 6.0 of Method 2A, Method 10, and Method 25A and/or Method 25B as applicable, with the addition of the following:
6.1 This analyzer must meet the specifications set forth in section 6.1.2 of Method 10, except that the span shall be 15 percent CO
Same as section 7.0 of Method 10 and Method 25A, with the following addition and exceptions:
7.1 Carbon Dioxide Analyzer Calibration. CO
7.2 Hydrocarbon Analyzer Calibration. Methane shall not be used as a calibration gas when performing this method.
7.3 Fuel Gas. If Method 25B is used to measure the organic carbon concentrations at both the inlet and exhaust, no fuel gas is required.
8.1 Pre-test Procedures. Perform all pre-test procedures (e.g., system performance checks, leak checks) necessary to determine gas volume flow rate and organic carbon concentration in the vapor line to the incinerator inlet and to determine organic carbon, carbon monoxide, and carbon dioxide concentrations at the incinerator exhaust, as outlined in Method 2A, Method 10, and Method 25A and/or Method 25B as applicable.
8.2 Sampling. At the beginning of the test period, record the initial parameters for the inlet volume meter according to the procedures in Method 2A and mark all of the recorder strip charts to indicate the start of the test. Conduct sampling and analysis as outlined in Method 2A, Method 10, and Method 25A and/or Method 25B as applicable. Continue recording inlet organic and exhaust CO
8.3 Post-test Procedures. Perform all post-test procedures (e.g., drift tests, leak checks), as outlined in Method 2A, Method 10, and Method 25A and/or Method 25B as applicable.
Same as section 9.0 of Method 2A, Method 10, and Method 25A.
Same as section 10.0 of Method 2A, Method 10, and Method 25A.
If a manifold system is used for the exhaust analyzers, all the analyzers and sample pumps must be operating when the analyzer calibrations are performed.
10.1 If an analyzer output does not meet the specifications of the method, invalidate the test data for the period. Alternatively, calculate the exhaust volume results using initial calibration data and using final calibration data and report both resulting volumes. Then, for emissions calculations, use the volume measurement resulting in the greatest emission rate or concentration.
Sample collection and analysis are concurrent for this method (see section 8.0).
Carry out the calculations, retaining at least one extra decimal figure beyond that of the acquired data. Round off figures after the final calculation.
12.1 Nomenclature.
θ = Sample run time, min.
S = Standard conditions: 20 °C, 760 mm Hg.
12.2 Concentrations. Determine mean concentrations of inlet organics, outlet CO
12.3 Exhaust Gas Volume. Calculate the exhaust gas volume as follows:
12.4 Exhaust Gas Volume Flow Rate. Calculate the exhaust gas volume flow rate as follows:
Same as section 16.0 of Method 2A, Method 10, and Method 25A.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should also have a thorough knowledge of at least the following additional test methods: Method 1, Method 2.
1.1 This method is applicable for the determination of average velocity and volumetric flow rate of gas streams in small stacks or ducts. Limits on the applicability of this method are identical to those set forth in Method 2, section 1.0, except that this method is limited to stationary source stacks or ducts less than about 0.30 meter (12 in.) in diameter, or 0.071 m
1.2 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 The average gas velocity in a stack or duct is determined from the gas density and from measurement of velocity heads with a standard pitot tube.
5.1 This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method.
Same as Method 2, section 6.0, with the exception of the following:
6.1 Standard Pitot Tube (instead of Type S). A standard pitot tube which meets the specifications of section 6.7 of Method 2. Use a coefficient of 0.99 unless it is calibrated against another standard pitot tube with a NIST-traceable coefficient (see section 10.2 of Method 2).
6.2 Alternative Pitot Tube. A modified hemispherical-nosed pitot tube (see Figure 2C-1), which features a shortened stem and enlarged impact and static pressure holes. Use a coefficient of 0.99 unless it is calibrated as mentioned in section 6.1 above. This pitot tube is useful in particulate liquid droplet-laden gas streams when a “back purge” is ineffective.
8.1 Follow the general procedures in section 8.0 of Method 2, except conduct the measurements at the traverse points specified in Method 1A. The static and impact pressure holes of standard pitot tubes are susceptible to plugging in particulate-laden gas streams. Therefore, adequate proof that the openings of the pitot tube have not plugged during the traverse period must be furnished; this can be done by taking the velocity head (Δp) heading at the final traverse point, cleaning out the impact and static holes of the standard pitot tube by “back-purging” with pressurized air, and then taking another Δp reading. If the Δp readings made before and after the air purge are the same (within ±5 percent) the traverse is acceptable. Otherwise, reject the run. Note that if the Δp at the final traverse point is unsuitably low, another point may be selected. If “back purging” at regular intervals is part of the procedure, then take comparative Δp readings, as above, for the last two back purges at which suitably high Δp readings are observed.
| Section | Quality control measure | Effect |
|---|---|---|
| 10.0 | Sampling equipment calibration | Ensure accurate measurement of stack gas velocity head. |
Same as Method 2, sections 10.2 through 10.4.
Sample collection and analysis are concurrent for this method (see section 8.0).
Same as Method 2, section 12.0.
Same as Method 2, section 16.0.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should also have a thorough knowledge of at least the following additional test methods: Method 1, Method 2, and Method 2A.
1.1 This method is applicable for the determination of the volumetric flow rates of gas streams in small pipes and ducts. It can be applied to intermittent or variable gas flows only with particular caution.
1.2 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 All the gas flow in the pipe or duct is directed through a rotameter, orifice plate or similar device to measure flow rate or pressure drop. The device has been previously calibrated in a manner that insures its proper calibration for the gas being measured. Absolute temperature and pressure measurements are made to allow correction of volumetric flow rates to standard conditions.
5.1 This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method.
Specifications for the apparatus are given below. Any other apparatus that has been demonstrated (subject to approval of the Administrator) to be capable of meeting the specifications will be considered acceptable.
6.1 Gas Metering Rate or Flow Element Device. A rotameter, orifice plate, or other volume rate or pressure drop measuring device capable of measuring the stack flow rate to within ±5 percent. The metering device shall be equipped with a temperature gauge accurate to within ±2 percent of the minimum absolute stack temperature and a pressure gauge (accurate to within ±5 mm Hg). The capacity of the metering device shall be sufficient for the expected maximum and minimum flow rates at the stack gas conditions. The magnitude and variability of stack gas flow rate, molecular weight, temperature, pressure, dewpoint, and corrosive characteristics, and pipe or duct size are factors to consider in choosing a suitable metering device.
6.2 Barometer. Same as Method 2, section 6.5.
6.3 Stopwatch. Capable of measurement to within 1 second.
8.1 Installation and Leak Check. Same as Method 2A, sections 8.1 and 8.2, respectively.
8.2 Volume Rate Measurement.
8.2.1 Continuous, Steady Flow. At least once an hour, record the metering device flow rate or pressure drop reading, and the metering device temperature and pressure. Make a minimum of 12 equally spaced readings of each parameter during the test period. Record the barometric pressure at the beginning and end of the test period. Record the data on a table similar to that shown in Figure 2D-1.
8.2.2 Noncontinuous and Nonsteady Flow. Use volume rate devices with particular caution. Calibration will be affected by variation in stack gas temperature, pressure and molecular weight. Use the procedure in section 8.2.1 with the addition of the following: Record all the metering device parameters on a time interval frequency sufficient to adequately profile each process cyclical or noncontinuous event. A multichannel continuous recorder may be used.
| Section | Quality control measure | Effect |
|---|---|---|
| 10.0 | Sampling equipment calibration | Ensure accurate measurement of stack gas flow rate or sample volume. |
Same as Method 2A, section 10.0, with the following exception:
10.1 Gas Metering Device. Same as Method 2A, section 10.1, except calibrate the metering device with the principle stack gas to be measured (examples: air, nitrogen) against a standard reference meter. A calibrated dry gas meter is an acceptable reference meter. Ideally, calibrate the metering device in the field with the actual gas to be metered. For metering devices that have a volume rate readout, calculate the test metering device calibration coefficient, Y
10.2 For metering devices that do not have a volume rate readout, refer to the manufacturer’s instructions to calculate the V
10.3 Temperature Gauge. Use the procedure and specifications in Method 2A, section 10.2. Perform the calibration at a temperature that approximates field test conditions.
10.4 Barometer. Calibrate the barometer used against a mercury barometer or NIST-traceable barometer prior to the field test.
Sample collection and analysis are concurrent for this method (see section 8.0).
12.1 Nomenclature.
12.2 Gas Flow Rate.
12.3 Test Meter Device Calibration Coefficient. Calculation for testing metering device calibration coefficient, Y
1. Spink, L.K. Principles and Practice of Flowmeter Engineering. The Foxboro Company. Foxboro, MA. 1967.
2. Benedict, R.P. Fundamentals of Temperature, Pressure, and Flow Measurements. John Wiley & Sons, Inc. New York, NY. 1969.
3. Orifice Metering of Natural Gas. American Gas Association. Arlington, VA. Report No. 3. March 1978. 88 pp.
| Time | Flow rate reading | Static Pressure [mm Hg (in. Hg)] | Temperature | |
|---|---|---|---|---|
| °C (°F) | °K (°R) | |||
| Average | ||||
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should also have a thorough knowledge of at least the following additional test methods: Methods 2 and 3C.
1.1 Applicability. This method applies to the measurement of landfill gas (LFG) production flow rate from municipal solid waste landfills and is used to calculate the flow rate of nonmethane organic compounds (NMOC) from landfills.
1.2 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 Extraction wells are installed either in a cluster of three or at five dispersed locations in the landfill. A blower is used to extract LFG from the landfill. LFG composition, landfill pressures, and orifice pressure differentials from the wells are measured and the landfill gas production flow rate is calculated.
5.1 Since this method is complex, only experienced personnel should perform the test. Landfill gas contains methane, therefore explosive mixtures may exist at or near the landfill. It is advisable to take appropriate safety precautions when testing landfills, such as refraining from smoking and installing explosion-proof equipment.
6.1 Well Drilling Rig. Capable of boring a 0.61 m (24 in.) diameter hole into the landfill to a minimum of 75 percent of the landfill depth. The depth of the well shall not extend to the bottom of the landfill or the liquid level.
6.2 Gravel. No fines. Gravel diameter should be appreciably larger than perforations stated in sections 6.10 and 8.2.
6.3 Bentonite.
6.4 Backfill Material. Clay, soil, and sandy loam have been found to be acceptable.
6.5 Extraction Well Pipe. Minimum diameter of 3 in., constructed of polyvinyl chloride (PVC), high density polyethylene (HDPE), fiberglass, stainless steel, or other suitable nonporous material capable of transporting landfill gas.
6.6 Above Ground Well Assembly. Valve capable of adjusting gas flow, such as a gate, ball, or butterfly valve; sampling ports at the well head and outlet; and a flow measuring device, such as an in-line orifice meter or pitot tube. A schematic of the aboveground well head assembly is shown in Figure 2E-1.
6.7 Cap. Constructed of PVC or HDPE.
6.8 Header Piping. Constructed of PVC or HDPE.
6.9 Auger. Capable of boring a 0.15-to 0.23-m (6-to 9-in.) diameter hole to a depth equal to the top of the perforated section of the extraction well, for pressure probe installation.
6.10 Pressure Probe. Constructed of PVC or stainless steel (316), 0.025-m (1-in.). Schedule 40 pipe. Perforate the bottom two-thirds. A minimum requirement for perforations is slots or holes with an open area equivalent to four 0.006-m (
6.11 Blower and Flare Assembly. Explosion-proof blower, capable of extracting LFG at a flow rate of 8.5 m
6.12 Standard Pitot Tube and Differential Pressure Gauge for Flow Rate Calibration with Standard Pitot. Same as Method 2, sections 6.7 and 6.8.
6.13 Orifice Meter. Orifice plate, pressure tabs, and pressure measuring device to measure the LFG flow rate.
6.14 Barometer. Same as Method 4, section 6.1.5.
6.15 Differential Pressure Gauge. Water-filled U-tube manometer or equivalent, capable of measuring within 0.02 mm Hg (0.01 in. H
8.1 Placement of Extraction Wells. The landfill owner or operator may install a single cluster of three extraction wells in a test area or space five equal-volume wells over the landfill. The cluster wells are recommended but may be used only if the composition, age of the refuse, and the landfill depth of the test area can be determined.
8.1.1 Cluster Wells. Consult landfill site records for the age of the refuse, depth, and composition of various sections of the landfill. Select an area near the perimeter of the landfill with a depth equal to or greater than the average depth of the landfill and with the average age of the refuse between 2 and 10 years old. Avoid areas known to contain nondecomposable materials, such as concrete and asbestos. Locate the cluster wells as shown in Figure 2E-2.
8.1.1.1 The age of the refuse in a test area will not be uniform, so calculate a weighted average age of the refuse as shown in section 12.2.
8.1.2 Equal Volume Wells. Divide the sections of the landfill that are at least 2 years old into five areas representing equal volumes. Locate an extraction well near the center of each area.
8.2 Installation of Extraction Wells. Use a well drilling rig to dig a 0.6 m (24 in.) diameter hole in the landfill to a minimum of 75 percent of the landfill depth, not to extend to the bottom of the landfill or the liquid level. Perforate the bottom two thirds of the extraction well pipe. A minimum requirement for perforations is holes or slots with an open area equivalent to 0.01-m (0.5-in.) diameter holes spaced 90° apart every 0.1 to 0.2 m (4 to 8 in.). Place the extraction well in the center of the hole and backfill with gravel to a level 0.30 m (1 ft) above the perforated section. Add a layer of backfill material 1.2 m (4 ft) thick. Add a layer of bentonite 0.9 m (3 ft) thick, and backfill the remainder of the hole with cover material or material equal in permeability to the existing cover material. The specifications for extraction well installation are shown in Figure 2E-3.
8.3 Pressure Probes. Shallow pressure probes are used in the check for infiltration of air into the landfill, and deep pressure probes are use to determine the radius of influence. Locate pressure probes along three radial arms approximately 120° apart at distances of 3, 15, 30, and 45 m (10, 50, 100, and 150 ft) from the extraction well. The tester has the option of locating additional pressure probes at distances every 15 m (50 feet) beyond 45 m (150 ft). Example placements of probes are shown in Figure 2E-4. The 15-, 30-, and 45-m, (50-, 100-, and 150-ft) probes from each well, and any additional probes located along the three radial arms (deep probes), shall extend to a depth equal to the top of the perforated section of the extraction wells. All other probes (shallow probes) shall extend to a depth equal to half the depth of the deep probes.
8.3.1 Use an auger to dig a hole, 0.15- to 0.23-m (6-to 9-in.) in diameter, for each pressure probe. Perforate the bottom two thirds of the pressure probe. A minimum requirement for perforations is holes or slots with an open area equivalent to four 0.006-m (0.25-in.) diameter holes spaced 90° apart every 0.15 m (6 in.). Place the pressure probe in the center of the hole and backfill with gravel to a level 0.30 m (1 ft) above the perforated section. Add a layer of backfill material at least 1.2 m (4 ft) thick. Add a layer of bentonite at least 0.3 m (1 ft) thick, and backfill the remainder of the hole with cover material or material equal in permeability to the existing cover material. The specifications for pressure probe installation are shown in Figure 2E-5.
8.4 LFG Flow Rate Measurement. Place the flow measurement device, such as an orifice meter, as shown in Figure 2E-1. Attach the wells to the blower and flare assembly. The individual wells may be ducted to a common header so that a single blower, flare assembly, and flow meter may be used. Use the procedures in section 10.1 to calibrate the flow meter.
8.5 Leak-Check. A leak-check of the above ground system is required for accurate flow rate measurements and for safety. Sample LFG at the well head sample port and at the outlet sample port. Use Method 3C to determine nitrogen (N
8.6 Static Testing. Close the control valves on the well heads during static testing. Measure the gauge pressure (P
8.6.1 For each probe, average all of the 8-hr deep pressure probe readings (P
8.6.2 Measure the static flow rate of each well once during static testing.
8.7 Short-Term Testing. The purpose of short-term testing is to determine the maximum vacuum that can be applied to the wells without infiltration of ambient air into the landfill. The short-term testing is performed on one well at a time. Burn all LFG with a flare or incinerator.
8.7.1 Use the blower to extract LFG from a single well at a rate at least twice the static flow rate of the respective well measured in section 8.6.2. If using a single blower and flare assembly and a common header system, close the control valve on the wells not being measured. Allow 24 hr for the system to stabilize at this flow rate.
8.7.2 Test for infiltration of air into the landfill by measuring the gauge pressures of the shallow pressure probes and using Method 3C to determine the LFG N
8.7.3 At this blower vacuum, measure atmospheric pressure (P
8.7.4 For each probe, average the 8-hr deep pressure probe absolute pressure readings and record as P
8.7.5 For each probe, compare the initial average pressure (P
8.7.6 Calculate the depth (D
8.7.7 Calculate the void volume (V) for the extraction well as shown in section 12.7.
8.7.8 Repeat the procedures in section 8.7 for each well.
8.8 Calculate the total void volume of the test wells (V
8.9 Long-Term Testing. The purpose of long-term testing is to extract two void volumes of LFG from the extraction wells. Use the blower to extract LFG from the wells. If a single Blower and flare assembly and common header system are used, open all control valves and set the blower vacuum equal to the highest stabilized blower vacuum demonstrated by any individual well in section 8.7. Every 8 hr, sample the LFG from the well head sample port, measure the gauge pressures of the shallow pressure probes, the blower vacuum, the LFG flow rate, and use the criteria for infiltration in section 8.7.2 and Method 3C to test for infiltration. If infiltration is detected, do not reduce the blower vacuum, instead reduce the LFG flow rate from the well by adjusting the control valve on the well head. Adjust each affected well individually. Continue until the equivalent of two total void volumes (V
8.9.1 Calculate V
8.9.2 Record the final stabilized flow rate as Q
8.9.3 For each deep probe, convert each gauge pressure to absolute pressure as in section 12.4. Average these values and record as P
8.10 Determine the NMOC mass emission rate using the procedures in section 12.9 through 12.15.
9.1 Miscellaneous Quality Control Measures.
| Section | Quality control measure | Effect |
|---|---|---|
| 10.1 | LFG flow rate meter calibration | Ensures accurate measurement of LFG flow rate and sample volume |
10.1 LFG Flow Rate Meter (Orifice) Calibration Procedure. Locate a standard pitot tube in line with an orifice meter. Use the procedures in section 8, 12.5, 12.6, and 12.7 of Method 2 to determine the average dry gas volumetric flow rate for at least five flow rates that bracket the expected LFG flow rates, except in section 8.1, use a standard pitot tube rather than a Type S pitot tube. Method 3C may be used to determine the dry molecular weight. It may be necessary to calibrate more than one orifice meter in order to bracket the LFG flow rates. Construct a calibration curve by plotting the pressure drops across the orifice meter for each flow rate versus the average dry gas volumetric flow rate in m
12.1 Nomenclature.
12.2 Use the following equation to calculate a weighted average age of landfill refuse.
12.3 Use the following equation to determine the difference in N
12.4 Use the following equation to convert the gauge pressure (P
12.5 Use the following equation to convert the gauge pressures of the deep probes to absolute pressures for each 8-hr reading at Q
12.6 Use the following equation to calculate the depth (D
12.7 Use the following equation to calculate the void volume for the extraction well (V).
12.8 Use the following equation to calculate V
12.9 Use the following equation to calculate the depth affected by the test well. If using cluster wells, use the average depth of the wells for WD. If the value of D is greater than the depth of the landfill, set D equal to the landfill depth.
12.10 Use the following equation to calculate the volume of refuse affected by the test well.
12.11 Use the following equation to calculate the mass affected by the test well.
12.12 Modify L
12.13 In the following equation, solve for k (landfill gas generation constant) by iteration. A suggested procedure is to select a value for k, calculate the left side of the equation, and if not equal to zero, select another value for k. Continue this process until the left hand side of the equation equals zero, ±0.001.
12.14 Use the following equation to determine landfill NMOC mass emission rate if the yearly acceptance rate of refuse has been consistent (10 percent) over the life of the landfill.
12.15 Use the following equation to determine landfill NMOC mass emission rate if the acceptance rate has not been consistent over the life of the landfill.
1. Same as Method 2, Appendix A, 40 CFR Part 60.
2. Emcon Associates, Methane Generation and Recovery from Landfills. Ann Arbor Science, 1982.
3. The Johns Hopkins University, Brown Station Road Landfill Gas Resource Assessment, Volume 1: Field Testing and Gas Recovery Projections. Laurel, Maryland: October 1982.
4. Mandeville and Associates, Procedure Manual for Landfill Gases Emission Testing.
5. Letter and attachments from Briggum, S., Waste Management of North America, to Thorneloe, S., EPA. Response to July 28, 1988 request for additional information. August 18, 1988.
6. Letter and attachments from Briggum, S., Waste Management of North America, to Wyatt, S., EPA. Response to December 7, 1988 request for additional information. January 16, 1989.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling) essential to its performance. Some material has been incorporated from other methods in this part. Therefore, to obtain reliable results, those using this method should have a thorough knowledge of at least the following additional test methods: Methods 1, 2, 3 or 3A, and 4.
2.1 A 3-D probe is used to determine the velocity pressure and the yaw and pitch angles of the flow velocity vector in a stack or duct. The method determines the yaw angle directly by rotating the probe to null the pressure across a pair of symmetrically placed ports on the probe head. The pitch angle is calculated using probe-specific calibration curves. From these values and a determination of the stack gas density, the average axial velocity of the stack gas is calculated. The average gas volumetric flow rate in the stack or duct is then determined from the average axial velocity.
3.1. Angle-measuring Device Rotational Offset (R
3.2 Axial Velocity. The velocity vector parallel to the axis of the stack or duct that accounts for the yaw and pitch angle components of gas flow. The term “axial” is used herein to indicate that the velocity and volumetric flow rate results account for the measured yaw and pitch components of flow at each measurement point.
3.3 Calibration Pitot Tube. The standard (Prandtl type) pitot tube used as a reference when calibrating a 3-D probe under this method.
3.4 Field Test. A set of measurements conducted at a specific unit or exhaust stack/duct to satisfy the applicable regulation (e.g., a three-run boiler performance test, a single-or multiple-load nine-run relative accuracy test).
3.5 Full Scale of Pressure-measuring Device. Full scale refers to the upper limit of the measurement range displayed by the device. For bi-directional pressure gauges, full scale includes the entire pressure range from the lowest negative value to the highest positive value on the pressure scale.
3.6 Main probe. Refers to the probe head and that section of probe sheath directly attached to the probe head. The main probe sheath is distinguished from probe extensions, which are sections of sheath added onto the main probe to extend its reach.
3.7 “May,” “Must,” “Shall,” “Should,” and the imperative form of verbs.
3.7.1 “May” is used to indicate that a provision of this method is optional.
3.7.2 “Must,” “Shall,” and the imperative form of verbs (such as “record” or “enter”) are used to indicate that a provision of this method is mandatory.
3.7.3 “Should” is used to indicate that a provision of this method is not mandatory, but is highly recommended as good practice.
3.8 Method 1. Refers to 40 CFR part 60, appendix A, “Method 1 – Sample and velocity traverses for stationary sources.”
3.9 Method 2. Refers to 40 CFR part 60, appendix A, “Method 2 – Determination of stack gas velocity and volumetric flow rate (Type S pitot tube).”
3.10 Method 2G. Refers to 40 CFR part 60, appendix A, “Method 2G – Determination of stack gas velocity and volumetric flow rate with two-dimensional probes.”
3.11 Nominal Velocity. Refers to a wind tunnel velocity setting that approximates the actual wind tunnel velocity to within ±1.5 m/sec (±5 ft/sec).
3.12 Pitch Angle. The angle between the axis of the stack or duct and the pitch component of flow, i.e., the component of the total velocity vector in a plane defined by the traverse line and the axis of the stack or duct. (Figure 2F-1 illustrates the “pitch plane.”) From the standpoint of a tester facing a test port in a vertical stack, the pitch component of flow is the vector of flow moving from the center of the stack toward or away from that test port. The pitch angle is the angle described by this pitch component of flow and the vertical axis of the stack.
3.13 Readability. For the purposes of this method, readability for an analog measurement device is one half of the smallest scale division. For a digital measurement device, it is the number of decimals displayed by the device.
3.14 Reference Scribe Line. A line permanently inscribed on the main probe sheath (in accordance with section 6.1.6.1) to serve as a reference mark for determining yaw angles.
3.15 Reference Scribe Line Rotational Offset (R
3.16 Response Time. The time required for the measurement system to fully respond to a change from zero differential pressure and ambient temperature to the stable stack or duct pressure and temperature readings at a traverse point.
3.17 Tested Probe. A 3-D probe that is being calibrated.
3.18 Three-dimensional (3-D) Probe. A directional probe used to determine the velocity pressure and yaw and pitch angles in a flowing gas stream.
3.19 Traverse Line. A diameter or axis extending across a stack or duct on which measurements of differential pressure and flow angles are made.
3.20 Wind Tunnel Calibration Location. A point, line, area, or volume within the wind tunnel test section at, along, or within which probes are calibrated. At a particular wind tunnel velocity setting, the average velocity pressures at specified points at, along, or within the calibration location shall vary by no more than 2 percent or 0.3 mm H
3.21 Wind Tunnel with Documented Axial Flow. A wind tunnel facility documented as meeting the provisions of sections 10.1.1 (velocity pressure cross-check) and 10.1.2 (axial flow verification) using the procedures described in these sections or alternative procedures determined to be technically equivalent.
3.22 Yaw Angle. The angle between the axis of the stack or duct and the yaw component of flow, i.e., the component of the total velocity vector in a plane perpendicular to the traverse line at a particular traverse point. (Figure 2F-1 illustrates the “yaw plane.”) From the standpoint of a tester facing a test port in a vertical stack, the yaw component of flow is the vector of flow moving to the left or right from the center of the stack as viewed by the tester. (This is sometimes referred to as “vortex flow,” i.e., flow around the centerline of a stack or duct.) The yaw angle is the angle described by this yaw component of flow and the vertical axis of the stack. The algebraic sign convention is illustrated in Figure 2F-2.
3.23 Yaw Nulling. A procedure in which a probe is rotated about its axis in a stack or duct until a zero differential pressure reading (“yaw null”) is obtained. When a 3-D probe is yaw-nulled, its impact pressure port (P
5.1 This test method may involve hazardous operations and the use of hazardous materials or equipment. This method does not purport to address all of the safety problems associated with its use. It is the responsibility of the user to establish and implement appropriate safety and health practices and to determine the applicability of regulatory limitations before using this test method.
6.1 Three-dimensional Probes. The 3-D probes as specified in subsections 6.1.1 through 6.1.3 below qualify for use based on comprehensive wind tunnel and field studies involving both inter-and intra-probe comparisons by multiple test teams. Other types of probes shall not be used unless approved by the Administrator. Each 3-D probe shall have a unique identification number or code permanently marked on the main probe sheath. The minimum recommended diameter of the sensing head of any probe used under this method is 2.5 cm (1 in.). Each probe shall be calibrated prior to use according to the procedures in section 10. Manufacturer-supplied calibration data shall be used as example information only, except when the manufacturer calibrates the 3-D probe as specified in section 10 and provides complete documentation.
6.1.1 Five-hole prism-shaped probe. This type of probe consists of five pressure taps in the flat facets of a prism-shaped sensing head. The pressure taps are numbered 1 through 5, with the pressures measured at each hole referred to as P
6.1.2 Five-hole spherical probe. This type of probe consists of five pressure taps in a spherical sensing head. As with the prism-shaped probe, the pressure taps are numbered 1 through 5, with the pressures measured at each hole referred to as P
6.1.3 A manual 3-D probe refers to a five-hole prism-shaped or spherical probe that is positioned at individual traverse points and yaw nulled manually by an operator. An automated 3-D probe refers to a system that uses a computer-controlled motorized mechanism to position the five-hole prism-shaped or spherical head at individual traverse points and perform yaw angle determinations.
6.1.4 Other three-dimensional probes. [Reserved]
6.1.5 Probe sheath. The probe shaft shall include an outer sheath to: (1) provide a surface for inscribing a permanent reference scribe line, (2) accommodate attachment of an angle-measuring device to the probe shaft, and (3) facilitate precise rotational movement of the probe for determining yaw angles. The sheath shall be rigidly attached to the probe assembly and shall enclose all pressure lines from the probe head to the farthest position away from the probe head where an angle-measuring device may be attached during use in the field. The sheath of the fully assembled probe shall be sufficiently rigid and straight at all rotational positions such that, when one end of the probe shaft is held in a horizontal position, the fully extended probe meets the horizontal straightness specifications indicated in section 8.2 below.
6.1.6 Scribe lines.
6.1.6.1 Reference scribe line. A permanent line, no greater than 1.6 mm (1/16 in.) in width, shall be inscribed on each manual probe that will be used to determine yaw angles of flow. This line shall be placed on the main probe sheath in accordance with the procedures described in section 10.4 and is used as a reference position for installation of the yaw angle-measuring device on the probe. At the discretion of the tester, the scribe line may be a single line segment placed at a particular position on the probe sheath (e.g., near the probe head), multiple line segments placed at various locations along the length of the probe sheath (e.g., at every position where a yaw angle-measuring device may be mounted), or a single continuous line extending along the full length of the probe sheath.
6.1.6.2 Scribe line on probe extensions. A permanent line may also be inscribed on any probe extension that will be attached to the main probe in performing field testing. This allows a yaw angle-measuring device mounted on the extension to be readily aligned with the reference scribe line on the main probe sheath.
6.1.6.3 Alignment specifications. This specification shall be met separately, using the procedures in section 10.4.1, on the main probe and on each probe extension. The rotational position of the scribe line or scribe line segments on the main probe or any probe extension must not vary by more than 2°. That is, the difference between the minimum and maximum of all of the rotational angles that are measured along the full length of the main probe or the probe extension must not exceed 2°.
6.1.7 Probe and system characteristics to ensure horizontal stability.
6.1.7.1 For manual probes, it is recommended that the effective length of the probe (coupled with a probe extension, if necessary) be at least 0.9 m (3 ft.) longer than the farthest traverse point mark on the probe shaft away from the probe head. The operator should maintain the probe’s horizontal stability when it is fully inserted into the stack or duct. If a shorter probe is used, the probe should be inserted through a bushing sleeve, similar to the one shown in Figure 2F-5, that is installed on the test port; such a bushing shall fit snugly around the probe and be secured to the stack or duct entry port in such a manner as to maintain the probe’s horizontal stability when fully inserted into the stack or duct.
6.1.7.2 An automated system that includes an external probe casing with a transport system shall have a mechanism for maintaining horizontal stability comparable to that obtained by manual probes following the provisions of this method. The automated probe assembly shall also be constructed to maintain the alignment and position of the pressure ports during sampling at each traverse point. The design of the probe casing and transport system shall allow the probe to be removed from the stack or duct and checked through direct physical measurement for angular position and insertion depth.
6.1.8 The tubing that is used to connect the probe and the pressure-measuring device should have an inside diameter of at least 3.2 mm (1/8 in.), to reduce the time required for pressure equilibration, and should be as short as practicable.
6.2 Yaw Angle-measuring Device. One of the following devices shall be used for measurement of the yaw angle of flow.
6.2.1 Digital inclinometer. This refers to a digital device capable of measuring and displaying the rotational position of the probe to within ±1°. The device shall be able to be locked into position on the probe sheath or probe extension, so that it indicates the probe’s rotational position throughout the test. A rotational position collar block that can be attached to the probe sheath (similar to the collar shown in Figure 2F-6) may be required to lock the digital inclinometer into position on the probe sheath.
6.2.2 Protractor wheel and pointer assembly. This apparatus, similar to that shown in Figure 2F-7, consists of the following components.
6.2.2.1 A protractor wheel that can be attached to a port opening and set in a fixed rotational position to indicate the yaw angle position of the probe’s scribe line relative to the longitudinal axis of the stack or duct. The protractor wheel must have a measurement ring on its face that is no less than 17.8 cm (7 in.) in diameter, shall be able to be rotated to any angle and then locked into position on the stack or duct port, and shall indicate angles to a resolution of 1°.
6.2.2.2 A pointer assembly that includes an indicator needle mounted on a collar that can slide over the probe sheath and be locked into a fixed rotational position on the probe sheath. The pointer needle shall be of sufficient length, rigidity, and sharpness to allow the tester to determine the probe’s angular position to within 1° from the markings on the protractor wheel. Corresponding to the position of the pointer, the collar must have a scribe line to be used in aligning the pointer with the scribe line on the probe sheath.
6.2.3 Other yaw angle-measuring devices. Other angle-measuring devices with a manufacturer’s specified precision of 1° or better may be used, if approved by the Administrator.
6.3 Probe Supports and Stabilization Devices. When probes are used for determining flow angles, the probe head should be kept in a stable horizontal position. For probes longer than 3.0 m (10 ft.), the section of the probe that extends outside the test port shall be secured. Three alternative devices are suggested for maintaining the horizontal position and stability of the probe shaft during flow angle determinations and velocity pressure measurements: (1) Monorails installed above each port, (2) probe stands on which the probe shaft may be rested, or (3) bushing sleeves of sufficient length secured to the test ports to maintain probes in a horizontal position. Comparable provisions shall be made to ensure that automated systems maintain the horizontal position of the probe in the stack or duct. The physical characteristics of each test platform may dictate the most suitable type of stabilization device. Thus, the choice of a specific stabilization device is left to the judgment of the testers.
6.4 Differential Pressure Gauges. The pressure (ΔP) measuring devices used during wind tunnel calibrations and field testing shall be either electronic manometers (e.g., pressure transducers), fluid manometers, or mechanical pressure gauges (e.g., Magnehelic
6.4.1 Differential pressure-measuring device. This refers to a device capable of measuring pressure differentials and having a readability of ±1 percent of full scale. The device shall be capable of accurately measuring the maximum expected pressure differential. Such devices are used to determine the following pressure measurements: velocity pressure, static pressure, yaw-null pressure, and pitch-angle pressure. For an inclined-vertical manometer, the readability specification of ±1 percent shall be met separately using the respective full-scale upper limits of the inclined and vertical portions of the scales. To the extent practicable, the device shall be selected such that most of the pressure readings are between 10 and 90 percent of the device’s full-scale measurement range (as defined in section 3.5). Typical velocity pressure (P
6.4.2 Gauge used for yaw nulling. The differential pressure-measuring device chosen for yaw nulling the probe during the wind tunnel calibrations and field testing shall be bi-directional, i.e., capable of reading both positive and negative differential pressures. If a mechanical, bi-directional pressure gauge is chosen, it shall have a full-scale range no greater than 2.6 cm H
6.4.3 Devices for calibrating differential pressure-measuring devices. A precision manometer (e.g., a U-tube, inclined, or inclined-vertical manometer, or micromanometer) or NIST (National Institute of Standards and Technology) traceable pressure source shall be used for calibrating differential pressure-measuring devices. The device shall be maintained under laboratory conditions or in a similar protected environment (e.g., a climate-controlled trailer). It shall not be used in field tests. The precision manometer shall have a scale gradation of 0.3 mm H
6.4.4 Devices used for post-test calibration check. A precision manometer meeting the specifications in section 6.4.3, a pressure-measuring device or pressure source with a documented calibration traceable to NIST, or an equivalent device approved by the Administrator shall be used for the post-test calibration check. The pressure-measuring device shall have a readability equivalent to or greater than the tested device. The pressure source shall be capable of generating pressures between 50 and 90 percent of the range of the tested device and known to within ±1 percent of the full scale of the tested device. The pressure source shall be recertified annually.
6.5 Data Display and Capture Devices. Electronic manometers (if used) shall be coupled with a data display device (such as a digital panel meter, personal computer display, or strip chart) that allows the tester to observe and validate the pressure measurements taken during testing. They shall also be connected to a data recorder (such as a data logger or a personal computer with data capture software) that has the ability to compute and retain the appropriate average value at each traverse point, identified by collection time and traverse point.
6.6 Temperature Gauges. For field tests, a thermocouple or resistance temperature detector (RTD) capable of measuring temperature to within ±3 °C (±5 °F) of the stack or duct temperature shall be used. The thermocouple shall be attached to the probe such that the sensor tip does not touch any metal and is located on the opposite side of the probe head from the pressure ports so as not to interfere with the gas flow around the probe head. The position of the thermocouple relative to the pressure port face openings shall be in the same configuration as used for the probe calibrations in the wind tunnel. Temperature gauges used for wind tunnel calibrations shall be capable of measuring temperature to within ±0.6 °C (±1 °F) of the temperature of the flowing gas stream in the wind tunnel.
6.7 Stack or Duct Static Pressure Measurement. The pressure-measuring device used with the probe shall be as specified in section 6.4 of this method. The static tap of a standard (Prandtl type) pitot tube or one leg of a Type S pitot tube with the face opening planes positioned parallel to the gas flow may be used for this measurement. Also acceptable is the pressure differential reading of P
6.8 Barometer. Same as Method 2, section 2.5.
6.9 Gas Density Determination Equipment. Method 3 or 3A shall be used to determine the dry molecular weight of the stack gas. Method 4 shall be used for moisture content determination and computation of stack gas wet molecular weight. Other methods may be used, if approved by the Administrator.
6.10 Calibration Pitot Tube. Same as Method 2, section 2.7.
6.11 Wind Tunnel for Probe Calibration. Wind tunnels used to calibrate velocity probes must meet the following design specifications.
6.11.1 Test section cross-sectional area. The flowing gas stream shall be confined within a circular, rectangular, or elliptical duct. The cross-sectional area of the tunnel must be large enough to ensure fully developed flow in the presence of both the calibration pitot tube and the tested probe. The calibration site, or “test section,” of the wind tunnel shall have a minimum diameter of 30.5 cm (12 in.) for circular or elliptical duct cross-sections or a minimum width of 30.5 cm (12 in.) on the shorter side for rectangular cross-sections. Wind tunnels shall meet the probe blockage provisions of this section and the qualification requirements prescribed in section 10.1. The projected area of the portion of the probe head, shaft, and attached devices inside the wind tunnel during calibration shall represent no more than 4 percent of the cross-sectional area of the tunnel. The projected area shall include the combined area of the calibration pitot tube and the tested probe if both probes are placed simultaneously in the same cross-sectional plane in the wind tunnel, or the larger projected area of the two probes if they are placed alternately in the wind tunnel.
6.11.2 Velocity range and stability. The wind tunnel should be capable of maintaining velocities between 6.1 m/sec and 30.5 m/sec (20 ft/sec and 100 ft/sec). The wind tunnel shall produce fully developed flow patterns that are stable and parallel to the axis of the duct in the test section.
6.11.3 Flow profile at the calibration location. The wind tunnel shall provide axial flow within the test section calibration location (as defined in section 3.20). Yaw and pitch angles in the calibration location shall be within ±3° of 0°. The procedure for determining that this requirement has been met is described in section 10.1.2.
6.11.4 Entry ports in the wind tunnel test section.
6.11.4.1 Port for tested probe. A port shall be constructed for the tested probe. The port should have an elongated slot parallel to the axis of the duct at the test section. The elongated slot should be of sufficient length to allow attaining all the pitch angles at which the probe will be calibrated for use in the field. To facilitate alignment of the probe during calibration, the test section should include a window constructed of a transparent material to allow the tested probe to be viewed. This port shall be located to allow the head of the tested probe to be positioned within the calibration location (as defined in section 3.20) at all pitch angle settings.
6.11.4.2 Port for verification of axial flow. Depending on the equipment selected to conduct the axial flow verification prescribed in section 10.1.2, a second port, located 90° from the entry port for the tested probe, may be needed to allow verification that the gas flow is parallel to the central axis of the test section. This port should be located and constructed so as to allow one of the probes described in section 10.1.2.2 to access the same test point(s) that are accessible from the port described in section 6.11.4.1.
6.11.4.3 Port for calibration pitot tube. The calibration pitot tube shall be used in the port for the tested probe or a separate entry port. In either case, all measurements with the calibration pitot tube shall be made at the same point within the wind tunnel over the course of a probe calibration. The measurement point for the calibration pitot tube shall meet the same specifications for distance from the wall and for axial flow as described in section 3.20 for the wind tunnel calibration location.
6.11.5 Pitch angle protractor plate. A protractor plate shall be attached directly under the port used with the tested probe and set in a fixed position to indicate the pitch angle position of the probe relative to the longitudinal axis of the wind tunnel duct (similar to Figure 2F-8). The protractor plate shall indicate angles in 5° increments with a minimum resolution of ±2°. The tested probe shall be able to be locked into position at the desired pitch angle delineated on the protractor. The probe head position shall be maintained within the calibration location (as defined in section 3.20) in the test section of the wind tunnel during all tests across the range of pitch angles.
8.1 Equipment Inspection and Set-Up
8.1.1 All probes, differential pressure-measuring devices, yaw angle-measuring devices, thermocouples, and barometers shall have a current, valid calibration before being used in a field test. (See sections 10.3.3, 10.3.4, and 10.5 through10.10 for the applicable calibration requirements.)
8.1.2 Before each field use of a 3-D probe, perform a visual inspection to verify the physical condition of the probe head according to the procedures in section 10.2. Record the inspection results on a form similar to Table 2F-1. If there is visible damage to the 3-D probe, the probe shall not be used until it is recalibrated.
8.1.3 After verifying that the physical condition of the probe head is acceptable, set up the apparatus using lengths of flexible tubing that are as short as practicable. Surge tanks installed between the probe and pressure-measuring device may be used to dampen pressure fluctuations provided that an adequate measurement response time (see section 8.8) is maintained.
8.2 Horizontal Straightness Check. A horizontal straightness check shall be performed before the start of each field test, except as otherwise specified in this section. Secure the fully assembled probe (including the probe head and all probe shaft extensions) in a horizontal position using a stationary support at a point along the probe shaft approximating the location of the stack or duct entry port when the probe is sampling at the farthest traverse point from the stack or duct wall. The probe shall be rotated to detect bends. Use an angle-measuring device or trigonometry to determine the bend or sag between the probe head and the secured end. (See Figure 2F-9.) Probes that are bent or sag by more than 5° shall not be used. Although this check does not apply when the probe is used for a vertical traverse, care should be taken to avoid the use of bent probes when conducting vertical traverses. If the probe is constructed of a rigid steel material and consists of a main probe without probe extensions, this check need only be performed before the initial field use of the probe, when the probe is recalibrated, when a change is made to the design or material of the probe assembly, and when the probe becomes bent. With such probes, a visual inspection shall be made of the fully assembled probe before each field test to determine if a bend is visible. The probe shall be rotated to detect bends. The inspection results shall be documented in the field test report. If a bend in the probe is visible, the horizontal straightness check shall be performed before the probe is used.
8.3 Rotational Position Check. Before each field test, and each time an extension is added to the probe during a field test, a rotational position check shall be performed on all manually operated probes (except as noted in section 8.3.5, below) to ensure that, throughout testing, the angle-measuring device is either: aligned to within ±1° of the rotational position of the reference scribe line; or is affixed to the probe such that the rotational offset of the device from the reference scribe line is known to within ±1°. This check shall consist of direct measurements of the rotational positions of the reference scribe line and angle-measuring device sufficient to verify that these specifications are met. Annex A in section 18 of this method gives recommended procedures for performing the rotational position check, and Table 2F-2 gives an example data form. Procedures other than those recommended in Annex A in section 18 may be used, provided they demonstrate whether the alignment specification is met and are explained in detail in the field test report.
8.3.1 Angle-measuring device rotational offset. The tester shall maintain a record of the angle-measuring device rotational offset, R
8.3.2 Sign of angle-measuring device rotational offset. The sign of R
8.3.3 Angle-measuring devices that can be independently adjusted (e.g., by means of a set screw), after being locked into position on the probe sheath, may be used. However, the R
8.3.4 Post-test check. If probe extensions remain attached to the main probe throughout the field test, the rotational position check shall be repeated, at a minimum, at the completion of the field test to ensure that the angle-measuring device has remained within ±2° of its rotational position established prior to testing. At the discretion of the tester, additional checks may be conducted after completion of testing at any sample port or after any test run. If the ±2° specification is not met, all measurements made since the last successful rotational position check must be repeated. section 18.1.1.3 of Annex A provides an example procedure for performing the post-test check.
8.3.5 Exceptions.
8.3.5.1 A rotational position check need not be performed if, for measurements taken at all velocity traverse points, the yaw angle-measuring device is mounted and aligned directly on the reference scribe line specified in sections 6.1.6.1 and 6.1.6.3 and no independent adjustments, as described in section 8.3.3, are made to the device’s rotational position.
8.3.5.2 If extensions are detached and re-attached to the probe during a field test, a rotational position check need only be performed the first time an extension is added to the probe, rather than each time the extension is re-attached, if the probe extension is designed to be locked into a mechanically fixed rotational position (e.g., through use of interlocking grooves) that can re-establish the initial rotational position to within ±1°.
8.4 Leak Checks. A pre-test leak check shall be conducted before each field test. A post-test check shall be performed at the end of the field test, but additional leak checks may be conducted after any test run or group of test runs. The post-test check may also serve as the pre-test check for the next group of test runs. If any leak check is failed, all runs since the last passed leak check are invalid. While performing the leak check procedures, also check each pressure device’s responsiveness to the changes in pressure.
8.4.1 To perform the leak check, pressurize the probe’s P
8.5 Zeroing the Differential Pressure-measuring Device. Zero each differential pressure-measuring device, including the device used for yaw nulling, before each field test. At a minimum, check the zero after each field test. A zero check may also be performed after any test run or group of test runs. For fluid manometers and mechanical pressure gauges (e.g., Magnehelic
8.6 Traverse Point Verification. The number and location of the traverse points shall be selected based on Method 1 guidelines. The stack or duct diameter and port nipple lengths, including any extension of the port nipples into stack or duct, shall be verified the first time the test is performed; retain and use this information for subsequent field tests, updating it as required. Physically measure the stack or duct dimensions or use a calibrated laser device; do not use engineering drawings of the stack or duct. The probe length necessary to reach each traverse point shall be recorded to within ±6.4 mm (±1/4 in.) and, for manual probes, marked on the probe sheath. In determining these lengths, the tester shall take into account both the distance that the port flange projects outside of the stack and the depth that any port nipple extends into the gas stream. The resulting point positions shall reflect the true distances from the inside wall of the stack or duct, so that when the tester aligns any of the markings with the outside face of the stack port, the probe’s impact port shall be located at the appropriate distance from the inside wall for the respective Method 1 traverse point. Before beginning testing at a particular location, an out-of-stack or duct verification shall be performed on each probe that will be used to ensure that these position markings are correct. The distances measured during the verification must agree with the previously calculated distances to within ±1/4 in. For manual probes, the traverse point positions shall be verified by measuring the distance of each mark from the probe’s P
8.7 Probe Installation. Insert the probe into the test port. A solid material shall be used to seal the port.
8.8 System Response Time. Determine the response time of the probe measurement system. Insert and position the “cold” probe (at ambient temperature and pressure) at any Method 1 traverse point. Read and record the probe’s P
8.9 Sampling.
8.9.1 Yaw angle measurement protocol. With manual probes, yaw angle measurements may be obtained in two alternative ways during the field test, either by using a yaw angle-measuring device (e.g., digital inclinometer) affixed to the probe, or using a protractor wheel and pointer assembly. For horizontal traversing, either approach may be used. For vertical traversing, i.e., when measuring from on top or into the bottom of a horizontal duct, only the protractor wheel and pointer assembly may be used. With automated probes, curve-fitting protocols may be used to obtain yaw-angle measurements.
8.9.1.1 If a yaw angle-measuring device affixed to the probe is to be used, lock the device on the probe sheath, aligning it either on the reference scribe line or in the rotational offset position established under section 8.3.1.
8.9.1.2 If a protractor wheel and pointer assembly is to be used, follow the procedures in Annex B of this method.
8.9.1.3 Other yaw angle-determination procedures. If approved by the Administrator, other procedures for determining yaw angle may be used, provided that they are verified in a wind tunnel to be able to perform the yaw angle calibration procedure as described in section 10.5.
8.9.2 Sampling strategy. At each traverse point, first yaw-null the probe, as described in section 8.9.3, below. Then, with the probe oriented into the direction of flow, measure and record the yaw angle, the differential pressures and the temperature at the traverse point, after stable readings are achieved, in accordance with sections 8.9.4 and 8.9.5. At the start of testing in each port (i.e., after a probe has been inserted into the flue gas stream), allow at least the response time to elapse before beginning to take measurements at the first traverse point accessed from that port. Provided that the probe is not removed from the flue gas stream, measurements may be taken at subsequent traverse points accessed from the same test port without waiting again for the response time to elapse.
8.9.3 Yaw-nulling procedure. In preparation for yaw angle determination, the probe must first be yaw nulled. After positioning the probe at the appropriate traverse point, perform the following procedures.
8.9.3.1 Rotate the probe until a null differential pressure reading (the difference in pressures across the P
8.9.3.2 Sign of the measured angle. The angle displayed on the angle-measuring device is considered positive when the probe’s impact pressure port (as viewed from the “tail” end of the probe) is oriented in a clockwise rotational position relative to the stack or duct axis and is considered negative when the probe’s impact pressure port is oriented in a counterclockwise rotational position (see Figure 2F-10).
8.9.4 Yaw angle determination. After performing the yaw-nulling procedure in section 8.9.3, determine the yaw angle of flow according to one of the following procedures. Special care must be observed to take into account the signs of the recorded angle and all offsets.
8.9.4.1 Direct-reading. If all rotational offsets are zero or if the angle-measuring device rotational offset (R
Under certain circumstances (e.g., testing of horizontal ducts), a 90° adjustment to the angle-measuring device readings may be necessary to obtain the correct yaw angles.
8.9.4.2 Compensation for rotational offsets during data reduction. When the angle-measuring device rotational offset does not compensate for reference scribe line rotational offset, the following procedure shall be used to determine the yaw angle:
(a) Enter the reading indicated by the angle-measuring device from section 8.9.3.1.
(b) Associate the proper algebraic sign from section 8.9.3.2 with the reading in step (a).
(c) Subtract the reference scribe line rotational offset, R
(d) Subtract the angle-measuring device rotational offset, R
(e) The final result obtained in step (d) is the yaw angle of flow.
It may be necessary to first apply a 90° adjustment to the reading in step (a), in order to obtain the correct yaw angle.
8.9.4.3 Record the yaw angle measurements on a form similar to Table 2F-3.
8.9.5 Velocity determination. Maintain the probe rotational position established during the yaw angle determination. Then, begin recording the pressure-measuring device readings for the impact pressure (P
8.9.6 Alignment check. For manually operated probes, after the required yaw angle and differential pressure and temperature measurements have been made at each traverse point, verify (e.g., by visual inspection) that the yaw angle-measuring device has remained in proper alignment with the reference scribe line or with the rotational offset position established in section 8.3. If, for a particular traverse point, the angle-measuring device is found to be in proper alignment, proceed to the next traverse point; otherwise, re-align the device and repeat the angle and differential pressure measurements at the traverse point. In the course of a traverse, if a mark used to properly align the angle-measuring device (e.g., as described in section 18.1.1.1) cannot be located, re-establish the alignment mark before proceeding with the traverse.
8.10 Probe Plugging. Periodically check for plugging of the pressure ports by observing the responses on pressure differential readouts. Plugging causes erratic results or sluggish responses. Rotate the probe to determine whether the readouts respond in the expected direction. If plugging is detected, correct the problem and repeat the affected measurements.
8.11 Static Pressure. Measure the static pressure in the stack or duct using the equipment described in section 6.7.
8.11.1 If a Type DA or DAT probe is used for this measurement, position the probe at or between any traverse point(s) and rotate the probe until a null differential pressure reading is obtained at P
8.11.2 If a Type S probe is used for this measurement, position the probe at or between any traverse point(s) and rotate the probe until a null differential pressure reading is obtained. Disconnect the tubing from one of the pressure ports; read and record the ΔP. For pressure devices with one-directional scales, if a deflection in the positive direction is noted with the negative side disconnected, then the static pressure is positive. Likewise, if a deflection in the positive direction is noted with the positive side disconnected, then the static pressure is negative.
8.12 Atmospheric Pressure. Determine the atmospheric pressure at the sampling elevation during each test run following the procedure described in section 2.5 of Method 2.
8.13 Molecular Weight. Determine the stack gas dry molecular weight. For combustion processes or processes that emit essentially CO
8.14 Moisture. Determine the moisture content of the stack gas using Method 4 or equivalent.
8.15 Data Recording and Calculations. Record all required data on a form similar to Table 2F-3.
8.15.1 Selection of appropriate calibration curves. Choose the appropriate pair of F
8.15.2 Pitch angle derivation. Use the appropriate calculation procedures in section 12.2 to find the pitch angle ratios that are applicable at each traverse point. Then, find the pitch angles corresponding to these pitch angle ratios on the “F
8.15.3 Velocity calibration coefficient derivation. Use the pitch angle obtained following the procedures described in section 8.15.2 to find the corresponding velocity calibration coefficients from the “F
8.15.4 Calculations. Calculate the axial velocity at each traverse point using the equations presented in section 12.2 to account for the yaw and pitch angles of flow. Calculate the test run average stack gas velocity by finding the arithmetic average of the point velocity results in accordance with sections 12.3 and 12.4, and calculate the stack gas volumetric flow rate in accordance with section 12.5 or 12.6, as applicable.
9.1 Quality Control Activities. In conjunction with the yaw angle determination and the pressure and temperature measurements specified in section 8.9, the following quality control checks should be performed.
9.1.1 Range of the differential pressure gauge. In accordance with the specifications in section 6.4, ensure that the proper differential pressure gauge is being used for the range of ΔP values encountered. If it is necessary to change to a more sensitive gauge, replace the gauge with a gauge calibrated according to section 10.3.3, perform the leak check described in section 8.4 and the zero check described in section 8.5, and repeat the differential pressure and temperature readings at each traverse point.
9.1.2 Horizontal stability check. For horizontal traverses of a stack or duct, visually check that the probe shaft is maintained in a horizontal position prior to taking a pressure reading. Periodically, during a test run, the probe’s horizontal stability should be verified by placing a carpenter’s level, a digital inclinometer, or other angle-measuring device on the portion of the probe sheath that extends outside of the test port. A comparable check should be performed by automated systems.
10.1 Wind Tunnel Qualification Checks. To qualify for use in calibrating probes, a wind tunnel shall have the design features specified in section 6.11 and satisfy the following qualification criteria. The velocity pressure cross-check in section 10.1.1 and axial flow verification in section 10.1.2 shall be performed before the initial use of the wind tunnel and repeated immediately after any alteration occurs in the wind tunnel’s configuration, fans, interior surfaces, straightening vanes, controls, or other properties that could reasonably be expected to alter the flow pattern or velocity stability in the tunnel. The owner or operator of a wind tunnel used to calibrate probes according to this method shall maintain records documenting that the wind tunnel meets the requirements of sections 10.1.1 and 10.1.2 and shall provide these records to the Administrator upon request.
10.1.1 Velocity pressure cross-check. To verify that the wind tunnel produces the same velocity at the tested probe head as at the calibration pitot tube impact port, perform the following cross-check. Take three differential pressure measurements at the fixed calibration pitot tube location, using the calibration pitot tube specified in section 6.10, and take three measurements with the calibration pitot tube at the wind tunnel calibration location, as defined in section 3.20. Alternate the measurements between the two positions. Perform this procedure at the lowest and highest velocity settings at which the probes will be calibrated. Record the values on a form similar to Table 2F-4. At each velocity setting, the average velocity pressure obtained at the wind tunnel calibration location shall be within ±2 percent or 2.5 mm H
10.1.2 Axial flow verification. The following procedures shall be performed to demonstrate that there is fully developed axial flow within the calibration location and at the calibration pitot tube location. Two testing options are available to conduct this check.
10.1.2.1 Using a calibrated 3-D probe. A 3-D probe that has been previously calibrated in a wind tunnel with documented axial flow (as defined in section 3.21) may be used to conduct this check. Insert the calibrated 3-D probe into the wind tunnel test section using the tested probe port. Following the procedures in sections 8.9 and 12.2 of this method, determine the yaw and pitch angles at all the point(s) in the test section where the velocity pressure cross-check, as specified in section 10.1.1, is performed. This includes all the points in the calibration location and the point where the calibration pitot tube will be located. Determine the yaw and pitch angles at each point. Repeat these measurements at the highest and lowest velocities at which the probes will be calibrated. Record the values on a form similar to Table 2F-5. Each measured yaw and pitch angle shall be within ±3° of 0°. Exceeding the limits indicates unacceptable flow in the test section. Until the problem is corrected and acceptable flow is verified by repetition of this procedure, the wind tunnel shall not be used for calibration of probes. Include the results of the axial flow verification in the calibration data section of the field test report. (See section 16.1.4.)
10.1.2.2 Using alternative probes. Axial flow verification may be performed using an uncalibrated prism-shaped 3-D probe (e.g., DA or DAT probe) or an uncalibrated wedge probe. (Figure 2F-11 illustrates a typical wedge probe.) This approach requires use of two ports: the tested probe port and a second port located 90° from the tested probe port. Each port shall provide access to all the points within the wind tunnel test section where the velocity pressure cross-check, as specified in section 10.1.1, is conducted. The probe setup shall include establishing a reference yaw-null position on the probe sheath to serve as the location for installing the angle-measuring device. Physical design features of the DA, DAT, and wedge probes are relied on to determine the reference position. For the DA or DAT probe, this reference position can be determined by setting a digital inclinometer on the flat facet where the P
10.1.3 Wind tunnel audits.
10.1.3.1 Procedure. Upon the request of the Administrator, the owner or operator of a wind tunnel shall calibrate a 3-D audit probe in accordance with the procedures described in sections 10.3 through 10.6. The calibration shall be performed at two velocities and over a pitch angle range that encompasses the velocities and pitch angles typically used for this method at the facility. The resulting calibration data and curves shall be submitted to the Agency in an audit test report. These results shall be compared by the Agency to reference calibrations of the audit probe at the same velocity and pitch angle settings obtained at two different wind tunnels.
10.1.3.2 Acceptance criteria. The audited tunnel’s calibration is acceptable if all of the following conditions are satisfied at each velocity and pitch setting for the reference calibration obtained from at least one of the wind tunnels. For pitch angle settings between −15° and + 15°, no velocity calibration coefficient (i.e., F
10.2 Probe Inspection. Before each calibration of a 3-D probe, carefully examine the physical condition of the probe head. Particular attention shall be paid to the edges of the pressure ports and the surfaces surrounding these ports. Any dents, scratches, or asymmetries on the edges of the pressure ports and any scratches or indentations on the surfaces surrounding the pressure ports shall be noted because of the potential effect on the probe’s pressure readings. If the probe has been previously calibrated, compare the current condition of the probe’s pressure ports and surfaces to the results of the inspection performed during the probe’s most recent wind tunnel calibration. Record the results of this inspection on a form and in diagrams similar to Table 2F-1. The information in Table 2F-1 will be used as the basis for comparison during the probe head inspections performed before each subsequent field use.
10.3 Pre-Calibration Procedures. Prior to calibration, a scribe line shall have been placed on the probe in accordance with section 10.4. The yaw angle and velocity calibration procedures shall not begin until the pre-test requirements in sections 10.3.1 through 10.3.4 have been met.
10.3.1 Perform the horizontal straightness check described in section 8.2 on the probe assembly that will be calibrated in the wind tunnel.
10.3.2 Perform a leak check in accordance with section 8.4.
10.3.3 Except as noted in section 10.3.3.3, calibrate all differential pressure-measuring devices to be used in the probe calibrations, using the following procedures. At a minimum, calibrate these devices on each day that probe calibrations are performed.
10.3.3.1 Procedure. Before each wind tunnel use, all differential pressure-measuring devices shall be calibrated against the reference device specified in section 6.4.3 using a common pressure source. Perform the calibration at three reference pressures representing 30, 60, and 90 percent of the full-scale range of the pressure-measuring device being calibrated. For an inclined-vertical manometer, perform separate calibrations on the inclined and vertical portions of the measurement scale, considering each portion of the scale to be a separate full-scale range. [For example, for a manometer with a 0- to 2.5-cm H
10.3.3.2 Acceptance criteria. At each pressure setting, the two pressure readings made using the reference device and the pressure-measuring device being calibrated shall agree to within ±2 percent of full scale of the device being calibrated or 0.5 mm H
10.3.3.3 Exceptions. Any precision manometer that meets the specifications for a reference device in section 6.4.3 and that is not used for field testing does not require calibration, but must be leveled and zeroed before each wind tunnel use. Any pressure device used exclusively for yaw nulling does not require calibration, but shall be checked for responsiveness to rotation of the probe prior to each wind tunnel use.
10.3.4 Calibrate digital inclinometers on each day of wind tunnel or field testing (prior to beginning testing) using the following procedures. Calibrate the inclinometer according to the manufacturer’s calibration procedures. In addition, use a triangular block (illustrated in Figure 2F-12) with a known angle, θ independently determined using a protractor or equivalent device, between two adjacent sides to verify the inclinometer readings.
If other angle-measuring devices meeting the provisions of section 6.2.3 are used in place of a digital inclinometer, comparable calibration procedures shall be performed on such devices.)
10.4 Placement of Reference Scribe Line. Prior to the first calibration of a probe, a line shall be permanently inscribed on the main probe sheath to serve as a reference mark for determining yaw angles. Annex C in section 18 of this method gives a guideline for placement of the reference scribe line.
10.4.1 This reference scribe line shall meet the specifications in sections 6.1.6.1 and 6.1.6.3 of this method. To verify that the alignment specification in section 6.1.6.3 is met, secure the probe in a horizontal position and measure the rotational angle of each scribe line and scribe line segment using an angle-measuring device that meets the specifications in section 6.2.1 or 6.2.3. For any scribe line that is longer than 30.5 cm (12 in.), check the line’s rotational position at 30.5-cm (12-in.) intervals. For each line segment that is 30.5 cm (12 in.) or less in length, check the rotational position at the two endpoints of the segment. To meet the alignment specification in section 6.1.6.3, the minimum and maximum of all of the rotational angles that are measured along the full length of the main probe must not differ by more than 2°.
A short reference scribe line segment [e.g., 15.2 cm (6 in.) or less in length] meeting the alignment specifications in section 6.1.6.3 is fully acceptable under this method. See section 18.1.1.1 of Annex A for an example of a probe marking procedure, suitable for use with a short reference scribe line.
10.4.2 The scribe line should be placed on the probe first and then its offset from the yaw-null position established (as specified in section 10.5). The rotational position of the reference scribe line relative to the yaw-null position of the probe, as determined by the yaw angle calibration procedure in section 10.5, is defined as the reference scribe line rotational offset, R
10.4.3 Scribe line for automated probes. A scribe line may not be necessary for an automated probe system if a reference rotational position of the probe is built into the probe system design. For such systems, a “flat” (or comparable, clearly identifiable physical characteristic) should be provided on the probe casing or flange plate to ensure that the reference position of the probe assembly remains in a vertical or horizontal position. The rotational offset of the flat (or comparable, clearly identifiable physical characteristic) needed to orient the reference position of the probe assembly shall be recorded and maintained as part of the automated probe system’s specifications.
10.5 Yaw Angle Calibration Procedure. For each probe used to measure yaw angles with this method, a calibration procedure shall be performed in a wind tunnel meeting the specifications in section 10.1 to determine the rotational position of the reference scribe line relative to the probe’s yaw-null position. This procedure shall be performed on the main probe with all devices that will be attached to the main probe in the field [such as thermocouples or resistance temperature detectors (RTDs)] that may affect the flow around the probe head. Probe shaft extensions that do not affect flow around the probe head need not be attached during calibration. At a minimum, this procedure shall include the following steps.
10.5.1 Align and lock the angle-measuring device on the reference scribe line. If a marking procedure (such as that described in section 18.1.1.1) is used, align the angle-measuring device on a mark within ±1° of the rotational position of the reference scribe line. Lock the angle-measuring device onto the probe sheath at this position.
10.5.2 Zero the pressure-measuring device used for yaw nulling.
10.5.3 Insert the probe assembly into the wind tunnel through the entry port, positioning the probe’s impact port at the calibration location. Check the responsiveness of the pressure-measurement device to probe rotation, taking corrective action if the response is unacceptable.
10.5.4 Ensure that the probe is in a horizontal position, using a carpenter’s level.
10.5.5 Rotate the probe either clockwise or counterclockwise until a yaw null (P
10.5.6 Use the reading displayed by the angle-measuring device at the yaw-null position to determine the magnitude of the reference scribe line rotational offset, R
10.5.7 The steps in sections 10.5.3 through 10.5.6 shall be performed twice at each of the velocities at which the probe will be calibrated (in accordance with section 10.6). Record the values of R
10.5.8 The average of all of the R
10.5.9 Use of reference scribe line offset. The reference scribe line rotational offset shall be used to determine the yaw angle of flow in accordance with section 8.9.4.
10.6 Pitch Angle and Velocity Pressure Calibrations. Use the procedures in sections 10.6.1 through 10.6.16 to generate an appropriate set (or sets) of pitch angle and velocity pressure calibration curves for each probe. The calibration procedure shall be performed on the main probe and all devices that will be attached to the main probe in the field (e.g., thermocouple or RTDs) that may affect the flow around the probe head. Probe shaft extensions that do not affect flow around the probe head need not be attached during calibration. (Note: If a sampling nozzle is part of the assembly, a wind tunnel demonstration shall be performed that shows the probe’s ability to measure velocity and yaw null is not impaired when the nozzle is drawing a sample.) The calibration procedure involves generating two calibration curves, F
10.6.1 Calibration velocities. The tester may calibrate the probe at two nominal wind tunnel velocity settings of 18.3 m/sec and 27.4 m/sec (60 ft/sec and 90 ft/sec) and average the results of these calibrations, as described in section 10.6.16.1, in order to generate a set of calibration curves. If this option is selected, this single set of calibration curves may be used for all field applications over the entire velocity range allowed by the method. Alternatively, the tester may customize the probe calibration for a particular field test application (or for a series of applications), based on the expected average velocity(ies) at the test site(s). If this option is selected, generate each set of calibration curves by calibrating the probe at two nominal wind tunnel velocity settings, at least one of which is greater than or equal to the expected average velocity(ies) for the field application(s), and average the results as described in section 10.6.16.1. Whichever calibration option is selected, the probe calibration coefficients (F
10.6.2 Pitch angle calibration curve (F
10.6.3 Velocity calibration curve (F
10.6.4 Connect the tested probe and calibration pitot probe to their respective pressure-measuring devices. Zero the pressure-measuring devices. Inspect and leak-check all pitot lines; repair or replace, if necessary. Turn on the fan, and allow the wind tunnel air flow to stabilize at the first of the two selected nominal velocity settings.
10.6.5 Position the calibration pitot tube at its measurement location (determined as outlined in section 6.11.4.3), and align the tube so that its tip is pointed directly into the flow. Ensure that the entry port surrounding the tube is properly sealed. The calibration pitot tube may either remain in the wind tunnel throughout the calibration, or be removed from the wind tunnel while measurements are taken with the probe being calibrated.
10.6.6 Set up the pitch protractor plate on the tested probe’s entry port to establish the pitch angle positions of the probe to within ±2°.
10.6.7 Check the zero setting of each pressure-measuring device.
10.6.8 Insert the tested probe into the wind tunnel and align it so that its P
10.6.9 Read the differential pressure from the calibration pitot tube (ΔP
10.6.10 After the tested probe’s differential pressure gauges have had sufficient time to stabilize, yaw null the probe, then obtain differential pressure readings for (P
10.6.11 Either take paired differential pressure measurements with both the calibration pitot tube and tested probe (according to sections 10.6.9 and 10.6.10) or take readings only with the tested probe (according to section 10.6.10) in 5° increments over the pitch-angle range for which the probe is to be calibrated. The calibration pitch-angle range shall be symmetric around 0° and shall exceed the largest pitch angle expected in the field by 5°. At a minimum, probes shall be calibrated over the range of −15° to + 15°. If paired calibration pitot tube and tested probe measurements are not taken at each pitch angle setting, the differential pressure from the calibration pitot tube shall be read, at a minimum, before taking the tested probe’s differential pressure reading at the first pitch angle setting and after taking the tested probe’s differential pressure readings at the last pitch angle setting in each replicate.
10.6.12 Perform a second replicate of the procedures in sections 10.6.5 through 10.6.11 at the same nominal velocity setting.
10.6.13 For each replicate, calculate the F
If the percent difference is less than or equal to 2 percent, calculate an average F
10.6.14 Repeat the calibration procedures in sections 10.6.5 through 10.6.13 at the second selected nominal wind tunnel velocity setting.
10.6.15 Velocity drift check. The following check shall be performed, except when paired calibration pitot tube and tested probe pressure measurements are taken at each pitch angle setting. At each velocity setting, calculate the percent difference between consecutive differential pressure measurements made with the calibration pitot tube. If a measurement differs from the previous measurement by more than 2 percent or 0.25 mm H
10.6.16 Compare the averaged F
10.6.16.1 If the applicable specification in section 10.6.16 is met at each pitch angle setting, average the results obtained at the two nominal calibration velocities to produce a calibration record of F
10.6.16.2 If the applicable specification in section 10.6.16 is exceeded at any pitch angle setting, the probe shall not be used unless: (1) the calibration is repeated at that pitch angle and acceptable results are obtained or (2) values of F
10.7 Recalibration. Recalibrate the probe using the procedures in section 10 either within 12 months of its first field use after its most recent calibration or after 10 field tests (as defined in section 3.4), whichever occurs later. In addition, whenever there is visible damage to the 3-D head, the probe shall be recalibrated before it is used again.
10.8 Calibration of pressure-measuring devices used in field tests. Before its initial use in a field test, calibrate each pressure-measuring device (except those used exclusively for yaw nulling) using the three-point calibration procedure described in section 10.3.3. The device shall be recalibrated according to the procedure in section 10.3.3 no later than 90 days after its first field use following its most recent calibration. At the discretion of the tester, more frequent calibrations (e.g., after a field test) may be performed. No adjustments, other than adjustments to the zero setting, shall be made to the device between calibrations.
10.8.1 Post-test calibration check. A single-point calibration check shall be performed on each pressure-measuring device after completion of each field test. At the discretion of the tester, more frequent single-point calibration checks (e.g., after one or more field test runs) may be performed. It is recommended that the post-test check be performed before leaving the field test site. The check shall be performed at a pressure between 50 and 90 percent of full scale by taking a common pressure reading with the tested device and a reference pressure-measuring device (as described in section 6.4.4) or by challenging the tested device with a reference pressure source (as described in section 6.4.4) or by performing an equivalent check using a reference device approved by the Administrator.
10.8.2 Acceptance criterion. At the selected pressure setting, the pressure readings made using the reference device and the tested device shall agree to within 3 percent of full scale of the tested device or 0.8 mm H
10.9 Temperature Gauges. Same as Method 2, section 4.3. The alternative thermocouple calibration procedures outlined in Emission Measurement Center (EMC) Approved Alternative Method (ALT-011) “Alternative Method 2 Thermocouple Calibration Procedure” may be performed. Temperature gauges shall be calibrated no more than 30 days prior to the start of a field test or series of field tests and recalibrated no more than 30 days after completion of a field test or series of field tests.
10.10 Barometer. Same as Method 2, section 4.4. The barometer shall be calibrated no more than 30 days prior to the start of a field test or series of field tests.
Sample collection and analysis are concurrent for this method (see section 8.0).
These calculations use the measured yaw angle, derived pitch angle, and the differential pressure and temperature measurements at individual traverse points to derive the axial flue gas velocity (v
12.1 Nomenclature
12.2 Traverse Point Velocity Calculations. Perform the following calculations from the measurements obtained at each traverse point.
12.2.1 Selection of calibration curves. Select calibration curves as described in section 10.6.1.
12.2.2 Traverse point pitch angle ratio. Use Equation 2F-1, as described in section 10.6.2, to calculate the pitch angle ratio, F
12.2.3 Pitch angle. Use the pitch angle ratio, F
12.2.4 Velocity calibration coefficient. Use the pitch angle, θ
12.2.5 Axial velocity. Use the following equation to calculate the axial velocity, v
12.2.6 Handling multiple measurements at a traverse point. For pressure or temperature devices that take multiple measurements at a traverse point, the multiple measurements (or where applicable, their square roots) may first be averaged and the resulting average values used in the equations above. Alternatively, the individual measurements may be used in the equations above and the resulting multiple calculated values may then be averaged to obtain a single traverse point value. With either approach, all of the individual measurements recorded at a traverse point must be used in calculating the applicable traverse point value.
12.3 Average Axial Velocity in Stack or Duct. Use the reported traverse point axial velocity in the following equation.
12.4 Acceptability of Results. The test results are acceptable and the calculated value of v
12.4.1 The calibration curves were generated at nominal velocities of 18.3 m/sec and 27.4 m/sec (60 ft/sec and 90 ft/sec).
12.4.2 The calibration curves were generated at nominal velocities other than 18.3 m/sec and 27.4 m/sec (60 ft/sec and 90 ft/sec), and the value of v
12.4.3 If the conditions in neither section 12.4.1 nor section 12.4.2 are met, the test results obtained in Equation 2F-9 are not acceptable, and the steps in sections 12.2 and 12.3 must be repeated using a set of F
12.5 Average Gas Wet Volumetric Flow Rate in Stack or Duct. Use the following equation to compute the average volumetric flow rate on a wet basis.
12.6 Average Gas Dry Volumetric Flow Rate in Stack or Duct. Use the following equation to compute the average volumetric flow rate on a dry basis.
16.1 Field Test Reports. Field test reports shall be submitted to the Agency according to applicable regulatory requirements. Field test reports should, at a minimum, include the following elements.
16.1.1 Description of the source. This should include the name and location of the test site, descriptions of the process tested, a description of the combustion source, an accurate diagram of stack or duct cross-sectional area at the test site showing the dimensions of the stack or duct, the location of the test ports, and traverse point locations and identification numbers or codes. It should also include a description and diagram of the stack or duct layout, showing the distance of the test location from the nearest upstream and downstream disturbances and all structural elements (including breachings, baffles, fans, straighteners, etc.) affecting the flow pattern. If the source and test location descriptions have been previously submitted to the Agency in a document (e.g., a monitoring plan or test plan), referencing the document in lieu of including this information in the field test report is acceptable.
16.1.2 Field test procedures. These should include a description of test equipment and test procedures. Testing conventions, such as traverse point numbering and measurement sequence (e.g., sampling from center to wall, or wall to center), should be clearly stated. Test port identification and directional reference for each test port should be included on the appropriate field test data sheets.
16.1.3 Field test data.
16.1.3.1 Summary of results. This summary should include the dates and times of testing and the average axial gas velocity and the average flue gas volumetric flow results for each run and tested condition.
16.1.3.2 Test data. The following values for each traverse point should be recorded and reported:
(a) P
(b) Stack or duct gas temperature at traverse point i (t
(c) Absolute stack or duct gas temperature at traverse point i (T
(d) Yaw angle at each traverse point i (θ
(e) Pitch angle at each traverse point i (θ
(f) Stack or duct gas axial velocity at traverse point i (v
16.1.3.3 The following values should be reported once per run:
(a) Water vapor in the gas stream (from Method 4 or alternative), proportion by volume (B
(b) Molecular weight of stack or duct gas, dry basis (M
(c) Molecular weight of stack or duct gas, wet basis (M
(d) Stack or duct static pressure (P
(e) Absolute stack or duct pressure (P
(f) Carbon dioxide concentration in the flue gas, dry basis (
(g) Oxygen concentration in the flue gas, dry basis (
(h) Average axial stack or duct gas velocity (v
(i) Gas volumetric flow rate corrected to standard conditions, dry or wet basis as required by the applicable regulation (Q
(a) Cross-sectional area of stack or duct at the test location (A)
(b) Measurement system response time (sec)
(c) Barometric pressure at measurement site (P
16.1.4 Calibration data. The field test report should include calibration data for all probes and test equipment used in the field test. At a minimum, the probe calibration data reported to the Agency should include the following:
(a) Date of calibration
(b) Probe type
(c) Probe identification number(s) or code(s)
(d) Probe inspection sheets
(e) Pressure measurements and intermediate calculations of F
(f) Calibration curves (in graphic or equation format) obtained in accordance with sections 10.6.11 of this method
(g) Description and diagram of wind tunnel used for the calibration, including dimensions of cross-sectional area and position and size of the test section
(h) Documentation of wind tunnel qualification tests performed in accordance with section 10.1 of this method
16.1.5 Quality Assurance. Specific quality assurance and quality control procedures used during the test should be described.
(1) 40 CFR Part 60, Appendix A, Method 1 – Sample and velocity traverses for stationary sources.
(2) 40 CFR Part 60, Appendix A, Method 2H – Determination of stack gas velocity taking into account velocity decay near the stack wall.
(3) 40 CFR Part 60, Appendix A, Method 2 – Determination of stack gas velocity and volumetric flow rate (Type S pitot tube).
(4) 40 CFR Part 60, Appendix A, Method 3 – Gas analysis for carbon dioxide, oxygen, excess air, and dry molecular weight.
(5) 40 CFR Part 60, Appendix A, Method 3A – Determination of oxygen and carbon dioxide concentrations in emissions from stationary sources (instrumental analyzer procedure).
(6) 40 CFR Part 60, Appendix A, Method 4 – Determination of moisture content in stack gases.
(7) Emission Measurement Center (EMC) Approved Alternative Method (ALT-011) “Alternative Method 2 Thermocouple Calibration Procedure.”
(8) Electric Power Research Institute, Interim Report EPRI TR-106698, “Flue Gas Flow Rate Measurement Errors,” June 1996.
(9) Electric Power Research Institute, Final Report EPRI TR-108110, “Evaluation of Heat Rate Discrepancy from Continuous Emission Monitoring Systems,” August 1997.
(10) Fossil Energy Research Corporation, Final Report, “Velocity Probe Tests in Non-axial Flow Fields,” November 1998, Prepared for the U.S. Environmental Protection Agency.
(11) Fossil Energy Research Corporation, “Additional Swirl Tunnel Tests: E-DAT and T-DAT Probes,” February 24, 1999, Technical Memorandum Prepared for U.S. Environmental Protection Agency, P.O. No. 7W-1193-NALX.
(12) Massachusetts Institute of Technology, Report WBWT-TR-1317, “Calibration of Eight Wind Speed Probes Over a Reynolds Number Range of 46,000 to 725,000 Per Foot, Text and Summary Plots,” Plus appendices, October 15, 1998, Prepared for The Cadmus Group, Inc.
(13) National Institute of Standards and Technology, Special Publication 250, “NIST Calibration Services Users Guide 1991,” Revised October 1991, U.S. Department of Commerce, p. 2.
(14) National Institute of Standards and Technology, 1998, “Report of Special Test of Air Speed Instrumentation, Four Prandtl Probes, Four S-Type Probes, Four French Probes, Four Modified Kiel Probes,” Prepared for the U.S. Environmental Protection Agency under IAG #DW13938432-01-0.
(15) National Institute of Standards and Technology, 1998, “Report of Special Test of Air Speed Instrumentation, Five Autoprobes,” Prepared for the U.S. Environmental Protection Agency under IAG #DW13938432-01-0.
(16) National Institute of Standards and Technology, 1998, “Report of Special Test of Air Speed Instrumentation, Eight Spherical Probes,” Prepared for the U.S. Environmental Protection Agency under IAG #DW13938432-01-0.
(17) National Institute of Standards and Technology, 1998, “Report of Special Test of Air Speed Instrumentation, Four DAT Probes,” Prepared for the U.S. Environmental Protection Agency under IAG #DW13938432-01-0.
(18) Norfleet, S.K., “An Evaluation of Wall Effects on Stack Flow Velocities and Related Overestimation Bias in EPA’s Stack Flow Reference Methods,” EPRI CEMS User’s Group Meeting, New Orleans, Louisiana, May 13-15, 1998.
(19) Page, J.J., E.A. Potts, and R.T. Shigehara, “3-D Pitot Tube Calibration Study,” EPA Contract No. 68-D1-0009, Work Assignment No. I-121, March 11, 1993.
(20) Shigehara, R.T., W.F. Todd, and W.S. Smith, “Significance of Errors in Stack Sampling Measurements,” Presented at the Annual Meeting of the Air Pollution Control Association, St. Louis, Missouri, June 14-19, 1970.
(21) The Cadmus Group, Inc., May 1999, “EPA Flow Reference Method Testing and Analysis: Findings Report,” EPA/430-R-99-009.
(22) The Cadmus Group, Inc., 1998, “EPA Flow Reference Method Testing and Analysis: Data Report, Texas Utilities, DeCordova Steam Electric Station, Volume I: Test Description and Appendix A (Data Distribution Package),” EPA/430-R-98-015a.
(23) The Cadmus Group, Inc., 1998, “EPA Flow Reference Method Testing and Analysis: Data Report, Texas Utilities, Lake Hubbard Steam Electric Station, Volume I: Test Description and Appendix A (Data Distribution Package),” EPA/430-R-98-017a.
(24) The Cadmus Group, Inc., 1998, “EPA Flow Reference Method Testing and Analysis: Data Report, Pennsylvania Electric Co., G.P.U. Genco Homer City Station: Unit 1, Volume I: Test Description and Appendix A (Data Distribution Package),” EPA/430-R-98-018a.
(25) The Cadmus Group, Inc., 1997, “EPA Flow Reference Method Testing and Analysis: Wind Tunnel Experimental Results,” EPA/430-R-97-013.
Annex A, C, and D describe recommended procedures for meeting certain provisions in sections 8.3, 10.4, and 10.5 of this method. Annex B describes procedures to be followed when using the protractor wheel and pointer assembly to measure yaw angles, as provided under section 8.9.1.
18.1 Annex A – Rotational Position Check. The following are recommended procedures that may be used to satisfy the rotational position check requirements of section 8.3 of this method and to determine the angle-measuring device rotational offset R
18.1.1 Rotational position check with probe outside stack. Where physical constraints at the sampling location allow full assembly of the probe outside the stack and insertion into the test port, the following procedures should be performed before the start of testing. Two angle-measuring devices that meet the specifications in section 6.2.1 or 6.2.3 are required for the rotational position check. An angle measuring device whose position can be independently adjusted (e.g., by means of a set screw) after being locked into position on the probe sheath shall not be used for this check unless the independent adjustment is set so that the device performs exactly like a device without the capability for independent adjustment. That is, when aligned on the probe such a device must give the same reading as a device that does not have the capability of being independently adjusted. With the fully assembled probe (including probe shaft extensions, if any) secured in a horizontal position, affix one yaw angle-measuring device to the probe sheath and lock it into position on the reference scribe line specified in section 6.1.6.1. Position the second angle-measuring device using the procedure in section 18.1.1.1 or 18.1.1.2.
18.1.1.1 Marking procedure. The procedures in this section should be performed at each location on the fully assembled probe where the yaw angle-measuring device will be mounted during the velocity traverse. Place the second yaw angle-measuring device on the main probe sheath (or extension) at the position where a yaw angle will be measured during the velocity traverse. Adjust the position of the second angle-measuring device until it indicates the same angle (±1°) as the reference device, and affix the second device to the probe sheath (or extension). Record the angles indicated by the two angle-measuring devices on a form similar to Table 2F-2. In this position, the second angle-measuring device is considered to be properly positioned for yaw angle measurement. Make a mark, no wider than 1.6 mm (1/16 in.), on the probe sheath (or extension), such that the yaw angle-measuring device can be re-affixed at this same properly aligned position during the velocity traverse.
18.1.1.2 Procedure for probe extensions with scribe lines. If, during a velocity traverse the angle-measuring device will be affixed to a probe extension having a scribe line as specified in section 6.1.6.2, the following procedure may be used to align the extension’s scribe line with the reference scribe line instead of marking the extension as described in section 18.1.1.1. Attach the probe extension to the main probe. Align and lock the second angle-measuring device on the probe extension’s scribe line. Then, rotate the extension until both measuring devices indicate the same angle (±1°). Lock the extension at this rotational position. Record the angles indicated by the two angle-measuring devices on a form similar to Table 2F-2. An angle-measuring device may be aligned at any position on this scribe line during the velocity traverse, if the scribe line meets the alignment specification in section 6.1.6.3.
18.1.1.3 Post-test rotational position check. If the fully assembled probe includes one or more extensions, the following check should be performed immediately after the completion of a velocity traverse. At the discretion of the tester, additional checks may be conducted after completion of testing at any sample port. Without altering the alignment of any of the components of the probe assembly used in the velocity traverse, secure the fully assembled probe in a horizontal position. Affix an angle-measuring device at the reference scribe line specified in section 6.1.6.1. Use the other angle-measuring device to check the angle at each location where the device was checked prior to testing. Record the readings from the two angle-measuring devices.
18.1.2 Rotational position check with probe in stack. This section applies only to probes that, due to physical constraints, cannot be inserted into the test port as fully assembled with all necessary extensions needed to reach the inner-most traverse point(s).
18.1.2.1 Perform the out-of-stack procedure in section 18.1.1 on the main probe and any attached extensions that will be initially inserted into the test port.
18.1.2.2 Use the following procedures to perform additional rotational position check(s) with the probe in the stack, each time a probe extension is added. Two angle-measuring devices are required. The first of these is the device that was used to measure yaw angles at the preceding traverse point, left in its properly aligned measurement position. The second angle-measuring device is positioned on the added probe extension. Use the applicable procedures in section 18.1.1.1 or 18.1.1.2 to align, adjust, lock, and mark (if necessary) the position of the second angle-measuring device to within ±1° of the first device. Record the readings of the two devices on a form similar to Table 2F-2.
18.1.2.3 The procedure in section 18.1.2.2 should be performed at the first port where measurements are taken. The procedure should be repeated each time a probe extension is re-attached at a subsequent port, unless the probe extensions are designed to be locked into a mechanically fixed rotational position (e.g., through use of interlocking grooves), which can be reproduced from port to port as specified in section 8.3.5.2.
18.2 Annex B – Angle Measurement Protocol for Protractor Wheel and Pointer Device. The following procedure shall be used when a protractor wheel and pointer assembly, such as the one described in section 6.2.2 and illustrated in Figure 2F-7 is used to measure the yaw angle of flow. With each move to a new traverse point, unlock, re-align, and re-lock the probe, angle-pointer collar, and protractor wheel to each other. At each such move, particular attention is required to ensure that the scribe line on the angle pointer collar is either aligned with the reference scribe line on the main probe sheath or is at the rotational offset position established under section 8.3.1. The procedure consists of the following steps:
18.2.1 Affix a protractor wheel to the entry port for the test probe in the stack or duct.
18.2.2 Orient the protractor wheel so that the 0° mark corresponds to the longitudinal axis of the stack or duct. For stacks, vertical ducts, or ports on the side of horizontal ducts, use a digital inclinometer meeting the specifications in section 6.2.1 to locate the 0° orientation. For ports on the top or bottom of horizontal ducts, identify the longitudinal axis at each test port and permanently mark the duct to indicate the 0° orientation. Once the protractor wheel is properly aligned, lock it into position on the test port.
18.2.3 Move the pointer assembly along the probe sheath to the position needed to take measurements at the first traverse point. Align the scribe line on the pointer collar with the reference scribe line or at the rotational offset position established under section 8.3.1. Maintaining this rotational alignment, lock the pointer device onto the probe sheath. Insert the probe into the entry port to the depth needed to take measurements at the first traverse point.
18.2.4 Perform the yaw angle determination as specified in sections 8.9.3 and 8.9.4 and record the angle as shown by the pointer on the protractor wheel. Then, take velocity pressure and temperature measurements in accordance with the procedure in section 8.9.5. Perform the alignment check described in section 8.9.6.
18.2.5 After taking velocity pressure measurements at that traverse point, unlock the probe from the collar and slide the probe through the collar to the depth needed to reach the next traverse point.
18.2.6 Align the scribe line on the pointer collar with the reference scribe line on the main probe or at the rotational offset position established under section 8.3.1. Lock the collar onto the probe.
18.2.7 Repeat the steps in sections 18.2.4 through 18.2.6 at the remaining traverse points accessed from the current stack or duct entry port.
18.2.8 After completing the measurement at the last traverse point accessed from a port, verify that the orientation of the protractor wheel on the test port has not changed over the course of the traverse at that port. For stacks, vertical ducts, or ports on the side of horizontal ducts, use a digital inclinometer meeting the specifications in section 6.2.1 to check the rotational position of the 0° mark on the protractor wheel. For ports on the top or bottom of horizontal ducts, observe the alignment of the angle wheel 0° mark relative to the permanent 0° mark on the duct at that test port. If these observed comparisons exceed ±2° of 0°, all angle and pressure measurements taken at that port since the protractor wheel was last locked into position on the port shall be repeated.
18.2.9 Move to the next stack or duct entry port and repeat the steps in sections 18.2.1 through 18.2.8.
18.3 Annex C – Guideline for Reference Scribe Line Placement. Use of the following guideline is recommended to satisfy the requirements of section 10.4 of this method. The rotational position of the reference scribe line should be either 90° or 180° from the probe’s impact pressure port.
18.4 Annex D – Determination of Reference Scribe Line Rotational Offset. The following procedures are recommended for determining the magnitude and sign of a probe’s reference scribe line rotational offset, R
18.4.1 Perform the following procedures on the main probe with all devices that will be attached to the main probe in the field [such as thermocouples or resistance temperature detectors (RTDs)] that may affect the flow around the probe head. Probe shaft extensions that do not affect flow around the probe head need not be attached during calibration.
18.4.2 The procedures below assume that the wind tunnel duct used for probe calibration is horizontal and that the flow in the calibration wind tunnel is axial as determined by the axial flow verification check described in section 10.1.2. Angle-measuring devices are assumed to display angles in alternating 0° to 90° and 90° to 0° intervals. If angle-measuring devices with other readout conventions are used or if other calibration wind tunnel duct configurations are used, make the appropriate calculational corrections.
18.4.2.1 Position the angle-measuring device in accordance with one of the following procedures.
18.4.2.1.1 If using a digital inclinometer, affix the calibrated digital inclinometer to the probe. If the digital inclinometer can be independently adjusted after being locked into position on the probe sheath (e.g., by means of a set screw), the independent adjustment must be set so that the device performs exactly like a device without the capability for independent adjustment. That is, when aligned on the probe the device must give the same readings as a device that does not have the capability of being independently adjusted. Either align it directly on the reference scribe line or on a mark aligned with the scribe line determined according to the procedures in section 18.1.1.1. Maintaining this rotational alignment, lock the digital inclinometer onto the probe sheath.
18.4.2.1.2 If using a protractor wheel and pointer device, orient the protractor wheel on the test port so that the 0° mark is aligned with the longitudinal axis of the wind tunnel duct. Maintaining this alignment, lock the wheel into place on the wind tunnel test port. Align the scribe line on the pointer collar with the reference scribe line or with a mark aligned with the reference scribe line, as determined under section 18.1.1.1. Maintaining this rotational alignment, lock the pointer device onto the probe sheath.
18.4.2.2 Zero the pressure-measuring device used for yaw nulling.
18.4.2.3 Insert the probe assembly into the wind tunnel through the entry port, positioning the probe’s impact port at the calibration location. Check the responsiveness of the pressure-measuring device to probe rotation, taking corrective action if the response is unacceptable.
18.4.2.4 Ensure that the probe is in a horizontal position using a carpenter’s level.
18.4.2.5 Rotate the probe either clockwise or counterclockwise until a yaw null (P
18.4.2.6 Read and record the value of θ
18.4.2.7 Determine the magnitude and algebraic sign of the reference scribe line rotational offset, R
18.4.2.8 Perform the steps in sections 18.4.2.3 through 18.4.2.7 twice at each of the two calibration velocities selected for the probe under section 10.6. Record the values of R
18.4.2.9 The average of all R
Appendix A-2 to Part 60 – Test Methods 2G through 3C
The test methods in this appendix are referred to in § 60.8 (Performance Tests) and § 60.11 (Compliance With Standards and Maintenance Requirements) of 40 CFR part 60, subpart A (General Provisions). Specific uses of these test methods are described in the standards of performance contained in the subparts, beginning with Subpart D.
Within each standard of performance, a section title “Test Methods and Procedures” is provided to: (1) Identify the test methods to be used as reference methods to the facility subject to the respective standard and (2) identify any special instructions or conditions to be followed when applying a method to the respective facility. Such instructions (for example, establish sampling rates, volumes, or temperatures) are to be used either in addition to, or as a substitute for procedures in a test method. Similarly, for sources subject to emission monitoring requirements, specific instructions pertaining to any use of a test method as a reference method are provided in the subpart or in Appendix B.
Inclusion of methods in this appendix is not intended as an endorsement or denial of their applicability to sources that are not subject to standards of performance. The methods are potentially applicable to other sources; however, applicability should be confirmed by careful and appropriate evaluation of the conditions prevalent at such sources.
The approach followed in the formulation of the test methods involves specifications for equipment, procedures, and performance. In concept, a performance specification approach would be preferable in all methods because this allows the greatest flexibility to the user. In practice, however, this approach is impractical in most cases because performance specifications cannot be established. Most of the methods described herein, therefore, involve specific equipment specifications and procedures, and only a few methods in this appendix rely on performance criteria.
Minor changes in the test methods should not necessarily affect the validity of the results and it is recognized that alternative and equivalent methods exist. section 60.8 provides authority for the Administrator to specify or approve (1) equivalent methods, (2) alternative methods, and (3) minor changes in the methodology of the test methods. It should be clearly understood that unless otherwise identified all such methods and changes must have prior approval of the Administrator. An owner employing such methods or deviations from the test methods without obtaining prior approval does so at the risk of subsequent disapproval and retesting with approved methods.
Within the test methods, certain specific equipment or procedures are recognized as being acceptable or potentially acceptable and are specifically identified in the methods. The items identified as acceptable options may be used without approval but must be identified in the test report. The potentially approvable options are cited as “subject to the approval of the Administrator” or as “or equivalent.” Such potentially approvable techniques or alternatives may be used at the discretion of the owner without prior approval. However, detailed descriptions for applying these potentially approvable techniques or alternatives are not provided in the test methods. Also, the potentially approvable options are not necessarily acceptable in all applications. Therefore, an owner electing to use such potentially approvable techniques or alternatives is responsible for: (1) assuring that the techniques or alternatives are in fact applicable and are properly executed; (2) including a written description of the alternative method in the test report (the written method must be clear and must be capable of being performed without additional instruction, and the degree of detail should be similar to the detail contained in the test methods); and (3) providing any rationale or supporting data necessary to show the validity of the alternative in the particular application. Failure to meet these requirements can result in the Administrator’s disapproval of the alternative.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling) essential to its performance. Some material has been incorporated from other methods in this part. Therefore, to obtain reliable results, those using this method should have a thorough knowledge of at least the following additional test methods: Methods 1, 2, 3 or 3A, and 4.
1.1 This method is applicable for the determination of yaw angle, near-axial velocity, and the volumetric flow rate of a gas stream in a stack or duct using a two-dimensional (2-D) probe.
3.1. Angle-measuring Device Rotational Offset (R
3.2 Calibration Pitot Tube. The standard (Prandtl type) pitot tube used as a reference when calibrating a probe under this method.
3.3 Field Test. A set of measurements conducted at a specific unit or exhaust stack/duct to satisfy the applicable regulation (e.g., a three-run boiler performance test, a single-or multiple-load nine-run relative accuracy test).
3.4 Full Scale of Pressure-measuring Device. Full scale refers to the upper limit of the measurement range displayed by the device. For bi-directional pressure gauges, full scale includes the entire pressure range from the lowest negative value to the highest positive value on the pressure scale.
3.5 Main probe. Refers to the probe head and that section of probe sheath directly attached to the probe head. The main probe sheath is distinguished from probe extensions, which are sections of sheath added onto the main probe to extend its reach.
3.6 “May,” “Must,” “Shall,” “Should,” and the imperative form of verbs.
3.6.1 “May” is used to indicate that a provision of this method is optional.
3.6.2 “Must,” “Shall,” and the imperative form of verbs (such as “record” or “enter”) are used to indicate that a provision of this method is mandatory.
3.6.3 “Should” is used to indicate that a provision of this method is not mandatory, but is highly recommended as good practice.
3.7 Method 1. Refers to 40 CFR part 60, appendix A, “Method 1 – Sample and velocity traverses for stationary sources.”
3.8 Method 2. Refers to 40 CFR part 60, appendix A, “Method 2 – Determination of stack gas velocity and volumetric flow rate (Type S pitot tube).”
3.9 Method 2F. Refers to 40 CFR part 60, appendix A, “Method 2F – Determination of stack gas velocity and volumetric flow rate with three-dimensional probes.”
3.10 Near-axial Velocity. The velocity vector parallel to the axis of the stack or duct that accounts for the yaw angle component of gas flow. The term “near-axial” is used herein to indicate that the velocity and volumetric flow rate results account for the measured yaw angle component of flow at each measurement point.
3.11 Nominal Velocity. Refers to a wind tunnel velocity setting that approximates the actual wind tunnel velocity to within ±1.5 m/sec (±5 ft/sec).
3.12 Pitch Angle. The angle between the axis of the stack or duct and the pitch component of flow, i.e., the component of the total velocity vector in a plane defined by the traverse line and the axis of the stack or duct. (Figure 2G-1 illustrates the “pitch plane.”) From the standpoint of a tester facing a test port in a vertical stack, the pitch component of flow is the vector of flow moving from the center of the stack toward or away from that test port. The pitch angle is the angle described by this pitch component of flow and the vertical axis of the stack.
3.13 Readability. For the purposes of this method, readability for an analog measurement device is one half of the smallest scale division. For a digital measurement device, it is the number of decimals displayed by the device.
3.14 Reference Scribe Line. A line permanently inscribed on the main probe sheath (in accordance with section 6.1.5.1) to serve as a reference mark for determining yaw angles.
3.15 Reference Scribe Line Rotational Offset (R
3.16 Response Time. The time required for the measurement system to fully respond to a change from zero differential pressure and ambient temperature to the stable stack or duct pressure and temperature readings at a traverse point.
3.17 Tested Probe. A probe that is being calibrated.
3.18 Three-dimensional (3-D) Probe. A directional probe used to determine the velocity pressure and the yaw and pitch angles in a flowing gas stream.
3.19 Two-dimensional (2-D) Probe. A directional probe used to measure velocity pressure and yaw angle in a flowing gas stream.
3.20 Traverse Line. A diameter or axis extending across a stack or duct on which measurements of velocity pressure and flow angles are made.
3.21 Wind Tunnel Calibration Location. A point, line, area, or volume within the wind tunnel test section at, along, or within which probes are calibrated. At a particular wind tunnel velocity setting, the average velocity pressures at specified points at, along, or within the calibration location shall vary by no more than 2 percent or 0.3 mm H
3.22 Wind Tunnel with Documented Axial Flow. A wind tunnel facility documented as meeting the provisions of sections 10.1.1 (velocity pressure cross-check) and 10.1.2 (axial flow verification) using the procedures described in these sections or alternative procedures determined to be technically equivalent.
3.23 Yaw Angle. The angle between the axis of the stack or duct and the yaw component of flow, i.e., the component of the total velocity vector in a plane perpendicular to the traverse line at a particular traverse point. (Figure 2G-1 illustrates the “yaw plane.”) From the standpoint of a tester facing a test port in a vertical stack, the yaw component of flow is the vector of flow moving to the left or right from the center of the stack as viewed by the tester. (This is sometimes referred to as “vortex flow,” i.e., flow around the centerline of a stack or duct.) The yaw angle is the angle described by this yaw component of flow and the vertical axis of the stack. The algebraic sign convention is illustrated in Figure 2G-2.
3.24 Yaw Nulling. A procedure in which a Type-S pitot tube or a 3-D probe is rotated about its axis in a stack or duct until a zero differential pressure reading (“yaw null”) is obtained. When a Type S probe is yaw-nulled, the rotational position of its impact port is 90° from the direction of flow in the stack or duct and the ΔP reading is zero. When a 3-D probe is yaw-nulled, its impact pressure port (P
5.1 This test method may involve hazardous operations and the use of hazardous materials or equipment. This method does not purport to address all of the safety problems associated with its use. It is the responsibility of the user to establish and implement appropriate safety and health practices and to determine the applicability of regulatory limitations before using this test method.
6.1 Two-dimensional Probes. Probes that provide both the velocity pressure and the yaw angle of the flow vector in a stack or duct, as listed in sections 6.1.1 and 6.1.2, qualify for use based on comprehensive wind tunnel and field studies involving both inter-and intra-probe comparisons by multiple test teams. Each 2-D probe shall have a unique identification number or code permanently marked on the main probe sheath. Each probe shall be calibrated prior to use according to the procedures in section 10. Manufacturer-supplied calibration data shall be used as example information only, except when the manufacturer calibrates the probe as specified in section 10 and provides complete documentation.
6.1.1 Type S (Stausscheibe or reverse type) pitot tube. This is the same as specified in Method 2, section 2.1, except for the following additional specifications that enable the pitot tube to accurately determine the yaw component of flow. For the purposes of this method, the external diameter of the tubing used to construct the Type S pitot tube (dimension D
6.1.1.1 Manual Type S probe. This refers to a Type S probe that is positioned at individual traverse points and yaw nulled manually by an operator.
6.1.1.2 Automated Type S probe. This refers to a system that uses a computer-controlled motorized mechanism to position the Type S pitot head at individual traverse points and perform yaw angle determinations.
6.1.2 Three-dimensional probes used in 2-D mode. A 3-D probe, as specified in sections 6.1.1 through 6.1.3 of Method 2F, may, for the purposes of this method, be used in a two-dimensional mode (i.e., measuring yaw angle, but not pitch angle). When the 3-D probe is used as a 2-D probe, only the velocity pressure and yaw-null pressure are obtained using the pressure taps referred to as P
6.1.3 Other probes. [Reserved]
6.1.4 Probe sheath. The probe shaft shall include an outer sheath to: (1) provide a surface for inscribing a permanent reference scribe line, (2) accommodate attachment of an angle-measuring device to the probe shaft, and (3) facilitate precise rotational movement of the probe for determining yaw angles. The sheath shall be rigidly attached to the probe assembly and shall enclose all pressure lines from the probe head to the farthest position away from the probe head where an angle-measuring device may be attached during use in the field. The sheath of the fully assembled probe shall be sufficiently rigid and straight at all rotational positions such that, when one end of the probe shaft is held in a horizontal position, the fully extended probe meets the horizontal straightness specifications indicated in section 8.2 below.
6.1.5 Scribe lines.
6.1.5.1 Reference scribe line. A permanent line, no greater than 1.6 mm (1/16 in.) in width, shall be inscribed on each manual probe that will be used to determine yaw angles of flow. This line shall be placed on the main probe sheath in accordance with the procedures described in section 10.4 and is used as a reference position for installation of the yaw angle-measuring device on the probe. At the discretion of the tester, the scribe line may be a single line segment placed at a particular position on the probe sheath (e.g., near the probe head), multiple line segments placed at various locations along the length of the probe sheath (e.g., at every position where a yaw angle-measuring device may be mounted), or a single continuous line extending along the full length of the probe sheath.
6.1.5.2 Scribe line on probe extensions. A permanent line may also be inscribed on any probe extension that will be attached to the main probe in performing field testing. This allows a yaw angle-measuring device mounted on the extension to be readily aligned with the reference scribe line on the main probe sheath.
6.1.5.3 Alignment specifications. This specification shall be met separately, using the procedures in section 10.4.1, on the main probe and on each probe extension. The rotational position of the scribe line or scribe line segments on the main probe or any probe extension must not vary by more than 2°. That is, the difference between the minimum and maximum of all of the rotational angles that are measured along the full length of the main probe or the probe extension must not exceed 2°.
6.1.6 Probe and system characteristics to ensure horizontal stability.
6.1.6.1 For manual probes, it is recommended that the effective length of the probe (coupled with a probe extension, if necessary) be at least 0.9 m (3 ft.) longer than the farthest traverse point mark on the probe shaft away from the probe head. The operator should maintain the probe’s horizontal stability when it is fully inserted into the stack or duct. If a shorter probe is used, the probe should be inserted through a bushing sleeve, similar to the one shown in Figure 2G-3, that is installed on the test port; such a bushing shall fit snugly around the probe and be secured to the stack or duct entry port in such a manner as to maintain the probe’s horizontal stability when fully inserted into the stack or duct.
6.1.6.2 An automated system that includes an external probe casing with a transport system shall have a mechanism for maintaining horizontal stability comparable to that obtained by manual probes following the provisions of this method. The automated probe assembly shall also be constructed to maintain the alignment and position of the pressure ports during sampling at each traverse point. The design of the probe casing and transport system shall allow the probe to be removed from the stack or duct and checked through direct physical measurement for angular position and insertion depth.
6.1.7 The tubing that is used to connect the probe and the pressure-measuring device should have an inside diameter of at least 3.2 mm (
6.1.8 If a detachable probe head without a sheath [e.g., a pitot tube, typically 15.2 to 30.5 cm (6 to 12 in.) in length] is coupled with a probe sheath and calibrated in a wind tunnel in accordance with the yaw angle calibration procedure in section 10.5, the probe head shall remain attached to the probe sheath during field testing in the same configuration and orientation as calibrated. Once the detachable probe head is uncoupled or re-oriented, the yaw angle calibration of the probe is no longer valid and must be repeated before using the probe in subsequent field tests.
6.2 Yaw Angle-measuring Device. One of the following devices shall be used for measurement of the yaw angle of flow.
6.2.1 Digital inclinometer. This refers to a digital device capable of measuring and displaying the rotational position of the probe to within ±1°. The device shall be able to be locked into position on the probe sheath or probe extension, so that it indicates the probe’s rotational position throughout the test. A rotational position collar block that can be attached to the probe sheath (similar to the collar shown in Figure 2G-4) may be required to lock the digital inclinometer into position on the probe sheath.
6.2.2 Protractor wheel and pointer assembly. This apparatus, similar to that shown in Figure 2G-5, consists of the following components.
6.2.2.1 A protractor wheel that can be attached to a port opening and set in a fixed rotational position to indicate the yaw angle position of the probe’s scribe line relative to the longitudinal axis of the stack or duct. The protractor wheel must have a measurement ring on its face that is no less than 17.8 cm (7 in.) in diameter, shall be able to be rotated to any angle and then locked into position on the stack or duct test port, and shall indicate angles to a resolution of 1°.
6.2.2.2 A pointer assembly that includes an indicator needle mounted on a collar that can slide over the probe sheath and be locked into a fixed rotational position on the probe sheath. The pointer needle shall be of sufficient length, rigidity, and sharpness to allow the tester to determine the probe’s angular position to within 1° from the markings on the protractor wheel. Corresponding to the position of the pointer, the collar must have a scribe line to be used in aligning the pointer with the scribe line on the probe sheath.
6.2.3 Other yaw angle-measuring devices. Other angle-measuring devices with a manufacturer’s specified precision of 1° or better may be used, if approved by the Administrator.
6.3 Probe Supports and Stabilization Devices. When probes are used for determining flow angles, the probe head should be kept in a stable horizontal position. For probes longer than 3.0 m (10 ft.), the section of the probe that extends outside the test port shall be secured. Three alternative devices are suggested for maintaining the horizontal position and stability of the probe shaft during flow angle determinations and velocity pressure measurements: (1) monorails installed above each port, (2) probe stands on which the probe shaft may be rested, or (3) bushing sleeves of sufficient length secured to the test ports to maintain probes in a horizontal position. Comparable provisions shall be made to ensure that automated systems maintain the horizontal position of the probe in the stack or duct. The physical characteristics of each test platform may dictate the most suitable type of stabilization device. Thus, the choice of a specific stabilization device is left to the judgement of the testers.
6.4 Differential Pressure Gauges. The velocity pressure (ΔP) measuring devices used during wind tunnel calibrations and field testing shall be either electronic manometers (e.g., pressure transducers), fluid manometers, or mechanical pressure gauges (e.g., Magnehelic
6.4.1 Differential pressure-measuring device. This refers to a device capable of measuring pressure differentials and having a readability of ±1 percent of full scale. The device shall be capable of accurately measuring the maximum expected pressure differential. Such devices are used to determine the following pressure measurements: velocity pressure, static pressure, and yaw-null pressure. For an inclined-vertical manometer, the readability specification of ±1 percent shall be met separately using the respective full-scale upper limits of the inclined anvertical portions of the scales. To the extent practicable, the device shall be selected such that most of the pressure readings are between 10 and 90 percent of the device’s full-scale measurement range (as defined in section 3.4). In addition, pressure-measuring devices should be selected such that the zero does not drift by more than 5 percent of the average expected pressure readings to be encountered during the field test. This is particularly important under low pressure conditions.
6.4.2 Gauge used for yaw nulling. The differential pressure-measuring device chosen for yaw nulling the probe during the wind tunnel calibrations and field testing shall be bi-directional, i.e., capable of reading both positive and negative differential pressures. If a mechanical, bi-directional pressure gauge is chosen, it shall have a full-scale range no greater than 2.6 cm (i.e., −1.3 to + 1.3 cm) [1 in. H
6.4.3 Devices for calibrating differential pressure-measuring devices. A precision manometer (e.g., a U-tube, inclined, or inclined-vertical manometer, or micromanometer) or NIST (National Institute of Standards and Technology) traceable pressure source shall be used for calibrating differential pressure-measuring devices. The device shall be maintained under laboratory conditions or in a similar protected environment (e.g., a climate-controlled trailer). It shall not be used in field tests. The precision manometer shall have a scale gradation of 0.3 mm H
6.4.4 Devices used for post-test calibration check. A precision manometer meeting the specifications in section 6.4.3, a pressure-measuring device or pressure source with a documented calibration traceable to NIST, or an equivalent device approved by the Administrator shall be used for the post-test calibration check. The pressure-measuring device shall have a readability equivalent to or greater than the tested device. The pressure source shall be capable of generating pressures between 50 and 90 percent of the range of the tested device and known to within ±1 percent of the full scale of the tested device. The pressure source shall be recertified annually.
6.5 Data Display and Capture Devices. Electronic manometers (if used) shall be coupled with a data display device (such as a digital panel meter, personal computer display, or strip chart) that allows the tester to observe and validate the pressure measurements taken during testing. They shall also be connected to a data recorder (such as a data logger or a personal computer with data capture software) that has the ability to compute and retain the appropriate average value at each traverse point, identified by collection time and traverse point.
6.6 Temperature Gauges. For field tests, a thermocouple or resistance temperature detector (RTD) capable of measuring temperature to within ±3 °C (±5 °F) of the stack or duct temperature shall be used. The thermocouple shall be attached to the probe such that the sensor tip does not touch any metal. The position of the thermocouple relative to the pressure port face openings shall be in the same configuration as used for the probe calibrations in the wind tunnel. Temperature gauges used for wind tunnel calibrations shall be capable of measuring temperature to within ±0.6 °C (±1 °F) of the temperature of the flowing gas stream in the wind tunnel.
6.7 Stack or Duct Static Pressure Measurement. The pressure-measuring device used with the probe shall be as specified in section 6.4 of this method. The static tap of a standard (Prandtl type) pitot tube or one leg of a Type S pitot tube with the face opening planes positioned parallel to the gas flow may be used for this measurement. Also acceptable is the pressure differential reading of P
6.8 Barometer. Same as Method 2, section 2.5.
6.9 Gas Density Determination Equipment. Method 3 or 3A shall be used to determine the dry molecular weight of the stack or duct gas. Method 4 shall be used for moisture content determination and computation of stack or duct gas wet molecular weight. Other methods may be used, if approved by the Administrator.
6.10 Calibration Pitot Tube. Same as Method 2, section 2.7.
6.11 Wind Tunnel for Probe Calibration. Wind tunnels used to calibrate velocity probes must meet the following design specifications.
6.11.1 Test section cross-sectional area. The flowing gas stream shall be confined within a circular, rectangular, or elliptical duct. The cross-sectional area of the tunnel must be large enough to ensure fully developed flow in the presence of both the calibration pitot tube and the tested probe. The calibration site, or “test section,” of the wind tunnel shall have a minimum diameter of 30.5 cm (12 in.) for circular or elliptical duct cross-sections or a minimum width of 30.5 cm (12 in.) on the shorter side for rectangular cross-sections. Wind tunnels shall meet the probe blockage provisions of this section and the qualification requirements prescribed in section 10.1. The projected area of the portion of the probe head, shaft, and attached devices inside the wind tunnel during calibration shall represent no more than 2 percent of the cross-sectional area of the tunnel. If the pitot and/or probe assembly blocks more than 2 percent of the cross-sectional area at an insertion point only 4 inches inside the wind tunnel, the diameter of the wind tunnel must be increased.
6.11.2 Velocity range and stability. The wind tunnel should be capable of achieving and maintaining a constant and steady velocity between 6.1 m/sec and 30.5 m/sec (20 ft/sec and 100 ft/sec) for the entire calibration period for each selected calibration velocity. The wind tunnel shall produce fully developed flow patterns that are stable and parallel to the axis of the duct in the test section.
6.11.3 Flow profile at the calibration location. The wind tunnel shall provide axial flow within the test section calibration location (as defined in section 3.21). Yaw and pitch angles in the calibration location shall be within ±3° of 0°. The procedure for determining that this requirement has been met is described in section 10.1.2.
6.11.4 Entry ports in the wind tunnel test section.
6.11.4.1 Port for tested probe. A port shall be constructed for the tested probe. This port shall be located to allow the head of the tested probe to be positioned within the wind tunnel calibration location (as defined in section 3.21). The tested probe shall be able to be locked into the 0° pitch angle position. To facilitate alignment of the probe during calibration, the test section should include a window constructed of a transparent material to allow the tested probe to be viewed.
6.11.4.2 Port for verification of axial flow. Depending on the equipment selected to conduct the axial flow verification prescribed in section 10.1.2, a second port, located 90° from the entry port for the tested probe, may be needed to allow verification that the gas flow is parallel to the central axis of the test section. This port should be located and constructed so as to allow one of the probes described in section 10.1.2.2 to access the same test point(s) that are accessible from the port described in section 6.11.4.1.
6.11.4.3 Port for calibration pitot tube. The calibration pitot tube shall be used in the port for the tested probe or in a separate entry port. In either case, all measurements with the calibration pitot tube shall be made at the same point within the wind tunnel over the course of a probe calibration. The measurement point for the calibration pitot tube shall meet the same specifications for distance from the wall and for axial flow as described in section 3.21 for the wind tunnel calibration location.
8.1 Equipment Inspection and Set Up
8.1.1 All 2-D and 3-D probes, differential pressure-measuring devices, yaw angle-measuring devices, thermocouples, and barometers shall have a current, valid calibration before being used in a field test. (See sections 10.3.3, 10.3.4, and 10.5 through 10.10 for the applicable calibration requirements.)
8.1.2 Before each field use of a Type S probe, perform a visual inspection to verify the physical condition of the pitot tube. Record the results of the inspection. If the face openings are noticeably misaligned or there is visible damage to the face openings, the probe shall not be used until repaired, the dimensional specifications verified (according to the procedures in section 10.2.1), and the probe recalibrated.
8.1.3 Before each field use of a 3-D probe, perform a visual inspection to verify the physical condition of the probe head according to the procedures in section 10.2 of Method 2F. Record the inspection results on a form similar to Table 2F-1 presented in Method 2F. If there is visible damage to the 3-D probe, the probe shall not be used until it is recalibrated.
8.1.4 After verifying that the physical condition of the probe head is acceptable, set up the apparatus using lengths of flexible tubing that are as short as practicable. Surge tanks installed between the probe and pressure-measuring device may be used to dampen pressure fluctuations provided that an adequate measurement system response time (see section 8.8) is maintained.
8.2 Horizontal Straightness Check. A horizontal straightness check shall be performed before the start of each field test, except as otherwise specified in this section. Secure the fully assembled probe (including the probe head and all probe shaft extensions) in a horizontal position using a stationary support at a point along the probe shaft approximating the location of the stack or duct entry port when the probe is sampling at the farthest traverse point from the stack or duct wall. The probe shall be rotated to detect bends. Use an angle-measuring device or trigonometry to determine the bend or sag between the probe head and the secured end. (See Figure 2G-6.) Probes that are bent or sag by more than 5° shall not be used. Although this check does not apply when the probe is used for a vertical traverse, care should be taken to avoid the use of bent probes when conducting vertical traverses. If the probe is constructed of a rigid steel material and consists of a main probe without probe extensions, this check need only be performed before the initial field use of the probe, when the probe is recalibrated, when a change is made to the design or material of the probe assembly, and when the probe becomes bent. With such probes, a visual inspection shall be made of the fully assembled probe before each field test to determine if a bend is visible. The probe shall be rotated to detect bends. The inspection results shall be documented in the field test report. If a bend in the probe is visible, the horizontal straightness check shall be performed before the probe is used.
8.3 Rotational Position Check. Before each field test, and each time an extension is added to the probe during a field test, a rotational position check shall be performed on all manually operated probes (except as noted in section 8.3.5 below) to ensure that, throughout testing, the angle-measuring device is either: aligned to within ±1° of the rotational position of the reference scribe line; or is affixed to the probe such that the rotational offset of the device from the reference scribe line is known to within ±1°. This check shall consist of direct measurements of the rotational positions of the reference scribe line and angle-measuring device sufficient to verify that these specifications are met. Annex A in section 18 of this method gives recommended procedures for performing the rotational position check, and Table 2G-2 gives an example data form. Procedures other than those recommended in Annex A in section 18 may be used, provided they demonstrate whether the alignment specification is met and are explained in detail in the field test report.
8.3.1 Angle-measuring device rotational offset. The tester shall maintain a record of the angle-measuring device rotational offset, R
8.3.2 Sign of angle-measuring device rotational offset. The sign of R
8.3.3 Angle-measuring devices that can be independently adjusted (e.g., by means of a set screw), after being locked into position on the probe sheath, may be used. However, the R
8.3.4 Post-test check. If probe extensions remain attached to the main probe throughout the field test, the rotational position check shall be repeated, at a minimum, at the completion of the field test to ensure that the angle-measuring device has remained within ±2° of its rotational position established prior to testing. At the discretion of the tester, additional checks may be conducted after completion of testing at any sample port or after any test run. If the ±2° specification is not met, all measurements made since the last successful rotational position check must be repeated. section 18.1.1.3 of Annex A provides an example procedure for performing the post-test check.
8.3.5 Exceptions.
8.3.5.1 A rotational position check need not be performed if, for measurements taken at all velocity traverse points, the yaw angle-measuring device is mounted and aligned directly on the reference scribe line specified in sections 6.1.5.1 and 6.1.5.3 and no independent adjustments, as described in section 8.3.3, are made to device’s rotational position.
8.3.5.2 If extensions are detached and re-attached to the probe during a field test, a rotational position check need only be performed the first time an extension is added to the probe, rather than each time the extension is re-attached, if the probe extension is designed to be locked into a mechanically fixed rotational position (e.g., through the use of interlocking grooves), that can re-establish the initial rotational position to within ±1°.
8.4 Leak Checks. A pre-test leak check shall be conducted before each field test. A post-test check shall be performed at the end of the field test, but additional leak checks may be conducted after any test run or group of test runs. The post-test check may also serve as the pre-test check for the next group of test runs. If any leak check is failed, all runs since the last passed leak check are invalid. While performing the leak check procedures, also check each pressure device’s responsiveness to changes in pressure.
8.4.1 To perform the leak check on a Type S pitot tube, pressurize the pitot impact opening until at least 7.6 cm H
8.4.2 To perform the leak check on a 3-D probe, pressurize the probe’s impact (P
8.5 Zeroing the Differential Pressure-measuring Device. Zero each differential pressure-measuring device, including the device used for yaw nulling, before each field test. At a minimum, check the zero after each field test. A zero check may also be performed after any test run or group of test runs. For fluid manometers and mechanical pressure gauges (e.g., Magnehelic
8.6 Traverse Point Verification. The number and location of the traverse points shall be selected based on Method 1 guidelines. The stack or duct diameter and port nipple lengths, including any extension of the port nipples into the stack or duct, shall be verified the first time the test is performed; retain and use this information for subsequent field tests, updating it as required. Physically measure the stack or duct dimensions or use a calibrated laser device; do not use engineering drawings of the stack or duct. The probe length necessary to reach each traverse point shall be recorded to within ±6.4 mm (±
8.7 Probe Installation. Insert the probe into the test port. A solid material shall be used to seal the port.
8.8 System Response Time. Determine the response time of the probe measurement system. Insert and position the “cold” probe (at ambient temperature and pressure) at any Method 1 traverse point. Read and record the probe differential pressure, temperature, and elapsed time at 15-second intervals until stable readings for both pressure and temperature are achieved. The response time is the longer of these two elapsed times. Record the response time.
8.9 Sampling.
8.9.1 Yaw angle measurement protocol. With manual probes, yaw angle measurements may be obtained in two alternative ways during the field test, either by using a yaw angle-measuring device (e.g., digital inclinometer) affixed to the probe, or using a protractor wheel and pointer assembly. For horizontal traversing, either approach may be used. For vertical traversing, i.e., when measuring from on top or into the bottom of a horizontal duct, only the protractor wheel and pointer assembly may be used. With automated probes, curve-fitting protocols may be used to obtain yaw-angle measurements.
8.9.1.1 If a yaw angle-measuring device affixed to the probe is to be used, lock the device on the probe sheath, aligning it either on the reference scribe line or in the rotational offset position established under section 8.3.1.
8.9.1.2 If a protractor wheel and pointer assembly is to be used, follow the procedures in Annex B of this method.
8.9.1.3 Curve-fitting procedures. Curve-fitting routines sweep through a range of yaw angles to create curves correlating pressure to yaw position. To find the zero yaw position and the yaw angle of flow, the curve found in the stack is computationally compared to a similar curve that was previously generated under controlled conditions in a wind tunnel. A probe system that uses a curve-fitting routine for determining the yaw-null position of the probe head may be used, provided that it is verified in a wind tunnel to be able to determine the yaw angle of flow to within ±1°.
8.9.1.4 Other yaw angle determination procedures. If approved by the Administrator, other procedures for determining yaw angle may be used, provided that they are verified in a wind tunnel to be able to perform the yaw angle calibration procedure as described in section 10.5.
8.9.2 Sampling strategy. At each traverse point, first yaw-null the probe, as described in section 8.9.3, below. Then, with the probe oriented into the direction of flow, measure and record the yaw angle, the differential pressure and the temperature at the traverse point, after stable readings are achieved, in accordance with sections 8.9.4 and 8.9.5. At the start of testing in each port (i.e., after a probe has been inserted into the flue gas stream), allow at least the response time to elapse before beginning to take measurements at the first traverse point accessed from that port. Provided that the probe is not removed from the flue gas stream, measurements may be taken at subsequent traverse points accessed from the same test port without waiting again for the response time to elapse.
8.9.3 Yaw-nulling procedure. In preparation for yaw angle determination, the probe must first be yaw nulled. After positioning the probe at the appropriate traverse point, perform the following procedures.
8.9.3.1 For Type S probes, rotate the probe until a null differential pressure reading is obtained. The direction of the probe rotation shall be such that the thermocouple is located downstream of the probe pressure ports at the yaw-null position. Rotate the probe 90° back from the yaw-null position to orient the impact pressure port into the direction of flow. Read and record the angle displayed by the angle-measuring device.
8.9.3.2 For 3-D probes, rotate the probe until a null differential pressure reading (the difference in pressures across the P
8.9.3.3 Sign of the measured angle. The angle displayed on the angle-measuring device is considered positive when the probe’s impact pressure port (as viewed from the “tail” end of the probe) is oriented in a clockwise rotational position relative to the stack or duct axis and is considered negative when the probe’s impact pressure port is oriented in a counterclockwise rotational position (see Figure 2G-7).
8.9.4 Yaw angle determination. After performing the applicable yaw-nulling procedure in section 8.9.3, determine the yaw angle of flow according to one of the following procedures. Special care must be observed to take into account the signs of the recorded angle reading and all offsets.
8.9.4.1 Direct-reading. If all rotational offsets are zero or if the angle-measuring device rotational offset (R
8.9.4.2 Compensation for rotational offsets during data reduction. When the angle-measuring device rotational offset does not compensate for reference scribe line rotational offset, the following procedure shall be used to determine the yaw angle:
(a) Enter the reading indicated by the angle-measuring device from section 8.9.3.1 or 8.9.3.2.
(b) Associate the proper algebraic sign from section 8.9.3.3 with the reading in step (a).
(c) Subtract the reference scribe line rotational offset, R
(d) Subtract the angle-measuring device rotational offset, R
(e) The final result obtained in step (d) is the yaw angle of flow.
It may be necessary to first apply a 90° adjustment to the reading in step (a), in order to obtain the correct yaw angle.
8.9.4.3 Record the yaw angle measurements on a form similar to Table 2G-3.
8.9.5 Impact velocity determination. Maintain the probe rotational position established during the yaw angle determination. Then, begin recording the pressure-measuring device readings. These pressure measurements shall be taken over a sampling period of sufficiently long duration to ensure representative readings at each traverse point. If the pressure measurements are determined from visual readings of the pressure device or display, allow sufficient time to observe the pulsation in the readings to obtain a sight-weighted average, which is then recorded manually. If an automated data acquisition system (e.g., data logger, computer-based data recorder, strip chart recorder) is used to record the pressure measurements, obtain an integrated average of all pressure readings at the traverse point. Stack or duct gas temperature measurements shall be recorded, at a minimum, once at each traverse point. Record all necessary data as shown in the example field data form (Table 2G-3).
8.9.6 Alignment check. For manually operated probes, after the required yaw angle and differential pressure and temperature measurements have been made at each traverse point, verify (e.g., by visual inspection) that the yaw angle-measuring device has remained in proper alignment with the reference scribe line or with the rotational offset position established in section 8.3. If, for a particular traverse point, the angle-measuring device is found to be in proper alignment, proceed to the next traverse point; otherwise, re-align the device and repeat the angle and differential pressure measurements at the traverse point. In the course of a traverse, if a mark used to properly align the angle-measuring device (e.g., as described in section 18.1.1.1) cannot be located, re-establish the alignment mark before proceeding with the traverse.
8.10 Probe Plugging. Periodically check for plugging of the pressure ports by observing the responses on the pressure differential readouts. Plugging causes erratic results or sluggish responses. Rotate the probe to determine whether the readouts respond in the expected direction. If plugging is detected, correct the problem and repeat the affected measurements.
8.11 Static Pressure. Measure the static pressure in the stack or duct using the equipment described in section 6.7.
8.11.1 If a Type S probe is used for this measurement, position the probe at or between any traverse point(s) and rotate the probe until a null differential pressure reading is obtained. Disconnect the tubing from one of the pressure ports; read and record the ΔP. For pressure devices with one-directional scales, if a deflection in the positive direction is noted with the negative side disconnected, then the static pressure is positive. Likewise, if a deflection in the positive direction is noted with the positive side disconnected, then the static pressure is negative.
8.11.2 If a 3-D probe is used for this measurement, position the probe at or between any traverse point(s) and rotate the probe until a null differential pressure reading is obtained at P
8.12 Atmospheric Pressure. Determine the atmospheric pressure at the sampling elevation during each test run following the procedure described in section 2.5 of Method 2.
8.13 Molecular Weight. Determine the stack or duct gas dry molecular weight. For combustion processes or processes that emit essentially CO
8.14 Moisture. Determine the moisture content of the stack gas using Method 4 or equivalent.
8.15 Data Recording and Calculations. Record all required data on a form similar to Table 2G-3.
8.15.1 2-D probe calibration coefficient. When a Type S pitot tube is used in the field, the appropriate calibration coefficient as determined in section 10.6 shall be used to perform velocity calculations. For calibrated Type S pitot tubes, the A-side coefficient shall be used when the A-side of the tube faces the flow, and the B-side coefficient shall be used when the B-side faces the flow.
8.15.2 3-D calibration coefficient. When a 3-D probe is used to collect data with this method, follow the provisions for the calibration of 3-D probes in section 10.6 of Method 2F to obtain the appropriate velocity calibration coefficient (F
8.15.3 Calculations. Calculate the yaw-adjusted velocity at each traverse point using the equations presented in section 12.2. Calculate the test run average stack gas velocity by finding the arithmetic average of the point velocity results in accordance with sections 12.3 and 12.4, and calculate the stack gas volumetric flow rate in accordance with section 12.5 or 12.6, as applicable.
9.1 Quality Control Activities. In conjunction with the yaw angle determination and the pressure and temperature measurements specified in section 8.9, the following quality control checks should be performed.
9.1.1 Range of the differential pressure gauge. In accordance with the specifications in section 6.4, ensure that the proper differential pressure gauge is being used for the range of ΔP values encountered. If it is necessary to change to a more sensitive gauge, replace the gauge with a gauge calibrated according to section 10.3.3, perform the leak check described in section 8.4 and the zero check described in section 8.5, and repeat the differential pressure and temperature readings at each traverse point.
9.1.2 Horizontal stability check. For horizontal traverses of a stack or duct, visually check that the probe shaft is maintained in a horizontal position prior to taking a pressure reading. Periodically, during a test run, the probe’s horizontal stability should be verified by placing a carpenter’s level, a digital inclinometer, or other angle-measuring device on the portion of the probe sheath that extends outside of the test port. A comparable check should be performed by automated systems.
10.1 Wind Tunnel Qualification Checks. To qualify for use in calibrating probes, a wind tunnel shall have the design features specified in section 6.11 and satisfy the following qualification criteria. The velocity pressure cross-check in section 10.1.1 and axial flow verification in section 10.1.2 shall be performed before the initial use of the wind tunnel and repeated immediately after any alteration occurs in the wind tunnel’s configuration, fans, interior surfaces, straightening vanes, controls, or other properties that could reasonably be expected to alter the flow pattern or velocity stability in the tunnel. The owner or operator of a wind tunnel used to calibrate probes according to this method shall maintain records documenting that the wind tunnel meets the requirements of sections 10.1.1 and 10.1.2 and shall provide these records to the Administrator upon request.
10.1.1 Velocity pressure cross-check. To verify that the wind tunnel produces the same velocity at the tested probe head as at the calibration pitot tube impact port, perform the following cross-check. Take three differential pressure measurements at the fixed calibration pitot tube location, using the calibration pitot tube specified in section 6.10, and take three measurements with the calibration pitot tube at the wind tunnel calibration location, as defined in section 3.21. Alternate the measurements between the two positions. Perform this procedure at the lowest and highest velocity settings at which the probes will be calibrated. Record the values on a form similar to Table 2G-4. At each velocity setting, the average velocity pressure obtained at the wind tunnel calibration location shall be within ±2 percent or 2.5 mm H
10.1.2 Axial flow verification. The following procedures shall be performed to demonstrate that there is fully developed axial flow within the wind tunnel calibration location and at the calibration pitot tube location. Two options are available to conduct this check.
10.1.2.1 Using a calibrated 3-D probe. A probe that has been previously calibrated in a wind tunnel with documented axial flow (as defined in section 3.22) may be used to conduct this check. Insert the calibrated 3-D probe into the wind tunnel test section using the tested probe port. Following the procedures in sections 8.9 and 12.2 of Method 2F, determine the yaw and pitch angles at all the point(s) in the test section where the velocity pressure cross-check, as specified in section 10.1.1, is performed. This includes all the points in the calibration location and the point where the calibration pitot tube will be located. Determine the yaw and pitch angles at each point. Repeat these measurements at the highest and lowest velocities at which the probes will be calibrated. Record the values on a form similar to Table 2G-5. Each measured yaw and pitch angle shall be within ±3° of 0°. Exceeding the limits indicates unacceptable flow in the test section. Until the problem is corrected and acceptable flow is verified by repetition of this procedure, the wind tunnel shall not be used for calibration of probes. Include the results of the axial flow verification in the calibration data section of the field test report. (See section 16.1.4.)
10.1.2.2 Using alternative probes. Axial flow verification may be performed using an uncalibrated prism-shaped 3-D probe (e.g., DA or DAT probe) or an uncalibrated wedge probe. (Figure 2G-8 illustrates a typical wedge probe.) This approach requires use of two ports: the tested probe port and a second port located 90° from the tested probe port. Each port shall provide access to all the points within the wind tunnel test section where the velocity pressure cross-check, as specified in section 10.1.1, is conducted. The probe setup shall include establishing a reference yaw-null position on the probe sheath to serve as the location for installing the angle-measuring device. Physical design features of the DA, DAT, and wedge probes are relied on to determine the reference position. For the DA or DAT probe, this reference position can be determined by setting a digital inclinometer on the flat facet where the P
10.1.3 Wind tunnel audits.
10.1.3.1 Procedure. Upon the request of the Administrator, the owner or operator of a wind tunnel shall calibrate a 2-D audit probe in accordance with the procedures described in sections 10.3 through 10.6. The calibration shall be performed at two velocities that encompass the velocities typically used for this method at the facility. The resulting calibration data shall be submitted to the Agency in an audit test report. These results shall be compared by the Agency to reference calibrations of the audit probe at the same velocity settings obtained at two different wind tunnels.
10.1.3.2 Acceptance criterion. The audited tunnel’s calibration coefficient is acceptable if it is within ±3 percent of the reference calibrations obtained at each velocity setting by one (or both) of the wind tunnels. If the acceptance criterion is not met at each calibration velocity setting, the audited wind tunnel shall not be used to calibrate probes for use under this method until the problems are resolved and acceptable results are obtained upon completion of a subsequent audit.
10.2 Probe Inspection.
10.2.1 Type S probe. Before each calibration of a Type S probe, verify that one leg of the tube is permanently marked A, and the other, B. Carefully examine the pitot tube from the top, side, and ends. Measure the angles (α
10.2.2 3-D probe. If a 3-D probe is used to collect data with this method, perform the pre-calibration inspection according to procedures in Method 2F, section 10.2.
10.3 Pre-Calibration Procedures. Prior to calibration, a scribe line shall have been placed on the probe in accordance with section 10.4. The yaw angle and velocity calibration procedures shall not begin until the pre-test requirements in sections 10.3.1 through 10.3.4 have been met.
10.3.1 Perform the horizontal straightness check described in section 8.2 on the probe assembly that will be calibrated in the wind tunnel.
10.3.2 Perform a leak check in accordance with section 8.4.
10.3.3 Except as noted in section 10.3.3.3, calibrate all differential pressure-measuring devices to be used in the probe calibrations, using the following procedures. At a minimum, calibrate these devices on each day that probe calibrations are performed.
10.3.3.1 Procedure. Before each wind tunnel use, all differential pressure-measuring devices shall be calibrated against the reference device specified in section 6.4.3 using a common pressure source. Perform the calibration at three reference pressures representing 30, 60, and 90 percent of the full-scale range of the pressure-measuring device being calibrated. For an inclined-vertical manometer, perform separate calibrations on the inclined and vertical portions of the measurement scale, considering each portion of the scale to be a separate full-scale range. [For example, for a manometer with a 0-to 2.5-cm H
10.3.3.2 Acceptance criteria. At each pressure setting, the two pressure readings made using the reference device and the pressure-measuring device being calibrated shall agree to within ±2 percent of full scale of the device being calibrated or 0.5 mm H
10.3.3.3 Exceptions. Any precision manometer that meets the specifications for a reference device in section 6.4.3 and that is not used for field testing does not require calibration, but must be leveled and zeroed before each wind tunnel use. Any pressure device used exclusively for yaw nulling does not require calibration, but shall be checked for responsiveness to rotation of the probe prior to each wind tunnel use.
10.3.4 Calibrate digital inclinometers on each day of wind tunnel or field testing (prior to beginning testing) using the following procedures. Calibrate the inclinometer according to the manufacturer’s calibration procedures. In addition, use a triangular block (illustrated in Figure 2G-9) with a known angle θ, independently determined using a protractor or equivalent device, between two adjacent sides to verify the inclinometer readings. (
10.4 Placement of Reference Scribe Line. Prior to the first calibration of a probe, a line shall be permanently inscribed on the main probe sheath to serve as a reference mark for determining yaw angles. Annex C in section 18 of this method gives a guideline for placement of the reference scribe line.
10.4.1 This reference scribe line shall meet the specifications in sections 6.1.5.1 and 6.1.5.3 of this method. To verify that the alignment specification in section 6.1.5.3 is met, secure the probe in a horizontal position and measure the rotational angle of each scribe line and scribe line segment using an angle-measuring device that meets the specifications in section 6.2.1 or 6.2.3. For any scribe line that is longer than 30.5 cm (12 in.), check the line’s rotational position at 30.5-cm (12-in.) intervals. For each line segment that is 12 in. or less in length, check the rotational position at the two endpoints of the segment. To meet the alignment specification in section 6.1.5.3, the minimum and maximum of all of the rotational angles that are measured along the full length of main probe must not differ by more than 2°. (
10.4.2 The scribe line should be placed on the probe first and then its offset from the yaw-null position established (as specified in section 10.5). The rotational position of the reference scribe line relative to the yaw-null position of the probe, as determined by the yaw angle calibration procedure in section 10.5, is the reference scribe line rotational offset, R
10.4.3 Scribe line for automated probes. A scribe line may not be necessary for an automated probe system if a reference rotational position of the probe is built into the probe system design. For such systems, a “flat” (or comparable, clearly identifiable physical characteristic) should be provided on the probe casing or flange plate to ensure that the reference position of the probe assembly remains in a vertical or horizontal position. The rotational offset of the flat (or comparable, clearly identifiable physical characteristic) needed to orient the reference position of the probe assembly shall be recorded and maintained as part of the automated probe system’s specifications.
10.5 Yaw Angle Calibration Procedure. For each probe used to measure yaw angles with this method, a calibration procedure shall be performed in a wind tunnel meeting the specifications in section 10.1 to determine the rotational position of the reference scribe line relative to the probe’s yaw-null position. This procedure shall be performed on the main probe with all devices that will be attached to the main probe in the field [such as thermocouples, resistance temperature detectors (RTDs), or sampling nozzles] that may affect the flow around the probe head. Probe shaft extensions that do not affect flow around the probe head need not be attached during calibration. At a minimum, this procedure shall include the following steps.
10.5.1 Align and lock the angle-measuring device on the reference scribe line. If a marking procedure (such as described in section 18.1.1.1) is used, align the angle-measuring device on a mark within ±1° of the rotational position of the reference scribe line. Lock the angle-measuring device onto the probe sheath at this position.
10.5.2 Zero the pressure-measuring device used for yaw nulling.
10.5.3 Insert the probe assembly into the wind tunnel through the entry port, positioning the probe’s impact port at the calibration location. Check the responsiveness of the pressure-measurement device to probe rotation, taking corrective action if the response is unacceptable.
10.5.4 Ensure that the probe is in a horizontal position, using a carpenter’s level.
10.5.5 Rotate the probe either clockwise or counterclockwise until a yaw null [zero ΔP for a Type S probe or zero (P
10.5.6 Use the reading displayed by the angle-measuring device at the yaw-null position to determine the magnitude of the reference scribe line rotational offset, R
10.5.7 The steps in sections 10.5.3 through 10.5.6 shall be performed twice at each of the velocities at which the probe will be calibrated (in accordance with section 10.6). Record the values of R
10.5.8 The average of all of the R
10.5.9 Use of reference scribe line offset. The reference scribe line rotational offset shall be used to determine the yaw angle of flow in accordance with section 8.9.4.
10.6 Velocity Calibration Procedure. When a 3-D probe is used under this method, follow the provisions for the calibration of 3-D probes in section 10.6 of Method 2F to obtain the necessary velocity calibration coefficients (F
10.6.1 Calibration velocities. The tester may calibrate the probe at two nominal wind tunnel velocity settings of 18.3 m/sec and 27.4 m/sec (60 ft/sec and 90 ft/sec) and average the results of these calibrations, as described in sections 10.6.12 through 10.6.14, in order to generate the calibration coefficient, C
10.6.2 Connect the tested probe and calibration pitot tube to their respective pressure-measuring devices. Zero the pressure-measuring devices. Inspect and leak-check all pitot lines; repair or replace them, if necessary. Turn on the fan, and allow the wind tunnel air flow to stabilize at the first of the selected nominal velocity settings.
10.6.3 Position the calibration pitot tube at its measurement location (determined as outlined in section 6.11.4.3), and align the tube so that its tip is pointed directly into the flow. Ensure that the entry port surrounding the tube is properly sealed. The calibration pitot tube may either remain in the wind tunnel throughout the calibration, or be removed from the wind tunnel while measurements are taken with the probe being calibrated.
10.6.4 Check the zero setting of each pressure-measuring device.
10.6.5 Insert the tested probe into the wind tunnel and align it so that the designated pressure port (e.g., either the A-side or B-side of a Type S probe) is pointed directly into the flow and is positioned within the wind tunnel calibration location (as defined in section 3.21). Secure the probe at the 0° pitch angle position. Ensure that the entry port surrounding the probe is properly sealed.
10.6.6 Read the differential pressure from the calibration pitot tube (ΔP
10.6.7 After the tested probe’s differential pressure gauges have had sufficient time to stabilize, yaw null the probe (and then rotate it back 90° for Type S probes), then obtain the differential pressure reading (ΔP). Record the yaw angle and differential pressure readings.
10.6.8 Take paired differential pressure measurements with the calibration pitot tube and tested probe (according to sections 10.6.6 and 10.6.7). The paired measurements in each replicate can be made either simultaneously (i.e., with both probes in the wind tunnel) or by alternating the measurements of the two probes (i.e., with only one probe at a time in the wind tunnel). Adjustments made to the fan speed or other changes to the system designed to change the air flow velocity of the wind tunnel between observation of the calibration pitot tube (ΔP
10.6.9 Repeat the steps in sections 10.6.6 through 10.6.8 at the same nominal velocity setting until three pairs of ΔP readings have been obtained from the calibration pitot tube and the tested probe.
10.6.10 Repeat the steps in sections 10.6.6 through 10.6.9 above for the A-side and B-side of the Type S pitot tube. For a probe assembly constructed such that its pitot tube is always used in the same orientation, only one side of the pitot tube need be calibrated (the side that will face the flow). However, the pitot tube must still meet the alignment and dimension specifications in section 6.1.1 and must have an average deviation (σ) value of 0.01 or less as provided in section 10.6.12.4.
10.6.11 Repeat the calibration procedures in sections 10.6.6 through 10.6.10 at the second selected nominal wind tunnel velocity setting.
10.6.12 Perform the following calculations separately on the A-side and B-side values.
10.6.12.1 Calculate a C
10.6.12.2 Calculate the arithmetic average, C
10.6.12.3 Calculate the deviation of each of the three individual values of C
10.6.12.4 Calculate the average deviation (σ) of the three individual C
10.6.13 Repeat the calculations in section 10.6.12 using the data obtained at the higher velocity setting to derive the arithmetic C
10.6.14 Use equation 2G-1 to calculate the percent difference of the averaged C
10.6.15 If the two nominal velocities used in the calibration were 18.3 and 27.4 m/sec (60 and 90 ft/sec), the average C
10.7 Recalibration. Recalibrate the probe using the procedures in section 10 either within 12 months of its first field use after its most recent calibration or after 10 field tests (as defined in section 3.3), whichever occurs later. In addition, whenever there is visible damage to the probe head, the probe shall be recalibrated before it is used again.
10.8 Calibration of pressure-measuring devices used in the field. Before its initial use in a field test, calibrate each pressure-measuring device (except those used exclusively for yaw nulling) using the three-point calibration procedure described in section 10.3.3. The device shall be recalibrated according to the procedure in section 10.3.3 no later than 90 days after its first field use following its most recent calibration. At the discretion of the tester, more frequent calibrations (e.g., after a field test) may be performed. No adjustments, other than adjustments to the zero setting, shall be made to the device between calibrations.
10.8.1 Post-test calibration check. A single-point calibration check shall be performed on each pressure-measuring device after completion of each field test. At the discretion of the tester, more frequent single-point calibration checks (e.g., after one or more field test runs) may be performed. It is recommended that the post-test check be performed before leaving the field test site. The check shall be performed at a pressure between 50 and 90 percent of full scale by taking a common pressure reading with the tested probe and a reference pressure-measuring device (as described in section 6.4.4) or by challenging the tested device with a reference pressure source (as described in section 6.4.4) or by performing an equivalent check using a reference device approved by the Administrator.
10.8.2 Acceptance criterion. At the selected pressure setting, the pressure readings made using the reference device and the tested device shall agree to within ±3 percent of full scale of the tested device or 0.8 mm H
10.9 Temperature Gauges. Same as Method 2, section 4.3. The alternative thermocouple calibration procedures outlined in Emission Measurement Center (EMC) Approved Alternative Method (ALT-011) “Alternative Method 2 Thermocouple Calibration Procedure” may be performed. Temperature gauges shall be calibrated no more than 30 days prior to the start of a field test or series of field tests and recalibrated no more than 30 days after completion of a field test or series of field tests.
10.10 Barometer. Same as Method 2, section 4.4. The barometer shall be calibrated no more than 30 days prior to the start of a field test or series of field tests.
Sample collection and analysis are concurrent for this method (see section 8.0).
These calculations use the measured yaw angle and the differential pressure and temperature measurements at individual traverse points to derive the near-axial flue gas velocity (v
12.2 Traverse Point Velocity Calculations. Perform the following calculations from the measurements obtained at each traverse point.
12.2.1 Selection of calibration coefficient. Select the calibration coefficient as described in section 10.6.1.
12.2.2 Near-axial traverse point velocity. When using a Type S probe, use the following equation to calculate the traverse point near-axial velocity (v
12.2.3 Handling multiple measurements at a traverse point. For pressure or temperature devices that take multiple measurements at a traverse point, the multiple measurements (or where applicable, their square roots) may first be averaged and the resulting average values used in the equations above. Alternatively, the individual measurements may be used in the equations above and the resulting calculated values may then be averaged to obtain a single traverse point value. With either approach, all of the individual measurements recorded at a traverse point must be used in calculating the applicable traverse point value.
12.3 Average Near-Axial Velocity in Stack or Duct. Use the reported traverse point near-axial velocity in the following equation.
12.4 Acceptability of Results. The acceptability provisions in section 12.4 of Method 2F apply to 3-D probes used under Method 2G. The following provisions apply to Type S probes. For Type S probes, the test results are acceptable and the calculated value of v
12.4.1 The average calibration coefficient C
12.4.2 The average calibration coefficient C
12.4.3 If the conditions in neither section 12.4.1 nor section 12.4.2 are met, the test results obtained from Equation 2G-8 are not acceptable, and the steps in sections 12.2 and 12.3 must be repeated using an average calibration coefficient C
12.5 Average Gas Volumetric Flow Rate in Stack or Duct (Wet Basis). Use the following equation to compute the average volumetric flow rate on a wet basis.
12.6 Average Gas Volumetric Flow Rate in Stack or Duct (Dry Basis). Use the following equation to compute the average volumetric flow rate on a dry basis.
16.1 Field Test Reports. Field test reports shall be submitted to the Agency according to applicable regulatory requirements. Field test reports should, at a minimum, include the following elements.
16.1.1 Description of the source. This should include the name and location of the test site, descriptions of the process tested, a description of the combustion source, an accurate diagram of stack or duct cross-sectional area at the test site showing the dimensions of the stack or duct, the location of the test ports, and traverse point locations and identification numbers or codes. It should also include a description and diagram of the stack or duct layout, showing the distance of the test location from the nearest upstream and downstream disturbances and all structural elements (including breachings, baffles, fans, straighteners, etc.) affecting the flow pattern. If the source and test location descriptions have been previously submitted to the Agency in a document (e.g., a monitoring plan or test plan), referencing the document in lieu of including this information in the field test report is acceptable.
16.1.2 Field test procedures. These should include a description of test equipment and test procedures. Testing conventions, such as traverse point numbering and measurement sequence (e.g., sampling from center to wall, or wall to center), should be clearly stated. Test port identification and directional reference for each test port should be included on the appropriate field test data sheets.
16.1.3 Field test data.
16.1.3.1 Summary of results. This summary should include the dates and times of testing, and the average near-axial gas velocity and the average flue gas volumetric flow results for each run and tested condition.
16.1.3.2 Test data. The following values for each traverse point should be recorded and reported:
(a) Differential pressure at traverse point i (ΔP
(b) Stack or duct temperature at traverse point i (t
(c) Absolute stack or duct temperature at traverse point i (T
(d) Yaw angle at traverse point i (θ
(e) Stack gas near-axial velocity at traverse point i (v
16.1.3.3 The following values should be reported once per run:
(a) Water vapor in the gas stream (from Method 4 or alternative), proportion by volume (B
(b) Molecular weight of stack or duct gas, dry basis (M
(c) Molecular weight of stack or duct gas, wet basis (M
(d) Stack or duct static pressure (P
(e) Absolute stack or duct pressure (P
(f) Carbon dioxide concentration in the flue gas, dry basis (%
(g) Oxygen concentration in the flue gas, dry basis (%
(h) Average near-axial stack or duct gas velocity (v
(i) Gas volumetric flow rate corrected to standard conditions, dry or wet basis as required by the applicable regulation (Q
16.1.3.4 The following should be reported once per complete set of test runs:
(a) Cross-sectional area of stack or duct at the test location (A)
(b) Pitot tube calibration coefficient (C
(c) Measurement system response time (sec)
(d) Barometric pressure at measurement site (P
16.1.4 Calibration data. The field test report should include calibration data for all probes and test equipment used in the field test. At a minimum, the probe calibration data reported to the Agency should include the following:
(a) Date of calibration
(b) Probe type
(c) Probe identification number(s) or code(s)
(d) Probe inspection sheets
(e) Pressure measurements and calculations used to obtain calibration coefficients in accordance with section 10.6 of this method
(f) Description and diagram of wind tunnel used for the calibration, including dimensions of cross-sectional area and position and size of the test section
(g) Documentation of wind tunnel qualification tests performed in accordance with section 10.1 of this method
16.1.5 Quality assurance. Specific quality assurance and quality control procedures used during the test should be described.
(1) 40 CFR Part 60, Appendix A, Method 1 – Sample and velocity traverses for stationary sources.
(2) 40 CFR Part 60, Appendix A, Method 2 – Determination of stack gas velocity and volumetric flow rate (Type S pitot tube) .
(3) 40 CFR Part 60, Appendix A, Method 2F – Determination of stack gas velocity and volumetric flow rate with three-dimensional probes.
(4) 40 CFR Part 60, Appendix A, Method 2H – Determination of stack gas velocity taking into account velocity decay near the stack wall.
(5) 40 CFR Part 60, Appendix A, Method 3 – Gas analysis for carbon dioxide, oxygen, excess air, and dry molecular weight.
(6) 40 CFR Part 60, Appendix A, Method 3A – Determination of oxygen and carbon dioxide concentrations in emissions from stationary sources (instrumental analyzer procedure).
(7) 40 CFR Part 60, Appendix A, Method 4 – Determination of moisture content in stack gases.
(8) Emission Measurement Center (EMC) Approved Alternative Method (ALT-011) “Alternative Method 2 Thermocouple Calibration Procedure.”
(9) Electric Power Research Institute, Interim Report EPRI TR-106698, “Flue Gas Flow Rate Measurement Errors,” June 1996.
(10) Electric Power Research Institute, Final Report EPRI TR-108110, “Evaluation of Heat Rate Discrepancy from Continuous Emission Monitoring Systems,” August 1997.
(11) Fossil Energy Research Corporation, Final Report, “Velocity Probe Tests in Non-axial Flow Fields,” November 1998, Prepared for the U.S. Environmental Protection Agency.
(12) Fossil Energy Research Corporation, “Additional Swirl Tunnel Tests: E-DAT and T-DAT Probes,” February 24, 1999, Technical Memorandum Prepared for U.S. Environmental Protection Agency, P.O. No. 7W-1193-NALX.
(13) Massachusetts Institute of Technology, Report WBWT-TR-1317, “Calibration of Eight Wind Speed Probes Over a Reynolds Number Range of 46,000 to 725,000 Per Foot, Text and Summary Plots,” Plus appendices, October 15, 1998, Prepared for The Cadmus Group, Inc.
(14) National Institute of Standards and Technology, Special Publication 250, “NIST Calibration Services Users Guide 1991,” Revised October 1991, U.S. Department of Commerce, p. 2.
(15) National Institute of Standards and Technology, 1998, “Report of Special Test of Air Speed Instrumentation, Four Prandtl Probes, Four S-Type Probes, Four French Probes, Four Modified Kiel Probes,” Prepared for the U.S. Environmental Protection Agency under IAG #DW13938432-01-0.
(16) National Institute of Standards and Technology, 1998, “Report of Special Test of Air Speed In-strumentation, Five Autoprobes,” Prepared for the U.S. Environmental Protection Agency under IAG #DW13938432-01-0.
(17) National Institute of Standards and Technology, 1998, “Report of Special Test of Air Speed Instrumentation, Eight Spherical Probes,” Prepared for the U.S. Environmental Protection Agency under IAG #DW13938432-01-0.
(18) National Institute of Standards and Technology, 1998, “Report of Special Test of Air Speed Instrumentation, Four DAT Probes, “ Prepared for the U.S. Environmental Protection Agency under IAG #DW13938432-01-0.
(19) Norfleet, S.K., “An Evaluation of Wall Effects on Stack Flow Velocities and Related Overestimation Bias in EPA’s Stack Flow Reference Methods,” EPRI CEMS User’s Group Meeting, New Orleans, Louisiana, May 13-15, 1998.
(20) Page, J.J., E.A. Potts, and R.T. Shigehara, “3-D Pitot Tube Calibration Study,” EPA Contract No. 68D10009, Work Assignment No. I-121, March 11, 1993.
(21) Shigehara, R.T., W.F. Todd, and W.S. Smith, “Significance of Errors in Stack Sampling Measurements,” Presented at the Annual Meeting of the Air Pollution Control Association, St. Louis, Missouri, June 1419, 1970.
(22) The Cadmus Group, Inc., May 1999, “EPA Flow Reference Method Testing and Analysis: Findings Report,” EPA/430-R-99-009.
(23) The Cadmus Group, Inc., 1998, “EPA Flow Reference Method Testing and Analysis: Data Report, Texas Utilities, DeCordova Steam Electric Station, Volume I: Test Description and Appendix A (Data Distribution Package),” EPA/430-R-98-015a.
(24) The Cadmus Group, Inc., 1998, “EPA Flow Reference Method Testing and Analysis: Data Report, Texas Utilities, Lake Hubbard Steam Electric Station, Volume I: Test Description and Appendix A (Data Distribution Package),” EPA/430-R-98-017a.
(25) The Cadmus Group, Inc., 1998, “EPA Flow Reference Method Testing and Analysis: Data Report, Pennsylvania Electric Co., G.P.U. Genco Homer City Station: Unit 1, Volume I: Test Description and Appendix A (Data Distribution Package),” EPA/430-R-98-018a.
(26) The Cadmus Group, Inc., 1997, “EPA Flow Reference Method Testing and Analysis: Wind Tunnel Experimental Results,” EPA/430-R-97-013.
Annex A, C, and D describe recommended procedures for meeting certain provisions in sections 8.3, 10.4, and 10.5 of this method. Annex B describes procedures to be followed when using the protractor wheel and pointer assembly to measure yaw angles, as provided under section 8.9.1.
18.1 Annex A – Rotational Position Check. The following are recommended procedures that may be used to satisfy the rotational position check requirements of section 8.3 of this method and to determine the angle-measuring device rotational offset (R
18.1.1 Rotational position check with probe outside stack. Where physical constraints at the sampling location allow full assembly of the probe outside the stack and insertion into the test port, the following procedures should be performed before the start of testing. Two angle-measuring devices that meet the specifications in section 6.2.1 or 6.2.3 are required for the rotational position check. An angle measuring device whose position can be independently adjusted (e.g., by means of a set screw) after being locked into position on the probe sheath shall not be used for this check unless the independent adjustment is set so that the device performs exactly like a device without the capability for independent adjustment. That is, when aligned on the probe such a device must give the same reading as a device that does not have the capability of being independently adjusted. With the fully assembled probe (including probe shaft extensions, if any) secured in a horizontal position, affix one yaw angle-measuring device to the probe sheath and lock it into position on the reference scribe line specified in section 6.1.5.1. Position the second angle-measuring device using the procedure in section 18.1.1.1 or 18.1.1.2.
18.1.1.1 Marking procedure. The procedures in this section should be performed at each location on the fully assembled probe where the yaw angle-measuring device will be mounted during the velocity traverse. Place the second yaw angle-measuring device on the main probe sheath (or extension) at the position where a yaw angle will be measured during the velocity traverse. Adjust the position of the second angle-measuring device until it indicates the same angle (±1°) as the reference device, and affix the second device to the probe sheath (or extension). Record the angles indicated by the two angle-measuring devices on a form similar to table 2G-2. In this position, the second angle-measuring device is considered to be properly positioned for yaw angle measurement. Make a mark, no wider than 1.6 mm (
18.1.1.2 Procedure for probe extensions with scribe lines. If, during a velocity traverse the angle-measuring device will be affixed to a probe extension having a scribe line as specified in section 6.1.5.2, the following procedure may be used to align the extension’s scribe line with the reference scribe line instead of marking the extension as described in section 18.1.1.1. Attach the probe extension to the main probe. Align and lock the second angle-measuring device on the probe extension’s scribe line. Then, rotate the extension until both measuring devices indicate the same angle (±1°). Lock the extension at this rotational position. Record the angles indicated by the two angle-measuring devices on a form similar to table 2G-2. An angle-measuring device may be aligned at any position on this scribe line during the velocity traverse, if the scribe line meets the alignment specification in section 6.1.5.3.
18.1.1.3 Post-test rotational position check. If the fully assembled probe includes one or more extensions, the following check should be performed immediately after the completion of a velocity traverse. At the discretion of the tester, additional checks may be conducted after completion of testing at any sample port. Without altering the alignment of any of the components of the probe assembly used in the velocity traverse, secure the fully assembled probe in a horizontal position. Affix an angle-measuring device at the reference scribe line specified in section 6.1.5.1. Use the other angle-measuring device to check the angle at each location where the device was checked prior to testing. Record the readings from the two angle-measuring devices.
18.1.2 Rotational position check with probe in stack. This section applies only to probes that, due to physical constraints, cannot be inserted into the test port as fully assembled with all necessary extensions needed to reach the inner-most traverse point(s).
18.1.2.1 Perform the out-of-stack procedure in section 18.1.1 on the main probe and any attached extensions that will be initially inserted into the test port.
18.1.2.2 Use the following procedures to perform additional rotational position check(s) with the probe in the stack, each time a probe extension is added. Two angle-measuring devices are required. The first of these is the device that was used to measure yaw angles at the preceding traverse point, left in its properly aligned measurement position. The second angle-measuring device is positioned on the added probe extension. Use the applicable procedures in section 18.1.1.1 or 18.1.1.2 to align, adjust, lock, and mark (if necessary) the position of the second angle-measuring device to within ±1° of the first device. Record the readings of the two devices on a form similar to Table 2G-2.
18.1.2.3 The procedure in section 18.1.2.2 should be performed at the first port where measurements are taken. The procedure should be repeated each time a probe extension is re-attached at a subsequent port, unless the probe extensions are designed to be locked into a mechanically fixed rotational position (e.g., through use of interlocking grooves), which can be reproduced from port to port as specified in section 8.3.5.2.
18.2 Annex B – Angle Measurement Protocol for Protractor Wheel and Pointer Device. The following procedure shall be used when a protractor wheel and pointer assembly, such as the one described in section 6.2.2 and illustrated in Figure 2G-5 is used to measure the yaw angle of flow. With each move to a new traverse point, unlock, re-align, and re-lock the probe, angle-pointer collar, and protractor wheel to each other. At each such move, particular attention is required to ensure that the scribe line on the angle pointer collar is either aligned with the reference scribe line on the main probe sheath or is at the rotational offset position established under section 8.3.1. The procedure consists of the following steps:
18.2.1 Affix a protractor wheel to the entry port for the test probe in the stack or duct.
18.2.2 Orient the protractor wheel so that the 0° mark corresponds to the longitudinal axis of the stack or duct. For stacks, vertical ducts, or ports on the side of horizontal ducts, use a digital inclinometer meeting the specifications in section 6.2.1 to locate the 0° orientation. For ports on the top or bottom of horizontal ducts, identify the longitudinal axis at each test port and permanently mark the duct to indicate the 0° orientation. Once the protractor wheel is properly aligned, lock it into position on the test port.
18.2.3 Move the pointer assembly along the probe sheath to the position needed to take measurements at the first traverse point. Align the scribe line on the pointer collar with the reference scribe line or at the rotational offset position established under section 8.3.1. Maintaining this rotational alignment, lock the pointer device onto the probe sheath. Insert the probe into the entry port to the depth needed to take measurements at the first traverse point.
18.2.4 Perform the yaw angle determination as specified in sections 8.9.3 and 8.9.4 and record the angle as shown by the pointer on the protractor wheel. Then, take velocity pressure and temperature measurements in accordance with the procedure in section 8.9.5. Perform the alignment check described in section 8.9.6.
18.2.5 After taking velocity pressure measurements at that traverse point, unlock the probe from the collar and slide the probe through the collar to the depth needed to reach the next traverse point.
18.2.6 Align the scribe line on the pointer collar with the reference scribe line on the main probe or at the rotational offset position established under section 8.3.1. Lock the collar onto the probe.
18.2.7 Repeat the steps in sections 18.2.4 through 18.2.6 at the remaining traverse points accessed from the current stack or duct entry port.
18.2.8 After completing the measurement at the last traverse point accessed from a port, verify that the orientation of the protractor wheel on the test port has not changed over the course of the traverse at that port. For stacks, vertical ducts, or ports on the side of horizontal ducts, use a digital inclinometer meeting the specifications in section 6.2.1 to check the rotational position of the 0° mark on the protractor wheel. For ports on the top or bottom of horizontal ducts, observe the alignment of the angle wheel 0° mark relative to the permanent 0° mark on the duct at that test port. If these observed comparisons exceed ±2° of 0°, all angle and pressure measurements taken at that port since the protractor wheel was last locked into position on the port shall be repeated.
18.2.9 Move to the next stack or duct entry port and repeat the steps in sections 18.2.1 through 18.2.8.
18.3 Annex C – Guideline for Reference Scribe Line Placement. Use of the following guideline is recommended to satisfy the requirements of section 10.4 of this method. The rotational position of the reference scribe line should be either 90° or 180° from the probe’s impact pressure port. For Type-S probes, place separate scribe lines, on opposite sides of the probe sheath, if both the A and B sides of the pitot tube are to be used for yaw angle measurements.
18.4 Annex D – Determination of Reference Scribe Line Rotational Offset. The following procedures are recommended for determining the magnitude and sign of a probe’s reference scribe line rotational offset, R
18.4.1 Perform the following procedures on the main probe with all devices that will be attached to the main probe in the field [such as thermocouples, resistance temperature detectors (RTDs), or sampling nozzles] that may affect the flow around the probe head. Probe shaft extensions that do not affect flow around the probe head need not be attached during calibration.
18.4.2 The procedures below assume that the wind tunnel duct used for probe calibration is horizontal and that the flow in the calibration wind tunnel is axial as determined by the axial flow verification check described in section 10.1.2. Angle-measuring devices are assumed to display angles in alternating 0° to 90° and 90° to 0° intervals. If angle-measuring devices with other readout conventions are used or if other calibration wind tunnel duct configurations are used, make the appropriate calculational corrections. For Type-S probes, calibrate the A-side and B-sides separately, using the appropriate scribe line (see section 18.3, above), if both the A and B sides of the pitot tube are to be used for yaw angle determinations.
18.4.2.1 Position the angle-measuring device in accordance with one of the following procedures.
18.4.2.1.1 If using a digital inclinometer, affix the calibrated digital inclinometer to the probe. If the digital inclinometer can be independently adjusted after being locked into position on the probe sheath (e.g., by means of a set screw), the independent adjustment must be set so that the device performs exactly like a device without the capability for independent adjustment. That is, when aligned on the probe the device must give the same readings as a device that does not have the capability of being independently adjusted. Either align it directly on the reference scribe line or on a mark aligned with the scribe line determined according to the procedures in section 18.1.1.1. Maintaining this rotational alignment, lock the digital inclinometer onto the probe sheath.
18.4.2.1.2 If using a protractor wheel and pointer device, orient the protractor wheel on the test port so that the 0° mark is aligned with the longitudinal axis of the wind tunnel duct. Maintaining this alignment, lock the wheel into place on the wind tunnel test port. Align the scribe line on the pointer collar with the reference scribe line or with a mark aligned with the reference scribe line, as determined under section 18.1.1.1. Maintaining this rotational alignment, lock the pointer device onto the probe sheath.
18.4.2.2 Zero the pressure-measuring device used for yaw nulling.
18.4.2.3 Insert the probe assembly into the wind tunnel through the entry port, positioning the probe’s impact port at the calibration location. Check the responsiveness of the pressure-measuring device to probe rotation, taking corrective action if the response is unacceptable.
18.4.2.4 Ensure that the probe is in a horizontal position using a carpenter’s level.
18.4.2.5 Rotate the probe either clockwise or counterclockwise until a yaw null [zero ΔP for a Type S probe or zero (P
18.4.2.6 Read and record the value of θ
18.4.2.7 Determine the magnitude and algebraic sign of the reference scribe line rotational offset, R
18.4.2.8 Perform the steps in sections 18.3.2.3 through 18.3.2.7 twice at each of the two calibration velocities selected for the probe under section 10.6. Record the values of R
18.4.2.9 The average of all R
1.1 This method is applicable in conjunction with Methods 2, 2F, and 2G (40 CFR Part 60, Appendix A) to account for velocity decay near the wall in circular stacks and ducts.
1.2 This method is not applicable for testing stacks and ducts less than 3.3 ft (1.0 m) in diameter.
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 A wall effects adjustment factor is determined. It is used to adjust the average stack gas velocity obtained under Method 2, 2F, or 2G of this appendix to take into account velocity decay near the stack or duct wall.
2.2 The method contains two possible procedures: a calculational approach which derives an adjustment factor from velocity measurements and a default procedure which assigns a generic adjustment factor based on the construction of the stack or duct.
2.2.1 The calculational procedure derives a wall effects adjustment factor from velocity measurements taken using Method 2, 2F, or 2G at 16 (or more) traverse points specified under Method 1 of this appendix and a total of eight (or more) wall effects traverse points specified under this method. The calculational procedure based on velocity measurements is not applicable for horizontal circular ducts where build-up of particulate matter or other material in the bottom of the duct is present.
2.2.2 A default wall effects adjustment factor of 0.9900 for brick and mortar stacks and 0.9950 for all other types of stacks and ducts may be used without taking wall effects measurements in a stack or duct.
2.3 When the calculational procedure is conducted as part of a relative accuracy test audit (RATA) or other multiple-run test procedure, the wall effects adjustment factor derived from a single traverse (i.e., single RATA run) may be applied to all runs of the same RATA without repeating the wall effects measurements. Alternatively, wall effects adjustment factors may be derived for several traverses and an average wall effects adjustment factor applied to all runs of the same RATA.
3.1 Complete wall effects traverse means a traverse in which measurements are taken at d
3.2 d
3.3 d
3.4 “May,” “Must,” “Shall,” “Should,” and the imperative form of verbs.
3.4.1 “May” is used to indicate that a provision of this method is optional.
3.4.2 “Must,” “Shall,” and the imperative form of verbs (such as “record” or “enter”) are used to indicate that a provision of this method is mandatory.
3.4.3 “Should” is used to indicate that a provision of this method is not mandatory but is highly recommended as good practice.
3.5 Method 1 refers to 40 CFR part 60, appendix A, “Method 1 – Sample and velocity traverses for stationary sources.”
3.6 Method 1 exterior equal-area sector and Method 1 equal-area sector closest to the wall mean any one of the four equal-area sectors that are closest to the wall for a circular stack or duct laid out in accordance with section 2.3.1 of Method 1 (see Figure 2H-1).
3.7 Method 1 interior equal-area sector means any of the equal-area sectors other than the Method 1 exterior equal-area sectors (as defined in section 3.6) for a circular stack or duct laid out in accordance with section 2.3.1 of Method 1 (see Figure 2H-1).
3.8 Method 1 traverse point and Method 1 equal-area traverse point mean a traverse point located at the centroid of an equal-area sector of a circular stack laid out in accordance with section 2.3.1 of Method 1.
3.9 Method 2 refers to 40 CFR part 60, appendix A, “Method 2 – Determination of stack gas velocity and volumetric flow rate (Type S pitot tube).”
3.10 Method 2F refers to 40 CFR part 60, appendix A, “Method 2F – Determination of stack gas velocity and volumetric flow rate with three-dimensional probes.”
3.11 Method 2G refers to 40 CFR part 60, appendix A, “Method 2G – Determination of stack gas velocity and volumetric flow rate with two-dimensional probes.”
3.12 1-in. incremented wall effects traverse point means any of the wall effects traverse points that are located at 1-in. intervals, i.e., traverse points d
3.13 Partial wall effects traverse means a traverse in which measurements are taken at fewer than the number of traverse points required for a “complete wall effects traverse” (as defined in section 3.1), but are taken at a minimum of two traverse points in each Method 1 equal-area sector closest to the wall, as specified in section 8.2.2.
3.14 Relative accuracy test audit (RATA) is a field test procedure performed in a stack or duct in which a series of concurrent measurements of the same stack gas stream is taken by a reference method and an installed monitoring system. A RATA usually consists of series of 9 to 12 sets of such concurrent measurements, each of which is referred to as a RATA run. In a volumetric flow RATA, each reference method run consists of a complete traverse of the stack or duct.
3.15 Wall effects-unadjusted average velocity means the average stack gas velocity, not accounting for velocity decay near the wall, as determined in accordance with Method 2, 2F, or 2G for a Method 1 traverse consisting of 16 or more points.
3.16 Wall effects-adjusted average velocity means the average stack gas velocity, taking into account velocity decay near the wall, as calculated from measurements at 16 or more Method 1 traverse points and at the additional wall effects traverse points specified in this method.
3.17 Wall effects traverse point means a traverse point located in accordance with sections 8.2.2 or 8.2.3 of this method.
5.1 This method may involve hazardous materials, operations, and equipment. This method does not purport to address all of the health and safety considerations associated with its use. It is the responsibility of the user of this method to establish appropriate health and safety practices and to determine the applicability of occupational health and safety regulatory requirements prior to performing this method.
6.1 The provisions pertaining to equipment and supplies in the method that is used to take the traverse point measurements (i.e., Method 2, 2F, or 2G) are applicable under this method.
8.1 Default Wall Effects Adjustment Factors. A default wall effects adjustment factor of 0.9900 for brick and mortar stacks and 0.9950 for all other types of stacks and ducts may be used without conducting the following procedures.
8.2 Traverse Point Locations. Determine the location of the Method 1 traverse points in accordance with section 8.2.1 and the location of the traverse points for either a partial wall effects traverse in accordance with section 8.2.2 or a complete wall effects traverse in accordance with section 8.2.3.
8.2.1 Method 1 equal-area traverse point locations. Determine the location of the Method 1 equal-area traverse points for a traverse consisting of 16 or more points using Table 1-2 (Location of Traverse Points in Circular Stacks) of Method 1.
8.2.2 Partial wall effects traverse. For a partial wall effects traverse, measurements must be taken at a minimum of the following two wall effects traverse point locations in all four Method 1 equal-area sectors closest to the wall: (1) 1 in. (2.5 cm) from the wall (except as provided in section 8.2.2.1) and (2) d
8.2.2.1 If the probe cannot be positioned at 1 in. (2.5 cm) from the wall (e.g., because of insufficient room to withdraw the probe shaft) or if velocity pressure cannot be detected at 1 in. (2.5 cm) from the wall (for any reason other than build-up of particulate matter in the bottom of a duct), take measurements at the 1-in. incremented wall effects traverse point closest to the wall where the probe can be positioned and velocity pressure can be detected.
8.2.2.2 Calculate the distance of d
8.2.2.3 Measurements may be taken at any number of additional wall effects traverse points, with the following provisions.
(a) d
(b) Each point must be located at a distance that is a whole number (e.g., 1, 2, 3) multiple of 1 in. (2.5 cm).
(c) Points do not have to be located at consecutive 1-in. intervals. That is, one or more 1-in. incremented points may be skipped. For example, it would be acceptable for points to be located at 1 in. (2.5 cm), 3 in. (7.6 cm), 5 in. (12.7 cm), d
8.2.3 Complete wall effects traverse. For a complete wall effects traverse, measurements must be taken at the following points in all four Method 1 equal-area sectors closest to the wall.
(a) The 1-in. incremented wall effects traverse point closest to the wall where the probe can be positioned and velocity can be detected, but no farther than 4 in. (10.2 cm) from the wall.
(b) Every subsequent 1-in. incremented wall effects traverse point out to the interior edge of the Method 1 equal-area sector or to 12 in. (30.5 cm) from the wall, whichever comes first. Note: In stacks or ducts with diameters greater than 15.6 ft (4.8 m) the interior edge of the Method 1 equal-area sector is farther from the wall than 12 in. (30.5 cm).
(c) d
8.2.4 Special considerations. The following special considerations apply when the distance between traverse points is less than or equal to
8.2.4.1 A wall effects traverse point and the Method 1 traverse point. If the distance between a wall effects traverse point and the Method 1 traverse point is less than or equal to
8.2.4.2 d
8.3 Traverse Point Sampling Order and Probe Selection. Determine the sampling order of the Method 1 and wall effects traverse points and select the appropriate probe for the measurements, taking into account the following considerations.
8.3.1 Traverse points on any radius may be sampled in either direction (i.e., from the wall toward the center of the stack or duct, or vice versa).
8.3.2 To reduce the likelihood of velocity variations during the time of the traverse and the attendant potential impact on the wall effects-adjusted and unadjusted average velocities, the following provisions of this method shall be met.
8.3.2.1 Each complete set of Method 1 and wall effects traverse points accessed from the same port shall be sampled without interruption. Unless traverses are performed simultaneously in all ports using separate probes at each port, this provision disallows first sampling all Method 1 points at all ports and then sampling all the wall effects points.
8.3.2.2 The entire integrated Method 1 and wall effects traverse across all test ports shall be as short as practicable, consistent with the measurement system response time (see section 8.4.1.1) and sampling (see section 8.4.1.2) provisions of this method.
8.3.3 It is recommended but not required that in each Method 1 equal-area sector closest to the wall, the Method 1 equal-area traverse point should be sampled in sequence between the adjacent wall effects traverse points. For example, for the traverse point configuration shown in Figure 2H-2, it is recommended that the Method 1 equal-area traverse point be sampled between d
8.3.4 The same type of probe must be used to take measurements at all Method 1 and wall effects traverse points. However, different copies of the same type of probe may be used at different ports (e.g., Type S probe 1 at port A, Type S probe 2 at port B) or at different traverse points accessed from a particular port (e.g., Type S probe 1 for Method 1 interior traverse points accessed from port A, Type S probe 2 for wall effects traverse points and the Method 1 exterior traverse point accessed from port A). The identification number of the probe used to obtain measurements at each traverse point must be recorded.
8.4 Measurements at Method 1 and Wall Effects Traverse Points. Conduct measurements at Method 1 and wall effects traverse points in accordance with Method 2, 2F, or 2G and in accordance with the provisions of the following subsections (some of which are included in Methods 2F and 2G but not in Method 2), which are particularly important for wall effects testing.
8.4.1 Probe residence time at wall effects traverse points. Due to the steep temperature and pressure gradients that can occur close to the wall, it is very important for the probe residence time (i.e., the total time spent at a traverse point) to be long enough to ensure collection of representative temperature and pressure measurements. The provisions of Methods 2F and 2G in the following subsections shall be observed.
8.4.1.1 System response time. Determine the response time of each probe measurement system by inserting and positioning the “cold” probe (at ambient temperature and pressure) at any Method 1 traverse point. Read and record the probe differential pressure, temperature, and elapsed time at 15-second intervals until stable readings for both pressure and temperature are achieved. The response time is the longer of these two elapsed times. Record the response time.
8.4.1.2 Sampling. At the start of testing in each port (i.e., after a probe has been inserted into the stack gas stream), allow at least the response time to elapse before beginning to take measurements at the first traverse point accessed from that port. Provided that the probe is not removed from the stack gas stream, measurements may be taken at subsequent traverse points accessed from the same test port without waiting again for the response time to elapse.
8.4.2 Temperature measurement for wall effects traverse points. Either (1) take temperature measurements at each wall effects traverse point in accordance with the applicable provisions of Method 2, 2F, or 2G; or (2) use the temperature measurement at the Method 1 traverse point closest to the wall as the temperature measurement for all the wall effects traverse points in the corresponding equal-area sector.
8.4.3 Non-detectable velocity pressure at wall effects traverse points. If the probe cannot be positioned at a wall effects traverse point or if no velocity pressure can be detected at a wall effects point, measurements shall be taken at the first subsequent wall effects traverse point farther from the wall where velocity can be detected. Follow the instructions in section 8.7.1.2 of this method for recording results for wall effects traverse points where velocity pressure cannot be detected. It should be noted that the full extent of velocity decay may not be accounted for if measurements are not taken at the 1-in. incremented wall effects traverse points closest to the wall.
8.5 Data Recording. For each wall effects and Method 1 traverse point where measurements are taken, record all pressure, temperature, and attendant measurements prescribed in section 3 of Method 2 or section 8.0 of Method 2F or 2G, as applicable.
8.6 Point Velocity Calculation. For each wall effects and Method 1 traverse point, calculate the point velocity value (v
8.7 Tabulating Calculated Point Velocity Values for Wall Effects Traverse Points. Enter the following values in a hardcopy or electronic form similar to Form 2H-1 (for 16-point Method 1 traverses) or Form 2H-2 (for Method 1 traverses consisting of more than 16 points). A separate form must be completed for each of the four Method 1 equal-area sectors that are closest to the wall.
(a) Port ID (e.g., A, B, C, or D)
(b) Probe type
(c) Probe ID
(d) Stack or duct diameter in ft (m) (determined in accordance with section 8.6 of Method 2F or Method 2G)
(e) Stack or duct radius in in. (cm)
(f) Distance from the wall of wall effects traverse points at 1-in. intervals, in ascending order starting with 1 in. (2.5 cm) (column A of Form 2H-1 or 2H-2)
(g) Point velocity values (v
(h) Point velocity value (v
8.7.1 Point velocity values at wall effects traverse points other than d
8.7.1.1 For wall effects traverse points where the probe can be positioned and velocity pressure can be detected, enter the value obtained in accordance with section 8.6.
8.7.1.2 For wall effects traverse points that were skipped [see section 8.2.2.3(c)] and for points where the probe cannot be positioned or where no velocity pressure can be detected, enter the value obtained at the first subsequent traverse point farther from the wall where velocity pressure was detected and measured and follow the entered value with a “flag,” such as the notation “NM,” to indicate that “no measurements” were actually taken at this point.
8.7.2 Point velocity value at d
8.7.3 Point velocity value (v
9.1 Particulate Matter Build-up in Horizontal Ducts. Wall effects testing of horizontal circular ducts should be conducted only if build-up of particulate matter or other material in the bottom of the duct is not present.
9.2 Verifying Traverse Point Distances. In taking measurements at wall effects traverse points, it is very important for the probe impact pressure port to be positioned as close as practicable to the traverse point locations in the gas stream. For this reason, before beginning wall effects testing, it is important to calculate and record the traverse point positions that will be marked on each probe for each port, taking into account the distance that each port nipple (or probe mounting flange for automated probes) extends out of the stack and any extension of the port nipple (or mounting flange) into the gas stream. To ensure that traverse point positions are properly identified, the following procedures should be performed on each probe used.
9.2.1 Manual probes. Mark the probe insertion distance of the wall effects and Method 1 traverse points on the probe sheath so that when a mark is aligned with the outside face of the stack port, the probe impact port is located at the calculated distance of the traverse point from the stack inside wall. The use of different colored marks is recommended for designating the wall effects and Method 1 traverse points. Before the first use of each probe, check to ensure that the distance of each mark from the center of the probe impact pressure port agrees with the previously calculated traverse point positions to within ±
9.2.2 Automated probe systems. For automated probe systems that mechanically position the probe head at prescribed traverse point positions, activate the system with the probe assemblies removed from the test ports and sequentially extend the probes to the programmed location of each wall effects traverse point and the Method 1 traverse points. Measure the distance between the center of the probe impact pressure port and the inside of the probe assembly mounting flange for each traverse point. The measured distances must agree with the previously calculated traverse point positions to within ±
9.3 Probe Installation. Properly sealing the port area is particularly important in taking measurements at wall effects traverse points. For testing involving manual probes, the area between the probe sheath and the port should be sealed with a tightly fitting flexible seal made of an appropriate material such as heavy cloth so that leakage is minimized. For automated probe systems, the probe assembly mounting flange area should be checked to verify that there is no leakage.
9.4 Velocity Stability. This method should be performed only when the average gas velocity in the stack or duct is relatively constant over the duration of the test. If the average gas velocity changes significantly during the course of a wall effects test, the test results should be discarded.
10.1 The calibration coefficient(s) or curves obtained under Method 2, 2F, or 2G and used to perform the Method 1 traverse are applicable under this method.
11.1 Sample collection and analysis are concurrent for this method (see section 8).
12.1 The following calculations shall be performed to obtain a wall effects adjustment factor (WAF) from (1) the wall effects-unadjusted average velocity (T4avg), (2) the replacement velocity (v
12.2 Nomenclature. The following terms are listed in the order in which they appear in Equations 2H-5 through 2H-21.
12.3 Calculate the average stack gas velocity that does not account for velocity decay near the wall (v
For a 16-point traverse, Equation 2H-5 may be written as follows:
12.4 Calculate the replacement velocity, v
12.4.1 Calculate the average velocity (designated the “decay velocity,” vdec
12.4.2 Calculate the cross-sectional area between the wall and the first 1-in. incremented wall effects traverse point and between successive 1-in. incremented wall effects traverse points, from the wall to d
12.4.3 Calculate the volumetric flow through each cross-sectional area derived in section 12.4.2 by multiplying the values of vdec
12.4.4 Calculate the total volumetric flow through all sub-sectors located between the wall and d
12.4.5 Calculate the cross-sectional area of the sub-sector located between d
12.4.6 Calculate the volumetric flow for the sub-sector located between d
12.4.7 Calculate the total volumetric flow for the Method 1 equal-area sector closest to the wall, using Equation 2H-14.
12.4.8 Calculate the wall effects-adjusted replacement velocity value for the Method 1 equal-area sector closest to the wall, using Equation 2H-15.
12.5 Calculate the wall effects-adjusted average velocity, v
12.6 Calculate the wall effects adjustment factor, WAF, using Equation 2H-19.
12.6.1 Partial wall effects traverse. If a partial wall effects traverse (see section 8.2.2) is conducted, the value obtained from Equation 2H-19 is acceptable and may be reported as the wall effects adjustment factor provided that the value is greater than or equal to 0.9800. If the value is less than 0.9800, it shall not be used and a wall effects adjustment factor of 0.9800 may be used instead.
12.6.2 Complete wall effects traverse. If a complete wall effects traverse (see section 8.2.3) is conducted, the value obtained from Equation 2H-19 is acceptable and may be reported as the wall effects adjustment factor provided that the value is greater than or equal to 0.9700. If the value is less than 0.9700, it shall not be used and a wall effects adjustment factor of 0.9700 may be used instead. If the wall effects adjustment factor for a particular stack or duct is less than 0.9700, the tester may (1) repeat the wall effects test, taking measurements at more Method 1 traverse points and (2) recalculate the wall effects adjustment factor from these measurements, in an attempt to obtain a wall effects adjustment factor that meets the 0.9700 specification and completely characterizes the wall effects.
12.7 Applying a Wall Effects Adjustment Factor. A default wall effects adjustment factor, as specified in section 8.1, or a calculated wall effects adjustment factor meeting the requirements of section 12.6.1 or 12.6.2 may be used to adjust the average stack gas velocity obtained using Methods 2, 2F, or 2G to take into account velocity decay near the wall of circular stacks or ducts. Default wall effects adjustment factors specified in section 8.1 and calculated wall effects adjustment factors that meet the requirements of section 12.6.1 and 12.6.2 are summarized in Table 2H-2.
12.7.1 Single-run tests. Calculate the final wall effects-adjusted average stack gas velocity for field tests consisting of a single traverse using Equation 2H-20.
12.7.2 RATA or other multiple run test procedure. Calculate the final wall effects-adjusted average stack gas velocity for any run k of a RATA or other multiple-run procedure using Equation 2H-21.
12.8 Calculating Volumetric Flow Using Final Wall Effects-Adjusted Average Velocity Value. To obtain a stack gas flow rate that accounts for velocity decay near the wall of circular stacks or ducts, replace v
12.8.1 For single-run test procedures, use the final wall effects-adjusted average stack gas velocity, v
12.8.2 For RATA and other multiple run test procedures, use the final wall effects-adjusted average stack gas velocity, v
16.1 Field Test Reports. Field test reports shall be submitted to the Agency according to the applicable regulatory requirements. When Method 2H is performed in conjunction with Method 2, 2F, or 2G to derive a wall effects adjustment factor, a single consolidated Method 2H/2F (or 2H/2G) field test report should be prepared. At a minimum, the consolidated field test report should contain (1) all of the general information, and data for Method 1 points, specified in section 16.0 of Method 2F (when Method 2H is used in conjunction with Method 2F) or section 16.0 of Method 2G (when Method 2H is used in conjunction with Method 2 or 2G) and (2) the additional general information, and data for Method 1 points and wall effects points, specified in this section (some of which are included in section 16.0 of Methods 2F and 2G and are repeated in this section to ensure complete reporting for wall effects testing).
16.1.1 Description of the source and site. The field test report should include the descriptive information specified in section 16.1.1 of Method 2F (when using Method 2F) or 2G (when using either Method 2 or 2G). It should also include a description of the stack or duct’s construction material along with the diagram showing the dimensions of the stack or duct at the test port elevation prescribed in Methods 2F and 2G. The diagram should indicate the location of all wall effects traverse points where measurements were taken as well as the Method 1 traverse points. The diagram should provide a unique identification number for each wall effects and Method 1 traverse point, its distance from the wall, and its location relative to the probe entry ports.
16.1.2 Field test forms. The field test report should include a copy of Form 2H-1, 2H-2, or an equivalent for each Method 1 exterior equal-area sector.
16.1.3 Field test data. The field test report should include the following data for the Method 1 and wall effects traverse.
16.1.3.1 Data for each traverse point. The field test report should include the values specified in section 16.1.3.2 of Method 2F (when using Method 2F) or 2G (when using either Method 2 or 2G) for each Method 1 and wall effects traverse point. The provisions of section 8.4.2 of Method 2H apply to the temperature measurements reported for wall effects traverse points. For each wall effects and Method 1 traverse point, the following values should also be included in the field test report.
(a) Traverse point identification number for each Method 1 and wall effects traverse point.
(b) Probe type.
(c) Probe identification number.
(d) Probe velocity calibration coefficient (i.e., C
For each Method 1 traverse point in an exterior equal-area sector, the following additional value should be included.
(e) Calculated replacement velocity, v
16.1.3.2 Data for each run. The values specified in section 16.1.3.3 of Method 2F (when using Method 2F) or 2G (when using either Method 2 or 2G) should be included in the field test report once for each run. The provisions of section 12.8 of Method 2H apply for calculating the reported gas volumetric flow rate. In addition, the following Method 2H run values should also be included in the field test report.
(a) Average velocity for run, accounting for wall effects, v
(b) Wall effects adjustment factor derived from a test run, WAF.
16.1.3.3 Data for a complete set of runs. The values specified in section 16.1.3.4 of Method 2F (when using Method 2F) or 2G (when using either Method 2 or 2G) should be included in the field test report once for each complete set of runs. In addition, the field test report should include the wall effects adjustment factor, W
16.1.4 Quality assurance and control. Quality assurance and control procedures, specifically tailored to wall effects testing, should be described.
16.2 Reporting a Default Wall Effects Adjustment Factor. When a default wall effects adjustment factor is used in accordance with section 8.1 of this method, its value and a description of the stack or duct’s construction material should be reported in lieu of submitting a test report.
(1) 40 CFR Part 60, Appendix A, Method 1 – Sample and velocity traverses for stationary sources.
(2) 40 CFR Part 60, Appendix A, Method 2 – Determination of stack gas velocity and volumetric flow rate (Type S pitot tube).
(3) 40 CFR Part 60, Appendix A, Method 2F – Determination of stack gas velocity and volumetric flow rate with three-dimensional probes.
(4) 40 CFR Part 60, Appendix A, Method 2G – Determination of stack gas velocity and volumetric flow rate with two-dimensional probes.
(5) 40 CFR Part 60, Appendix A, Method 3 – Gas analysis for carbon dioxide, oxygen, excess air, and dry molecular weight.
(6) 40 CFR Part 60, Appendix A, Method 3A – Determination of oxygen and carbon dioxide concentrations in emissions from stationary sources (instrumental analyzer procedure).
(7) 40 CFR Part 60, Appendix A, Method 4 – Determination of moisture content in stack gases.
(8) Emission Measurement Center (EMC) Approved Alternative Method (ALT-011) “Alternative Method 2 Thermocouple Calibration Procedure.”
(9) The Cadmus Group, Inc., 1998, “EPA Flow Reference Method Testing and Analysis: Data Report, Texas Utilities, DeCordova Steam Electric Station, Volume I: Test Description and Appendix A (Data Distribution Package),” EPA/430-R-98-015a.
(10) The Cadmus Group, Inc., 1998, “EPA Flow Reference Method Testing and Analysis: Data Report, Texas Utilities, Lake Hubbard Steam Electric Station, Volume I: Test Description and Appendix A (Data Distribution Package),” EPA/430-R-98-017a.
(11) The Cadmus Group, Inc., 1998, “EPA Flow Reference Method Testing and Analysis: Data Report, Pennsylvania Electric Co., G.P.U. Genco Homer City Station: Unit 1, Volume I: Test Description and Appendix A (Data Distribution Package),” EPA/430-R-98-018a.
(12) The Cadmus Group, Inc., May 1999, “EPA Flow Reference Method Testing and Analysis: Findings Report,” EPA/430-R-99-009.
(13) The Cadmus Group, Inc., 1997, “EPA Flow Reference Method Testing and Analysis: Wind Tunnel Experimental Results,” EPA/430-R-97-013.
(14) National Institute of Standards and Technology, 1998, “Report of Special Test of Air Speed Instrumentation, Four Prandtl Probes, Four S-Type Probes, Four French Probes, Four Modified Kiel Probes,” Prepared for the U.S. Environmental Protection Agency under IAG No. DW13938432-01-0.
(15) National Institute of Standards and Technology, 1998, “Report of Special Test of Air Speed Instrumentation, Five Autoprobes,” Prepared for the U.S. Environmental Protection Agency under IAG No. DW13938432-01-0.
(16) National Institute of Standards and Technology, 1998, “Report of Special Test of Air Speed Instrumentation, Eight Spherical Probes,” Prepared for the U.S. Environmental Protection Agency under IAG No. DW13938432-01-0.
(17) National Institute of Standards and Technology, 1998, “Report of Special Test of Air Speed Instrumentation, Four DAT Probes,” Prepared for the U.S. Environmental Protection Agency under IAG No. DW13938432-01-0.
(18) Massachusetts Institute of Technology (MIT), 1998, “Calibration of Eight Wind Speed Probes Over a Reynolds Number Range of 46,000 to 725,000 per Foot, Text and Summary Plots,” Plus Appendices, WBWT-TR-1317, Prepared for The Cadmus Group, Inc., under EPA Contract 68-W6-0050, Work Assignment 0007AA-3.
(19) Fossil Energy Research Corporation, Final Report, “Velocity Probe Tests in Non-axial Flow Fields,” November 1998, Prepared for the U.S. Environmental Protection Agency.
(20) Fossil Energy Research Corporation, “Additional Swirl Tunnel Tests: E-DAT and T-DAT Probes,” February 24, 1999, Technical Memorandum Prepared for U.S. Environmental Protection Agency, P.O. No. 7W-1193-NALX.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should also have a thorough knowledge of Method 1.
1.1 Analytes.
| Analytes | CAS No. | Sensitivity |
|---|---|---|
| Oxygen (O | 7782-44-7 | 2,000 ppmv. |
| Nitrogen (N | 7727-37-9 | N/A. |
| Carbon dioxide (CO | 124-38-9 | 2,000 ppmv. |
| Carbon monoxide (CO) | 630-08-0 | N/A. |
1.2 Applicability. This method is applicable for the determination of CO
1.3 Other methods, as well as modifications to the procedure described herein, are also applicable for all of the above determinations. Examples of specific methods and modifications include: (1) A multi-point grab sampling method using an Orsat analyzer to analyze the individual grab sample obtained at each point; (2) a method for measuring either CO
1.4 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 A gas sample is extracted from a stack by one of the following methods: (1) single-point, grab sampling; (2) single-point, integrated sampling; or (3) multi-point, integrated sampling. The gas sample is analyzed for percent CO
4.1 Several compounds can interfere, to varying degrees, with the results of Orsat or Fyrite analyses. Compounds that interfere with CO
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method.
5.2 Corrosive Reagents.
5.2.1 A typical Orsat analyzer requires four reagents: a gas-confining solution, CO
5.2.2 A typical Fyrite analyzer contains zinc chloride, hydrochloric acid, and either potassium hydroxide or chromous chloride. Follow manufacturer’s operating instructions and observe all warning labels for reagent use.
As an alternative to the sampling apparatus and systems described herein, other sampling systems (e.g., liquid displacement) may be used, provided such systems are capable of obtaining a representative sample and maintaining a constant sampling rate, and are, otherwise, capable of yielding acceptable results. Use of such systems is subject to the approval of the Administrator.
6.1 Grab Sampling (See Figure 3-1).
6.1.1 Probe. Stainless steel or borosilicate glass tubing equipped with an in-stack or out-of-stack filter to remove particulate matter (a plug of glass wool is satisfactory for this purpose). Any other materials, resistant to temperature at sampling conditions and inert to all components of the gas stream, may be used for the probe. Examples of such materials may include aluminum, copper, quartz glass, and Teflon.
6.1.2 Pump. A one-way squeeze bulb, or equivalent, to transport the gas sample to the analyzer.
6.2 Integrated Sampling (Figure 3-2).
6.2.1 Probe. Same as in section 6.1.1.
6.2.2 Condenser. An air-cooled or water-cooled condenser, or other condenser no greater than 250 ml that will not remove O
6.2.3 Valve. A needle valve, to adjust sample gas flow rate.
6.2.4 Pump. A leak-free, diaphragm-type pump, or equivalent, to transport sample gas to the flexible bag. Install a small surge tank between the pump and rate meter to eliminate the pulsation effect of the diaphragm pump on the rate meter.
6.2.5 Rate Meter. A rotameter, or equivalent, capable of measuring flow rate to ±2 percent of the selected flow rate. A flow rate range of 500 to 1000 ml/min is suggested.
6.2.6 Flexible Bag. Any leak-free plastic (e.g., Tedlar, Mylar, Teflon) or plastic-coated aluminum (e.g., aluminized Mylar) bag, or equivalent, having a capacity consistent with the selected flow rate and duration of the test run. A capacity in the range of 55 to 90 liters (1.9 to 3.2 ft
6.2.7 Pressure Gauge. A water-filled U-tube manometer, or equivalent, of about 30 cm (12 in.), for the flexible bag leak-check.
6.2.8 Vacuum Gauge. A mercury manometer, or equivalent, of at least 760 mm (30 in.) Hg, for the sampling train leak-check.
6.3 Analysis. An Orsat or Fyrite type combustion gas analyzer.
7.1 Reagents. As specified by the Orsat or Fyrite-type combustion analyzer manufacturer.
7.2 Standards. Two standard gas mixtures, traceable to National Institute of Standards and Technology (NIST) standards, to be used in auditing the accuracy of the analyzer and the analyzer operator technique:
7.2.1. Gas cylinder containing 2 to 4 percent O
7.2.2. Gas cylinder containing 2 to 4 percent CO
8.1 Single Point, Grab Sampling Procedure.
8.1.1 The sampling point in the duct shall either be at the centroid of the cross section or at a point no closer to the walls than 1.0 m (3.3 ft), unless otherwise specified by the Administrator.
8.1.2 Set up the equipment as shown in Figure 3-1, making sure all connections ahead of the analyzer are tight. If an Orsat analyzer is used, it is recommended that the analyzer be leak-checked by following the procedure in section 11.5; however, the leak-check is optional.
8.1.3 Place the probe in the stack, with the tip of the probe positioned at the sampling point. Purge the sampling line long enough to allow at least five exchanges. Draw a sample into the analyzer, and immediately analyze it for percent CO
8.2 Single-Point, Integrated Sampling Procedure.
8.2.1 The sampling point in the duct shall be located as specified in section 8.1.1.
8.2.2 Leak-check (optional) the flexible bag as in section 6.2.6. Set up the equipment as shown in Figure 3-2. Just before sampling, leak-check (optional) the train by placing a vacuum gauge at the condenser inlet, pulling a vacuum of at least 250 mm Hg (10 in. Hg), plugging the outlet at the quick disconnect, and then turning off the pump. The vacuum should remain stable for at least 0.5 minute. Evacuate the flexible bag. Connect the probe, and place it in the stack, with the tip of the probe positioned at the sampling point. Purge the sampling line. Next, connect the bag, and make sure that all connections are tight.
8.2.3 Sample Collection. Sample at a constant rate (±10 percent). The sampling run should be simultaneous with, and for the same total length of time as, the pollutant emission rate determination. Collection of at least 28 liters (1.0 ft
8.2.4 Obtain one integrated flue gas sample during each pollutant emission rate determination. Within 8 hours after the sample is taken, analyze it for percent CO
When using an Orsat analyzer, periodic Fyrite readings may be taken to verify/confirm the results obtained from the Orsat.
8.3 Multi-Point, Integrated Sampling Procedure.
8.3.1 Unless otherwise specified in an applicable regulation, or by the Administrator, a minimum of eight traverse points shall be used for circular stacks having diameters less than 0.61 m (24 in.), a minimum of nine shall be used for rectangular stacks having equivalent diameters less than 0.61 m (24 in.), and a minimum of 12 traverse points shall be used for all other cases. The traverse points shall be located according to Method 1.
8.3.2 Follow the procedures outlined in sections 8.2.2 through 8.2.4, except for the following: Traverse all sampling points, and sample at each point for an equal length of time. Record sampling data as shown in Figure 3-3.
| Section | Quality control measure | Effect |
|---|---|---|
| 8.2 | Use of Fyrite to confirm Orsat results | Ensures the accurate measurement of CO |
| 10.1 | Periodic audit of analyzer and operator technique | Ensures that the analyzer is operating properly and that the operator performs the sampling procedure correctly and accurately. |
| 11.3 | Replicable analyses of integrated samples | Minimizes experimental error. |
10.1 Analyzer. The analyzer and analyzer operator’s technique should be audited periodically as follows: take a sample from a manifold containing a known mixture of CO
10.2 Rotameter. The rotameter need not be calibrated, but should be cleaned and maintained according to the manufacturer’s instruction.
11.1 Maintenance. The Orsat or Fyrite-type analyzer should be maintained and operated according to the manufacturers specifications.
11.2 Grab Sample Analysis. Use either an Orsat analyzer or a Fyrite-type combustion gas analyzer to measure O
11.3 Integrated Sample Analysis. Use either an Orsat analyzer or a Fyrite-type combustion gas analyzer to measure O
11.4 Standardization. A periodic check of the reagents and of operator technique should be conducted at least once every three series of test runs as outlined in section 10.1.
11.5 Leak-Check Procedure for Orsat Analyzer. Moving an Orsat analyzer frequently causes it to leak. Therefore, an Orsat analyzer should be thoroughly leak-checked on site before the flue gas sample is introduced into it. The procedure for leak-checking an Orsat analyzer is as follows:
11.5.1 Bring the liquid level in each pipette up to the reference mark on the capillary tubing, and then close the pipette stopcock.
11.5.2 Raise the leveling bulb sufficiently to bring the confining liquid meniscus onto the graduated portion of the burette, and then close the manifold stopcock.
11.5.3 Record the meniscus position.
11.5.4 Observe the meniscus in the burette and the liquid level in the pipette for movement over the next 4 minutes.
11.5.5 For the Orsat analyzer to pass the leak-check, two conditions must be met:
11.5.5.1 The liquid level in each pipette must not fall below the bottom of the capillary tubing during this 4-minute interval.
11.5.5.2 The meniscus in the burette must not change by more than 0.2 ml during this 4-minute interval.
11.5.6 If the analyzer fails the leak-check procedure, check all rubber connections and stopcocks to determine whether they might be the cause of the leak. Disassemble, clean, and regrease any leaking stopcocks. Replace leaking rubber connections. After the analyzer is reassembled, repeat the leak-check procedure.
12.1 Nomenclature.
12.2 Nitrogen, Carbon Monoxide Concentration. Determine the percentage of the gas that is N
12.3 Dry Molecular Weight. Use Equation 3-1 to calculate the dry molecular weight of the stack gas.
The above Equation 3-1 does not consider the effect on calculated dry molecular weight of argon in the effluent gas. The concentration of argon, with a molecular weight of 39.9, in ambient air is about 0.9 percent. A negative error of approximately 0.4 percent is introduced. The tester may choose to include argon in the analysis using procedures subject to approval of the Administrator.
1. Altshuller, A.P. Storage of Gases and Vapors in Plastic Bags. International Journal of Air and Water Pollution. 6:75-81. 1963.
2. Conner, William D. and J.S. Nader. Air Sampling with Plastic Bags. Journal of the American Industrial Hygiene Association. 25:291-297. 1964.
3. Burrell Manual for Gas Analysts, Seventh edition. Burrell Corporation, 2223 Fifth Avenue, Pittsburgh, PA. 15219. 1951.
4. Mitchell, W.J. and M.R. Midgett. Field Reliability of the Orsat Analyzer. Journal of Air Pollution Control Association. 26:491-495. May 1976.
5. Shigehara, R.T., R.M. Neulicht, and W.S. Smith. Validating Orsat Analysis Data from Fossil Fuel-Fired Units. Stack Sampling News. 4(2):21-26. August 1976.
| Time | Traverse point | Q (liter/min) | % Deviation a |
|---|---|---|---|
| Average |
a % Dev.=[(Q−Q
Method 3A is a procedure for measuring oxygen (O
This method does not completely describe all equipment, supplies, and sampling and analytical procedures you will need but refers to other methods for some of the details. Therefore, to obtain reliable results, you should also have a thorough knowledge of these additional test methods which are found in appendix A to this part:
(a) Method 1 – Sample and Velocity Traverses for Stationary Sources.
(b) Method 3 – Gas Analysis for the Determination of Molecular Weight.
(c) Method 4 – Determination of Moisture Content in Stack Gases.
(d) Method 7E – Determination of Nitrogen Oxides Emissions from Stationary Sources (Instrumental Analyzer Procedure).
1.1 Analytes. What does this method determine? This method measures the concentration of oxygen and carbon dioxide.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Oxygen (O | 7782-44-7 | Typically |
| Carbon dioxide (CO | 124-38-9 | Typically |
1.2 Applicability. When is this method required? The use of Method 3A may be required by specific New Source Performance Standards, Clean Air Marketing rules, State Implementation Plans and permits, where measurements of O
1.3 Data Quality Objectives. How good must my collected data be? Refer to section 1.3 of Method 7E.
In this method, you continuously or intermittently sample the effluent gas and convey the sample to an analyzer that measures the concentration of O
Refer to section 3.0 of Method 7E for the applicable definitions.
Refer to section 5.0 of Method 7E.
Figure 7E-1 in Method 7E is a schematic diagram of an acceptable measurement system.
6.1 What do I need for the measurement system? The components of the measurement system are described (as applicable) in sections 6.1 and 6.2 of Method 7E, except that the analyzer described in section 6.2 of this method must be used instead of the analyzer described in Method 7E. You must follow the noted specifications in section 6.1 of Method 7E except that the requirements to use stainless steel, Teflon, or non-reactive glass filters do not apply. Also, a heated sample line is not required to transport dry gases or for systems that measure the O
6.2 What analyzer must I use? You must use an analyzer that continuously measures O
7.1 Calibration Gas. What calibration gases do I need? Refer to Section 7.1 of Method 7E for the calibration gas requirements. Example calibration gas mixtures are listed below. Pre-cleaned or scrubbed air may be used for the O
(a) CO
(b) CO
(c) O
(d) O
(e) CO
(f) CO
The tests for analyzer calibration error and system bias require high-, mid-, and low-level gases.
7.2 Interference Check. What reagents do I need for the interference check? Potential interferences may vary among available analyzers. Table 7E-3 of Method 7E lists a number of gases that should be considered in conducting the interference test.
8.1 Sampling Site and Sampling Points. You must follow the procedures of section 8.1 of Method 7E to determine the appropriate sampling points, unless you are using Method 3A only to determine the stack gas molecular weight and for no other purpose. In that case, you may use single-point integrated sampling as described in section 8.2.1 of Method 3. If the stratification test provisions in section 8.1.2 of Method 7E are used to reduce the number of required sampling points, the alternative acceptance criterion for 3-point sampling will be ±0.5 percent CO
8.2 Initial Measurement System Performance Tests. You must follow the procedures in section 8.2 of Method 7E. If a dilution-type measurement system is used, the special considerations in section 8.3 of Method 7E apply.
8.3 Interference Check. The O
8.4 Sample Collection. You must follow the procedures in section 8.4 of Method 7E.
8.5 Post-Run System Bias Check and Drift Assessment. You must follow the procedures in section 8.5 of Method 7E.
Follow quality control procedures in section 9.0 of Method 7E.
Follow the procedures for calibration and standardization in section 10.0 of Method 7E.
Because sample collection and analysis are performed together (see section 8), additional discussion of the analytical procedure is not necessary.
You must follow the applicable procedures for calculations and data analysis in section 12.0 of Method 7E, substituting percent O
The specifications for the applicable performance checks are the same as in section 13.0 of Method 7E except for the alternative specifications for system bias, drift, and calibration error. In these alternative specifications, replace the term “0.5 ppmv” with the term “0.5 percent O
1. “EPA Traceability Protocol for Assay and Certification of Gaseous Calibration Standards” September 1997 as amended, EPA-600/R-97/121.
Refer to section 18.0 of Method 7E.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1 and 3.
1.1 Analytes.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Oxygen (O | 7782-44-7 | 2,000 ppmv. |
| Carbon Dioxide (CO | 124-38-9 | 2,000 ppmv. |
| Carbon Monoxide (CO) | 630-08-0 | N/A. |
1.2 Applicability. This method is applicable for the determination of O
1.3 Other methods, as well as modifications to the procedure described herein, are also applicable for all of the above determinations. Examples of specific methods and modifications include: (1) A multi-point sampling method using an Orsat analyzer to analyze individual grab samples obtained at each point, and (2) a method using CO
1.4 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 A gas sample is extracted from a stack by one of the following methods: (1) Single-point, grab sampling; (2) single-point, integrated sampling; or (3) multi-point, integrated sampling. The gas sample is analyzed for percent CO
4.1 Several compounds can interfere, to varying degrees, with the results of Orsat analyses. Compounds that interfere with CO2 concentration measurement include acid gases (e.g., sulfur dioxide, hydrogen chloride); compounds that interfere with O
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method.
5.2 Corrosive Reagents. A typical Orsat analyzer requires four reagents: a gas-confining solution, CO
As an alternative to the sampling apparatus and systems described herein, other sampling systems (e.g., liquid displacement) may be used, provided such systems are capable of obtaining a representative sample and maintaining a constant sampling rate, and are, otherwise, capable of yielding acceptable results. Use of such systems is subject to the approval of the Administrator.
6.1 Grab Sampling and Integrated Sampling. Same as in sections 6.1 and 6.2, respectively for Method 3.
6.2 Analysis. An Orsat analyzer only. For low CO
7.1 Reagents. Same as in Method 3, section 7.1.
7.2 Standards. Same as in Method 3, section 7.2.
Each of the three procedures below shall be used only when specified in an applicable subpart of the standards. The use of these procedures for other purposes must have specific prior approval of the Administrator. A Fyrite-type combustion gas analyzer is not acceptable for excess air or emission rate correction factor determinations, unless approved by the Administrator. If both percent CO
8.1 Single-Point, Grab Sampling and Analytical Procedure.
8.1.1 The sampling point in the duct shall either be at the centroid of the cross section or at a point no closer to the walls than 1.0 m (3.3 ft), unless otherwise specified by the Administrator.
8.1.2 Set up the equipment as shown in Figure 3-1 of Method 3, making sure all connections ahead of the analyzer are tight. Leak-check the Orsat analyzer according to the procedure described in section 11.5 of Method 3. This leak-check is mandatory.
8.1.3 Place the probe in the stack, with the tip of the probe positioned at the sampling point; purge the sampling line long enough to allow at least five exchanges. Draw a sample into the analyzer. For emission rate correction factor determinations, immediately analyze the sample for percent CO
8.1.4 After the analysis is completed, leak-check (mandatory) the Orsat analyzer once again, as described in section 11.5 of Method 3. For the results of the analysis to be valid, the Orsat analyzer must pass this leak-test before and after the analysis.
8.2 Single-Point, Integrated Sampling and Analytical Procedure.
8.2.1 The sampling point in the duct shall be located as specified in section 8.1.1.
8.2.2 Leak-check (mandatory) the flexible bag as in section 6.2.6 of Method 3. Set up the equipment as shown in Figure 3-2 of Method 3. Just before sampling, leak-check (mandatory) the train by placing a vacuum gauge at the condenser inlet, pulling a vacuum of at least 250 mm Hg (10 in. Hg), plugging the outlet at the quick disconnect, and then turning off the pump. The vacuum should remain stable for at least 0.5 minute. Evacuate the flexible bag. Connect the probe, and place it in the stack, with the tip of the probe positioned at the sampling point; purge the sampling line. Next, connect the bag, and make sure that all connections are tight.
8.2.3 Sample at a constant rate, or as specified by the Administrator. The sampling run must be simultaneous with, and for the same total length of time as, the pollutant emission rate determination. Collect at least 28 liters (1.0 ft
8.2.4 Obtain one integrated flue gas sample during each pollutant emission rate determination. For emission rate correction factor determination, analyze the sample within 4 hours after it is taken for percent CO
8.3 Multi-Point, Integrated Sampling and Analytical Procedure.
8.3.1 Unless otherwise specified in an applicable regulation, or by the Administrator, a minimum of eight traverse points shall be used for circular stacks having diameters less than 0.61 m (24 in.), a minimum of nine shall be used for rectangular stacks having equivalent diameters less than 0.61 m (24 in.), and a minimum of 12 traverse points shall be used for all other cases. The traverse points shall be located according to Method 1.
8.3.2 Follow the procedures outlined in sections 8.2.2 through 8.2.4, except for the following: Traverse all sampling points, and sample at each point for an equal length of time. Record sampling data as shown in Figure 3-3 of Method 3.
9.1 Data Validation Using Fuel Factor. Although in most instances, only CO
Since this method for validating the CO
10.1 Analyzer. The analyzer and analyzer operator technique should be audited periodically as follows: take a sample from a manifold containing a known mixture of CO
10.2 Rotameter. The rotameter need not be calibrated, but should be cleaned and maintained according to the manufacturer’s instruction.
11.1 Maintenance. The Orsat analyzer should be maintained according to the manufacturers specifications.
11.2 Grab Sample Analysis. To ensure complete absorption of the CO
Since this single-point, grab sampling and analytical procedure is normally conducted in conjunction with a single-point, grab sampling and analytical procedure for a pollutant, only one analysis is ordinarily conducted. Therefore, great care must be taken to obtain a valid sample and analysis.
11.3 Integrated Sample Analysis. The Orsat analyzer must be leak-checked (see section 11.5 of Method 3) before the analysis. If excess air is desired, proceed as follows: (1) within 4 hours after the sample is taken, analyze it (as in sections 11.3.1 through 11.3.3) for percent CO
11.3.1 To ensure complete absorption of the CO
Although in most instances only CO
11.3.2 Repeat the analysis until the following criteria are met:
11.3.2.1 For percent CO
11.3.2.2 For percent O
11.3.2.3 For percent CO, repeat the analytical procedure until the results of any three analyses differ by no more than 0.3 percent. Average the three acceptable values of percent CO, and report the results to the nearest 0.1 percent.
11.3.3 After the analysis is completed, leak-check (mandatory) the Orsat analyzer once again, as described in section 11.5 of Method 3. For the results of the analysis to be valid, the Orsat analyzer must pass this leak-test before and after the analysis.
11.4 Standardization. A periodic check of the reagents and of operator technique should be conducted at least once every three series of test runs as indicated in section 10.1.
12.1 Nomenclature. Same as section 12.1 of Method 3 with the addition of the following:
12.2 Percent Excess Air. Determine the percentage of the gas that is N
The equation above assumes that ambient air is used as the source of O
12.3 Data Validation When Both CO
12.3.1 Fuel Factor, F
If CO is present in quantities measurable by this method, adjust the O
12.3.2 Compare the calculated F
12.3.3 Calculated F
Same as Method 3, section 16.0.
Table 3B-1 – F
| Fuel type | F |
|---|---|
| Coal: | |
| Anthracite and lignite | 1.016-1.130 |
| Bituminous | 1.083-1.230 |
| Oil: | |
| Distillate | 1.260-1.413 |
| Residual | 1.210-1.370 |
| Gas: | |
| Natural | 1.600-1.836 |
| Propane | 1.434-1.586 |
| Butane | 1.405-1.553 |
| Wood | 1.000-1.120 |
| Wood bark | 1.003-1.130 |
1.1 Applicability. This method applies to the analysis of carbon dioxide (CO
1.2 Principle. A portion of the sample is injected into a gas chromatograph (GC) and the CO
2.1 Range. The range of this method depends upon the concentration of samples. The analytical range of TCD’s is generally between approximately 10 ppmv and the upper percent range.
2.2 Sensitivity. The sensitivity limit for a compound is defined as the minimum detectable concentration of that compound, or the concentration that produces a signal-to-noise ratio of three to one. For CO
Since the TCD exhibits universal response and detects all gas components except the carrier, interferences may occur. Choosing the appropriate GC or shifting the retention times by changing the column flow rate may help to eliminate resolution interferences.
To assure consistent detector response, helium is used to prepare calibration gases. Frequent exposure to samples or carrier gas containing oxygen may gradually destroy filaments.
4.1 Gas Chromatograph. GC having at least the following components:
4.1.1 Separation Column. Appropriate column(s) to resolve CO
4.1.2 Sample Loop. Teflon or stainless steel tubing of the appropriate diameter.
Mention of trade names or specific products does not constitute endorsement or recommendation by the U. S. Environmental Protection Agency.
4.1.3 Conditioning System. To maintain the column and sample loop at constant temperature.
4.1.4 Thermal Conductivity Detector.
4.2 Recorder. Recorder with linear strip chart. Electronic integrator (optional) is recommended.
4.3 Teflon Tubing. Diameter and length determined by connection requirements of cylinder regulators and the GC.
4.4 Regulators. To control gas cylinder pressures and flow rates.
4.5 Adsorption Tubes. Applicable traps to remove any O
5.1 Calibration and Linearity Gases. Standard cylinder gas mixtures for each compound of interest with at least three concentration levels spanning the range of suspected sample concentrations. The calibration gases shall be prepared in helium.
5.2 Carrier Gas. Helium, high-purity.
6.1 Sample Collection. Use the sample collection procedures described in Methods 3 or 25C to collect a sample of landfill gas (LFG).
6.2 Preparation of GC. Before putting the GC analyzer into routine operation, optimize the operational conditions according to the manufacturer’s specifications to provide good resolution and minimum analysis time. Establish the appropriate carrier gas flow and set the detector sample and reference cell flow rates at exactly the same levels. Adjust the column and detector temperatures to the recommended levels. Allow sufficient time for temperature stabilization. This may typically require 1 hour for each change in temperature.
6.3 Analyzer Linearity Check and Calibration. Perform this test before sample analysis.
6.3.1 Using the gas mixtures in section 5.1, verify the detector linearity over the range of suspected sample concentrations with at least three concentrations per compound of interest. This initial check may also serve as the initial instrument calibration.
6.3.2 You may extend the use of the analyzer calibration by performing a single-point calibration verification. Calibration verifications shall be performed by triplicate injections of a single-point standard gas. The concentration of the single-point calibration must either be at the midpoint of the calibration curve or at approximately the source emission concentration measured during operation of the analyzer.
6.3.3 Triplicate injections must agree within 5 percent of their mean, and the average calibration verification point must agree within 10 percent of the initial calibration response factor. If these calibration verification criteria are not met, the initial calibration described in section 6.3.1, using at least three concentrations, must be repeated before analysis of samples can continue.
6.3.4 For each instrument calibration, record the carrier and detector flow rates, detector filament and block temperatures, attenuation factor, injection time, chart speed, sample loop volume, and component concentrations.
6.3.5 Plot a linear regression of the standard concentrations versus area values to obtain the response factor of each compound. Alternatively, response factors of uncorrected component concentrations (wet basis) may be generated using instrumental integration.
Peak height may be used instead of peak area throughout this method.
6.4 Sample Analysis. Purge the sample loop with sample, and allow to come to atmospheric pressure before each injection. Analyze each sample in duplicate, and calculate the average sample area (A). The results are acceptable when the peak areas for two consecutive injections agree within 5 percent of their average. If they do not agree, run additional samples until consistent area data are obtained. Determine the tank sample concentrations according to section 7.2.
Carry out calculations retaining at least one extra decimal figure beyond that of the acquired data. Round off results only after the final calculation.
7.1 Nomenclature.
7.2 Concentration of Sample Components. Calculate C for each compound using Equations 3C-1 and 3C-2. Use the temperature and barometric pressure at the sampling site to calculate Bw. If the sample was diluted with helium using the procedures in Method 25C, use Equation 3C-3 to calculate the concentration.
7.3 Measured N
1. McNair, H.M., and E.J. Bonnelli. Basic Gas Chromatography. Consolidated Printers, Berkeley, CA. 1969.
Appendix A-3 to Part 60 – Test Methods 4 through 5I
The test methods in this appendix are referred to in § 60.8 (Performance Tests) and § 60.11 (Compliance With Standards and Maintenance Requirements) of 40 CFR part 60, subpart A (General Provisions). Specific uses of these test methods are described in the standards of performance contained in the subparts, beginning with Subpart D.
Within each standard of performance, a section title “Test Methods and Procedures” is provided to: (1) Identify the test methods to be used as reference methods to the facility subject to the respective standard and (2) identify any special instructions or conditions to be followed when applying a method to the respective facility. Such instructions (for example, establish sampling rates, volumes, or temperatures) are to be used either in addition to, or as a substitute for procedures in a test method. Similarly, for sources subject to emission monitoring requirements, specific instructions pertaining to any use of a test method as a reference method are provided in the subpart or in Appendix B.
Inclusion of methods in this appendix is not intended as an endorsement or denial of their applicability to sources that are not subject to standards of performance. The methods are potentially applicable to other sources; however, applicability should be confirmed by careful and appropriate evaluation of the conditions prevalent at such sources.
The approach followed in the formulation of the test methods involves specifications for equipment, procedures, and performance. In concept, a performance specification approach would be preferable in all methods because this allows the greatest flexibility to the user. In practice, however, this approach is impractical in most cases because performance specifications cannot be established. Most of the methods described herein, therefore, involve specific equipment specifications and procedures, and only a few methods in this appendix rely on performance criteria.
Minor changes in the test methods should not necessarily affect the validity of the results and it is recognized that alternative and equivalent methods exist. section 60.8 provides authority for the Administrator to specify or approve (1) equivalent methods, (2) alternative methods, and (3) minor changes in the methodology of the test methods. It should be clearly understood that unless otherwise identified all such methods and changes must have prior approval of the Administrator. An owner employing such methods or deviations from the test methods without obtaining prior approval does so at the risk of subsequent disapproval and retesting with approved methods.
Within the test methods, certain specific equipment or procedures are recognized as being acceptable or potentially acceptable and are specifically identified in the methods. The items identified as acceptable options may be used without approval but must be identified in the test report. The potentially approvable options are cited as “subject to the approval of the Administrator” or as “or equivalent.” Such potentially approvable techniques or alternatives may be used at the discretion of the owner without prior approval. However, detailed descriptions for applying these potentially approvable techniques or alternatives are not provided in the test methods. Also, the potentially approvable options are not necessarily acceptable in all applications. Therefore, an owner electing to use such potentially approvable techniques or alternatives is responsible for: (1) assuring that the techniques or alternatives are in fact applicable and are properly executed; (2) including a written description of the alternative method in the test report (the written method must be clear and must be capable of being performed without additional instruction, and the degree of detail should be similar to the detail contained in the test methods); and (3) providing any rationale or supporting data necessary to show the validity of the alternative in the particular application. Failure to meet these requirements can result in the Administrator’s disapproval of the alternative.
This method does not include all the specifications (e.g., equipment and supplies) and procedures (e.g., sampling) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 5, and Method 6.
1.1 Analytes.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Water vapor (H | 7732-18-5 | N/A |
1.2 Applicability. This method is applicable for the determination of the moisture content of stack gas.
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 A gas sample is extracted at a constant rate from the source; moisture is removed from the sample stream and determined gravimetrically.
2.2 The method contains two possible procedures: a reference method and an approximation method.
2.2.1 The reference method is used for accurate determinations of moisture content (such as are needed to calculate emission data). The approximation method, provides estimates of percent moisture to aid in setting isokinetic sampling rates prior to a pollutant emission measurement run. The approximation method described herein is only a suggested approach; alternative means for approximating the moisture content (e.g., drying tubes, wet bulb-dry bulb techniques, condensation techniques, stoichiometric calculations, previous experience, etc.) are also acceptable.
2.2.2 The reference method is often conducted simultaneously with a pollutant emission measurement run. When it is, calculation of percent isokinetic, pollutant emission rate, etc., for the run shall be based upon the results of the reference method or its equivalent. These calculations shall not be based upon the results of the approximation method, unless the approximation method is shown, to the satisfaction of the Administrator, to be capable of yielding results within one percent H
4.1 The moisture content of saturated gas streams or streams that contain water droplets, as measured by the reference method, may be positively biased. Therefore, when these conditions exist or are suspected, a second determination of the moisture content shall be made simultaneously with the reference method, as follows: Assume that the gas stream is saturated. Attach a temperature sensor [capable of measuring to ±1 °C (2 °F)] to the reference method probe. Measure the stack gas temperature at each traverse point (see section 8.1.1.1) during the reference method traverse, and calculate the average stack gas temperature. Next, determine the moisture percentage, either by: (1) Using a psychrometric chart and making appropriate corrections if the stack pressure is different from that of the chart, or (2) using saturation vapor pressure tables. In cases where the psychrometric chart or the saturation vapor pressure tables are not applicable (based on evaluation of the process), alternative methods, subject to the approval of the Administrator, shall be used.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method.
6.1 Reference Method. A schematic of the sampling train used in this reference method is shown in Figure 4-1.
6.1.1 Probe. Stainless steel or glass tubing, sufficiently heated to prevent water condensation, and equipped with a filter, either in-stack (e.g., a plug of glass wool inserted into the end of the probe) or heated out-of-stack (e.g., as described in Method 5), to remove particulate matter. When stack conditions permit, other metals or plastic tubing may be used for the probe, subject to the approval of the Administrator.
6.1.2 Condenser. Same as Method 5, section 6.1.1.8.
6.1.3 Cooling System. An ice bath container, crushed ice, and water (or equivalent), to aid in condensing moisture.
6.1.4 Metering System. Same as in Method 5, section 6.1.1.9, except do not use sampling systems designed for flow rates higher than 0.0283 m
6.1.5 Barometer and Balance. Same as Method 5, sections 6.1.2 and 6.2.5, respectively.
6.2. Approximation Method. A schematic of the sampling train used in this approximation method is shown in Figure 4-2.
6.2.1 Probe. Same as section 6.1.1.
6.2.2 Condenser. Two midget impingers, each with 30-ml capacity, or equivalent.
6.2.3 Cooling System. Ice bath container, crushed ice, and water, to aid in condensing moisture in impingers.
6.2.4 Drying Tube. Tube packed with new or regenerated 6- to 16-mesh indicating-type silica gel (or equivalent desiccant), to dry the sample gas and to protect the meter and pump.
6.2.5 Valve. Needle valve, to regulate the sample gas flow rate.
6.2.6 Pump. Leak-free, diaphragm type, or equivalent, to pull the gas sample through the train.
6.2.7 Volume Meter. Dry gas meter, sufficiently accurate to measure the sample volume to within 2 percent, and calibrated over the range of flow rates and conditions actually encountered during sampling.
6.2.8 Rate Meter. Rotameter, or equivalent, to measure the flow range from 0 to 3 liters/min (0 to 0.11 cfm).
6.2.9 Graduated Cylinder. 25-ml.
6.2.10 Barometer. Same as Method 5, section 6.1.2.
6.2.11 Vacuum Gauge. At least 760-mm (30-in.) Hg gauge, to be used for the sampling leak check.
8.1 Reference Method. The following procedure is intended for a condenser system (such as the impinger system described in section 6.1.1.8 of Method 5) incorporating volumetric analysis to measure the condensed moisture, and silica gel and gravimetric analysis to measure the moisture leaving the condenser.
8.1.1 Preliminary Determinations.
8.1.1.1 Unless otherwise specified by the Administrator, a minimum of eight traverse points shall be used for circular stacks having diameters less than 0.61 m (24 in.), a minimum of nine points shall be used for rectangular stacks having equivalent diameters less than 0.61 m (24 in.), and a minimum of twelve traverse points shall be used in all other cases. The traverse points shall be located according to Method 1. The use of fewer points is subject to the approval of the Administrator. Select a suitable probe and probe length such that all traverse points can be sampled. Consider sampling from opposite sides of the stack (four total sampling ports) for large stacks, to permit use of shorter probe lengths. Mark the probe with heat resistant tape or by some other method to denote the proper distance into the stack or duct for each sampling point.
8.1.1.2 Select a total sampling time such that a minimum total gas volume of 0.60 scm (21 scf) will be collected, at a rate no greater than 0.021 m
8.1.2 Preparation of Sampling Train.
8.1.2.1 Transfer water into the first two impingers, leave the third impinger empty and add silica gel to the fourth impinger. Weigh the impingers before sampling and record the weight to the nearest 0.5g at a minimum.
8.1.2.2 Set up the sampling train as shown in Figure 4-1. Turn on the probe heater and (if applicable) the filter heating system to temperatures of approximately 120 °C (248 °F), to prevent water condensation ahead of the condenser. Allow time for the temperatures to stabilize. Place crushed ice and water in the ice bath container.
8.1.3 Leak-Check Procedures.
8.1.3.1 Leak Check of Metering System Shown in Figure 4-1. That portion of the sampling train from the pump to the orifice meter should be leak-checked prior to initial use and after each shipment. Leakage after the pump will result in less volume being recorded than is actually sampled. The following procedure is suggested (see Figure 5-2 of Method 5): Close the main valve on the meter box. Insert a one-hole rubber stopper with rubber tubing attached into the orifice exhaust pipe. Disconnect and vent the low side of the orifice manometer. Close off the low side orifice tap. Pressurize the system to 13 to 18 cm (5 to 7 in.) water column by blowing into the rubber tubing. Pinch off the tubing and observe the manometer for one minute. A loss of pressure on the manometer indicates a leak in the meter box; leaks, if present, must be corrected.
8.1.3.2 Pretest Leak Check. A pretest leak check of the sampling train is recommended, but not required. If the pretest leak check is conducted, the following procedure should be used.
8.1.3.2.1 After the sampling train has been assembled, turn on and set the filter and probe heating systems to the desired operating temperatures. Allow time for the temperatures to stabilize.
8.1.3.2.2 Leak-check the train by first plugging the inlet to the filter holder and pulling a 380 mm (15 in.) Hg vacuum. Then connect the probe to the train, and leak-check at approximately 25 mm (1 in.) Hg vacuum; alternatively, the probe may be leak-checked with the rest of the sampling train, in one step, at 380 mm (15 in.) Hg vacuum. Leakage rates in excess of 4 percent of the average sampling rate or 0.00057 m
8.1.3.2.3 Start the pump with the bypass valve fully open and the coarse adjust valve completely closed. Partially open the coarse adjust valve, and slowly close the bypass valve until the desired vacuum is reached. Do not reverse the direction of the bypass valve, as this will cause water to back up into the filter holder. If the desired vacuum is exceeded, either leak-check at this higher vacuum, or end the leak check and start over.
8.1.3.2.4 When the leak check is completed, first slowly remove the plug from the inlet to the probe, filter holder, and immediately turn off the vacuum pump. This prevents the water in the impingers from being forced backward into the filter holder and the silica gel from being entrained backward into the third impinger.
8.1.3.3 Leak Checks During Sample Run. If, during the sampling run, a component (e.g., filter assembly or impinger) change becomes necessary, a leak check shall be conducted immediately before the change is made. The leak check shall be done according to the procedure outlined in section 8.1.3.2, except that it shall be done at a vacuum equal to or greater than the maximum value recorded up to that point in the test. If the leakage rate is found to be no greater than 0.00057 m
Note: Immediately after component changes, leak checks are optional. If such leak checks are done, the procedure outlined in section 8.1.3.2 should be used.
8.1.3.4 Post-Test Leak Check. A leak check of the sampling train is mandatory at the conclusion of each sampling run. The leak check shall be performed in accordance with the procedures outlined in section 8.1.3.2, except that it shall be conducted at a vacuum equal to or greater than the maximum value reached during the sampling run. If the leakage rate is found to be no greater than 0.00057 m
8.1.4 Sampling Train Operation. During the sampling run, maintain a sampling rate within 10 percent of constant rate, or as specified by the Administrator. For each run, record the data required on a data sheet similar to that shown in Figure 4-3. Be sure to record the dry gas meter reading at the beginning and end of each sampling time increment and whenever sampling is halted. Take other appropriate readings at each sample point at least once during each time increment.
When Method 4 is used concurrently with an isokinetic method (e.g., Method 5) the sampling rate should be maintained at isokinetic conditions rather than 10 percent of constant rate.
8.1.4.1 To begin sampling, position the probe tip at the first traverse point. Immediately start the pump, and adjust the flow to the desired rate. Traverse the cross section, sampling at each traverse point for an equal length of time. Add more ice and, if necessary, salt to maintain a temperature of less than 20 °C (68 °F) at the silica gel outlet.
8.1.4.2 At the end of the sample run, close the coarse adjust valve, remove the probe and nozzle from the stack, turn off the pump, record the final DGM meter reading, and conduct a post-test leak check, as outlined in section 8.1.3.4.
8.2 Approximation Method.
The approximation method described below is presented only as a suggested method (see section 2.0).
8.2.1 Place exactly 5 ml water in each impinger. Leak check the sampling train as follows: Temporarily insert a vacuum gauge at or near the probe inlet. Then, plug the probe inlet and pull a vacuum of at least 250 mm (10 in.) Hg. Note the time rate of change of the dry gas meter dial; alternatively, a rotameter (0 to 40 ml/min) may be temporarily attached to the dry gas meter outlet to determine the leakage rate. A leak rate not in excess of 2 percent of the average sampling rate is acceptable.
Release the probe inlet plug slowly before turning off the pump.
8.2.2 Connect the probe, insert it into the stack, and sample at a constant rate of 2 liters/min (0.071 cfm). Continue sampling until the dry gas meter registers about 30 liters (1.1 ft
9.1 Miscellaneous Quality Control Measures.
| Section | Quality control measure | Effect |
|---|---|---|
| Section 8.1.3.2.2 | Leak rate of the sampling system cannot exceed four percent of the average sampling rate or 0.00057 m 3/min (0.020 cfm) | Ensures the accuracy of the volume of gas sampled. (Reference Method). |
| Section 8.2.1 | Leak rate of the sampling system cannot exceed two percent of the average sampling rate | Ensures the accuracy of the volume of gas sampled. (Approximation Method). |
9.2 Volume Metering System Checks. Same as Method 5, section 9.2.
Maintain a laboratory log of all calibrations.
10.1 Reference Method. Calibrate the metering system, temperature sensors, and barometer according to Method 5, sections 10.3, 10.5, and 10.6, respectively.
10.2 Approximation Method. Calibrate the metering system and the barometer according to Method 6, section 10.1 and Method 5, section 10.6, respectively.
10.3 Field Balance Calibration Check. Check the calibration of the balance used to weigh impingers with a weight that is at least 500g or within 50g of a loaded impinger. The weight must be ASTM E617-13 “Standard Specification for Laboratory Weights and Precision Mass Standards” (incorporated by reference-see 40 CFR 60.17) Class 6 (or better). Daily, before use, the field balance must measure the weight within ± 0.5g of the certified mass. If the daily balance calibration check fails, perform corrective measures and repeat the check before using balance.
11.1 Reference Method. Weigh the impingers after sampling and record the difference in weight to the nearest 0.5 g at a minimum. Determine the increase in weight of the silica gel (or silica gel plus impinger) to the nearest 0.5 g at a minimum. Record this information (see example data sheet, Figure 4-5), and calculate the moisture content, as described in section 12.0.
11.2 Approximation Method. Weigh the contents of the two impingers, and measure the weight to the nearest 0.5 g.
Carry out the following calculations, retaining at least one extra significant figure beyond that of the acquired data. Round off figures after final calculation.
12.1 Reference Method.
12.1.1 Nomenclature.
B
M
P
P
R = Ideal gas constant, 0.06236 (mm Hg)(m
T
T
V
V
V
V
V
V
W
W
Y = Dry gas meter calibration factor.
ΔV
12.1.2 Volume of Water Vapor Condensed.
12.1.3 Volume of Water Collected in Silica Gel.
12.1.4 Sample Gas Volume.
If the post-test leak rate (Section 8.1.4.2) exceeds the allowable rate, correct the value of Vm in Equation 4-3, as described in section 12.3 of Method 5.
12.1.5 Moisture Content.
12.1.6 Verification of Constant Sampling Rate. For each time increment, determine the ΔV
12.1.7 In saturated or moisture droplet-laden gas streams, two calculations of the moisture content of the stack gas shall be made, one using a value based upon the saturated conditions (see section 4.1), and another based upon the results of the impinger analysis. The lower of these two values of B
12.2 Approximation Method. The approximation method presented is designed to estimate the moisture in the stack gas; therefore, other data, which are only necessary for accurate moisture determinations, are not collected. The following equations adequately estimate the moisture content for the purpose of determining isokinetic sampling rate settings.
12.2.1 Nomenclature.
B
B
M
P
P
R = Ideal gas constant, 0.06236 [(mm Hg)(m
T
T
V
V
V
V
V
Y = Dry gas meter calibration factor.
12.2.2 Volume of Water Vapor Collected.
K
= 0.04716 ft
12.2.3 Sample Gas Volume.
12.2.4 Approximate Moisture Content.
12.2.5 Using F-factors to determine approximate moisture for estimating moisture content where no wet scrubber is being used, for the purpose of determining isokinetic sampling rate settings with no fuel sample, is acceptable using the average F
Btu (scm/J). See Table 19-2 in Method 19.
scf/10
16.1 The procedure described in Method 5 for determining moisture content is an acceptable alternative to Method 4.
16.2 The procedures in Method 6A for determining moisture is an acceptable alternative to Method 4.
16.3 Method 320 is an acceptable alternative to Method 4 for determining moisture.
16.4 Using F-factors to determine moisture is an acceptable alternative to Method 4 for a combustion stack not using a scrubber, and where a fuel sample is taken during the test run and analyzed for development of an F
Values of B
Free water in fuel is minimal for distillate oil and gases, such as propane and natural gas, so this step may be omitted for those fuels.
1. Air Pollution Engineering Manual (Second Edition). Danielson, J.A. (ed.). U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards. Research Triangle Park, NC. Publication No. AP-40. 1973.
2. Devorkin, Howard, et al. Air Pollution Source Testing Manual. Air Pollution Control District, Los Angeles, CA. November 1963.
3. Methods for Determination of Velocity, Volume, Dust and Mist Content of Gases. Western Precipitation Division of Joy Manufacturing Co. Los Angeles, CA. Bulletin WP-50. 1968.
Schematic of Stack Cross section
| Traverse Pt. No. | Sampling time (Δ), min | Stack temperature °C ( °F) | Pressure differential across orifice meter ΔH mm (in.) H | Meter reading gas sample volume m 3 (ft 3) | ΔV 3 (ft 3) | Gas sample temperature at dry gas meter | Temperature of gas leaving condenser or last impinger °C ( °F) | |
|---|---|---|---|---|---|---|---|---|
| Inlet Tm °C ( °F) | Outlet Tm °C ( °F) | |||||||
| Average | ||||||||
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 2, Method 3.
1.1 Analyte. Particulate matter (PM). No CAS number assigned.
1.2 Applicability. This method is applicable for the determination of PM emissions from stationary sources.
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
Particulate matter is withdrawn isokinetically from the source and collected on a glass fiber filter maintained at a temperature of 120 ±14 °C (248 ±25 °F) or such other temperature as specified by an applicable subpart of the standards or approved by the Administrator for a particular application. The PM mass, which includes any material that condenses at or above the filtration temperature, is determined gravimetrically after the removal of uncombined water.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to performing this test method.
6.1 Sample Collection. The following items are required for sample collection:
6.1.1 Sampling Train. A schematic of the sampling train used in this method is shown in Figure 5-1 in section 18.0. Complete construction details are given in APTD-0581 (Reference 2 in section 17.0); commercial models of this train are also available. For changes from APTD-0581 and for allowable modifications of the train shown in Figure 5-1, see the following subsections.
The operating and maintenance procedures for the sampling train are described in APTD-0576 (Reference 3 in section 17.0). Since correct usage is important in obtaining valid results, all users should read APTD-0576 and adopt the operating and maintenance procedures outlined in it, unless otherwise specified herein.
6.1.1.1 Probe Nozzle. Stainless steel (316) or glass with a sharp, tapered leading edge. The angle of taper shall be ≤30°, and the taper shall be on the outside to preserve a constant internal diameter. The probe nozzle shall be of the button-hook or elbow design, unless otherwise specified by the Administrator. If made of stainless steel, the nozzle shall be constructed from seamless tubing. Other materials of construction may be used, subject to the approval of the Administrator. A range of nozzle sizes suitable for isokinetic sampling should be available. Typical nozzle sizes range from 0.32 to 1.27 cm (
6.1.1.2 Probe Liner. Borosilicate or quartz glass tubing with a heating system capable of maintaining a probe gas temperature during sampling of 120 ±14 °C (248 ±25 °F), or such other temperature as specified by an applicable subpart of the standards or as approved by the Administrator for a particular application. Since the actual temperature at the outlet of the probe is not usually monitored during sampling, probes constructed according to APTD-0581 and utilizing the calibration curves of APTD-0576 (or calibrated according to the procedure outlined in APTD-0576) will be considered acceptable. Either borosilicate or quartz glass probe liners may be used for stack temperatures up to about 480 °C (900 °F); quartz glass liners shall be used for temperatures between 480 and 900 °C (900 and 1,650 °F). Both types of liners may be used at higher temperatures than specified for short periods of time, subject to the approval of the Administrator. The softening temperature for borosilicate glass is 820 °C (1500 °F), and for quartz glass it is 1500 °C (2700 °F). Whenever practical, every effort should be made to use borosilicate or quartz glass probe liners. Alternatively, metal liners (e.g., 316 stainless steel, Incoloy 825 or other corrosion resistant metals) made of seamless tubing may be used, subject to the approval of the Administrator.
6.1.1.3 Pitot Tube. Type S, as described in section 6.1 of Method 2, or other device approved by the Administrator. The pitot tube shall be attached to the probe (as shown in Figure 5-1) to allow constant monitoring of the stack gas velocity. The impact (high pressure) opening plane of the pitot tube shall be even with or above the nozzle entry plane (see Method 2, Figure 2-7) during sampling. The Type S pitot tube assembly shall have a known coefficient, determined as outlined in section 10.0 of Method 2.
6.1.1.4 Differential Pressure Gauge. Inclined manometer or equivalent device (two), as described in section 6.2 of Method 2. One manometer shall be used for velocity head (Δp) readings, and the other, for orifice differential pressure readings.
6.1.1.5 Filter Holder. Borosilicate glass, with a glass or Teflon frit filter support and a silicone rubber gasket. Other materials of construction (e.g., stainless steel or Viton) may be used, subject to the approval of the Administrator. The holder design shall provide a positive seal against leakage from the outside or around the filter. The holder shall be attached immediately at the outlet of the probe (or cyclone, if used).
6.1.1.6 Filter Heating System. Any heating system capable of monitoring and maintaining temperature around the filter shall be used to ensure the sample gas temperature exiting the filter of 120 ±14 °C (248 ±25 °F) during sampling or such other temperature as specified by an applicable subpart of the standards or approved by the Administrator for a particular application. The monitoring and regulation of the temperature around the filter may be done with the filter temperature sensor or another temperature sensor.
6.1.1.7 Filter Temperature Sensor. A temperature sensor capable of measuring temperature to within ±3 °C (5.4 °F) shall be installed so that the sensing tip of the temperature sensor is in direct contact with the sample gas exiting the filter. The sensing tip of the sensor may be encased in glass, Teflon, or metal and must protrude at least
6.1.1.8 Condenser. The following system shall be used to determine the stack gas moisture content: Four impingers connected in series with leak-free ground glass fittings or any similar leak-free noncontaminating fittings. The first, third, and fourth impingers shall be of the Greenburg-Smith design, modified by replacing the tip with a 1.3 cm (
If a determination of the PM collected in the impingers is desired in addition to moisture content, the impinger system described above shall be used, without modification. Individual States or control agencies requiring this information shall be contacted as to the sample recovery and analysis of the impinger contents.
6.1.1.9 Metering System. Vacuum gauge, leak-free pump, calibrated temperature sensors, dry gas meter (DGM) capable of measuring volume to within 2 percent, and related equipment, as shown in Figure 5-1. Other metering systems capable of maintaining sampling rates within 10 percent of isokinetic and of determining sample volumes to within 2 percent may be used, subject to the approval of the Administrator. When the metering system is used in conjunction with a pitot tube, the system shall allow periodic checks of isokinetic rates. The average DGM temperature for use in the calculations of section 12.0 may be obtained by averaging the two temperature sensors located at the inlet and outlet of the DGM as shown in Figure 5-3 or alternatively from a single temperature sensor located at the immediate outlet of the DGM or the plenum of the DGM.
6.1.1.10 Sampling trains utilizing metering systems designed for higher flow rates than that described in APTD-0581 or APTD-0576 may be used provided that the specifications of this method are met.
6.1.2 Barometer. Mercury, aneroid, or other barometer capable of measuring atmospheric pressure to within 2.5 mm Hg (0.1 in.).
The barometric pressure reading may be obtained from a nearby National Weather Service station. In this case, the station value (which is the absolute barometric pressure) shall be requested and an adjustment for elevation differences between the weather station and sampling point shall be made at a rate of minus 2.5 mm Hg (0.1 in.) per 30 m (100 ft) elevation increase or plus 2.5 mm Hg (0.1 in) per 30 m (100 ft) elevation decrease.
6.1.3 Gas Density Determination Equipment. Temperature sensor and pressure gauge, as described in sections 6.3 and 6.4 of Method 2, and gas analyzer, if necessary, as described in Method 3. The temperature sensor shall, preferably, be permanently attached to the pitot tube or sampling probe in a fixed configuration, such that the tip of the sensor extends beyond the leading edge of the probe sheath and does not touch any metal. Alternatively, the sensor may be attached just prior to use in the field. Note, however, that if the temperature sensor is attached in the field, the sensor must be placed in an interference-free arrangement with respect to the Type S pitot tube openings (see Method 2, Figure 2-4). As a second alternative, if a difference of not more than 1 percent in the average velocity measurement is to be introduced, the temperature sensor need not be attached to the probe or pitot tube. (This alternative is subject to the approval of the Administrator.)
6.2 Sample Recovery. The following items are required for sample recovery:
6.2.1 Probe-Liner and Probe-Nozzle Brushes. Nylon bristle brushes with stainless steel wire handles. The probe brush shall have extensions (at least as long as the probe) constructed of stainless steel, Nylon, Teflon, or similarly inert material. The brushes shall be properly sized and shaped to brush out the probe liner and nozzle.
6.2.2 Wash Bottles. Two Glass wash bottles are recommended. Alternatively, polyethylene wash bottles may be used. It is recommended that acetone not be stored in polyethylene bottles for longer than a month.
6.2.3 Glass Sample Storage Containers. Chemically resistant, borosilicate glass bottles, for acetone washes, 500 ml or 1000 ml. Screw cap liners shall either be rubber-backed Teflon or shall be constructed so as to be leak-free and resistant to chemical attack by acetone. (Narrow mouth glass bottles have been found to be less prone to leakage.) Alternatively, polyethylene bottles may be used.
6.2.4 Petri dishes. For filter samples; glass, polystyrene, or polyethylene, unless otherwise specified by the Administrator.
6.2.5 Balance. To measure condensed water to within 0.5 g at a minimum.
6.2.6 Plastic Storage Containers. Air-tight containers to store silica gel.
6.2.7 Funnel and Rubber Policeman. To aid in transfer of silica gel to container; not necessary if silica gel is weighed in the field.
6.2.8 Funnel. Glass or polyethylene, to aid in sample recovery.
6.3 Sample Analysis. The following equipment is required for sample analysis:
6.3.1 Glass Weighing Dishes.
6.3.2 Desiccator.
6.3.3 Analytical Balance. To measure to within 0.1 mg.
6.3.4 Balance. To measure to within 0.5 g.
6.3.5 Beakers. 250 ml.
6.3.6 Hygrometer. To measure the relative humidity of the laboratory environment.
6.3.7 Temperature Sensor. To measure the temperature of the laboratory environment.
7.1 Sample Collection. The following reagents are required for sample collection:
7.1.1 Filters. Glass fiber filters, without organic binder, exhibiting at least 99.95 percent efficiency (2 or SO
7.1.2 Silica Gel. Indicating type, 6 to 16 mesh. If previously used, dry at 175 °C (350 °F) for 2 hours. New silica gel may be used as received. Alternatively, other types of desiccants (equivalent or better) may be used, subject to the approval of the Administrator.
7.1.3 Water. When analysis of the material caught in the impingers is required, deionized distilled water [to conform to ASTM D1193-77 or 91 Type 3 (incorporated by reference – see § 60.17)] with at least
7.1.4 Crushed Ice.
7.2 Sample Recovery. Acetone, reagent grade, ≤0.001 percent residue, in glass bottles, is required. Acetone from metal containers generally has a high residue blank and should not be used. Sometimes, suppliers transfer acetone to glass bottles from metal containers; thus, acetone blanks shall be run prior to field use and only acetone with low blank values (≤0.001 percent) shall be used. In no case shall a blank value of greater than 0.001 percent of the weight of acetone used be subtracted from the sample weight.
7.3 Sample Analysis. The following reagents are required for sample analysis:
7.3.1 Acetone. Same as in section 7.2.
7.3.2 Desiccant. Anhydrous calcium sulfate, indicating type. Alternatively, other types of desiccants may be used, subject to the approval of the Administrator.
8.1 Pretest Preparation. It is suggested that sampling equipment be maintained according to the procedures described in APTD-0576. Alternative mercury-free thermometers may be used if the thermometers are at a minimum equivalent in terms of performance or suitably effective for the specific temperature measurement application.
8.1.1 Place 200 to 300 g of silica gel in each of several air-tight containers. Weigh each container, including silica gel, to the nearest 0.5 g, and record this weight. As an alternative, the silica gel need not be preweighed, but may be weighed directly in its impinger or sampling holder just prior to train assembly.
8.1.2 Check filters visually against light for irregularities, flaws, or pinhole leaks. Label filters of the proper diameter on the back side near the edge using numbering machine ink. As an alternative, label the shipping containers (glass, polystyrene or polyethylene petri dishes), and keep each filter in its identified container at all times except during sampling.
8.1.3 Desiccate the filters at 20 ±5.6 °C (68 ±10 °F) and ambient pressure for at least 24 hours. Weigh each filter (or filter and shipping container) at intervals of at least 6 hours to a constant weight (i.e., ≤0.5 mg change from previous weighing). Record results to the nearest 0.1 mg. During each weighing, the period for which the filter is exposed to the laboratory atmosphere shall be less than 2 minutes. Alternatively (unless otherwise specified by the Administrator), the filters may be oven dried at 105 °C (220 °F) for 2 to 3 hours, desiccated for 2 hours, and weighed. Procedures other than those described, which account for relative humidity effects, may be used, subject to the approval of the Administrator.
8.2 Preliminary Determinations.
8.2.1 Select the sampling site and the minimum number of sampling points according to Method 1 or as specified by the Administrator. Determine the stack pressure, temperature, and the range of velocity heads using Method 2; it is recommended that a leak check of the pitot lines (see Method 2, section 8.1) be performed. Determine the moisture content using Approximation Method 4 or its alternatives for the purpose of making isokinetic sampling rate settings. Determine the stack gas dry molecular weight, as described in Method 2, section 8.6; if integrated Method 3 sampling is used for molecular weight determination, the integrated bag sample shall be taken simultaneously with, and for the same total length of time as, the particulate sample run.
8.2.2 Select a nozzle size based on the range of velocity heads, such that it is not necessary to change the nozzle size in order to maintain isokinetic sampling rates. During the run, do not change the nozzle size. Ensure that the proper differential pressure gauge is chosen for the range of velocity heads encountered (see section 8.3 of Method 2).
8.2.3 Select a suitable probe liner and probe length such that all traverse points can be sampled. For large stacks, consider sampling from opposite sides of the stack to reduce the required probe length.
8.2.4 Select a total sampling time greater than or equal to the minimum total sampling time specified in the test procedures for the specific industry such that (l) the sampling time per point is not less than 2 minutes (or some greater time interval as specified by the Administrator), and (2) the sample volume taken (corrected to standard conditions) will exceed the required minimum total gas sample volume. The latter is based on an approximate average sampling rate.
8.2.5 The sampling time at each point shall be the same. It is recommended that the number of minutes sampled at each point be an integer or an integer plus one-half minute, in order to avoid timekeeping errors.
8.2.6 In some circumstances (e.g., batch cycles) it may be necessary to sample for shorter times at the traverse points and to obtain smaller gas sample volumes. In these cases, the Administrator’s approval must first be obtained.
8.3 Preparation of Sampling Train.
8.3.1 During preparation and assembly of the sampling train, keep all openings where contamination can occur covered until just prior to assembly or until sampling is about to begin. Place 100 ml of water in each of the first two impingers, leave the third impinger empty, and transfer approximately 200 to 300 g of preweighed silica gel from its container to the fourth impinger. More silica gel may be used, but care should be taken to ensure that it is not entrained and carried out from the impinger during sampling. Place the container in a clean place for later use in the sample recovery. Alternatively, the weight of the silica gel plus impinger may be determined to the nearest 0.5 g and recorded.
8.3.2 Using a tweezer or clean disposable surgical gloves, place a labeled (identified) and weighed filter in the filter holder. Be sure that the filter is properly centered and the gasket properly placed so as to prevent the sample gas stream from circumventing the filter. Check the filter for tears after assembly is completed.
8.3.3 When glass probe liners are used, install the selected nozzle using a Viton A O-ring when stack temperatures are less than 260 °C (500 °F) or a heat-resistant string gasket when temperatures are higher. See APTD-0576 for details. Other connecting systems using either 316 stainless steel or Teflon ferrules may be used. When metal liners are used, install the nozzle as discussed above or by a leak-free direct mechanical connection. Mark the probe with heat resistant tape or by some other method to denote the proper distance into the stack or duct for each sampling point.
8.3.4 Set up the train as shown in Figure 5-1 ensuring that the connections are leak-tight. Subject to the approval of the Administrator, a glass cyclone may be used between the probe and filter holder when the total particulate catch is expected to exceed 100 mg or when water droplets are present in the stack gas.
8.3.5 Place crushed ice around the impingers.
8.4 Leak-Check Procedures.
8.4.1 Leak Check of Metering System Shown in Figure 5-1. That portion of the sampling train from the pump to the orifice meter should be leak-checked prior to initial use and after each shipment. Leakage after the pump will result in less volume being recorded than is actually sampled. The following procedure is suggested (see Figure 5-2): Close the main valve on the meter box. Insert a one-hole rubber stopper with rubber tubing attached into the orifice exhaust pipe. Disconnect and vent the low side of the orifice manometer. Close off the low side orifice tap. Pressurize the system to 13 to 18 cm (5 to 7 in.) water column by blowing into the rubber tubing. Pinch off the tubing, and observe the manometer for one minute. A loss of pressure on the manometer indicates a leak in the meter box; leaks, if present, must be corrected.
8.4.2 Pretest Leak Check. A pretest leak check of the sampling train is recommended, but not required. If the pretest leak check is conducted, the following procedure should be used.
8.4.2.1 After the sampling train has been assembled, turn on and set the filter and probe heating systems to the desired operating temperatures. Allow time for the temperatures to stabilize. If a Viton A O-ring or other leak-free connection is used in assembling the probe nozzle to the probe liner, leak-check the train at the sampling site by plugging the nozzle and pulling a 380 mm (15 in.) Hg vacuum.
A lower vacuum may be used, provided that it is not exceeded during the test.
8.4.2.2 If a heat-resistant string is used, do not connect the probe to the train during the leak check. Instead, leak-check the train by first plugging the inlet to the filter holder (cyclone, if applicable) and pulling a 380 mm (15 in.) Hg vacuum (see note in section 8.4.2.1). Then connect the probe to the train, and leak-check at approximately 25 mm (1 in.) Hg vacuum; alternatively, the probe may be leak-checked with the rest of the sampling train, in one step, at 380 mm (15 in.) Hg vacuum. Leakage rates in excess of 4 percent of the average sampling rate or 0.00057 m
8.4.2.3 The following leak-check instructions for the sampling train described in APTD-0576 and APTD-0581 may be helpful. Start the pump with the bypass valve fully open and the coarse adjust valve completely closed. Partially open the coarse adjust valve, and slowly close the bypass valve until the desired vacuum is reached. Do not reverse the direction of the bypass valve, as this will cause water to back up into the filter holder. If the desired vacuum is exceeded, either leak-check at this higher vacuum, or end the leak check and start over.
8.4.2.4 When the leak check is completed, first slowly remove the plug from the inlet to the probe, filter holder, or cyclone (if applicable), and immediately turn off the vacuum pump. This prevents the water in the impingers from being forced backward into the filter holder and the silica gel from being entrained backward into the third impinger.
8.4.3 Leak Checks During Sample Run. If, during the sampling run, a component (e.g., filter assembly or impinger) change becomes necessary, a leak check shall be conducted immediately before the change is made. The leak check shall be done according to the procedure outlined in section 8.4.2 above, except that it shall be done at a vacuum equal to or greater than the maximum value recorded up to that point in the test. If the leakage rate is found to be no greater than 0.00057 m
Immediately after component changes, leak checks are optional. If such leak checks are done, the procedure outlined in section 8.4.2 above should be used.
8.4.4 Post-Test Leak Check. A leak check of the sampling train is mandatory at the conclusion of each sampling run. The leak check shall be performed in accordance with the procedures outlined in section 8.4.2, except that it shall be conducted at a vacuum equal to or greater than the maximum value reached during the sampling run. If the leakage rate is found to be no greater than 0.00057 m
8.5 Sampling Train Operation. During the sampling run, maintain an isokinetic sampling rate (within 10 percent of true isokinetic unless otherwise specified by the Administrator) and a sample gas temperature through the filter of 120 ±14 °C (248 ±25 °F) or such other temperature as specified by an applicable subpart of the standards or approved by the Administrator.
8.5.1 For each run, record the data required on a data sheet such as the one shown in Figure 5-3. Be sure to record the initial DGM reading. Record the DGM readings at the beginning and end of each sampling time increment, when changes in flow rates are made, before and after each leak check, and when sampling is halted. Take other readings indicated by Figure 5-3 at least once at each sample point during each time increment and additional readings when significant changes (20 percent variation in velocity head readings) necessitate additional adjustments in flow rate. Level and zero the manometer. Because the manometer level and zero may drift due to vibrations and temperature changes, make periodic checks during the traverse.
8.5.2 Clean the portholes prior to the test run to minimize the chance of collecting deposited material. To begin sampling, verify that the filter and probe heating systems are up to temperature, remove the nozzle cap, verify that the pitot tube and probe are properly positioned. Position the nozzle at the first traverse point with the tip pointing directly into the gas stream. Immediately start the pump, and adjust the flow to isokinetic conditions. Nomographs are available which aid in the rapid adjustment of the isokinetic sampling rate without excessive computations. These nomographs are designed for use when the Type S pitot tube coefficient (C
8.5.3 When the stack is under significant negative pressure (i.e., height of impinger stem), take care to close the coarse adjust valve before inserting the probe into the stack to prevent water from backing into the filter holder. If necessary, the pump may be turned on with the coarse adjust valve closed.
8.5.4 When the probe is in position, block off the openings around the probe and porthole to prevent unrepresentative dilution of the gas stream.
8.5.5 Traverse the stack cross-section, as required by Method 1 or as specified by the Administrator, being careful not to bump the probe nozzle into the stack walls when sampling near the walls or when removing or inserting the probe through the portholes; this minimizes the chance of extracting deposited material.
8.5.6 During the test run, make periodic adjustments to keep the temperature around the filter holder at the proper level to maintain the sample gas temperature exiting the filter; add more ice and, if necessary, salt to maintain a temperature of less than 20 °C (68 °F) at the condenser/silica gel outlet. Also, periodically check the level and zero of the manometer.
8.5.7 If the pressure drop across the filter becomes too high, making isokinetic sampling difficult to maintain, the filter may be replaced in the midst of the sample run. It is recommended that another complete filter assembly be used rather than attempting to change the filter itself. Before a new filter assembly is installed, conduct a leak check (see section 8.4.3). The total PM weight shall include the summation of the filter assembly catches.
8.5.8 A single train shall be used for the entire sample run, except in cases where simultaneous sampling is required in two or more separate ducts or at two or more different locations within the same duct, or in cases where equipment failure necessitates a change of trains. In all other situations, the use of two or more trains will be subject to the approval of the Administrator.
When two or more trains are used, separate analyses of the front-half and (if applicable) impinger catches from each train shall be performed, unless identical nozzle sizes were used on all trains, in which case, the front-half catches from the individual trains may be combined (as may the impinger catches) and one analysis of front-half catch and one analysis of impinger catch may be performed. Consult with the Administrator for details concerning the calculation of results when two or more trains are used.
8.5.9 At the end of the sample run, close the coarse adjust valve, remove the probe and nozzle from the stack, turn off the pump, record the final DGM meter reading, and conduct a post-test leak check, as outlined in section 8.4.4. Also, leak-check the pitot lines as described in Method 2, section 8.1. The lines must pass this leak check, in order to validate the velocity head data.
8.6 Calculation of Percent Isokinetic. Calculate percent isokinetic (see Calculations, section 12.11) to determine whether the run was valid or another test run should be made. If there was difficulty in maintaining isokinetic rates because of source conditions, consult with the Administrator for possible variance on the isokinetic rates.
8.7 Sample Recovery.
8.7.1 Proper cleanup procedure begins as soon as the probe is removed from the stack at the end of the sampling period. Allow the probe to cool.
8.7.2 When the probe can be safely handled, wipe off all external PM near the tip of the probe nozzle, and place a cap over it to prevent losing or gaining PM. Do not cap off the probe tip tightly while the sampling train is cooling down. This would create a vacuum in the filter holder, thereby drawing water from the impingers into the filter holder.
8.7.3 Before moving the sample train to the cleanup site, remove the probe from the sample train and cap the open outlet of the probe. Be careful not to lose any condensate that might be present. Cap the filter inlet where the probe was fastened. Remove the umbilical cord from the last impinger, and cap the impinger. If a flexible line is used between the first impinger or condenser and the filter holder, disconnect the line at the filter holder, and let any condensed water or liquid drain into the impingers or condenser. Cap off the filter holder outlet and impinger inlet. Either ground-glass stoppers, plastic caps, or serum caps may be used to close these openings.
8.7.4 Transfer the probe and filter-impinger assembly to the cleanup area. This area should be clean and protected from the wind so that the chances of contaminating or losing the sample will be minimized.
8.7.5 Save a portion of the acetone used for cleanup as a blank. From each storage container of acetone used for cleanup, save 200 ml and place in a glass sample container labeled “acetone blank.” To minimize any particulate contamination, rinse the wash bottle prior to filling from the tested container.
8.7.6 Inspect the train prior to and during disassembly, and note any abnormal conditions. Treat the samples as follows:
8.7.6.1 Container No. 1. Carefully remove the filter from the filter holder, and place it in its identified petri dish container. Use a pair of tweezers and/or clean disposable surgical gloves to handle the filter. If it is necessary to fold the filter, do so such that the PM cake is inside the fold. Using a dry Nylon bristle brush and/or a sharp-edged blade, carefully transfer to the petri dish any PM and/or filter fibers that adhere to the filter holder gasket. Seal the container.
8.7.6.2 Container No. 2. Taking care to see that dust on the outside of the probe or other exterior surfaces does not get into the sample, quantitatively recover PM or any condensate from the probe nozzle, probe fitting, probe liner, and front half of the filter holder by washing these components with acetone and placing the wash in a glass container. Deionized distilled water may be used instead of acetone when approved by the Administrator and shall be used when specified by the Administrator. In these cases, save a water blank, and follow the Administrator’s directions on analysis. Perform the acetone rinse as follows:
8.7.6.2.1 Carefully remove the probe nozzle. Clean the inside surface by rinsing with acetone from a wash bottle and brushing with a Nylon bristle brush. Brush until the acetone rinse shows no visible particles, after which make a final rinse of the inside surface with acetone.
8.7.6.2.2 Brush and rinse the inside parts of the fitting with acetone in a similar way until no visible particles remain.
8.7.6.2.3 Rinse the probe liner with acetone by tilting and rotating the probe while squirting acetone into its upper end so that all inside surfaces will be wetted with acetone. Let the acetone drain from the lower end into the sample container. A funnel (glass or polyethylene) may be used to aid in transferring liquid washes to the container. Follow the acetone rinse with a probe brush. Hold the probe in an inclined position, squirt acetone into the upper end as the probe brush is being pushed with a twisting action through the probe; hold a sample container underneath the lower end of the probe, and catch any acetone and particulate matter that is brushed from the probe. Run the brush through the probe three times or more until no visible PM is carried out with the acetone or until none remains in the probe liner on visual inspection. With stainless steel or other metal probes, run the brush through in the above prescribed manner at least six times since metal probes have small crevices in which particulate matter can be entrapped. Rinse the brush with acetone, and quantitatively collect these washings in the sample container. After the brushing, make a final acetone rinse of the probe.
8.7.6.2.4 It is recommended that two people clean the probe to minimize sample losses. Between sampling runs, keep brushes clean and protected from contamination.
8.7.6.2.5 Clean the inside of the front half of the filter holder by rubbing the surfaces with a Nylon bristle brush and rinsing with acetone. Rinse each surface three times or more if needed to remove visible particulate. Make a final rinse of the brush and filter holder. Carefully rinse out the glass cyclone, also (if applicable). After all acetone washings and particulate matter have been collected in the sample container, tighten the lid on the sample container so that acetone will not leak out when it is shipped to the laboratory. Mark the height of the fluid level to allow determination of whether leakage occurred during transport. Label the container to clearly identify its contents.
8.7.6.3 Container No. 3. Note the color of the indicating silica gel to determine whether it has been completely spent, and make a notation of its condition. Transfer the silica gel from the fourth impinger to its original container, and seal. A funnel may make it easier to pour the silica gel without spilling. A rubber policeman may be used as an aid in removing the silica gel from the impinger. It is not necessary to remove the small amount of dust particles that may adhere to the impinger wall and are difficult to remove. Since the gain in weight is to be used for moisture calculations, do not use any water or other liquids to transfer the silica gel. If a balance is available in the field, follow the procedure for Container No. 3 in section 11.2.3.
8.7.6.4 Impinger Water. Treat the impingers as follows: Make a notation of any color or film in the liquid catch. Measure the liquid that is in the first three impingers by weighing it to within 0.5 g at a minimum by using a balance. Record the weight of liquid present. This information is required to calculate the moisture content of the effluent gas. Discard the liquid after measuring and recording the weight, unless analysis of the impinger catch is required (see Note, section 6.1.1.8). If a different type of condenser is used, measure the amount of moisture condensed gravimetrically.
8.8 Sample Transport. Whenever possible, containers should be shipped in such a way that they remain upright at all times.
9.1 Miscellaneous Quality Control Measures.
| Section | Quality control measure | Effect |
|---|---|---|
| 8.4, 10.1-10.6 | Sampling equipment leak check and calibration | Ensures accurate measurement of stack gas flow rate, sample volume. |
9.2 Volume Metering System Checks. The following procedures are suggested to check the volume metering system calibration values at the field test site prior to sample collection. These procedures are optional.
9.2.1 Meter Orifice Check. Using the calibration data obtained during the calibration procedure described in section 10.3, determine the ΔH@ for the metering system orifice. The ΔH@ is the orifice pressure differential in units of in. H
9.2.1.1 Before beginning the field test (a set of three runs usually constitutes a field test), operate the metering system (i.e., pump, volume meter, and orifice) at the ΔH@ pressure differential for 10 minutes. Record the volume collected, the DGM temperature, and the barometric pressure. Calculate a DGM calibration check value, Y
9.2.1.2 Compare the Y
9.2.2 Calibrated Critical Orifice. A critical orifice, calibrated against a wet test meter or spirometer and designed to be inserted at the inlet of the sampling meter box, may be used as a check by following the procedure of section 16.2.
Maintain a laboratory log of all calibrations.
10.1 Probe Nozzle. Probe nozzles shall be calibrated before their initial use in the field. Using a micrometer, measure the ID of the nozzle to the nearest 0.025 mm (0.001 in.). Make three separate measurements using different diameters each time, and obtain the average of the measurements. The difference between the high and low numbers shall not exceed 0.1 mm (0.004 in.). When nozzles become nicked, dented, or corroded, they shall be reshaped, sharpened, and recalibrated before use. Each nozzle shall be permanently and uniquely identified.
10.2 Pitot Tube Assembly. The Type S pitot tube assembly shall be calibrated according to the procedure outlined in section 10.1 of Method 2.
10.3 Metering System.
10.3.1 Calibration Prior to Use. Before its initial use in the field, the metering system shall be calibrated as follows: Connect the metering system inlet to the outlet of a wet test meter that is accurate to within 1 percent. Refer to Figure 5-4. The wet test meter should have a capacity of 30 liters/rev (1 ft
10.3.1.1 Before calibrating the metering system, it is suggested that a leak check be conducted. For metering systems having diaphragm pumps, the normal leak-check procedure will not detect leakages within the pump. For these cases the following leak-check procedure is suggested: make a 10-minute calibration run at 0.00057 m
10.3.2 Calibration After Use. After each field use, the calibration of the metering system shall be checked by performing three calibration runs at a single, intermediate orifice setting (based on the previous field test), with the vacuum set at the maximum value reached during the test series. To adjust the vacuum, insert a valve between the wet test meter and the inlet of the metering system. Calculate the average value of the DGM calibration factor. If the value has changed by more than 5 percent, recalibrate the meter over the full range of orifice settings, as detailed in section 10.3.1.
Alternative procedures (e.g., rechecking the orifice meter coefficient) may be used, subject to the approval of the Administrator.
10.3.3 Acceptable Variation in Calibration Check. If the DGM coefficient values obtained before and after a test series differ by more than 5 percent, the test series shall either be voided, or calculations for the test series shall be performed using whichever meter coefficient value (i.e., before or after) gives the lower value of total sample volume.
10.4 Probe Heater Calibration. Use a heat source to generate air heated to selected temperatures that approximate those expected to occur in the sources to be sampled. Pass this air through the probe at a typical sample flow rate while measuring the probe inlet and outlet temperatures at various probe heater settings. For each air temperature generated, construct a graph of probe heating system setting versus probe outlet temperature. The procedure outlined in APTD-0576 can also be used. Probes constructed according to APTD-0581 need not be calibrated if the calibration curves in APTD-0576 are used. Also, probes with outlet temperature monitoring capabilities do not require calibration.
The probe heating system shall be calibrated before its initial use in the field.
10.5 Temperature Sensors. Use the procedure in Section 10.3 of Method 2 to calibrate in-stack temperature sensors. Dial thermometers, such as are used for the DGM and condenser outlet, shall be calibrated against mercury-in-glass thermometers. An alternative mercury-free NIST-traceable thermometer may be used if the thermometer is, at a minimum, equivalent in terms of performance or suitably effective for the specific temperature measurement application. As an alternative, the following single-point calibration procedure may be used. After each test run series, check the accuracy (and, hence, the calibration) of each thermocouple system at ambient temperature, or any other temperature, within the range specified by the manufacturer, using a reference thermometer (either ASTM reference thermometer or a thermometer that has been calibrated against an ASTM reference thermometer). The temperatures of the thermocouple and reference thermometers shall agree to within ±2 °F.
10.6 Barometer. Calibrate against a mercury barometer or NIST-traceable barometer prior to the field test. Alternatively, barometric pressure may be obtained from a weather report that has been adjusted for the test point (on the stack) elevation.
10.7 Field Balance Calibration Check. Check the calibration of the balance used to weigh impingers with a weight that is at least 500g or within 50g of a loaded impinger. The weight must be ASTM E617-13 “Standard Specification for Laboratory Weights and Precision Mass Standards” (incorporated by reference – see 40 CFR 60.17) Class 6 (or better). Daily before use, the field balance must measure the weight within ±0.5g of the certified mass. If the daily balance calibration check fails, perform corrective measures and repeat the check before using balance.
10.8 Analytical Balance Calibration. Perform a multipoint calibration (at least five points spanning the operational range) of the analytical balance before the first use, and semiannually thereafter. The calibration of the analytical balance must be conducted using ASTM E617-13 “Standard Specification for Laboratory Weights and Precision Mass Standards” (incorporated by reference – see 40 CFR 60.17) Class 2 (or better) tolerance weights. Audit the balance each day it is used for gravimetric measurements by weighing at least one ASTM E617-13 Class 2 tolerance (or better) calibration weight that corresponds to 50 to 150 percent of the weight of one filter or between 1g and 5g. If the scale cannot reproduce the value of the calibration weight to within 0.5 mg of the certified mass, perform corrective measures, and conduct the multipoint calibration before use.
11.1 Record the data required on a sheet such as the one shown in Figure 5-6.
11.2 Handle each sample container as follows:
11.2.1 Container No. 1. Leave the contents in the shipping container or transfer the filter and any loose PM from the sample container to a tared weighing container. Desiccate for 24 hours in a desiccator containing anhydrous calcium sulfate. Weigh to a constant weight, and report the results to the nearest 0.1 mg. For the purposes of this section, the term “constant weight” means a difference of no more than 0.5 mg or 1 percent of total weight less tare weight, whichever is greater, between two consecutive weighings, with no less than 6 hours of desiccation time between weighings. Alternatively, the sample may be oven dried at 104 °C (220 °F) for 2 to 3 hours, cooled in the desiccator, and weighed to a constant weight, unless otherwise specified by the Administrator. The sample may be oven dried at 104 °C (220 °F) for 2 to 3 hours. Once the sample has cooled, weigh the sample, and use this weight as a final weight.
11.2.2 Container No. 2. Note the level of liquid in the container, and confirm on the analysis sheet whether leakage occurred during transport. If a noticeable amount of leakage has occurred, either void the sample or use methods, subject to the approval of the Administrator, to correct the final results. Measure the liquid in this container either volumetrically to ±1 ml or gravimetrically to ±0.5 g. Transfer the contents to a tared 250 ml beaker, and evaporate to dryness at ambient temperature and pressure. Desiccate for 24 hours, and weigh to a constant weight. Report the results to the nearest 0.1 mg.
11.2.3 Container No. 3. Weigh the spent silica gel (or silica gel plus impinger) to the nearest 0.5 g using a balance. This step may be conducted in the field.
11.2.4 Acetone Blank Container. Measure the acetone in this container either volumetrically or gravimetrically. Transfer the acetone to a tared 250 ml beaker, and evaporate to dryness at ambient temperature and pressure. Desiccate for 24 hours, and weigh to a constant weight. Report the results to the nearest 0.1 mg.
The contents of Container No. 2 as well as the acetone blank container may be evaporated at temperatures higher than ambient. If evaporation is done at an elevated temperature, the temperature must be below the boiling point of the solvent; also, to prevent “bumping,” the evaporation process must be closely supervised, and the contents of the beaker must be swirled occasionally to maintain an even temperature. Use extreme care, as acetone is highly flammable and has a low flash point.
Carry out calculations, retaining at least one extra significant figure beyond that of the acquired data. Round off figures after the final calculation. Other forms of the equations may be used, provided that they give equivalent results.
12.1 Nomenclature.
A
B
C
c
I = Percent of isokinetic sampling.
L
L
L
L
m
m
M
P
P
P
R = Ideal gas constant, 0.06236 ((mm Hg)(m
T
T
T
V
V
V
V
V
V
V
W
Y = Dry gas meter calibration factor.
ΔH = Average pressure differential across the orifice meter (see Figure 5-4), mm H
ρ
θ = Total sampling time, min.
θ
θ
θ
13.6 = Specific gravity of mercury.
60 = Sec/min.
100 = Conversion to percent.
12.2 Average Dry Gas Meter Temperature and Average Orifice Pressure Drop. See data sheet (Figure 5-3).
12.3 Dry Gas Volume. Correct the sample volume measured by the dry gas meter to standard conditions (20 °C, 760mm Hg or 68 °F, 29.92 in. Hg) by using Equation 5-1.
Note: Equation 5-1 can be used as written unless the leakage rate observed during any of the mandatory leak checks (i.e., the post-test leak check or leak checks conducted prior to component changes) exceeds L
(a) Case I. No component changes made during sampling run. In this case, replace V
(b) Case II. One or more component changes made during the sampling run. In this case, replace Vm in Equation 5-1 by the expression:
12.4 Volume of Water Vapor Condensed
12.5 Moisture Content.
In saturated or water droplet-laden gas streams, two calculations of the moisture content of the stack gas shall be made, one from the impinger analysis (Equation 5-3), and a second from the assumption of saturated conditions. The lower of the two values of B
12.6 Acetone Blank Concentration.
12.7 Acetone Wash Blank.
12.8 Total Particulate Weight. Determine the total particulate matter catch from the sum of the weights obtained from Containers 1 and 2 less the acetone blank (see Figure 5-6).
In no case shall a blank value of greater than 0.001 percent of the weight of acetone used be subtracted from the sample weight. Refer to section 8.5.8 to assist in calculation of results involving two or more filter assemblies or two or more sampling trains.
12.9 Particulate Concentration.
12.10 Conversion Factors:
| From | To | Multiply by |
|---|---|---|
| ft 3 | m 3 | 0.02832 |
| gr | mg | 64.80004 |
| gr/ft 3 | mg/m 3 | 2288.4 |
| mg | g | 0.001 |
| gr | lb | 1.429 × 10 |
12.11 Isokinetic Variation.
12.11.1 Calculation from Raw Data.
12.11.2 Calculation from Intermediate Values.
12.11.3 Acceptable Results. If 90 percent ≤I ≤110 percent, the results are acceptable. If the PM results are low in comparison to the standard, and “I” is over 110 percent or less than 90 percent, the Administrator may opt to accept the results. Reference 4 in section 17.0 may be used to make acceptability judgments. If “I” is judged to be unacceptable, reject the results, and repeat the sampling run.
12.12 Stack Gas Velocity and Volumetric Flow Rate. Calculate the average stack gas velocity and volumetric flow rate, if needed, using data obtained in this method and the equations in sections 12.3 and 12.4 of Method 2.
16.1 Dry Gas Meter as a Calibration Standard. A DGM may be used as a calibration standard for volume measurements in place of the wet test meter specified in section 10.3, provided that it is calibrated initially and recalibrated periodically as follows:
16.1.1 Standard Dry Gas Meter Calibration.
16.1.1.1. The DGM to be calibrated and used as a secondary reference meter should be of high quality and have an appropriately sized capacity (e.g., 3 liters/rev (0.1 ft
16.1.1.2 Set up the components as shown in Figure 5-7. A spirometer, or equivalent, may be used in place of the wet test meter in the system. Run the pump for at least 5 minutes at a flow rate of about 10 liters/min (0.35 cfm) to condition the interior surface of the wet test meter. The pressure drop indicated by the manometer at the inlet side of the DGM should be minimized (no greater than 100 mm H
16.1.1.3 Collect the data as shown in the example data sheet (see Figure 5-8). Make triplicate runs at each of the flow rates and at no less than five different flow rates. The range of flow rates should be between 10 and 34 liters/min (0.35 and 1.2 cfm) or over the expected operating range.
16.1.1.4 Calculate flow rate, Q, for each run using the wet test meter volume, V
16.1.1.5 Compare the three Y
16.1.1.6 Prepare a curve of meter coefficient, Y
16.1.2 Standard Dry Gas Meter Recalibration.
16.1.2.1 Recalibrate the standard DGM against a wet test meter or spirometer annually or after every 200 hours of operation, whichever comes first. This requirement is valid provided the standard DGM is kept in a laboratory and, if transported, cared for as any other laboratory instrument. Abuse to the standard meter may cause a change in the calibration and will require more frequent recalibrations.
16.1.2.2 As an alternative to full recalibration, a two-point calibration check may be made. Follow the same procedure and equipment arrangement as for a full recalibration, but run the meter at only two flow rates [suggested rates are 14 and 30 liters/min (0.5 and 1.0 cfm)]. Calculate the meter coefficients for these two points, and compare the values with the meter calibration curve. If the two coefficients are within 1.5 percent of the calibration curve values at the same flow rates, the meter need not be recalibrated until the next date for a recalibration check.
16.2 Critical Orifices As Calibration Standards. Critical orifices may be used as calibration standards in place of the wet test meter specified in section 16.1, provided that they are selected, calibrated, and used as follows:
16.2.1 Selection of Critical Orifices.
16.2.1.1 The procedure that follows describes the use of hypodermic needles or stainless steel needle tubings which have been found suitable for use as critical orifices. Other materials and critical orifice designs may be used provided the orifices act as true critical orifices (i.e., a critical vacuum can be obtained, as described in section 16.2.2.2.3). Select five critical orifices that are appropriately sized to cover the range of flow rates between 10 and 34 liters/min (0.35 and 1.2 cfm) or the expected operating range. Two of the critical orifices should bracket the expected operating range. A minimum of three critical orifices will be needed to calibrate a Method 5 DGM; the other two critical orifices can serve as spares and provide better selection for bracketing the range of operating flow rates. The needle sizes and tubing lengths shown in Table 5-1 in section 18.0 give the approximate flow rates.
16.2.1.2 These needles can be adapted to a Method 5 type sampling train as follows: Insert a serum bottle stopper, 13 by 20 mm sleeve type, into a
16.2.2 Critical Orifice Calibration. The procedure described in this section uses the Method 5 meter box configuration with a DGM as described in section 6.1.1.9 to calibrate the critical orifices. Other schemes may be used, subject to the approval of the Administrator.
16.2.2.1 Calibration of Meter Box. The critical orifices must be calibrated in the same configuration as they will be used (i.e., there should be no connections to the inlet of the orifice).
16.2.2.1.1 Before calibrating the meter box, leak check the system as follows: Fully open the coarse adjust valve, and completely close the by-pass valve. Plug the inlet. Then turn on the pump, and determine whether there is any leakage. The leakage rate shall be zero (i.e., no detectable movement of the DGM dial shall be seen for 1 minute).
16.2.2.1.2 Check also for leakages in that portion of the sampling train between the pump and the orifice meter. See section 8.4.1 for the procedure; make any corrections, if necessary. If leakage is detected, check for cracked gaskets, loose fittings, worn O-rings, etc., and make the necessary repairs.
16.2.2.1.3 After determining that the meter box is leakless, calibrate the meter box according to the procedure given in section 10.3. Make sure that the wet test meter meets the requirements stated in section 16.1.1.1. Check the water level in the wet test meter. Record the DGM calibration factor, Y.
16.2.2.2 Calibration of Critical Orifices. Set up the apparatus as shown in Figure 5-10.
16.2.2.2.1 Allow a warm-up time of 15 minutes. This step is important to equilibrate the temperature conditions through the DGM.
16.2.2.2.2 Leak check the system as in section 16.2.2.1.1. The leakage rate shall be zero.
16.2.2.2.3 Before calibrating the critical orifice, determine its suitability and the appropriate operating vacuum as follows: Turn on the pump, fully open the coarse adjust valve, and adjust the by-pass valve to give a vacuum reading corresponding to about half of atmospheric pressure. Observe the meter box orifice manometer reading, ΔH. Slowly increase the vacuum reading until a stable reading is obtained on the meter box orifice manometer. Record the critical vacuum for each orifice. Orifices that do not reach a critical value shall not be used.
16.2.2.2.4 Obtain the barometric pressure using a barometer as described in section 6.1.2. Record the barometric pressure, P
16.2.2.2.5 Conduct duplicate runs at a vacuum of 25 to 50 mm Hg (1 to 2 in. Hg) above the critical vacuum. The runs shall be at least 5 minutes each. The DGM volume readings shall be in increments of complete revolutions of the DGM. As a guideline, the times should not differ by more than 3.0 seconds (this includes allowance for changes in the DGM temperatures) to achieve ±0.5 percent in K′ (see Eq. 5-11). Record the information listed in Figure 5-11.
16.2.2.2.6 Calculate K′ using Equation 5-11.
Calculate the arithmetic mean of the K′ values. The individual K’ values should not differ by more than ±0.5 percent from the mean value.
16.2.3 Using the Critical Orifices as Calibration Standards.
16.2.3.1 Record the barometric pressure.
16.2.3.2 Calibrate the metering system according to the procedure outlined in section 16.2.2. Record the information listed in Figure 5-12.
16.2.3.3 Calculate the standard volumes of air passed through the DGM and the critical orifices, and calculate the DGM calibration factor, Y, using the equations below:
16.2.3.4 Average the DGM calibration values for each of the flow rates. The calibration factor, Y, at each of the flow rates should not differ by more than ±2 percent from the average.
16.2.3.5 To determine the need for recalibrating the critical orifices, compare the DGM Y factors obtained from two adjacent orifices each time a DGM is calibrated; for example, when checking orifice 13/2.5, use orifices 12/10.2 and 13/5.1. If any critical orifice yields a DGM Y factor differing by more than 2 percent from the others, recalibrate the critical orifice according to section 16.2.2.
16.3 Alternative Post-Test Metering System Calibration. The following procedure may be used as an alternative to the post-test calibration described in Section 10.3.2. This alternative procedure does not detect leakages between the inlet of the metering system and the dry gas meter. Therefore, two steps must be included to make it an equivalent alternative:
(1) The metering system must pass the post-test leak-check from either the inlet of the sampling train or the inlet of the metering system. Therefore, if the train fails the former leak-check, another leak-check from the inlet of the metering system must be conducted;
(2) The metering system must pass the leak-check of that portion of the train from the pump to the orifice meter as described in Section 8.4.1.
16.3.1 After each test run, do the following:
16.3.1.1 Ensure that the metering system has passed the post-test leak-check. If not, conduct a leak-check of the metering system from its inlet.
16.3.1.2 Conduct the leak-check of that portion of the train from the pump to the orifice meter as described in Section 10.3.1.1.
16.3.1.3 Calculate Y
16.3.2 After each test run series, do the following:
16.3.2.1 Average the three or more Y
16.3.2.2 If the average Y
1. Addendum to Specifications for Incinerator Testing at Federal Facilities. PHS, NCAPC. December 6, 1967.
2. Martin, Robert M. Construction Details of Isokinetic Source-Sampling Equipment. Environmental Protection Agency. Research Triangle Park, NC. APTD-0581. April 1971.
3. Rom, Jerome J. Maintenance, Calibration, and Operation of Isokinetic Source Sampling Equipment. Environmental Protection Agency. Research Triangle Park, NC. APTD-0576. March 1972.
4. Smith, W.S., R.T. Shigehara, and W.F. Todd. A Method of Interpreting Stack Sampling Data. Paper Presented at the 63rd Annual Meeting of the Air Pollution Control Association, St. Louis, MO. June 14-19, 1970.
5. Smith, W.S., et al. Stack Gas Sampling Improved and Simplified With New Equipment. APCA Paper No. 67-119. 1967.
6. Specifications for Incinerator Testing at Federal Facilities. PHS, NCAPC. 1967.
7. Shigehara, R.T. Adjustment in the EPA Nomograph for Different Pitot Tube Coefficients and Dry Molecular Weights. Stack Sampling News 2:4-11. October 1974.
8. Vollaro, R.F. A Survey of Commercially Available Instrumentation for the Measurement of Low-Range Gas Velocities. U.S. Environmental Protection Agency, Emission Measurement Branch. Research Triangle Park, NC. November 1976 (unpublished paper).
9. Annual Book of ASTM Standards. Part 26. Gaseous Fuels; Coal and Coke; Atmospheric Analysis. American Society for Testing and Materials. Philadelphia, PA. 1974. pp. 617-622.
10. Felix, L.G., G.I. Clinard, G.E. Lacy, and J.D. McCain. Inertial Cascade Impactor Substrate Media for Flue Gas Sampling. U.S. Environmental Protection Agency. Research Triangle Park, NC 27711. Publication No. EPA-600/7-77-060. June 1977. 83 pp.
11. Westlin, P.R. and R.T. Shigehara. Procedure for Calibrating and Using Dry Gas Volume Meters as Calibration Standards. Source Evaluation Society Newsletter. 3(1):17-30. February 1978.
12. Lodge, J.P., Jr., J.B. Pate, B.E. Ammons, and G.A. Swanson. The Use of Hypodermic Needles as Critical Orifices in Air Sampling. J. Air Pollution Control Association. 16:197-200. 1966.
13. Shigehara, Roger T., P.G. Royals, and E.W. Steward. “Alternative Method 5 Post-Test Calibration.” Entropy Incorporated, Research Triangle Park, NC 27709.
Table 5-1 Flor Rates for Various needle Sizes and Tube Lengths
| Gauge/cm | Flow rate liters/min. | Gauge/cm | Flow rate liters/min. |
|---|---|---|---|
| 12/7.6 | 32.56 | 14/2.5 | 19.54 |
| 12/10.2 | 30.02 | 14/5.1 | 17.27 |
| 13/2.5 | 25.77 | 14/7.6 | 16.14 |
| 13/5.1 | 23.50 | 15/3.2 | 14.16 |
| 13/7.6 | 22.37 | 15/7.6 | 11.61 |
| 13/10.2 | 20.67 | 15/10.2 | 10.48 |
| Dry gas meter | Run No. | ||
|---|---|---|---|
| 1 | 2 | ||
| Final reading | m 3 (ft 3) | ||
| Initial reading | m 3 (ft 3) | ||
| Difference, V m | m 3 (ft 3) | ||
| Inlet/Outlet | |||
| Temperatures: | °C ( °F) | / | / |
| Initial | °C ( °F) | / | / |
| Final | min/sec | / | / |
| Av. Temeperature, t | min | ||
| Time, θ | |||
| Orifice man. rdg., ΔH | mm (in.) H | ||
| Bar. pressure, P bar | mm (in.) Hg | ||
| Ambient temperature, t | mm (in.) Hg | ||
| Pump vacuum | |||
| K′ factor | |||
| Average | |||
| Dry gas meter | Run No. | ||
|---|---|---|---|
| 1 | 2 | ||
| Final reading | m 3 (ft 3) | ||
| Initial reading | m 3 (ft 3) | ||
| Difference, V | m 3 (ft 3) | ||
| Inlet/outlet temperatures | °C ( °F) | / | / |
| Initial | °C ( °F) | / | / |
| Final | °C ( °F) | ||
| Avg. Temperature, t | min/sec | / | / |
| Time, θ | min | ||
| Orifice man. rdg., ΔH | min | ||
| Bar. pressure, P | mm (in.) H | ||
| Ambient temperature, t | mm (in.) Hg | ||
| Pump vacuum | °C ( °F) | ||
| V | mm (in.) Hg | ||
| V | m 3 (ft 3) | ||
| DGM cal. factor, Y | m 3 (ft 3) | ||
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 2, Method 3, and Method 5.
1.1 Analyte. Particulate matter (PM). No CAS number assigned.
1.2 Applicability. This method is applicable for the determination of PM emissions from asphalt roofing industry process saturators, blowing stills, and other sources as specified in the regulations.
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
Particulate matter is withdrawn isokinetically from the source and collected on a glass fiber filter maintained at a temperature of 42 ±10 °C (108 ±18 °F). The PM mass, which includes any material that condenses at or above the filtration temperature, is determined gravimetrically after the removal of uncombined water.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to performing this test method.
6.1 Sample Collection. Same as Method 5, section 6.1, with the following exceptions and additions:
6.1.1 Probe Liner. Same as Method 5, section 6.1.1.2, with the note that at high stack gas temperatures greater than 250 °C (480 °F), water-cooled probes may be required to control the probe exit temperature to 42 ±10 °C (108 ±18 °F).
6.1.2 Precollector Cyclone. Borosilicate glass following the construction details shown in Air Pollution Technical Document (APTD)-0581, “Construction Details of Isokinetic Source-Sampling Equipment” (Reference 2 in Method 5, section 17.0).
The cyclone shall be used when the stack gas moisture is greater than 10 percent, and shall not be used otherwise.
6.1.3 Filter Heating System. Any heating (or cooling) system capable of maintaining a sample gas temperature at the exit end of the filter holder during sampling at 42 ±10 °C (108 ±18 °F).
6.2 Sample Recovery. The following items are required for sample recovery:
6.2.1 Probe-Liner and Probe-Nozzle Brushes, Graduated Cylinder and/or Balance, Plastic Storage Containers, and Funnel and Rubber Policeman. Same as in Method 5, sections 6.2.1, 6.2.5, 6.2.6, and 6.2.7, respectively.
6.2.2 Wash Bottles. Glass.
6.2.3 Sample Storage Containers. Chemically resistant 500-ml or 1,000-ml borosilicate glass bottles, with rubber-backed Teflon screw cap liners or caps that are constructed so as to be leak-free, and resistant to chemical attack by 1,1,1-trichloroethane (TCE). (Narrow-mouth glass bottles have been found to be less prone to leakage.)
6.2.4 Petri Dishes. Glass, unless otherwise specified by the Administrator.
6.2.5 Funnel. Glass.
6.3 Sample Analysis. Same as Method 5, section 6.3, with the following additions:
6.3.1 Beakers. Glass, 250-ml and 500-ml.
6.3.2 Separatory Funnel. 100-ml or greater.
7.1 Sample Collection. The following reagents are required for sample collection:
7.1.1 Filters, Silica Gel, Water, and Crushed Ice. Same as in Method 5, sections 7.1.1, 7.1.2, 7.1.3, and 7.1.4, respectively.
7.1.2 Stopcock Grease. TCE-insoluble, heat-stable grease (if needed). This is not necessary if screw-on connectors with Teflon sleeves, or similar, are used.
7.2 Sample Recovery. Reagent grade TCE, ≤0.001 percent residue and stored in glass bottles. Run TCE blanks before field use, and use only TCE with low blank values (≤0.001 percent). In no case shall a blank value of greater than 0.001 percent of the weight of TCE used be subtracted from the sample weight.
7.3 Analysis. Two reagents are required for the analysis:
7.3.1 TCE. Same as in section 7.2.
7.3.2 Desiccant. Same as in Method 5, section 7.3.2.
8.1 Pretest Preparation. Unless otherwise specified, maintain and calibrate all components according to the procedure described in APTD-0576, “Maintenance, Calibration, and Operation of Isokinetic Source-Sampling Equipment” (Reference 3 in Method 5, Section 17.0). Alternative mercury-free thermometers may be used if the thermometers are, at a minimum, equivalent in terms of performance or suitably effective for the specific temperature measurement application.
8.1.1 Prepare probe liners and sampling nozzles as needed for use. Thoroughly clean each component with soap and water followed by a minimum of three TCE rinses. Use the probe and nozzle brushes during at least one of the TCE rinses (refer to section 8.7 for rinsing techniques). Cap or seal the open ends of the probe liners and nozzles to prevent contamination during shipping.
8.1.2 Prepare silica gel portions and glass filters as specified in Method 5, section 8.1.
8.2 Preliminary Determinations. Select the sampling site, probe nozzle, and probe length as specified in Method 5, section 8.2. Select a total sampling time greater than or equal to the minimum total sampling time specified in the “Test Methods and Procedures” section of the applicable subpart of the regulations. Follow the guidelines outlined in Method 5, section 8.2 for sampling time per point and total sample volume collected.
8.3 Preparation of Sampling Train. Prepare the sampling train as specified in Method 5, section 8.3, with the addition of the precollector cyclone, if used, between the probe and filter holder. The temperature of the precollector cyclone, if used, should be maintained in the same range as that of the filter, i.e., 42 ±10 °C (108 ±18 °F). Use no stopcock grease on ground glass joints unless grease is insoluble in TCE.
8.4 Leak-Check Procedures. Same as Method 5, section 8.4.
8.5 Sampling Train Operation. Operate the sampling train as described in Method 5, section 8.5, except maintain the temperature of the gas exiting the filter holder at 42 ±10 °C (108 ±18 °F).
8.6 Calculation of Percent Isokinetic. Same as Method 5, section 8.6.
8.7 Sample Recovery. Same as Method 5, section 8.7.1 through 8.7.6.1, with the addition of the following:
8.7.1 Container No. 2 (Probe to Filter Holder).
8.7.1.1 Taking care to see that material on the outside of the probe or other exterior surfaces does not get into the sample, quantitatively recover PM or any condensate from the probe nozzle, probe fitting, probe liner, precollector cyclone and collector flask (if used), and front half of the filter holder by washing these components with TCE and placing the wash in a glass container. Carefully measure the total amount of TCE used in the rinses. Perform the TCE rinses as described in Method 5, section 8.7.6.2, using TCE instead of acetone.
8.7.1.2 Brush and rinse the inside of the cyclone, cyclone collection flask, and the front half of the filter holder. Brush and rinse each surface three times or more, if necessary, to remove visible PM.
8.7.2 Container No. 3 (Silica Gel). Same as in Method 5, section 8.7.6.3.
8.7.3 Impinger Water. Same as Method 5, section 8.7.6.4.
8.8 Blank. Save a portion of the TCE used for cleanup as a blank. Take 200 ml of this TCE directly from the wash bottle being used, and place it in a glass sample container labeled “TCE Blank.”
9.1 Miscellaneous Quality Control Measures.
| Section | Quality control measure | Effect |
|---|---|---|
| 8.4, 10.0 | Sampling equipment leak check and calibration | Ensures accurate measurement of stack gas flow rate, sample volume. |
9.2 A quality control (QC) check of the volume metering system at the field site is suggested before collecting the sample. Use the procedure outlined in Method 5, section 9.2.
Same as Method 5, section 10.0.
11.1 Analysis. Record the data required on a sheet such as the one shown in Figure 5A-1. Handle each sample container as follows:
11.1.1 Container No. 1 (Filter). Transfer the filter from the sample container to a tared glass weighing dish, and desiccate for 24 hours in a desiccator containing anhydrous calcium sulfate. Rinse Container No. 1 with a measured amount of TCE, and analyze this rinse with the contents of Container No. 2. Weigh the filter to a constant weight. For the purpose of this analysis, the term “constant weight” means a difference of no more than 10 percent of the net filter weight or 2 mg (whichever is greater) between two consecutive weighings made 24 hours apart. Report the “final weight” to the nearest 0.1 mg as the average of these two values.
11.1.2 Container No. 2 (Probe to Filter Holder).
11.1.2.1 Before adding the rinse from Container No. 1 to Container No. 2, note the level of liquid in Container No. 2, and confirm on the analysis sheet whether leakage occurred during transport. If noticeable leakage occurred, either void the sample or take steps, subject to the approval of the Administrator, to correct the final results.
11.1.2.2 Add the rinse from Container No. 1 to Container No. 2 and measure the liquid in this container either volumetrically to ±1 ml or gravimetrically to ±0.5 g. Check to see whether there is any appreciable quantity of condensed water present in the TCE rinse (look for a boundary layer or phase separation). If the volume of condensed water appears larger than 5 ml, separate the oil-TCE fraction from the water fraction using a separatory funnel. Measure the volume of the water phase to the nearest ml; adjust the stack gas moisture content, if necessary (see sections 12.3 and 12.4). Next, extract the water phase with several 25-ml portions of TCE until, by visual observation, the TCE does not remove any additional organic material. Transfer the remaining water fraction to a tared beaker and evaporate to dryness at 93 °C (200 °F), desiccate for 24 hours, and weigh to the nearest 0.1 mg.
11.1.2.3 Treat the total TCE fraction (including TCE from the filter container rinse and water phase extractions) as follows: Transfer the TCE and oil to a tared beaker, and evaporate at ambient temperature and pressure. The evaporation of TCE from the solution may take several days. Do not desiccate the sample until the solution reaches an apparent constant volume or until the odor of TCE is not detected. When it appears that the TCE has evaporated, desiccate the sample, and weigh it at 24-hour intervals to obtain a “constant weight” (as defined for Container No. 1 above). The “total weight” for Container No. 2 is the sum of the evaporated PM weight of the TCE-oil and water phase fractions. Report the results to the nearest 0.1 mg.
11.1.3 Container No. 3 (Silica Gel). This step may be conducted in the field. Weigh the spent silica gel (or silica gel plus impinger) to the nearest 0.5 g using a balance.
11.1.4 “TCE Blank” Container. Measure TCE in this container either volumetrically or gravimetrically. Transfer the TCE to a tared 250-ml beaker, and evaporate to dryness at ambient temperature and pressure. Desiccate for 24 hours, and weigh to a constant weight. Report the results to the nearest 0.1 mg.
In order to facilitate the evaporation of TCE liquid samples, these samples may be dried in a controlled temperature oven at temperatures up to 38 °C (100 °F) until the liquid is evaporated.
Carry out calculations, retaining at least one extra significant figure beyond that of the acquired data. Round off figures after the final calculation. Other forms of the equations may be used as long as they give equivalent results.
12.1 Nomenclature. Same as Method 5, section 12.1, with the following additions:
12.2 Dry Gas Meter Temperature, Orifice Pressure Drop, and Dry Gas Volume. Same as Method 5, sections 12.2 and 12.3, except use data obtained in performing this test.
12.3 Volume of Water Vapor.
12.4 Moisture Content.
In saturated or water droplet-laden gas streams, two calculations of the moisture content of the stack gas shall be made, one from the impinger and precollector analysis (Equations 5A-1 and 5A-2) and a second from the assumption of saturated conditions. The lower of the two values of moisture content shall be considered correct. The procedure for determining the moisture content based upon assumption of saturated conditions is given in section 4.0 of Method 4. For the purpose of this method, the average stack gas temperature from Figure 5-3 of Method 5 may be used to make this determination, provided that the accuracy of the in-stack temperature sensor is within 1 °C (2 °F).
12.5 TCE Blank Concentration.
In no case shall a blank value of greater than 0.001 percent of the weight of TCE used be subtracted from the sample weight.
12.6 TCE Wash Blank.
12.7 Total PM Weight. Determine the total PM catch from the sum of the weights obtained from Containers 1 and 2, less the TCE blank.
12.8 PM Concentration.
12.9 Isokinetic Variation. Same as in Method 5, section 12.11.
Same as Method 5, section 17.0.
| Container number | Weight of particulate collected, mg | ||
|---|---|---|---|
| Final weight | Tare weight | Weight gain | |
| 1. | |||
| 2. | |||
| Total: | |||
| Less acetone blank | |||
| Weight of particulate matter | |||
| Volume of liquid water collected | ||
|---|---|---|
| Impinger volume, ml | Silica gel weight, g | |
| Final | ||
| Initial | ||
| Liquid collected | ||
| Total volume collected | g* ml | |
* Convert weight of water to volume by dividing total weight increase by density of water (1 g/ml).
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 2, Method 3, Method 5.
1.1 Analyte. Nonsulfuric acid particulate matter. No CAS number assigned.
1.2 Applicability. This method is determining applicable for the determination of nonsulfuric acid particulate matter from stationary sources, only where specified by an applicable subpart of the regulations or where approved by the Administrator for a particular application.
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
Particulate matter is withdrawn isokinetically from the source and collected on a glass fiber filter maintained at a temperature of 160 ±14 °C (320 ±25 °F). The collected sample is then heated in an oven at 160 °C (320 °F) for 6 hours to volatilize any condensed sulfuric acid that may have been collected, and the nonsulfuric acid particulate mass is determined gravimetrically.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to performing this test method.
Same as Method 5, section 6.0, with the following addition and exceptions:
6.1 Sample Collection. The probe liner heating system and filter heating system must be capable of maintaining a sample gas temperature of 160 ±14 °C (320 ±25 °F).
6.2 Sample Preparation. An oven is required for drying the sample.
Same as Method 5, section 7.0.
Same as Method 5, with the exception of the following:
8.1 Initial Filter Tare. Oven dry the filter at 160 ±5 °C (320 ±10 °F) for 2 to 3 hours, cool in a desiccator for 2 hours, and weigh. Desiccate to constant weight to obtain the initial tare weight. Use the applicable specifications and techniques of section 8.1.3 of Method 5 for this determination.
8.2 Probe and Filter Temperatures. Maintain the probe outlet and filter temperatures at 160 ±14 °C (320 ±25 °F).
Same as Method 5, section 9.0.
Same as Method 5, section 10.0.
11.1 Record and report the data required on a sheet such as the one shown in Figure 5B-1.
11.2 Handle each sample container as follows:
11.2.1 Container No. 1. Leave the contents in the shipping container or transfer the filter and any loose PM from the sample container to a tared non-reactive oven-proof container. Oven dry the filter sample at a temperature of 160 ±5 °C (320 ±9 °F) for 6 hours. Cool in a desiccator for 2 hours, and weigh to constant weight. Report the results to the nearest 0.1 mg. For the purposes of this section, the term “constant weight” means a difference of no more than 0.5 mg or 1 percent of total weight less tare weight, whichever is greater, between two consecutive weighings, with no less than 6 hours of desiccation time between weighings.
11.2.2 Container No. 2. Note the level of liquid in the container, and confirm on the analysis sheet whether leakage occurred during transport. If a noticeable amount of leakage has occurred, either void the sample or use methods, subject to the approval of the Administrator, to correct the final results. Measure the liquid in this container either volumetrically to ±1 ml or gravimetrically to ±0.5 g. Transfer the contents to a tared 250 ml beaker, and evaporate to dryness at ambient temperature and pressure. Then oven dry the probe sample at a temperature of 160 ±5 °C (320 ±9 °F) for 6 hours. Cool in a desiccator for 2 hours, and weigh to constant weight. Report the results to the nearest 0.1 mg.
11.2.3 Container No. 3. Weigh the spent silica gel (or silica gel plus impinger) to the nearest 0.5 g using a balance. This step may be conducted in the field.
11.2.4 Acetone Blank Container. Measure the acetone in this container either volumetrically or gravimetrically. Transfer the acetone to a tared 250 ml beaker, and evaporate to dryness at ambient temperature and pressure. Desiccate for 24 hours, and weigh to a constant weight. Report the results to the nearest 0.1 mg.
Same as in Method 5, section 12.0.
Same as Method 5, section 17.0.
| Container number | Weight of particulate collected, mg | ||
|---|---|---|---|
| Final weight | Tare weight | Weight gain | |
| 1. | |||
| 2. | |||
| Total: | |||
| Less acetone blank | |||
| Weight of particulate matter | |||
| Volume of liquid water collected | ||
|---|---|---|
| Impinger volume, | Silica gel weight, | |
| ml | g | |
| Final | ||
| Initial | ||
| Liquid collected | ||
| Total volume collected | g* ml | |
* Convert weight of water to volume by dividing total weight increase by density of water (1 g/ml).
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 2, Method 3, Method 5, Method 17.
1.1 Analyte. Particulate matter (PM). No CAS number assigned.
1.2 Applicability.
1.2.1 This method is applicable for the determination of PM emissions from positive pressure fabric filters. Emissions are determined in terms of concentration (mg/m
1.2.2 The General Provisions of 40 CFR part 60, § 60.8(e), require that the owner or operator of an affected facility shall provide performance testing facilities. Such performance testing facilities include sampling ports, safe sampling platforms, safe access to sampling sites, and utilities for testing. It is intended that affected facilities also provide sampling locations that meet the specification for adequate stack length and minimal flow disturbances as described in Method 1. Provisions for testing are often overlooked factors in designing fabric filters or are extremely costly. The purpose of this procedure is to identify appropriate alternative locations and procedures for sampling the emissions from positive pressure fabric filters. The requirements that the affected facility owner or operator provide adequate access to performance testing facilities remain in effect.
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 Particulate matter is withdrawn isokinetically from the source and collected on a glass fiber filter maintained at a temperature at or above the exhaust gas temperature up to a nominal 120 °C (248 ±25 °F). The particulate mass, which includes any material that condenses at or above the filtration temperature, is determined gravimetrically after the removal of uncombined water.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to performing this test method.
Same as section 6.0 of either Method 5 or Method 17.
Same as section 7.0 of either Method 5 or Method 17.
Same section 8.0 of either Method 5 or Method 17, except replace section 8.2.1 of Method 5 with the following:
8.1 Determination of Measurement Site. The configuration of positive pressure fabric filter structures frequently are not amenable to emission testing according to the requirements of Method 1. Following are several alternatives for determining measurement sites for positive pressure fabric filters.
8.1.1 Stacks Meeting Method 1 Criteria. Use a measurement site as specified in Method 1, section 11.1.
8.1.2 Short Stacks Not Meeting Method 1 Criteria. Use stack extensions and the procedures in Method 1. Alternatively, use flow straightening vanes of the “egg-crate” type (see Figure 5D-1). Locate the measurement site downstream of the straightening vanes at a distance equal to or greater than two times the average equivalent diameter of the vane openings and at least one-half of the overall stack diameter upstream of the stack outlet.
8.1.3 Roof Monitor or Monovent. (See Figure 5D-2). For a positive pressure fabric filter equipped with a peaked roof monitor, ridge vent, or other type of monovent, use a measurement site at the base of the monovent. Examples of such locations are shown in Figure 5D-2. The measurement site must be upstream of any exhaust point (e.g., louvered vent).
8.1.4 Compartment Housing. Sample immediately downstream of the filter bags directly above the tops of the bags as shown in the examples in Figure 5D-2. Depending on the housing design, use sampling ports in the housing walls or locate the sampling equipment within the compartment housing.
8.2 Determination of Number and Location of Traverse Points. Locate the traverse points according to Method 1, section 11.3. Because a performance test consists of at least three test runs and because of the varied configurations of positive pressure fabric filters, there are several schemes by which the number of traverse points can be determined and the three test runs can be conducted.
8.2.1 Single Stacks Meeting Method 1 Criteria. Select the number of traverse points according to Method 1. Sample all traverse points for each test run.
8.2.2 Other Single Measurement Sites. For a roof monitor or monovent, single compartment housing, or other stack not meeting Method 1 criteria, use at least 24 traverse points. For example, for a rectangular measurement site, such as a monovent, use a balanced 5 × 5 traverse point matrix. Sample all traverse points for each test run.
8.2.3 Multiple Measurement Sites. Sampling from two or more stacks or measurement sites may be combined for a test run, provided the following guidelines are met:
8.2.3.1 All measurement sites up to 12 must be sampled. For more than 12 measurement sites, conduct sampling on at least 12 sites or 50 percent of the sites, whichever is greater. The measurement sites sampled should be evenly, or nearly evenly, distributed among the available sites; if not, all sites are to be sampled.
8.2.3.2 The same number of measurement sites must be sampled for each test run.
8.2.3.3 The minimum number of traverse points per test run is 24. An exception to the 24-point minimum would be a test combining the sampling from two stacks meeting Method 1 criteria for acceptable stack length, and Method 1 specifies fewer than 12 points per site.
8.2.3.4 As long as the 24 traverse points per test run criterion is met, the number of traverse points per measurement site may be reduced to eight.
8.2.3.5 Alternatively, conduct a test run for each measurement site individually using the criteria in section 8.2.1 or 8.2.2 to determine the number of traverse points. Each test run shall count toward the total of three required for a performance test. If more than three measurement sites are sampled, the number of traverse points per measurement site may be reduced to eight as long as at least 72 traverse points are sampled for all the tests.
8.2.3.6 The following examples demonstrate the procedures for sampling multiple measurement sites.
8.2.3.6.1 Example 1: A source with nine circular measurement sites of equal areas may be tested as follows: For each test run, traverse three measurement sites using four points per diameter (eight points per measurement site). In this manner, test run number 1 will include sampling from sites 1,2, and 3; run 2 will include samples from sites 4, 5, and 6; and run 3 will include sites 7, 8, and 9. Each test area may consist of a separate test of each measurement site using eight points. Use the results from all nine tests in determining the emission average.
8.2.3.6.2 Example 2: A source with 30 rectangular measurement sites of equal areas may be tested as follows: For each of the three test runs, traverse five measurement sites using a 3 × 3 matrix of traverse points for each site. In order to distribute the sampling evenly over all the available measurement sites while sampling only 50 percent of the sites, number the sites consecutively from 1 to 30 and sample all the even numbered (or odd numbered) sites. Alternatively, conduct a separate test of each of 15 measurement sites using section 8.2.1 or 8.2.2 to determine the number and location of traverse points, as appropriate.
8.2.3.6.3 Example 3: A source with two measurement sites of equal areas may be tested as follows: For each test of three test runs, traverse both measurement sites, using section 8.2.3 in determining the number of traverse points. Alternatively, conduct two full emission test runs for each measurement site using the criteria in section 8.2.1 or 8.2.2 to determine the number of traverse points.
8.2.3.7 Other test schemes, such as random determination of traverse points for a large number of measurement sites, may be used with prior approval from the Administrator.
8.3 Velocity Determination.
8.3.1 The velocities of exhaust gases from positive pressure baghouses are often too low to measure accurately with the type S pitot tube specified in Method 2 (i.e., velocity head 2O (0.05 in. H
8.3.2 Velocity determinations to determine and maintain isokinetic rates at measurement sites with gas velocities within the range measurable with the type S pitot tube (i.e., velocity head greater than 1.3 mm H
8.4 Sampling. Follow the procedures specified in sections 8.1 through 8.6 of Method 5 or sections 8.1 through 8.25 in Method 17 with the exceptions as noted above.
8.5 Sample Recovery. Follow the procedures specified in section 8.7 of Method 5 or section 8.2 of Method 17.
9.1 Miscellaneous Quality Control Measures.
| Section | Quality control measure | Effect |
|---|---|---|
| 8.0, 10.0 | Sampling equipment leak check and calibration | Ensures accurate measurement of stack gas flow rate, sample volume. |
9.2 Volume Metering System Checks. Same as Method 5, section 9.2.
Same as section 10.0 of either Method 5 or Method 17.
Same as section 11.0 of either Method 5 or Method 17.
Same as section 12.0 of either Method 5 or Method 17 with the following exceptions:
12.1 Nomenclature.
12.2 Average Gas Velocity. When following section 8.3.1, calculate the average gas velocity at the measurement site as follows:
12.3 Volumetric Flow Rate. Total volumetric flow rate may be determined as follows:
12.4 Dilution Air Flow Rate.
12.5 Average PM Concentration. For multiple measurement sites, calculate the average PM concentration as follows:
Same as Method 5, section 17.0.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 2, Method 3, and Method 5.
1.1 Analyte. Particulate matter (PM). No CAS number assigned.
1.2 Applicability. This method is applicable for the determination of PM emissions from wool fiberglass insulation manufacturing sources.
Particulate matter is withdrawn isokinetically from the source and is collected either on a glass fiber filter maintained at a temperature in the range of 120 ±14 °C (248 ±25 °F) and in impingers in solutions of 0.1 N sodium hydroxide (NaOH). The filtered particulate mass, which includes any material that condenses at or above the filtration temperature, is determined gravimetrically after the removal of uncombined water. The condensed PM collected in the impinger solutions is determined as total organic carbon (TOC) using a nondispersive infrared type of analyzer. The sum of the filtered PM mass and the condensed PM is reported as the total PM mass.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to performing this test method.
5.2 Corrosive Reagents. The following reagents are hazardous. Personal protective equipment and safe procedures are useful in preventing chemical splashes. If contact occurs, immediately flush with copious amounts of water at least 15 minutes. Remove clothing under shower and decontaminate. Treat residual chemical burn as thermal burn.
5.2.1 Hydrochloric Acid (HCl). Highly toxic. Vapors are highly irritating to eyes, skin, nose, and lungs, causing severe damage. May cause bronchitis, pneumonia, or edema of lungs. Exposure to concentrations of 0.13 to 0.2 percent in air can be lethal in minutes. Will react with metals, producing hydrogen.
5.2.2 Sodium Hydroxide (NaOH). Causes severe damage to eye tissues and to skin. Inhalation causes irritation to nose, throat, and lungs. Reacts exothermically with limited amounts of water.
6.1 Sample Collection. Same as Method 5, section 6.1, with the exception of the following:
6.1.1 Probe Liner. Same as described in section 6.1.1.2 of Method 5 except use only borosilicate or quartz glass liners.
6.1.2 Filter Holder. Same as described in section 6.1.1.5 of Method 5 with the addition of a leak-tight connection in the rear half of the filter holder designed for insertion of a temperature sensor used for measuring the sample gas exit temperature.
6.2 Sample Recovery. Same as Method 5, section 6.2, except three wash bottles are needed instead of two and only glass storage bottles and funnels may be used.
6.3 Sample Analysis. Same as Method 5, section 6.3, with the additional equipment for TOC analysis as described below:
6.3.1 Sample Blender or Homogenizer. Waring type or ultrasonic.
6.3.2 Magnetic Stirrer.
6.3.3 Hypodermic Syringe. 0- to 100-µl capacity.
6.3.4 Total Organic Carbon Analyzer. Rosemount Model 2100A analyzer or equivalent and a recorder.
6.3.5 Beaker. 30-ml.
6.3.6 Water Bath. Temperature controlled.
6.3.7 Volumetric Flasks. 1000-ml and 500-ml.
Unless otherwise indicated, it is intended that all reagents conform to the specifications established by the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available; otherwise, use the best available grade.
7.1 Sample Collection. Same as Method 5, section 7.1, with the addition of 0.1 N NaOH (Dissolve 4 g of NaOH in water and dilute to 1 liter).
7.2 Sample Recovery. Same as Method 5, section 7.2, with the addition of the following:
7.2.1 Water. Deionized distilled to conform to ASTM Specification D 1193-77 or 91 Type 3 (incorporated by reference – see § 60.17). The potassium permanganate (KMnO
7.2.2 Sodium Hydroxide. Same as described in section 7.1.
7.3 Sample Analysis. Same as Method 5, section 7.3, with the addition of the following:
7.3.1 Carbon Dioxide-Free Water. Distilled or deionized water that has been freshly boiled for 15 minutes and cooled to room temperature while preventing exposure to ambient air by using a cover vented with an Ascarite tube.
7.3.2 Hydrochloric Acid. HCl, concentrated, with a dropper.
7.3.3 Organic Carbon Stock Solution. Dissolve 2.1254 g of dried potassium biphthalate (HOOCC
7.3.4 Inorganic Carbon Stock Solution. Dissolve 4.404 g anhydrous sodium carbonate (Na
7.3.5 Oxygen Gas. CO
8.1 Pretest Preparation and Preliminary Determinations. Same as Method 5, sections 8.1 and 8.2, respectively.
8.2 Preparation of Sampling Train. Same as Method 5, section 8.3, except that 0.1 N NaOH is used in place of water in the impingers. The volumes of the solutions are the same as in Method 5.
8.3 Leak-Check Procedures, Sampling Train Operation, Calculation of Percent Isokinetic. Same as Method 5, sections 8.4 through 8.6, respectively.
8.4 Sample Recovery. Same as Method 5, sections 8.7.1 through 8.7.4, with the addition of the following:
8.4.1 Save portions of the water, acetone, and 0.1 N NaOH used for cleanup as blanks. Take 200 ml of each liquid directly from the wash bottles being used, and place in glass sample containers labeled “water blank,” “acetone blank,” and “NaOH blank,” respectively.
8.4.2 Inspect the train prior to and during disassembly, and note any abnormal conditions. Treat the samples as follows:
8.4.2.1 Container No. 1. Same as Method 5, section 8.7.6.1.
8.4.2.2 Container No. 2. Use water to rinse the sample nozzle, probe, and front half of the filter holder three times in the manner described in section 8.7.6.2 of Method 5 except that no brushing is done. Put all the water wash in one container, seal, and label.
8.4.2.3 Container No. 3. Rinse and brush the sample nozzle, probe, and front half of the filter holder with acetone as described for Container No. 2 in section 8.7.6.2 of Method 5.
8.4.2.4 Container No. 4. Place the contents of the silica gel impinger in its original container as described for Container No. 3 in section 8.7.6.3 of Method 5.
8.4.2.5 Container No. 5. Measure the liquid in the first three impingers and record the volume or weight as described for the Impinger Water in section 8.7.6.4 of Method 5. Do not discard this liquid, but place it in a sample container using a glass funnel to aid in the transfer from the impingers or graduated cylinder (if used) to the sample container. Rinse each impinger thoroughly with 0.1 N NaOH three times, as well as the graduated cylinder (if used) and the funnel, and put these rinsings in the same sample container. Seal the container and label to clearly identify its contents.
8.5 Sample Transport. Whenever possible, containers should be shipped in such a way that they remain upright at all times.
9.1 Miscellaneous Quality Control Measures.
| Section | Quality control measure | Effect |
|---|---|---|
| 8.3, 10.0 | Sampling equipment leak-check and calibration | Ensures accurate measurement of stack gas flow rate, sample volume. |
| 10.1.2, 11.2.5.3 | Repetitive analyses | Ensures precise measurement of total carbon and inorganic carbon concentration of samples, blank, and standards. |
| 10.1.4 | TOC analyzer calibration | Ensures linearity of analyzer response to standards. |
9.2 Volume Metering System Checks. Same as Method 5, section 9.2.
Same as Method 5, section 10.0, with the addition of the following procedures for calibrating the total organic carbon analyzer:
10.1 Preparation of Organic Carbon Standard Curve.
10.1.1 Add 10 ml, 20 ml, 30 ml, 40 ml, and 50 ml of the organic carbon stock solution to a series of five 1000-ml volumetric flasks. Add 30 ml, 40 ml, and 50 ml of the same solution to a series of three 500-ml volumetric flasks. Dilute the contents of each flask to the mark using CO
10.1.2 Use a hypodermic syringe to withdraw a 20- to 50-µl aliquot from the 10 mg/L standard solution and inject it into the total carbon port of the analyzer. Measure the peak height. Repeat the injections until three consecutive peaks are obtained within 10 percent of their arithmetic mean. Repeat this procedure for the remaining organic carbon standard solutions.
10.1.3 Calculate the corrected peak height for each standard by deducting the blank correction (see section 11.2.5.3) as follows:
10.1.4 Prepare a linear regression plot of the arithmetic mean of the three consecutive peak heights obtained for each standard solution against the concentration of that solution. Calculate the calibration factor as the inverse of the slope of this curve. If the product of the arithmetic mean peak height for any standard solution and the calibration factor differs from the actual concentration by more than 5 percent, remake and reanalyze that standard.
10.2 Preparation of Inorganic Carbon Standard Curve. Repeat the procedures outlined in sections 10.1.1 through 10.1.4, substituting the inorganic carbon stock solution for the organic carbon stock solution, and the inorganic carbon port of the analyzer for the total carbon port.
11.1 Record the data required on a sheet such as the one shown in Figure 5-6 of Method 5.
11.2 Handle each sample container as follows:
11.2.1 Container No. 1. Same as Method 5, section 11.2.1, except that the filters must be dried at 20 ±6 °C (68 ±10 °F) and ambient pressure.
11.2.2 Containers No. 2 and No. 3. Same as Method 5, section 11.2.2, except that evaporation of the samples must be at 20 ±6 °C (68 ±10 °F) and ambient pressure.
11.2.3 Container No. 4. Same as Method 5, section 11.2.3.
11.2.4 “Water Blank” and “Acetone Blank” Containers. Determine the water and acetone blank values following the procedures for the “Acetone Blank” container in section 11.2.4 of Method 5. Evaporate the samples at ambient temperature (20 ±6 °C (68 ±10 °F)) and pressure.
11.2.5 Container No. 5. For the determination of total organic carbon, perform two analyses on successive identical samples, i.e., total carbon and inorganic carbon. The desired quantity is the difference between the two values obtained. Both analyses are based on conversion of sample carbon into carbon dioxide for measurement by a nondispersive infrared analyzer. Results of analyses register as peaks on a strip chart recorder.
11.2.5.1 The principal differences between the operating parameters for the two channels involve the combustion tube packing material and temperature. In the total carbon channel, a high temperature (950 °C (1740 °F)) furnace heats a Hastelloy combustion tube packed with cobalt oxide-impregnated asbestos fiber. The oxygen in the carrier gas, the elevated temperature, and the catalytic effect of the packing result in oxidation of both organic and inorganic carbonaceous material to CO
11.2.5.2 As samples collected in 0.1 N NaOH often contain a high measure of inorganic carbon that inhibits repeatable determinations of TOC, sample pretreatment is necessary. Measure and record the liquid volume of each sample (or impinger contents). If the sample contains solids or immiscible liquid matter, homogenize the sample with a blender or ultrasonics until satisfactory repeatability is obtained. Transfer a representative portion of 10 to 15 ml to a 30-ml beaker, and acidify with about 2 drops of concentrated HCl to a pH of 2 or less. Warm the acidified sample at 50 °C (120 °F) in a water bath for 15 minutes.
11.2.5.3 While stirring the sample with a magnetic stirrer, use a hypodermic syringe to withdraw a 20-to 50-µ1 aliquot from the beaker. Analyze the sample for total carbon and calculate its corrected mean peak height according to the procedures outlined in sections 10.1.2 and 10.1.3. Similarly analyze an aliquot of the sample for inorganic carbon. Repeat the analyses for all the samples and for the 0.1 N NaOH blank.
11.2.5.4 Ascertain the total carbon and inorganic carbon concentrations (C
If samples must be diluted for analysis, apply an appropriate dilution factor.
Same as Method 5, section 12.0, with the addition of the following:
12.1 Nomenclature.
12.2 Concentration of Condensed TOC in Liquid Sample.
12.3 Mass of Condensed TOC Collected.
12.4 Concentration of Condensed Particulate Material.
12.5 Total Particulate Concentration.
16.1 Total Organic Carbon Analyzer. Tekmar-Dohrmann analyzers using the single injection technique may be used as an alternative to Rosemount Model 2100A analyzers.
Same as section 17.0 of Method 5, with the addition of the following:
1. American Public Health Association, American Water Works Association, Water Pollution Control Federation. Standard Methods for the Examination of Water and Wastewater. Fifteenth Edition. Washington, D.C. 1980.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 2, Method 3, and Method 5.
1.1 Analyte. Nonsulfate particulate matter (PM). No CAS number assigned.
1.2 Applicability. This method is applicable for the determination of nonsulfate PM emissions from stationary sources. Use of this method must be specified by an applicable subpart of the standards, or approved by the Administrator for a particular application.
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
Particulate matter is withdrawn isokinetically from the source and collected on a filter maintained at a temperature in the range 160 ±14 °C (320 ±25 °F). The collected sample is extracted with water. A portion of the extract is analyzed for sulfate content by ion chromatography. The remainder is neutralized with ammonium hydroxide (NH
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to performing this test method.
6.1 Sample Collection and Recovery. Same as Method 5, sections 6.1 and 6.2, respectively.
6.2 Sample Analysis. Same as Method 5, section 6.3, with the addition of the following:
6.2.1 Erlenmeyer Flasks. 125-ml, with ground glass joints.
6.2.2 Air Condenser. With ground glass joint compatible with the Erlenmeyer flasks.
6.2.3 Beakers. 600-ml.
6.2.4 Volumetric Flasks. 1-liter, 500-ml (one for each sample), 200-ml, and 50-ml (one for each sample and standard).
6.2.5 Pipet. 5-ml (one for each sample and standard).
6.2.6 Ion Chromatograph. The ion chromatograph should have at least the following components.
6.2.6.1 Columns. An anion separation column or other column capable of resolving the sulfate ion from other species present and a standard anion suppressor column. Suppressor columns are produced as proprietary items; however, one can be produced in the laboratory using the resin available from BioRad Company, 32nd and Griffin Streets, Richmond, California. Other systems which do not use suppressor columns may also be used.
6.2.6.2 Pump. Capable of maintaining a steady flow as required by the system.
6.2.6.3 Flow Gauges. Capable of measuring the specified system flow rate.
6.2.6.4 Conductivity Detector.
6.2.6.5 Recorder. Compatible with the output voltage range of the detector.
Unless otherwise indicated, it is intended that all reagents conform to the specifications established by the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available; otherwise, use the best available grade.
7.1 Sample Collection. Same as Method 5, section 7.1.
7.2 Sample Recovery. Same as Method 5, section 7.2, with the addition of the following:
7.2.1 Water. Deionized distilled, to conform to ASTM D 1193-77 or 91 Type 3 (incorporated by reference – see § 60.17). The potassium permanganate (KMnO
7.3 Analysis. Same as Method 5, section 7.3, with the addition of the following:
7.3.1 Water. Same as in section 7.2.1.
7.3.2 Stock Standard Solution, 1 mg (NH
7.3.3 Working Standard Solution, 25 µg (NH
7.3.4 Eluent Solution. Weigh 1.018 g of sodium carbonate (Na
7.3.5 Ammonium Hydroxide. Concentrated, 14.8 M.
7.3.6 Phenolphthalein Indicator. 3,3-Bis(4-hydroxyphenyl)-1-(3H)-isobenzo-furanone. Dissolve 0.05 g in 50 ml of ethanol and 50 ml of water.
Same as Method 5, section 8.0, with the exception of the following:
8.1 Sampling Train Operation. Same as Method 5, section 8.5, except that the probe outlet and filter temperatures shall be maintained at 160 ±14 °C (320 ±25 °F).
8.2 Sample Recovery. Same as Method 5, section 8.7, except that the recovery solvent shall be water instead of acetone, and a clean filter from the same lot as those used during testing shall be saved for analysis as a blank.
9.1 Miscellaneous Quality Control Measures
| Section | Quality control measure | Effect |
|---|---|---|
| 8.3, 10.0 | Sampling equipment leak check and calibration | Ensures accurate measurement of stack gas flow rate, sample volume. |
| 10.1.2, 11.2.5.3 | Repetitive analyses | Ensures precise measurement of total carbon and inorganic carbon concentration of samples, blank, and standards. |
9.2 Volume Metering System Checks. Same as Method 5, section 9.2.
Same as Method 5, section 10.0, with the addition of the following:
10.1 Determination of Ion Chromatograph Calibration Factor S. Prepare a series of five standards by adding 1.0, 2.0, 4.0, 6.0, and 10.0 ml of working standard solution (25 µg/ml) to a series of five 50-ml volumetric flasks. (The standard masses will equal 25, 50, 100, 150, and 250 µg.) Dilute each flask to the mark with water, and mix well. Analyze each standard according to the chromatograph manufacturer’s instructions. Take peak height measurements with symmetrical peaks; in all other cases, calculate peak areas. Prepare or calculate a linear regression plot of the standard masses in µg (x-axis) versus their responses (y-axis). From this line, or equation, determine the slope and calculate its reciprocal which is the calibration factor, S. If any point deviates from the line by more than 7 percent of the concentration at that point, remake and reanalyze that standard. This deviation can be determined by multiplying S times the response for each standard. The resultant concentrations must not differ by more than 7 percent from each known standard mass (i.e., 25, 50, 100, 150, and 250 µg).
10.2 Conductivity Detector. Calibrate according to manufacturer’s specifications prior to initial use.
11.1 Sample Extraction.
11.1.1 Note on the analytical data sheet, the level of the liquid in the container, and whether any sample was lost during shipment. If a noticeable amount of leakage has occurred, either void the sample or use methods, subject to the approval of the Administrator, to correct the final results.
11.1.2 Cut the filter into small pieces, and place it in a 125-ml Erlenmeyer flask with a ground glass joint equipped with an air condenser. Rinse the shipping container with water, and pour the rinse into the flask. Add additional water to the flask until it contains about 75 ml, and place the flask on a hot plate. Gently reflux the contents for 6 to 8 hours. Cool the solution, and transfer it to a 500-ml volumetric flask. Rinse the Erlenmeyer flask with water, and transfer the rinsings to the volumetric flask including the pieces of filter.
11.1.3 Transfer the probe rinse to the same 500-ml volumetric flask with the filter sample. Rinse the sample bottle with water, and add the rinsings to the volumetric flask. Dilute the contents of the flask to the mark with water.
11.1.4 Allow the contents of the flask to settle until all solid material is at the bottom of the flask. If necessary, remove and centrifuge a portion of the sample.
11.1.5 Repeat the procedures outlined in sections 11.1.1 through 11.1.4 for each sample and for the filter blank.
11.2 Sulfate (SO
11.2.1 Prepare a standard calibration curve according to the procedures outlined in section 10.1.
11.2.2 Pipet 5 ml of the sample into a 50-ml volumetric flask, and dilute to 50 ml with water. (Alternatively, eluent solution may be used instead of water in all sample, standard, and blank dilutions.) Analyze the set of standards followed by the set of samples, including the filter blank, using the same injection volume used for the standards.
11.2.3 Repeat the analyses of the standards and the samples, with the standard set being done last. The two peak height or peak area responses for each sample must agree within 5 percent of their arithmetic mean for the analysis to be valid. Perform this analysis sequence on the same day. Dilute any sample and the blank with equal volumes of water if the concentration exceeds that of the highest standard.
11.2.4 Document each sample chromatogram by listing the following analytical parameters: injection point, injection volume, sulfate retention time, flow rate, detector sensitivity setting, and recorder chart speed.
11.3 Sample Residue.
11.3.1 Transfer the remaining contents of the volumetric flask to a tared 600-ml beaker or similar container. Rinse the volumetric flask with water, and add the rinsings to the tared beaker. Make certain that all particulate matter is transferred to the beaker. Evaporate the water in an oven at 105 °C (220 °F) until only about 100 ml of water remains. Remove the beakers from the oven, and allow them to cool.
11.3.2 After the beakers have cooled, add five drops of phenolphthalein indicator, and then add concentrated ammonium hydroxide until the solution turns pink. Return the samples to the oven at 105 °C (220 °F), and evaporate the samples to dryness. Cool the samples in a desiccator, and weigh the samples to constant weight.
Same as Method 5, section 12.0, with the addition of the following:
12.1 Nomenclature.
12.2 Water Blank Concentration.
12.3 Mass of Ammonium Sulfate.
12.4 Mass of Nonsulfate Particulate Matter.
16.1 The following procedure may be used as an alternative to the procedure in section 11.0
16.1.1 Apparatus. Same as for Method 6, sections 6.3.3 to 6.3.6 with the following additions.
16.1.1.1 Beakers. 250-ml, one for each sample, and 600-ml.
16.1.1.2 Oven. Capable of maintaining temperatures of 75 ±5 °C (167 ±9 °F) and 105 ±5 °C (221 ±9 °F).
16.1.1.3 Buchner Funnel.
16.1.1.4 Glass Columns. 25-mm × 305-mm (1-in. × 12-in.) with Teflon stopcock.
16.1.1.5 Volumetric Flasks. 50-ml and 500-ml, one set for each sample, and 100-ml, 200-ml, and 1000-ml.
16.1.1.6 Pipettes. Two 20-ml and one 200-ml, one set for each sample, and 5-ml.
16.1.1.7 Filter Flasks. 500-ml.
16.1.1.8 Polyethylene Bottle. 500-ml, one for each sample.
16.1.2 Reagents. Same as Method 6, sections 7.3.2 to 7.3.5 with the following additions:
16.1.2.1 Water, Ammonium Hydroxide, and Phenolphthalein. Same as sections 7.2.1, 7.3.5, and 7.3.6 of this method, respectively.
16.1.2.2 Filter. Glass fiber to fit Buchner funnel.
16.1.2.3 Hydrochloric Acid (HCl), 1 m. Add 8.3 ml of concentrated HCl (12 M) to 50 ml of water in a 100-ml volumetric flask. Dilute to 100 ml with water.
16.1.2.4 Glass Wool.
16.1.2.5 Ion Exchange Resin. Strong cation exchange resin, hydrogen form, analytical grade.
16.1.2.6 pH Paper. Range of 1 to 7.
16.1.3 Analysis.
16.1.3.1 Ion Exchange Column Preparation. Slurry the resin with 1 M HCl in a 250-ml beaker, and allow to stand overnight. Place 2.5 cm (1 in.) of glass wool in the bottom of the glass column. Rinse the slurried resin twice with water. Resuspend the resin in water, and pour sufficient resin into the column to make a bed 5.1 cm (2 in.) deep. Do not allow air bubbles to become entrapped in the resin or glass wool to avoid channeling, which may produce erratic results. If necessary, stir the resin with a glass rod to remove air bubbles, after the column has been prepared, never let the liquid level fall below the top of the upper glass wool plug. Place a 2.5-cm (1-in.) plug of glass wool on top of the resin. Rinse the column with water until the eluate gives a pH of 5 or greater as measured with pH paper.
16.1.3.2 Sample Extraction. Followup the procedure given in section 11.1.3 except do not dilute the sample to 500 ml.
16.1.3.3 Sample Residue.
16.1.3.3.1 Place at least one clean glass filter for each sample in a Buchner funnel, and rinse the filters with water. Remove the filters from the funnel, and dry them in an oven at 105 ±5 °C (221 ±9 °F); then cool in a desiccator. Weigh each filter to constant weight according to the procedure in Method 5, section 11.0. Record the weight of each filter to the nearest 0.1 mg.
16.1.3.3.2 Assemble the vacuum filter apparatus, and place one of the clean, tared glass fiber filters in the Buchner funnel. Decant the liquid portion of the extracted sample (Section 16.1.3.2) through the tared glass fiber filter into a clean, dry, 500-ml filter flask. Rinse all the particulate matter remaining in the volumetric flask onto the glass fiber filter with water. Rinse the particulate matter with additional water. Transfer the filtrate to a 500-ml volumetric flask, and dilute to 500 ml with water. Dry the filter overnight at 105 ±5 °C (221 ±9 °F), cool in a desiccator, and weigh to the nearest 0.1 mg.
16.1.3.3.3 Dry a 250-ml beaker at 75 ±5 °C (167 ±9 °F), and cool in a desiccator; then weigh to constant weight to the nearest 0.1 mg. Pipette 200 ml of the filtrate that was saved into a tared 250-ml beaker; add five drops of phenolphthalein indicator and sufficient concentrated ammonium hydroxide to turn the solution pink. Carefully evaporate the contents of the beaker to dryness at 75 ±5 °C (167 ±9 °F). Check for dryness every 30 minutes. Do not continue to bake the sample once it has dried. Cool the sample in a desiccator, and weigh to constant weight to the nearest 0.1 mg.
16.1.3.4 Sulfate Analysis. Adjust the flow rate through the ion exchange column to 3 ml/min. Pipette a 20-ml aliquot of the filtrate onto the top of the ion exchange column, and collect the eluate in a 50-ml volumetric flask. Rinse the column with two 15-ml portions of water. Stop collection of the eluate when the volume in the flask reaches 50-ml. Pipette a 20-ml aliquot of the eluate into a 250-ml Erlenmeyer flask, add 80 ml of 100 percent isopropanol and two to four drops of thorin indicator, and titrate to a pink end point using 0.0100 N barium perchlorate. Repeat and average the titration volumes. Run a blank with each series of samples. Replicate titrations must agree within 1 percent or 0.2 ml, whichever is larger. Perform the ion exchange and titration procedures on duplicate portions of the filtrate. Results should agree within 5 percent. Regenerate or replace the ion exchange resin after 20 sample aliquots have been analyzed or if the end point of the titration becomes unclear.
Protect the 0.0100 N barium perchlorate solution from evaporation at all times.
16.1.3.5 Blank Determination. Begin with a sample of water of the same volume as the samples being processed and carry it through the analysis steps described in sections 16.1.3.3 and 16.1.3.4. A blank value larger than 5 mg should not be subtracted from the final particulate matter mass. Causes for large blank values should be investigated and any problems resolved before proceeding with further analyses.
16.1.4 Calibration. Calibrate the barium perchlorate solutions as in Method 6, section 10.5.
16.1.5 Calculations.
16.1.5.1 Nomenclature. Same as section 12.1 with the following additions:
16.1.5.2 Mass of Insoluble Particulate Matter.
16.1.5.3 Mass of Dissolved Particulate Matter.
16.1.5.4 Mass of Ammonium Sulfate.
16.1.5.5 Mass of Nonsulfate Particulate Matter.
Same as Method 5, section 17.0, with the addition of the following:
1. Mulik, J.D. and E. Sawicki. Ion Chromatographic Analysis of Environmental Pollutants. Ann Arbor, Ann Arbor Science Publishers, Inc. Vol. 2, 1979.
2. Sawicki, E., J.D. Mulik, and E. Wittgenstein. Ion Chromatographic Analysis of Environmental Pollutants. Ann Arbor, Ann Arbor Science Publishers, Inc. Vol. 1. 1978.
3. Siemer, D.D. Separation of Chloride and Bromide from Complex Matrices Prior to Ion Chromatographic Determination. Analytical Chemistry 52(12): 1874-1877. October 1980.
4. Small, H., T.S. Stevens, and W.C. Bauman. Novel Ion Exchange Chromatographic Method Using Conductimetric Determination. Analytical Chemistry. 47(11):1801. 1975.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 2, Method 3, Method 4, Method 5, Method 5H, and Method 28.
1.1 Analyte. Particulate matter (PM). No CAS number assigned.
1.2 Applicability. This method is applicable for the determination of PM emissions from wood heaters.
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 The exhaust from a wood heater is collected with a total collection hood, and is combined with ambient dilution air. Particulate matter is withdrawn proportionally from a single point in a sampling tunnel, and is collected on two glass fiber filters in series. The filters are maintained at a temperature of no greater than 32 °C (90 °F). The particulate mass is determined gravimetrically after the removal of uncombined water.
2.2 There are three sampling train approaches described in this method: (1) One dual-filter dry sampling train operated at about 0.015 m
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to performing this test method.
6.1 Sample Collection. The following items are required for sample collection:
6.1.1 Sampling Train. The sampling train configuration is shown in Figure 5G-1 and consists of the following components:
6.1.1.1 Probe. Stainless steel (e.g., 316 or grade more corrosion resistant) or glass about 9.5 mm (
6.1.1.2 Pitot Tube. Type S, as described in section 6.1 of Method 2. The Type S pitot tube assembly shall have a known coefficient, determined as outlined in Method 2, section 10. Alternatively, a standard pitot may be used as described in Method 2, section 6.1.2.
6.1.1.3 Differential Pressure Gauge. Inclined manometer or equivalent device, as described in Method 2, section 6.2. One manometer shall be used for velocity head (Δp) readings and another (optional) for orifice differential pressure readings (ΔH).
6.1.1.4 Filter Holders. Two each made of borosilicate glass, stainless steel, or Teflon, with a glass frit or stainless steel filter support and a silicone rubber, Teflon, or Viton gasket. The holder design shall provide a positive seal against leakage from the outside or around the filters. The filter holders shall be placed in series with the backup filter holder located 25 to 100 mm (1 to 4 in.) downstream from the primary filter holder. The filter holder shall be capable of holding a filter with a 100 mm (4 in.) diameter, except as noted in section 16.
6.1.1.5 Filter Temperature Monitoring System. A temperature sensor capable of measuring temperature to within ±3 °C (±5 °F). The sensor shall be installed at the exit side of the front filter holder so that the sensing tip of the temperature sensor is in direct contact with the sample gas or in a thermowell as shown in Figure 5G-1. The temperature sensor shall comply with the calibration specifications in Method 2, section 10.3. Alternatively, the sensing tip of the temperature sensor may be installed at the inlet side of the front filter holder.
6.1.1.6 Dryer. Any system capable of removing water from the sample gas to less than 1.5 percent moisture (volume percent) prior to the metering system. The system shall include a temperature sensor for demonstrating that sample gas temperature exiting the dryer is less than 20 °C (68 °F).
6.1.1.7 Metering System. Same as Method 5, section 6.1.1.9.
6.1.2 Barometer. Same as Method 5, section 6.1.2.
6.1.3 Dilution Tunnel Gas Temperature Measurement. A temperature sensor capable of measuring temperature to within ±3 °C (±5 °F).
6.1.4 Dilution Tunnel. The dilution tunnel apparatus is shown in Figure 5G-2 and consists of the following components:
6.1.4.1 Hood. Constructed of steel with a minimum diameter of 0.3 m (1 ft) on the large end and a standard 0.15 to 0.3 m (0.5 to 1 ft) coupling capable of connecting to standard 0.15 to 0.3 m (0.5 to 1 ft) stove pipe on the small end.
6.1.4.2 90° Elbows. Steel 90° elbows, 0.15 to 0.3 m (0.5 to 1 ft) in diameter for connecting mixing duct, straight duct and optional damper assembly. There shall be at least two 90° elbows upstream of the sampling section (see Figure 5G-2).
6.1.4.3 Straight Duct. Steel, 0.15 to 0.3 m (0.5 to 1 ft) in diameter to provide the ducting for the dilution apparatus upstream of the sampling section. Steel duct, 0.15 m (0.5 ft) in diameter shall be used for the sampling section. In the sampling section, at least 1.2 m (4 ft) downstream of the elbow, shall be two holes (velocity traverse ports) at 90° to each other of sufficient size to allow entry of the pitot for traverse measurements. At least 1.2 m (4 ft) downstream of the velocity traverse ports, shall be one hole (sampling port) of sufficient size to allow entry of the sampling probe. Ducts of larger diameter may be used for the sampling section, provided the specifications for minimum gas velocity and the dilution rate range shown in section 8 are maintained. The length of duct from the hood inlet to the sampling ports shall not exceed 9.1 m (30 ft).
6.1.4.4 Mixing Baffles. Steel semicircles (two) attached at 90° to the duct axis on opposite sides of the duct midway between the two elbows upstream of sampling section. The space between the baffles shall be about 0.3 m (1 ft).
6.1.4.5 Blower. Squirrel cage or other fan capable of extracting gas from the dilution tunnel of sufficient flow to maintain the velocity and dilution rate specifications in section 8 and exhausting the gas to the atmosphere.
6.2 Sample Recovery. The following items are required for sample recovery: probe brushes, wash bottles, sample storage containers, petri dishes, and funnel. Same as Method 5, sections 6.2.1 through 6.2.4, and 6.2.8, respectively.
6.3 Sample Analysis. The following items are required for sample analysis: glass weighing dishes, desiccator, analytical balance, beakers (250-ml or smaller), hygrometer, and temperature sensor. Same as Method 5, sections 6.3.1 through 6.3.3 and 6.3.5 through 6.3.7, respectively.
7.1 Sample Collection. The following reagents are required for sample collection:
7.1.1 Filters. Glass fiber filters with a minimum diameter of 100 mm (4 in.), without organic binder, exhibiting at least 99.95 percent efficiency (
7.1.2 Stopcock Grease. Same as Method 5, section 7.1.5. 7.2 Sample Recovery. Acetone-reagent grade, same as Method 5, section 7.2.
7.3 Sample Analysis. Two reagents are required for the sample analysis:
7.3.1 Acetone. Same as in section 7.2.
7.3.2 Desiccant. Anhydrous calcium sulfate, calcium chloride, or silica gel, indicating type.
8.1 Dilution Tunnel Assembly and Cleaning. A schematic of a dilution tunnel is shown in Figure 5G-2. The dilution tunnel dimensions and other features are described in section 6.1.4. Assemble the dilution tunnel, sealing joints and seams to prevent air leakage. Clean the dilution tunnel with an appropriately sized wire chimney brush before each certification test.
8.2 Draft Determination. Prepare the wood heater as in Method 28, section 6.2.1. Locate the dilution tunnel hood centrally over the wood heater stack exhaust. Operate the dilution tunnel blower at the flow rate to be used during the test run. Measure the draft imposed on the wood heater by the dilution tunnel (i.e., the difference in draft measured with and without the dilution tunnel operating) as described in Method 28, section 6.2.3. Adjust the distance between the top of the wood heater stack exhaust and the dilution tunnel hood so that the dilution tunnel induced draft is less than 1.25 Pa (0.005 in. H
8.3 Pretest Ignition. Same as Method 28, section 8.7.
8.4 Smoke Capture. During the pretest ignition period, operate the dilution tunnel and visually monitor the wood heater stack exhaust. Operate the wood heater with the doors closed and determine that 100 percent of the exhaust gas is collected by the dilution tunnel hood. If less than 100 percent of the wood heater exhaust gas is collected, adjust the distance between the wood heater stack and the dilution tunnel hood until no visible exhaust gas is escaping. Stop the pretest ignition period, and repeat the draft determination procedure described in section 8.2.
8.5 Velocity Measurements. During the pretest ignition period, conduct a velocity traverse to identify the point of average velocity. This single point shall be used for measuring velocity during the test run.
8.5.1 Velocity Traverse. Measure the diameter of the duct at the velocity traverse port location through both ports. Calculate the duct area using the average of the two diameters. A pretest leak-check of pitot lines as in Method 2, section 8.1, is recommended. Place the calibrated pitot tube at the centroid of the stack in either of the velocity traverse ports. Adjust the damper or similar device on the blower inlet until the velocity indicated by the pitot is approximately 220 m/min (720 ft/min). Continue to read the Δp and temperature until the velocity has remained constant (less than 5 percent change) for 1 minute. Once a constant velocity is obtained at the centroid of the duct, perform a velocity traverse as outlined in Method 2, section 8.3 using four points per traverse as outlined in Method 1. Measure the Δp and tunnel temperature at each traverse point and record the readings. Calculate the total gas flow rate using calculations contained in Method 2, section 12. Verify that the flow rate is 4 ±0.40 dscm/min (140 ±14 dscf/min); if not, readjust the damper, and repeat the velocity traverse. The moisture may be assumed to be 4 percent (100 percent relative humidity at 85 °F). Direct moisture measurements (e.g., according to Method 4) are also permissible.
If burn rates exceed 3 kg/hr (6.6 lb/hr), dilution tunnel duct flow rates greater than 4 dscm/min (140 dscfm) and sampling section duct diameters larger than 150 mm (6 in.) are allowed. If larger ducts or flow rates are used, the sampling section velocity shall be at least 220 m/min (720 fpm). In order to ensure measurable particulate mass catch, it is recommended that the ratio of the average mass flow rate in the dilution tunnel to the average fuel burn rate be less than 150:1 if larger duct sizes or flow rates are used.
8.5.2 Testing Velocity Measurements. After obtaining velocity traverse results that meet the flow rate requirements, choose a point of average velocity and place the pitot and temperature sensor at that location in the duct. Alternatively, locate the pitot and the temperature sensor at the duct centroid and calculate a velocity correction factor for the centroidal position. Mount the pitot to ensure no movement during the test run and seal the port holes to prevent any air leakage. Align the pitot opening to be parallel with the duct axis at the measurement point. Check that this condition is maintained during the test run (about 30-minute intervals). Monitor the temperature and velocity during the pretest ignition period to ensure that the proper flow rate is maintained. Make adjustments to the dilution tunnel flow rate as necessary.
8.6 Pretest Preparation. Same as Method 5, section 8.1.
8.7 Preparation of Sampling Train. During preparation and assembly of the sampling train, keep all openings where contamination can occur covered until just prior to assembly or until sampling is about to begin.
Using a tweezer or clean disposable surgical gloves, place one labeled (identified) and weighed filter in each of the filter holders. Be sure that each filter is properly centered and that the gasket is properly placed so as to prevent the sample gas stream from circumventing the filter. Check each filter for tears after assembly is completed.
Mark the probe with heat resistant tape or by some other method to denote the proper distance into the stack or duct. Set up the train as shown in Figure 5G-1.
8.8 Leak-Check Procedures.
8.8.1 Leak-Check of Metering System Shown in Figure 5G-1. That portion of the sampling train from the pump to the orifice meter shall be leak-checked prior to initial use and after each certification or audit test. Leakage after the pump will result in less volume being recorded than is actually sampled. Use the procedure described in Method 5, section 8.4.1. Similar leak-checks shall be conducted for other types of metering systems (i.e., without orifice meters).
8.8.2 Pretest Leak-Check. A pretest leak-check of the sampling train is recommended, but not required. If the pretest leak check is conducted, the procedures outlined in Method 5, section 8.4.2 should be used. A vacuum of 130 mm Hg (5 in. Hg) may be used instead of 380 mm Hg (15 in. Hg).
8.8.3 Post-Test Leak-Check. A leak-check of the sampling train is mandatory at the conclusion of each test run. The leak-check shall be performed in accordance with the procedures outlined in Method 5, section 8.4.2. A vacuum of 130 mm Hg (5 in. Hg) or the highest vacuum measured during the test run, whichever is greater, may be used instead of 380 mm Hg (15 in. Hg).
8.9 Preliminary Determinations. Determine the pressure, temperature and the average velocity of the tunnel gases as in section 8.5. Moisture content of diluted tunnel gases is assumed to be 4 percent for making flow rate calculations; the moisture content may be measured directly as in Method 4.
8.10 Sampling Train Operation. Position the probe inlet at the stack centroid, and block off the openings around the probe and porthole to prevent unrepresentative dilution of the gas stream. Be careful not to bump the probe into the stack wall when removing or inserting the probe through the porthole; this minimizes the chance of extracting deposited material.
8.10.1 Begin sampling at the start of the test run as defined in Method 28, section 8.8.1. During the test run, maintain a sample flow rate proportional to the dilution tunnel flow rate (within 10 percent of the initial proportionality ratio) and a filter holder temperature of no greater than 32 °C (90 °F). The initial sample flow rate shall be approximately 0.015 m
8.10.2 For each test run, record the data required on a data sheet such as the one shown in Figure 5G-3. Be sure to record the initial dry gas meter reading. Record the dry gas meter readings at the beginning and end of each sampling time increment and when sampling is halted. Take other readings as indicated on Figure 5G-3 at least once each 10 minutes during the test run. Since the manometer level and zero may drift because of vibrations and temperature changes, make periodic checks during the test run.
8.10.3 For the purposes of proportional sampling rate determinations, data from calibrated flow rate devices, such as glass rotameters, may be used in lieu of incremental dry gas meter readings. Proportional rate calculation procedures must be revised, but acceptability limits remain the same.
8.10.4 During the test run, make periodic adjustments to keep the temperature between (or upstream of) the filters at the proper level. Do not change sampling trains during the test run.
8.10.5 At the end of the test run (see Method 28, section 6.4.6), turn off the coarse adjust valve, remove the probe from the stack, turn off the pump, record the final dry gas meter reading, and conduct a post-test leak-check, as outlined in section 8.8.2. Also, leak-check the pitot lines as described in Method 2, section 8.1; the lines must pass this leak-check in order to validate the velocity head data.
8.11 Calculation of Proportional Sampling Rate. Calculate percent proportionality (see section 12.7) to determine whether the run was valid or another test run should be made.
8.12 Sample Recovery. Same as Method 5, section 8.7, with the exception of the following:
8.12.1 An acetone blank volume of about 50-ml or more may be used.
8.12.2 Treat the samples as follows:
8.12.2.1 Container Nos. 1 and 1A. Treat the two filters according to the procedures outlined in Method 5, section 8.7.6.1. The filters may be stored either in a single container or in separate containers. Use the sum of the filter tare weights to determine the sample mass collected.
8.12.2.3 Container No. 2.
8.12.2.3.1 Taking care to see that dust on the outside of the probe or other exterior surfaces does not get into the sample, quantitatively recover particulate matter or any condensate from the probe and filter holders by washing and brushing these components with acetone and placing the wash in a labeled glass container. At least three cycles of brushing and rinsing are required.
8.12.2.3.2 Between sampling runs, keep brushes clean and protected from contamination.
8.12.2.3.3 After all acetone washings and particulate matter have been collected in the sample containers, tighten the lids on the sample containers so that the acetone will not leak out when transferred to the laboratory weighing area. Mark the height of the fluid levels to determine whether leakage occurs during transport. Label the containers clearly to identify contents.
8.13 Sample Transport. Whenever possible, containers should be shipped in such a way that they remain upright at all times.
Requirements for capping and transport of sample containers are not applicable if sample recovery and analysis occur in the same room.
9.1 Miscellaneous Quality Control Measures.
| Section | Quality control measure | Effect |
|---|---|---|
| 8.8, 10.1-10.4 | Sampling equipment leak check and calibration | Ensures accurate measurement of stack gas flow rate, sample volume. |
| 10.5 | Analytical balance calibration | Ensure accurate and precise measurement of collected particulate. |
| 16.2.5 | Simultaneous, dual-train sample collection | Ensure precision of measured particulate concentration. |
9.2 Volume Metering System Checks. Same as Method 5, section 9.2.
Maintain a laboratory record of all calibrations.
10.1 Pitot Tube. The Type S pitot tube assembly shall be calibrated according to the procedure outlined in Method 2, section 10.1, prior to the first certification test and checked semiannually, thereafter. A standard pitot need not be calibrated but shall be inspected and cleaned, if necessary, prior to each certification test.
10.2 Volume Metering System.
10.2.1 Initial and Periodic Calibration. Before its initial use and at least semiannually thereafter, calibrate the volume metering system as described in Method 5, section 10.3.1, except that the wet test meter with a capacity of 3.0 liters/rev (0.1 ft
Procedures and equipment specified in Method 5, section 16.0, for alternative calibration standards, including calibrated dry gas meters and critical orifices, are allowed for calibrating the dry gas meter in the sampling train. A dry gas meter used as a calibration standard shall be recalibrated at least once annually.
10.2.2 Calibration After Use. After each certification or audit test (four or more test runs conducted on a wood heater at the four burn rates specified in Method 28), check calibration of the metering system by performing three calibration runs at a single, intermediate flow rate as described in Method 5, section 10.3.2.
Procedures and equipment specified in Method 5, section 16.0, for alternative calibration standards are allowed for the post-test dry gas meter calibration check.
10.2.3 Acceptable Variation in Calibration. If the dry gas meter coefficient values obtained before and after a certification test differ by more than 5 percent, the certification test shall either be voided and repeated, or calculations for the certification test shall be performed using whichever meter coefficient value (i.e., before or after) gives the lower value of total sample volume.
10.3 Temperature Sensors. Use the procedure in Method 2, section 10.3, to calibrate temperature sensors before the first certification or audit test and at least semiannually, thereafter.
10.4 Barometer. Calibrate against a mercury barometer before the first certification test and at least semiannually, thereafter. If a mercury barometer is used, no calibration is necessary. Follow the manufacturer’s instructions for operation.
10.5 Analytical Balance. Perform a multipoint calibration (at least five points spanning the operational range) of the analytical balance before the first certification test and semiannually, thereafter. Before each certification test, audit the balance by weighing at least one calibration weight (class F) that corresponds to 50 to 150 percent of the weight of one filter. If the scale cannot reproduce the value of the calibration weight to within 0.1 mg, conduct the multipoint calibration before use.
11.1 Record the data required on a sheet such as the one shown in Figure 5G-4. Use the same analytical balance for determining tare weights and final sample weights.
11.2 Handle each sample container as follows:
11.2.1 Container Nos. 1 and 1A. Treat the two filters according to the procedures outlined in Method 5, section 11.2.1.
11.2.2 Container No. 2. Same as Method 5, section 11.2.2, except that the beaker may be smaller than 250 ml.
11.2.3 Acetone Blank Container. Same as Method 5, section 11.2.4, except that the beaker may be smaller than 250 ml.
Carry out calculations, retaining at least one extra significant figure beyond that of the acquired data. Round off figures after the final calculation. Other forms of the equations may be used as long as they give equivalent results.
12.1 Nomenclature.
12.2 Dry Gas Volume. Same as Method 5, section 12.2, except that component changes are not allowable.
12.3 Solvent Wash Blank.
12.4 Total Particulate Weight. Determine the total particulate catch, mn, from the sum of the weights obtained from Container Nos. 1, 1A, and 2, less the acetone blank (see Figure 5G-4).
12.5 Particulate Concentration.
12.6 Particulate Emission Rate.
Particulate emission rate results produced using the sampling train described in section 6 and shown in Figure 5G-1 shall be adjusted for reporting purposes by the following method adjustment factor:
12.7 Proportional Rate Variation. Calculate PR for each 10-minute interval, i, of the test run.
Alternate calculation procedures for proportional rate variation may be used if other sample flow rate data (e.g., orifice flow meters or rotameters) are monitored to maintain proportional sampling rates. The proportional rate variations shall be calculated for each 10-minute interval by comparing the stack to nozzle velocity ratio for each 10-minute interval to the average stack to nozzle velocity ratio for the test run. Proportional rate variation may be calculated for intervals shorter than 10 minutes with appropriate revisions to Equation 5G-5. If no more than 10 percent of the PR values for all the intervals exceed 90 percent ≤PR ≤110 percent, and if no PR value for any interval exceeds 80 percent ≤PR ≤120 percent, the results are acceptable. If the PR values for the test run are judged to be unacceptable, report the test run emission results, but do not include the results in calculating the weighted average emission rate, and repeat the test run.
16.1 Method 5H Sampling Train. The sampling train and sample collection, recovery, and analysis procedures described in Method 5H, sections 6.1.1, 7.1, 7.2, 8.1, 8.10, 8.11, and 11.0, respectively, may be used in lieu of similar sections in Method 5G. Operation of the Method 5H sampling train in the dilution tunnel is as described in section 8.10 of this method. Filter temperatures and condenser conditions are as described in Method 5H. No adjustment to the measured particulate matter emission rate (Equation 5G-4, section 12.6) is to be applied to the particulate emission rate measured by this alternative method.
16.2 Dual Sampling Trains. Two sampling trains may be operated simultaneously at sample flow rates other than that specified in section 8.10, provided that the following specifications are met.
16.2.1 Sampling Train. The sampling train configuration shall be the same as specified in section 6.1.1, except the probe, filter, and filter holder need not be the same sizes as specified in the applicable sections. Filter holders of plastic materials such as Nalgene or polycarbonate materials may be used (the Gelman 1119 filter holder has been found suitable for this purpose). With such materials, it is recommended that solvents not be used in sample recovery. The filter face velocity shall not exceed 150 mm/sec (30 ft/min) during the test run. The dry gas meter shall be calibrated for the same flow rate range as encountered during the test runs. Two separate, complete sampling trains are required for each test run.
16.2.2 Probe Location. Locate the two probes in the dilution tunnel at the same level (see section 6.1.4.3). Two sample ports are necessary. Locate the probe inlets within the 50 mm (2 in.) diameter centroidal area of the dilution tunnel no closer than 25 mm (1 in.) apart.
16.2.3 Sampling Train Operation. Operate the sampling trains as specified in section 8.10, maintaining proportional sampling rates and starting and stopping the two sampling trains simultaneously. The pitot values as described in section 8.5.2 shall be used to adjust sampling rates in both sampling trains.
16.2.4 Recovery and Analysis of Sample. Recover and analyze the samples from the two sampling trains separately, as specified in sections 8.12 and 11.0, respectively.
16.2.4.1 For this alternative procedure, the probe and filter holder assembly may be weighed without sample recovery (use no solvents) described above in order to determine the sample weight gains. For this approach, weigh the clean, dry probe and filter holder assembly upstream of the front filter (without filters) to the nearest 0.1 mg to establish the tare weights. The filter holder section between the front and second filter need not be weighed. At the end of the test run, carefully clean the outside of the probe, cap the ends, and identify the sample (label). Remove the filters from the filter holder assemblies as described for container Nos. 1 and 1A in section 8.12.2.1. Reassemble the filter holder assembly, cap the ends, identify the sample (label), and transfer all the samples to the laboratory weighing area for final weighing. Requirements for capping and transport of sample containers are not applicable if sample recovery and analysis occur in the same room.
16.2.4.2 For this alternative procedure, filters may be weighed directly without a petri dish. If the probe and filter holder assembly are to be weighed to determine the sample weight, rinse the probe with acetone to remove moisture before desiccating prior to the test run. Following the test run, transport the probe and filter holder to the desiccator, and uncap the openings of the probe and the filter holder assembly. Desiccate for 24 hours and weigh to a constant weight. Report the results to the nearest 0.1 mg.
16.2.5 Calculations. Calculate an emission rate (Section 12.6) for the sample from each sampling train separately and determine the average emission rate for the two values. The two emission rates shall not differ by more than 7.5 percent from the average emission rate, or 7.5 percent of the weighted average emission rate limit in the applicable subpart of the regulations, whichever is greater. If this specification is not met, the results are unacceptable. Report the results, but do not include the results in calculating the weighted average emission rate. Repeat the test run until acceptable results are achieved, report the average emission rate for the acceptable test run, and use the average in calculating the weighted average emission rate.
Same as Method 5, section 17.0, References 1 through 11, with the addition of the following:
1. Oregon Department of Environmental Quality. Standard Method for Measuring the Emissions and Efficiencies of Woodstoves. June 8, 1984. Pursuant to Oregon Administrative Rules Chapter 340, Division 21.
2. American Society for Testing and Materials. Proposed Test Methods for Heating Performance and Emissions of Residential Wood-fired Closed Combustion-Chamber Heating Appliances. E-6 Proposal P 180. August 1986.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 2, Method 3, Method 5, Method 5G, Method 6, Method 6C, Method 16A, and Method 28.
1.1 Analyte. Particulate matter (PM). No CAS number assigned.
1.2 Applicability. This method is applicable for the determination of PM and condensible emissions from wood heaters.
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 Particulate matter is withdrawn proportionally from the wood heater exhaust and is collected on two glass fiber filters separated by impingers immersed in an ice water bath. The first filter is maintained at a temperature of no greater than 120 °C (248 °F). The second filter and the impinger system are cooled such that the temperature of the gas exiting the second filter is no greater than 20 °C (68 °F). The particulate mass collected in the probe, on the filters, and in the impingers is determined gravimetrically after the removal of uncombined water.
Same as in Method 6C, section 3.0.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to performing this test method.
6.1 Sample Collection. The following items are required for sample collection:
6.1.1 Sampling Train. The sampling train configuration is shown in Figure 5H-1. Same as Method 5, section 6.1.1, with the exception of the following:
6.1.1.1 Probe Nozzle. The nozzle is optional; a straight sampling probe without a nozzle is an acceptable alternative.
6.1.1.2 Probe Liner. Same as Method 5, section 6.1.1.2, except that the maximum length of the sample probe shall be 0.6 m (2 ft) and probe heating is optional.
6.1.1.3 Filter Holders. Two each of borosilicate glass, with a glass frit or stainless steel filter support and a silicone rubber, Teflon, or Viton gasket. The holder design shall provide a positive seal against leakage from the outside or around the filter. The front filter holder shall be attached immediately at the outlet of the probe and prior to the first impinger. The second filter holder shall be attached on the outlet of the third impinger and prior to the inlet of the fourth (silica gel) impinger.
6.1.2 Barometer. Same as Method 5, section 6.2.
6.1.3 Stack Gas Flow Rate Measurement System. A schematic of an example test system is shown in Figure 5H-2. The flow rate measurement system consists of the following components:
6.1.3.1 Sample Probe. A glass or stainless steel sampling probe.
6.1.3.2 Gas Conditioning System. A high density filter to remove particulate matter and a condenser capable of lowering the dew point of the gas to less than 5 °C (40 °F). Desiccant, such as Drierite, may be used to dry the sample gas. Do not use silica gel.
6.1.3.3 Pump. An inert (e.g., Teflon or stainless steel heads) sampling pump capable of delivering more than the total amount of sample required in the manufacturer’s instructions for the individual instruments. A means of controlling the analyzer flow rate and a device for determining proper sample flow rate (e.g., precision rotameter, pressure gauge downstream of all flow controls) shall be provided at the analyzer. The requirements for measuring and controlling the analyzer flow rate are not applicable if data are presented that demonstrate that the analyzer is insensitive to flow variations over the range encountered during the test.
6.1.3.4 Carbon Monoxide (CO) Analyzer. Any analyzer capable of providing a measure of CO in the range of 0 to 10 percent by volume at least once every 10 minutes.
6.1.3.5 Carbon Dioxide (CO
Analyzers with ranges less than those specified above may be used provided actual concentrations do not exceed the range of the analyzer.
6.1.3.6 Manifold. A sampling tube capable of delivering the sample gas to two analyzers and handling an excess of the total amount used by the analyzers. The excess gas is exhausted through a separate port.
6.1.3.7 Recorders (optional). To provide a permanent record of the analyzer outputs.
6.1.4 Proportional Gas Flow Rate System. To monitor stack flow rate changes and provide a measurement that can be used to adjust and maintain particulate sampling flow rates proportional to the stack gas flow rate. A schematic of the proportional flow rate system is shown in Figure 5H-2 and consists of the following components:
6.1.4.1 Tracer Gas Injection System. To inject a known concentration of sulfur dioxide (SO
6.1.4.2 Sample Probe. A glass or stainless steel sampling probe.
6.1.4.3 Gas Conditioning System. A combustor as described in Method 16A, sections 6.1.5 and 6.1.6, followed by a high density filter to remove particulate matter, and a condenser capable of lowering the dew point of the gas to less than 5 °C (40 °F). Desiccant, such as Drierite, may be used to dry the sample gas. Do not use silica gel.
6.1.4.4 Pump. Same as described in section 6.1.3.3.
6.1.4.5 SO
6.1.4.6 Recorder (optional). To provide a permanent record of the analyzer outputs.
Other tracer gas systems, including helium gas systems, are acceptable for determination of instantaneous proportional sampling rates.
6.2 Sample Recovery. Same as Method 5, section 6.2.
6.3 Sample Analysis. Same as Method 5, section 6.3, with the addition of the following:
6.3.1 Separatory Funnel. Glass or Teflon, 500-ml or greater.
7.1 Sample Collection. Same as Method 5, section 7.1, including deionized distilled water.
7.2 Sample Recovery. Same as Method 5, section 7.2.
7.3 Sample Analysis. The following reagents and standards are required for sample analysis:
7.3.1 Acetone. Same as Method 5 section 7.2.
7.3.2 Dichloromethane (Methylene Chloride). Reagent grade,
7.3.3 Desiccant. Anhydrous calcium sulfate, calcium chloride, or silica gel, indicating type.
7.3.4 Cylinder Gases. For the purposes of this procedure, span value is defined as the upper limit of the range specified for each analyzer as described in section 6.1.3.4 or 6.1.3.5. If an analyzer with a range different from that specified in this method is used, the span value shall be equal to the upper limit of the range for the analyzer used (see note in section 6.1.3.5).
7.3.4.1 Calibration Gases. The calibration gases for the CO
7.3.4.2 SO
8.1 Pretest Preparation. Same as Method 5, section 8.1.
8.2 Calibration Gas and SO
8.3 Preliminary Determinations.
8.3.1 Sampling Location. The sampling location for the particulate sampling probe shall be 2.45 ±0.15 m (8 ±0.5 ft) above the platform upon which the wood heater is placed (i.e., the top of the scale).
8.3.2 Sampling Probe and Nozzle. Select a nozzle, if used, sized for the range of velocity heads, such that it is not necessary to change the nozzle size in order to maintain proportional sampling rates. During the run, do not change the nozzle size. Select a suitable probe liner and probe length to effect minimum blockage.
8.4 Preparation of Particulate Sampling Train. Same as Method 5, section 8.3, with the exception of the following:
8.4.1 The train should be assembled as shown in Figure 5H-1.
8.4.2 A glass cyclone may not be used between the probe and filter holder.
8.5 Leak-Check Procedures.
8.5.1 Leak-Check of Metering System Shown in Figure 5H-1. That portion of the sampling train from the pump to the orifice meter shall be leak-checked after each certification or audit test. Use the procedure described in Method 5, section 8.4.1.
8.5.2 Pretest Leak-Check. A pretest leak-check of the sampling train is recommended, but not required. If the pretest leak-check is conducted, the procedures outlined in Method 5, section 8.5.2 should be used. A vacuum of 130 mm Hg (5 in. Hg) may be used instead of 380 mm Hg (15 in. Hg).
8.5.2 Leak-Checks During Sample Run. If, during the sampling run, a component (e.g., filter assembly or impinger) change becomes necessary, conduct a leak-check as described in Method 5, section 8.4.3.
8.5.3 Post-Test Leak-Check. A leak-check is mandatory at the conclusion of each sampling run. The leak-check shall be performed in accordance with the procedures outlined in Method 5, section 8.4.4, except that a vacuum of 130 mm Hg (5 in. Hg) or the greatest vacuum measured during the test run, whichever is greater, may be used instead of 380 mm Hg (15 in. Hg).
8.6 Tracer Gas Procedure. A schematic of the tracer gas injection and sampling systems is shown in Figure 5H-2.
8.6.1 SO
8.6.2 SO
8.7 Flow Rate Measurement System. A schematic of the flow rate measurement system is shown in Figure 5H-2. Locate the flow rate measurement sampling probe at the centroid of the stack at a location 2.3 ±0.3 m (7.5 ±1 ft) above the sampling platform.
8.8 Tracer Gas Procedure. Within 1 minute after closing the wood heater door at the start of the test run (as defined in Method 28, section 8.8.1), meter a known concentration of SO
8.9 Volumetric Flow Rate Procedure. Apply stoichiometric relationships to the wood combustion process in determining the exhaust gas flow rate as follows:
8.9.1 Test Fuel Charge Weight. Record the test fuel charge weight (wet) as specified in Method 28, section 8.8.2. The wood is assumed to have the following weight percent composition: 51 percent carbon, 7.3 percent hydrogen, 41 percent oxygen. Record the wood moisture for each fuel charge as described in Method 28, section 8.6.5. The ash is assumed to have negligible effect on associated C, H, and O concentrations after the test burn.
8.9.2 Measured Values. Record the CO and CO
8.10 Sampling Train Operation.
8.10.1 For each run, record the data required on a data sheet such as the one shown in Figure 5H-3. Be sure to record the initial dry gas meter reading. Record the dry gas meter readings at the beginning and end of each sampling time increment, when changes in flow rates are made, before and after each leak-check, and when sampling is halted. Take other readings as indicated on Figure 5H-3 at least once each 10 minutes during the test run.
8.10.2 Remove the nozzle cap, verify that the filter and probe heating systems are up to temperature, and that the probe is properly positioned. Position the nozzle, if used, facing into gas stream, or the probe tip in the 50 mm (2 in.) centroidal area of the stack.
8.10.3 Be careful not to bump the probe tip into the stack wall when removing or inserting the probe through the porthole; this minimizes the chance of extracting deposited material.
8.10.4 When the probe is in position, block off the openings around the probe and porthole to prevent unrepresentative dilution of the gas stream.
8.10.5 Begin sampling at the start of the test run as defined in Method 28, section 8.8.1, start the sample pump, and adjust the sample flow rate to between 0.003 and 0.014 m
8.10.6 During the test run, make periodic adjustments to keep the temperature around the filter holder at the proper level. Add more ice to the impinger box and, if necessary, salt to maintain a temperature of less than 20 °C (68 °F) at the condenser/silica gel outlet.
8.10.7 If the pressure drop across the filter becomes too high, making proportional sampling difficult to maintain, either filter may be replaced during a sample run. It is recommended that another complete filter assembly be used rather than attempting to change the filter itself. Before a new filter assembly is installed, conduct a leak-check (see section 8.5.2). The total particulate weight shall include the summation of all filter assembly catches. The total time for changing sample train components shall not exceed 10 minutes. No more than one component change is allowed for any test run.
8.10.8 At the end of the test run, turn off the coarse adjust valve, remove the probe and nozzle from the stack, turn off the pump, record the final dry gas meter reading, and conduct a post-test leak-check, as outlined in section 8.5.3.
8.11 Sample Recovery. Same as Method 5, section 8.7, with the exception of the following:
8.11.1 Blanks. The volume of the acetone blank may be about 50-ml, rather than 200-ml; a 200-ml water blank shall also be saved for analysis.
8.11.2 Samples.
8.11.2.1 Container Nos. 1 and 1A. Treat the two filters according to the procedures outlined in Method 5, section 8.7.6.1. The filters may be stored either in a single container or in separate containers.
8.11.2.2 Container No. 2. Same as Method 5, section 8.7.6.2, except that the container should not be sealed until the impinger rinse solution is added (see section 8.10.2.4).
8.11.2.3 Container No. 3. Treat the impingers as follows: Measure the liquid which is in the first three impingers to within 1-ml by using a graduated cylinder or by weighing it to within 0.5 g by using a balance (if one is available). Record the volume or weight of liquid present. This information is required to calculate the moisture content of the effluent gas. Transfer the water from the first, second, and third impingers to a glass container. Tighten the lid on the sample container so that water will not leak out.
8.11.2.4 Rinse impingers and graduated cylinder, if used, with acetone three times or more. Avoid direct contact between the acetone and any stopcock grease or collection of any stopcock grease in the rinse solutions. Add these rinse solutions to sample Container No. 2.
8.11.2.5 Container No. 4. Same as Method 5, section 8.7.6.3
8.12 Sample Transport. Whenever possible, containers should be transferred in such a way that they remain upright at all times.
Requirements for capping and transport of sample containers are not applicable if sample recovery and analysis occur in the same room.
9.1 Miscellaneous Quality Control Measures.
| Section | Quality control measure | Effect |
|---|---|---|
| 8.2 | Sampling system bias check | Ensures that bias introduced by measurement system, minus analyzer, is no greater than 3 percent of span. |
| 8.2 | Analyzer zero and calibration drift tests | Ensures that bias introduced by drift in the measurement system output during the run is no greater than 3 percent of span. |
| 8.5, 10.1, 12.13 | Sampling equipment leak-check and calibration; proportional sampling rate verification | Ensures accurate measurement of stack gas flow rate, sample volume. |
| 10.1 | Analytical balance calibration | Ensure accurate and precise measurement of collected particulate. |
| 10.3 | Analyzer calibration error check | Ensures that bias introduced by analyzer calibration error is no greater than 2 percent of span. |
9.2 Volume Metering System Checks. Same as Method 5, section 9.2.
Maintain a laboratory record of all calibrations.
10.1 Volume Metering System, Temperature Sensors, Barometer, and Analytical Balance. Same as Method 5G, sections 10.2 through 10.5, respectively.
10.2 SO
10.3. Gas Analyzers. Same as Method 6C, section 10.0.
10.4 Field Balance Calibration Check. Check the calibration of the balance used to weigh impingers with a weight that is at least 500g or within 50g of a loaded impinger. The weight must be ASTM E617-13 “Standard Specification for Laboratory Weights and Precision Mass Standards” (incorporated by reference – see 40 CFR 60.17) Class 6 (or better). Daily before use, the field balance must measure the weight within ± 0.5g of the certified mass. If the daily balance calibration check fails, perform corrective measures and repeat the check before using balance.
10.5 Analytical Balance Calibration. Perform a multipoint calibration (at least five points spanning the operational range) of the analytical balance before the first use, and semiannually thereafter. The calibration of the analytical balance must be conducted using ASTM E617-13 “Standard Specification for Laboratory Weights and Precision Mass Standards” (incorporated by reference – see 40 CFR 60.17) Class 2 (or better) tolerance weights. Audit the balance each day it is used for gravimetric measurements by weighing at least one ASTM E617-13 Class 2 tolerance (or better) calibration weight that corresponds to 50 to 150 percent of the weight of one filter or between 1g and 5g. If the scale cannot reproduce the value of the calibration weight to within 0.5 mg of the certified mass, perform corrective measures, and conduct the multipoint calibration before use.
11.1 Record the data required on a sheet such as the one shown in Figure 5H-4.
11.2 Handle each sample container as follows:
11.2.1 Container Nos. 1 and 1A. Treat the two filters according to the procedures outlined in Method 5, section 11.2.1.
11.2.2 Container No. 2. Same as Method 5, section 11.2.2, except that the beaker may be smaller than 250-ml.
11.2.3 Container No. 3. Note the level of liquid in the container and confirm on the analysis sheet whether leakage occurred during transport. If a noticeable amount of leakage has occurred, either void the sample or use methods, subject to the approval of the Administrator, to correct the final results. Determination of sample leakage is not applicable if sample recovery and analysis occur in the same room. Measure the liquid in this container either volumetrically to within 1-ml or gravimetrically to within 0.5 g. Transfer the contents to a 500-ml or larger separatory funnel. Rinse the container with water, and add to the separatory funnel. Add 25-ml of dichloromethane to the separatory funnel, stopper and vigorously shake 1 minute, let separate and transfer the dichloromethane (lower layer) into a tared beaker or evaporating dish. Repeat twice more. It is necessary to rinse Container No. 3 with dichloromethane. This rinse is added to the impinger extract container. Transfer the remaining water from the separatory funnel to a tared beaker or evaporating dish and evaporate to dryness at 104 °C (220 °F). Desiccate and weigh to a constant weight. Evaporate the combined impinger water extracts at ambient temperature and pressure. Desiccate and weigh to a constant weight. Report both results to the nearest 0.1 mg.
11.2.4 Container No. 4. Weigh the spent silica gel (or silica gel plus impinger) to the nearest 0.5 g using a balance.
11.2.5 Acetone Blank Container. Same as Method 5, section 11.2.4, except that the beaker may be smaller than 250 ml.
11.2.6 Dichloromethane Blank Container. Treat the same as the acetone blank.
11.2.7 Water Blank Container. Transfer the water to a tared 250 ml beaker and evaporate to dryness at 104 °C (220 °F). Desiccate and weigh to a constant weight.
Carry out calculations, retaining at least one extra significant figure beyond that of the acquired data. Round off figures after the final calculation. Other forms of the equations may be used as long as they give equivalent results.
12.1 Nomenclature.
12.2 Average Dry Gas Meter Temperature and Average Orifice Pressure Drop. See data sheet (Figure 5H-3).
12.3 Dry Gas Volume. Same as Method 5, section 12.3.
12.4 Volume of Water Vapor.
12.5 Moisture Content.
12.6 Solvent Wash Blank.
12.7 Total Particulate Weight. Determine the total particulate catch from the sum of the weights obtained from containers 1, 2, 3, and 4 less the appropriate solvent blanks (see Figure 5H-4).
Refer to Method 5, section 8.5 to assist in calculation of results involving two filter assemblies.
12.8 Particulate Concentration.
12.9 Sample Flow Rate Adjustment.
12.10 Carbon Balance for Total Moles of Exhaust Gas (dry)/kg of Wood Burned in the Exhaust Gas.
The NO
12.11 Total Stack Gas Flow Rate.
12.12 Particulate Emission Rate.
12.13 Proportional Rate Variation. Calculate PR for each 10-minute interval, i, of the test run.
12.14 Acceptable Results. If no more than 15 percent of the PR values for all the intervals fall outside the range 90 percent ≤PR ≤110 percent, and if no PR value for any interval falls outside the range 75 ≤PR ≤125 percent, the results are acceptable. If the PR values for the test runs are judged to be unacceptable, report the test run emission results, but do not include the test run results in calculating the weighted average emission rate, and repeat the test.
12.15 Alternative Tracer Gas Flow Rate Determination.
This gives Q for a single instance only. Repeated multiple determinations are needed to track temporal variations. Very small variations in Q
16.1 Alternative Stack Gas Volumetric Flow Rate Determination (Tracer Gas).
16.1.1 Apparatus.
16.1.1.1 Tracer Gas Injector System. This is to inject a known concentration of tracer gas into the stack. This system consists of a cylinder of tracer gas, a gas cylinder regulator, a stainless steel needle valve or a flow controller, a nonreactive (stainless steel or glass) rotameter, and an injection loop to disperse the tracer gas evenly in the stack.
16.1.1.2 Tracer Gas Probe. A glass or stainless steel sampling probe.
16.1.1.3 Gas Conditioning System. A gas conditioning system is suitable for delivering a cleaned sample to the analyzer consisting of a filter to remove particulate and a condenser capable of lowering the dew point of the sample gas to less than 5 °C (40 °F). A desiccant such as anhydrous calcium sulfate may be used to dry the sample gas. Desiccants which react or absorb tracer gas or stack gas may not be used, e.g. silica gel absorbs CO
16.1.1.4 Pump. An inert (i.e., stainless steel or Teflon head) pump to deliver more than the total sample required by the manufacturer’s specifications for the analyzer used to measure the downstream tracer gas concentration.
16.1.1.5 Gas Analyzer. A gas analyzer is any analyzer capable of measuring the tracer gas concentration in the range necessary at least every 10 minutes. A means of controlling the analyzer flow rate and a device for determining proper sample flow rate shall be provided unless data is provided to show that the analyzer is insensitive to flow variations over the range encountered during the test. The gas analyzer needs to meet or exceed the following performance specifications:
| Linearity | ±1 percent of full scale. |
| Calibration Error | ≤2 percent of span. |
| Response Time | ≤10 seconds. |
| Zero Drift (24 hour) | ≤2 percent of full scale. |
| Span Drift (24 hour) | ≤2 percent of full scale. |
| Resolution | ≤0.5 percent of span. |
16.1.1.6 Recorder (optional). To provide a permanent record of the analyzer output.
16.1.2 Reagents.
16.1.2.1 Tracer Gas. The tracer gas is sulfur hexafluoride in an appropriate concentration for accurate analyzer measurement or pure sulfur dioxide. The gas used must be nonreactive with the stack effluent and give minimal (
16.1.3 Procedure. Select upstream and downstream locations in the stack or duct for introducing the tracer gas and delivering the sampled gas to the analyzer. The inlet location should be 8 or more duct diameters beyond any upstream flow disturbance. The outlet should be 8 or more undisturbed duct diameters from the inlet and 2 or more duct diameters from the duct exit. After installing the apparatus, meter a known concentration of the tracer gas into the stack at the inlet location. Use the gas sample probe and analyzer to show that no stratification of the tracer gas is found in the stack at the measurement locations. Monitor the tracer gas concentration from the outlet location and record the concentration at 10-minute intervals or more often at the option of the tester. A minimum of three measured intervals is recommended to determine the stack gas volumetric flow rate. Other statistical procedures may be applied for complete flow characterization and additional QA/QC.
Same as Method 5G, section 17.0.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Certain information is contained in other EPA procedures found in this part. Therefore, to obtain reliable results, persons using this method should have experience with and a thorough knowledge of the following Methods: Methods 1, 2, 3, 4 and 5.
1.1 Analyte. Particulate matter (PM). No CAS number assigned.
1.2 Applicability. This method is applicable for the determination of low level particulate matter (PM) emissions from stationary sources. The method is most effective for total PM catches of 50 mg or less. This method was initially developed for performing correlation of manual PM measurements to PM continuous emission monitoring systems (CEMS), however it is also useful for other low particulate concentration applications.
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods. Method 5I requires the use of paired trains. Acceptance criteria for the identification of data quality outliers from the paired trains are provided in section 12.2 of this Method.
2.1. Description. The system setup and operation is essentially identical to Method 5. Particulate is withdrawn isokinetically from the source and collected on a 47 mm glass fiber filter maintained at a temperature of 120 ±14 °C (248 ±25 °F). The PM mass is determined by gravimetric analysis after the removal of uncombined water. Specific measures in this procedure designed to improve system performance at low particulate levels include:
2.2 Paired Trains. This method must be performed using a paired train configuration. These trains may be operated as co-located trains (to trains operating collecting from one port) or as simultaneous trains (separate trains operating from different ports at the same time). Procedures for calculating precision of the paired trains are provided in section 12.
2.3 Detection Limit. a. Typical detection limit for manual particulate testing is 0.5 mg. This mass is also cited as the accepted weight variability limit in determination of “constant weight” as cited in section 8.1.2 of this Method. EPA has performed studies to provide guidance on minimum PM catch. The minimum detection limit (MDL) is the minimum concentration or amount of an analyte that can be determined with a specified degree of confidence to be different from zero. We have defined the minimum or target catch as a concentration or amount sufficiently larger than the MDL to ensure that the results are reliable and repeatable. The particulate matter catch is the product of the average particulate matter concentration on a mass per volume basis and the volume of gas collected by the sample train. The tester can generally control the volume of gas collected by increasing the sampling time or to a lesser extent by increasing the rate at which sample is collected. If the tester has a reasonable estimate of the PM concentration from the source, the tester can ensure that the target catch is collected by sampling the appropriate gas volume.
b. However, if the source has a very low particulate matter concentration in the stack, the volume of gas sampled may need to be very large which leads to unacceptably long sampling times. When determining compliance with an emission limit, EPA guidance has been that the tester does not always have to collect the target catch. Instead, we have suggested that the tester sample enough stack gas, that if the source were exactly at the level of the emission standard, the sample catch would equal the target catch. Thus, if at the end of the test the catch were smaller than the target, we could still conclude that the source is in compliance though we might not know the exact emission level. This volume of gas becomes a target volume that can be translated into a target sampling time by assuming an average sampling rate. Because the MDL forms the basis for our guidance on target sampling times, EPA has conducted a systematic laboratory study to define what is the MDL for Method 5 and determined the Method to have a calculated practical quantitation limit (PQL) of 3 mg of PM and an MDL of 1 mg.
c. Based on these results, the EPA has concluded that for PM testing, the target catch must be no less than 3 mg. Those sample catches between 1 mg and 3 mg are between the detection limit and the limit of quantitation. If a tester uses the target catch to estimate a target sampling time that results in sample catches that are less than 3 mg, you should not automatically reject the results. If the tester calculated the target sampling time as described above by assuming that the source was at the level of the emission limit, the results would still be valid for determining that the source was in compliance. For purposes other than determining compliance, results should be divided into two categories – those that fall between 3 mg and 1 mg and those that are below 1 mg. A sample catch between 1 and 3 mg may be used for such purposes as calculating emission rates with the understanding that the resulting emission rates can have a high degree of uncertainty. Results of less than 1 mg should not be used for calculating emission rates or pollutant concentrations.
d. When collecting small catches such as 3 mg, bias becomes an important issue. Source testers must use extreme caution to reach the PQL of 3 mg by assuring that sampling probes are very clean (perhaps confirmed by low blank weights) before use in the field. They should also use low tare weight sample containers, and establish a well-controlled balance room to weigh the samples.
3.1 Light Weight Filter Housing. A smaller housing that allows the entire filtering system to be weighed before and after sample collection. (See. 6.1.3)
3.2 Paired Train. Sample systems trains may be operated as co-located trains (two sample probes attached to each other in the same port) or as simultaneous trains (two separate trains operating from different ports at the same time).
a. There are numerous potential interferents that may be encountered during performance of Method 5I sampling and analyses. This Method should be considered more sensitive to the normal interferents typically encountered during particulate testing because of the low level concentrations of the flue gas stream being sampled.
b. Care must be taken to minimize field contamination, especially to the filter housing since the entire unit is weighed (not just the filter media). Care must also be taken to ensure that no sample is lost during the sampling process (such as during port changes, removal of the filter assemblies from the probes, etc.).
c. Balance room conditions are a source of concern for analysis of the low level samples. Relative humidity, ambient temperatures variations, air draft, vibrations and even barometric pressure can affect consistent reproducible measurements of the sample media. Ideally, the same analyst who performs the tare weights should perform the final weights to minimize the effects of procedural differences specific to the analysts.
d. Attention must also be provided to weighing artifacts caused by electrostatic charges which may have to be discharged or neutralized prior to sample analysis. Static charge can affect consistent and reliable gravimetric readings in low humidity environments. Method 5I recommends a relative humidity of less than 50 percent in the weighing room environment used for sample analyses. However, lower humidity may be encountered or required to address sample precision problems. Low humidity conditions can increase the effects of static charge.
e. Other interferences associated with typical Method 5 testing (sulfates, acid gases, etc.) are also applicable to Method 5I.
Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety concerns associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to determine the applicability and observe all regulatory limitations before using this method.
6.1 Sample Collection Equipment and Supplies. The sample train is nearly identical in configuration to the train depicted in Figure 5-1 of Method 5. The primary difference in the sample trains is the lightweight Method 5I filter assembly that attaches directly to the exit to the probe. Other exceptions and additions specific to Method 5I include:
6.1.1 Probe Nozzle. Same as Method 5, with the exception that it must be constructed of borosilicate or quartz glass tubing.
6.1.2 Probe Liner. Same as Method 5, with the exception that it must be constructed of borosilicate or quartz glass tubing.
6.1.3 Filter Holder. The filter holder is constructed of borosilicate or quartz glass front cover designed to hold a 47-mm glass fiber filter, with a wafer thin stainless steel (SS) filter support, a silicone rubber or Viton O-ring, and Teflon tape seal. This holder design will provide a positive seal against leakage from the outside or around the filter. The filter holder assembly fits into a SS filter holder and attaches directly to the outlet of the probe. The tare weight of the filter, borosilicate or quartz glass holder, SS filter support, O-ring and Teflon tape seal generally will not exceed approximately 35 grams. The filter holder is designed to use a 47-mm glass fiber filter meeting the quality criteria in of Method 5. These units are commercially available from several source testing equipment vendors. Once the filter holder has been assembled, desiccated and tared, protect it from external sources of contamination by covering the front socket with a ground glass plug. Secure the plug with an impinger clamp or other item that will ensure a leak-free fitting.
6.2 Sample Recovery Equipment and Supplies. Same as Method 5, with the following exceptions:
6.2.1 Probe-Liner and Probe-Nozzle Brushes. Teflon or nylon bristle brushes with stainless steel wire handles, should be used to clean the probe. The probe brush must have extensions (at least as long as the probe) of Teflon, nylon or similarly inert material. The brushes must be properly sized and shaped for brushing out the probe liner and nozzle.
6.2.2 Wash Bottles. Two Teflon wash bottles are recommended however, polyethylene wash bottles may be used at the option of the tester. Acetone should not be stored in polyethylene bottles for longer than one month.
6.2.3 Filter Assembly Transport. A system should be employed to minimize contamination of the filter assemblies during transport to and from the field test location. A carrying case or packet with clean compartments of sufficient size to accommodate each filter assembly can be used. This system should have an air tight seal to further minimize contamination during transport to and from the field.
6.3 Analysis Equipment and Supplies. Same as Method 5, with the following exception:
6.3.1 Lightweight Beaker Liner. Teflon or other lightweight beaker liners are used for the analysis of the probe and nozzle rinses. These light weight liners are used in place of the borosilicate glass beakers typically used for the Method 5 weighings in order to improve sample analytical precision.
6.3.2 Anti-static Treatment. Commercially available gaseous anti-static rinses are recommended for low humidity situations that contribute to static charge problems.
7.1 Sampling Reagents. The reagents used in sampling are the same as Method 5 with the following exceptions:
7.1.1 Filters. The quality specifications for the filters are identical to those cited for Method 5. The only difference is the filter diameter of 47 millimeters.
7.1.2 Stopcock Grease. Stopcock grease cannot be used with this sampling train. We recommend that the sampling train be assembled with glass joints containing O-ring seals or screw-on connectors, or similar.
7.1.3 Acetone. Low residue type acetone, ≤0.001 percent residue, purchased in glass bottles is used for the recovery of particulate matter from the probe and nozzle. Acetone from metal containers generally has a high residue blank and should not be used. Sometimes, suppliers transfer acetone to glass bottles from metal containers; thus, acetone blanks must be run prior to field use and only acetone with low blank values (≤0.001 percent residue, as specified by the manufacturer) must be used. Acetone blank correction is not allowed for this method; therefore, it is critical that high purity reagents be purchased and verified prior to use.
7.1.4 Gloves. Disposable, powder-free, latex surgical gloves, or their equivalent are used at all times when handling the filter housings or performing sample recovery.
7.2 Standards. There are no applicable standards commercially available for Method 5I analyses.
8.1 Pretest Preparation. Same as Method 5 with several exceptions specific to filter assembly and weighing.
8.1.1 Filter Assembly. Uniquely identify each filter support before loading filters into the holder assembly. This can be done with an engraving tool or a permanent marker. Use powder free latex surgical gloves whenever handling the filter holder assemblies. Place the O-ring on the back of the filter housing in the O-ring groove. Place a 47 mm glass fiber filter on the O-ring with the face down. Place a stainless steel filter holder against the back of the filter. Carefully wrap 5 mm (
8.1.2 Filter Weighing Procedures. a. Desiccate the entire filter holder assemblies at 20 ±5.6 °C (68 ±10 °F) and ambient pressure for at least 24 hours. Weigh at intervals of at least 6 hours to a constant weight, i.e., 0.5 mg change from previous weighing. Record the results to the nearest 0.1 mg. During each weighing, the filter holder assemblies must not be exposed to the laboratory atmosphere for a period greater than 2 minutes and a relative humidity above 50 percent. Lower relative humidity may be required in order to improve analytical precision. However, low humidity conditions increase static charge to the sample media.
b. Alternatively (unless otherwise specified by the Administrator), the filters holder assemblies may be oven dried at 105 °C (220 °F) for a minimum of 2 hours, desiccated for 2 hours, and weighed. The procedure used for the tare weigh must also be used for the final weight determination.
c. Experience has shown that weighing uncertainties are not only related to the balance performance but to the entire weighing procedure. Therefore, before performing any measurement, establish and follow standard operating procedures, taking into account the sampling equipment and filters to be used.
8.2 Preliminary Determinations. Select the sampling site, traverse points, probe nozzle, and probe length as specified in Method 5.
8.3 Preparation of Sampling Train. Same as Method 5, section 8.3, with the following exception: During preparation and assembly of the sampling train, keep all openings where contamination can occur covered until justbefore assembly or until sampling is about to begin. Using gloves, place a labeled (identified) and weighed filter holder assembly into the stainless steel holder. Then place this whole unit in the Method 5 hot box, and attach it to the probe. Do not use stopcock grease.
8.4 Leak-Check Procedures. Same as Method 5.
8.5 Sampling Train Operation.
8.5.1. Operation. Operate the sampling train in a manner consistent with those described in Methods 1, 2, 4 and 5 in terms of the number of sample points and minimum time per point. The sample rate and total gas volume should be adjusted based on estimated grain loading of the source being characterized. The total sampling time must be a function of the estimated mass of particulate to be collected for the run. Targeted mass to be collected in a typical Method 5I sample train should be on the order of 10 to 20 mg. Method 5I is most appropriate for total collected masses of less than 50 milligrams, however, there is not an exact particulate loading cutoff, and it is likely that some runs may exceed 50 mg. Exceeding 50 mg (or less than 10 mg) for the sample mass does not necessarily justify invalidating a sample run if all other Method criteria are met.
8.5.2 Paired Train. This Method requires PM samples be collected with paired trains.
8.5.2.1 It is important that the systems be operated truly simultaneously. This implies that both sample systems start and stop at the same times. This also means that if one sample system is stopped during the run, the other sample systems must also be stopped until the cause has been corrected.
8.5.2.2 Care should be taken to maintain the filter box temperature of the paired trains as close as possible to the Method required temperature of 120 ±14 °C (248 ±25 °F). If separate ovens are being used for simultaneously operated trains, it is recommended that the oven temperature of each train be maintained within ±14 °C (±25 °F) of each other.
8.5.2.3 The nozzles for paired trains need not be identically sized.
8.5.2.4 Co-located sample nozzles must be within the same plane perpendicular to the gas flow. Co-located nozzles and pitot assemblies should be within a 6.0 cm × 6.0 cm square (as cited for a quadruple train in Reference Method 301).
8.5.3 Duplicate gas samples for molecular weight determination need not be collected.
8.6 Sample Recovery. Same as Method 5 with several exceptions specific to the filter housing.
8.6.1 Before moving the sampling train to the cleanup site, remove the probe from the train and seal the nozzle inlet and outlet of the probe. Be careful not to lose any condensate that might be present. Cap the filter inlet using a standard ground glass plug and secure the cap with an impinger clamp. Remove the umbilical cord from the last impinger and cap the impinger. If a flexible line is used between the first impinger condenser and the filter holder, disconnect the line at the filter holder and let any condensed water or liquid drain into the impingers or condenser.
8.6.2 Transfer the probe and filter-impinger assembly to the cleanup area. This area must be clean and protected from the wind so that the possibility of losing any of the sample will be minimized.
8.6.3 Inspect the train prior to and during disassembly and note any abnormal conditions such as particulate color, filter loading, impinger liquid color, etc.
8.6.4 Container No. 1, Filter Assembly. Carefully remove the cooled filter holder assembly from the Method 5 hot box and place it in the transport case. Use a pair of clean gloves to handle the filter holder assembly.
8.6.5 Container No. 2, Probe Nozzle and Probe Liner Rinse. Rinse the probe and nozzle components with acetone. Be certain that the probe and nozzle brushes have been thoroughly rinsed prior to use as they can be a source of contamination.
8.6.6 All Other Train Components. (Impingers) Same as Method 5.
8.7 Sample Storage and Transport. Whenever possible, containers should be shipped in such a way that they remain upright at all times. All appropriate dangerous goods shipping requirements must be observed since acetone is a flammable liquid.
9.1 Miscellaneous Field Quality Control Measures.
9.1.1 A quality control (QC) check of the volume metering system at the field site is suggested before collecting the sample using the procedures in Method 5, section 4.4.1.
9.1.2 All other quality control checks outlined in Methods 1, 2, 4 and 5 also apply to Method 5I. This includes procedures such as leak-checks, equipment calibration checks, and independent checks of field data sheets for reasonableness and completeness.
9.2 Quality Control Samples.
9.2.1 Required QC Sample. A laboratory reagent blank must be collected and analyzed for each lot of acetone used for a field program to confirm that it is of suitable purity. The particulate samples cannot be blank corrected.
9.2.2 Recommended QC Samples. These samples may be collected and archived for future analyses.
9.2.2.1 A field reagent blank is a recommended QC sample collected from a portion of the acetone used for cleanup of the probe and nozzle. Take 100 ml of this acetone directly from the wash bottle being used and place it in a glass sample container labeled “field acetone reagent blank.” At least one field reagent blank is recommended for every five runs completed. The field reagent blank samples demonstrate the purity of the acetone was maintained throughout the program.
9.2.2.2 A field bias blank train is a recommended QC sample. This sample is collected by recovering a probe and filter assembly that has been assembled, taken to the sample location, leak checked, heated, allowed to sit at the sample location for a similar duration of time as a regular sample run, leak-checked again, and then recovered in the same manner as a regular sample. Field bias blanks are not a Method requirement, however, they are recommended and are very useful for identifying sources of contamination in emission testing samples. Field bias blank train results greater than 5 times the method detection limit may be considered problematic.
10.1 Field Balance Calibration Check. Check the calibration of the balance used to weigh impingers with a weight that is at least 500g or within 50g of a loaded impinger. The weight must be ASTM E617-13 “Standard Specification for Laboratory Weights and Precision Mass Standards” (incorporated by reference – see 40 CFR 60.17) Class 6 (or better). Daily, before use, the field balance must measure the weight within ±0.5g of the certified mass. If the daily balance calibration check fails, perform corrective measures and repeat the check before using balance.
10.2 Analytical Balance Calibration. Perform a multipoint calibration (at least five points spanning the operational range) of the analytical balance before the first use, and semiannually thereafter. The calibration of the analytical balance must be conducted using ASTM E617-13 “Standard Specification for Laboratory Weights and Precision Mass Standards” (incorporated by reference – see 40 CFR 60.17) Class 2 (or better) tolerance weights. Audit the balance each day it is used for gravimetric measurements by weighing at least one ASTM E617-13 Class 2 tolerance (or better) calibration weight that corresponds to 50 to 150 percent of the weight of one filter or between 1g and 5g. If the scale cannot reproduce the value of the calibration weight to within 0.5 mg of the certified mass, perform corrective measures and conduct the multipoint calibration before use.
11.1 Analysis. Same as Method 5, sections 11.1-11.2.4, with the following exceptions:
11.1.1 Container No. 1. Same as Method 5, section 11.2.1, with the following exception: Use disposable gloves to remove each of the filter holder assemblies from the desiccator, transport container, or sample oven (after appropriate cooling).
11.1.2 Container No. 2. Same as Method 5, section 11.2.2, with the following exception: It is recommended that the contents of Container No. 2 be transferred to a 250 ml beaker with a Teflon liner or similar container that has a minimal tare weight before bringing to dryness.
12.1 Particulate Emissions. The analytical results cannot be blank corrected for residual acetone found in any of the blanks. All other sample calculations are identical to Method 5.
12.2 Paired Trains Outliers. a. Outliers are identified through the determination of precision and any systemic bias of the paired trains. Data that do not meet this criteria should be flagged as a data quality problem. The primary reason for performing dual train sampling is to generate information to quantify the precision of the Reference Method data. The relative standard deviation (RSD) of paired data is the parameter used to quantify data precision. RSD for two simultaneously gathered data points is determined according to:
b. A minimum precision criteria for Reference Method PM data is that RSD for any data pair must be less than 10% as long as the mean PM concentration is greater than 10 mg/dscm. If the mean PM concentration is less than 10 mg/dscm higher RSD values are acceptable. At mean PM concentration of 1 mg/dscm acceptable RSD for paired trains is 25%. Between 1 and 10 mg/dscm acceptable RSD criteria should be linearly scaled from 25% to 10%. Pairs of manual method data exceeding these RSD criteria should be eliminated from the data set used to develop a PM CEMS correlation or to assess RCA. If the mean PM concentration is less than 1 mg/dscm, RSD does not apply and the mean result is acceptable.
16. Alternative Procedures. Same as Method 5.
17. Bibliography. Same as Method 5.
18. Tables, Diagrams, Flowcharts and Validation Data. Figure 5I-1 is a schematic of the sample train.
Appendix A-4 to Part 60 – Test Methods 6 through 10B
The test methods in this appendix are referred to in § 60.8 (Performance Tests) and § 60.11 (Compliance With Standards and Maintenance Requirements) of 40 CFR part 60, subpart A (General Provisions). Specific uses of these test methods are described in the standards of performance contained in the subparts, beginning with Subpart D.
Within each standard of performance, a section title “Test Methods and Procedures” is provided to: (1) Identify the test methods to be used as reference methods to the facility subject to the respective standard and (2) identify any special instructions or conditions to be followed when applying a method to the respective facility. Such instructions (for example, establish sampling rates, volumes, or temperatures) are to be used either in addition to, or as a substitute for procedures in a test method. Similarly, for sources subject to emission monitoring requirements, specific instructions pertaining to any use of a test method as a reference method are provided in the subpart or in Appendix B.
Inclusion of methods in this appendix is not intended as an endorsement or denial of their applicability to sources that are not subject to standards of performance. The methods are potentially applicable to other sources; however, applicability should be confirmed by careful and appropriate evaluation of the conditions prevalent at such sources.
The approach followed in the formulation of the test methods involves specifications for equipment, procedures, and performance. In concept, a performance specification approach would be preferable in all methods because this allows the greatest flexibility to the user. In practice, however, this approach is impractical in most cases because performance specifications cannot be established. Most of the methods described herein, therefore, involve specific equipment specifications and procedures, and only a few methods in this appendix rely on performance criteria.
Minor changes in the test methods should not necessarily affect the validity of the results and it is recognized that alternative and equivalent methods exist. section 60.8 provides authority for the Administrator to specify or approve (1) equivalent methods, (2) alternative methods, and (3) minor changes in the methodology of the test methods. It should be clearly understood that unless otherwise identified all such methods and changes must have prior approval of the Administrator. An owner employing such methods or deviations from the test methods without obtaining prior approval does so at the risk of subsequent disapproval and retesting with approved methods.
Within the test methods, certain specific equipment or procedures are recognized as being acceptable or potentially acceptable and are specifically identified in the methods. The items identified as acceptable options may be used without approval but must be identified in the test report. The potentially approvable options are cited as “subject to the approval of the Administrator” or as “or equivalent.” Such potentially approvable techniques or alternatives may be used at the discretion of the owner without prior approval. However, detailed descriptions for applying these potentially approvable techniques or alternatives are not provided in the test methods. Also, the potentially approvable options are not necessarily acceptable in all applications. Therefore, an owner electing to use such potentially approvable techniques or alternatives is responsible for: (1) assuring that the techniques or alternatives are in fact applicable and are properly executed; (2) including a written description of the alternative method in the test report (the written method must be clear and must be capable of being performed without additional instruction, and the degree of detail should be similar to the detail contained in the test methods); and (3) providing any rationale or supporting data necessary to show the validity of the alternative in the particular application. Failure to meet these requirements can result in the Administrator’s disapproval of the alternative.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 2, Method 3, Method 5, and Method 8.
1.1 Analytes.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| SO | 7449-09-5 | 3.4 mg SO 3 (2.12 × 10) 3 |
1.2 Applicability. This method applies to the measurement of sulfur dioxide (SO
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 A gas sample is extracted from the sampling point in the stack. The SO
4.1 Free Ammonia. Free ammonia interferes with this method by reacting with SO
4.2 Water-Soluble Cations and Fluorides. The cations and fluorides are removed by a glass wool filter and an isopropanol bubbler; therefore, they do not affect the SO
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and determine the applicability of regulatory limitations before performing this test method.
5.2 Corrosive reagents. The following reagents are hazardous. Personal protective equipment and safe procedures are useful in preventing chemical splashes. If contact occurs, immediately flush with copious amounts of water for at least 15 minutes. Remove clothing under shower and decontaminate. Treat residual chemical burns as thermal burns.
5.2.1 Hydrogen Peroxide (H
5.2.2 Sodium Hydroxide (NaOH). Causes severe damage to eyes and skin. Inhalation causes irritation to nose, throat, and lungs. Reacts exothermically with limited amounts of water.
5.2.3 Sulfuric Acid (H
6.1 Sample Collection. The following items are required for sample collection:
6.1.1 Sampling Train. A schematic of the sampling train is shown in Figure 6-1. The sampling equipment described in Method 8 may be substituted in place of the midget impinger equipment of Method 6. However, the Method 8 train must be modified to include a heated filter between the probe and isopropanol impinger, and the operation of the sampling train and sample analysis must be at the flow rates and solution volumes defined in Method 8. Alternatively, SO
6.1.1.1 Probe. Borosilicate glass or stainless steel (other materials of construction may be used, subject to the approval of the Administrator), approximately 6 mm (0.25 in.) inside diameter, with a heating system to prevent water condensation and a filter (either in-stack or heated out-of-stack) to remove particulate matter, including sulfuric acid mist. A plug of glass wool is a satisfactory filter.
6.1.1.2 Bubbler and Impingers. One midget bubbler with medium-coarse glass frit and borosilicate or quartz glass wool packed in top (see Figure 6-1) to prevent sulfuric acid mist carryover, and three 30-ml midget impingers. The midget bubbler and midget impingers must be connected in series with leak-free glass connectors. Silicone grease may be used, if necessary, to prevent leakage. A midget impinger may be used in place of the midget bubbler.
Other collection absorbers and flow rates may be used, subject to the approval of the Administrator, but the collection efficiency must be shown to be at least 99 percent for each test run and must be documented in the report. If the efficiency is found to be acceptable after a series of three tests, further documentation is not required. To conduct the efficiency test, an extra absorber must be added and analyzed separately. This extra absorber must not contain more than 1 percent of the total SO
6.1.1.3 Glass Wool. Borosilicate or quartz.
6.1.1.4 Stopcock Grease. Acetone-insoluble, heat-stable silicone grease may be used, if necessary.
6.1.1.5 Temperature Sensor. Dial thermometer, or equivalent, to measure temperature of gas leaving impinger train to within 1 °C (2 °F).
6.1.1.6 Drying Tube. Tube packed with 6- to 16- mesh indicating-type silica gel, or equivalent, to dry the gas sample and to protect the meter and pump. If silica gel is previously used, dry at 177 °C (350 °F) for 2 hours. New silica gel may be used as received. Alternatively, other types of desiccants (equivalent or better) may be used, subject to the approval of the Administrator.
6.1.1.7 Valve. Needle valve, to regulate sample gas flow rate.
6.1.1.8 Pump. Leak-free diaphragm pump, or equivalent, to pull gas through the train. Install a small surge tank between the pump and rate meter to negate the pulsation effect of the diaphragm pump on the rate meter.
6.1.1.9 Rate Meter. Rotameter, or equivalent, capable of measuring flow rate to within 2 percent of the selected flow rate of about 1 liter/min (0.035 cfm).
6.1.1.10 Volume Meter. Dry gas meter (DGM), sufficiently accurate to measure the sample volume to within 2 percent, calibrated at the selected flow rate and conditions actually encountered during sampling, and equipped with a temperature sensor (dial thermometer, or equivalent) capable of measuring temperature accurately to within 3 °C (5.4 °F). A critical orifice may be used in place of the DGM specified in this section provided that it is selected, calibrated, and used as specified in section 16.0.
6.1.2 Barometer. Mercury, aneroid, or other barometer capable of measuring atmospheric pressure to within 2.5 mm Hg (0.1 in. Hg). See the note in Method 5, section 6.1.2.
6.1.3 Vacuum Gauge and Rotameter. At least 760-mm Hg (30-in. Hg) gauge and 0- to 40-ml/min rotameter, to be used for leak-check of the sampling train.
6.2 Sample Recovery. The following items are needed for sample recovery:
6.2.1 Wash Bottles. Two polyethylene or glass bottles, 500-ml.
6.2.2 Storage Bottles. Polyethylene bottles, 100-ml, to store impinger samples (one per sample).
6.3 Sample Analysis. The following equipment is needed for sample analysis:
6.3.1 Pipettes. Volumetric type, 5-ml, 20-ml (one needed per sample), and 25-ml sizes.
6.3.2 Volumetric Flasks. 100-ml size (one per sample) and 1000-ml size.
6.3.3 Burettes. 5- and 50-ml sizes.
6.3.4 Erlenmeyer Flasks. 250-ml size (one for each sample, blank, and standard).
6.3.5 Dropping Bottle. 125-ml size, to add indicator.
6.3.6 Graduated Cylinder. 100-ml size.
6.3.7 Spectrophotometer. To measure absorbance at 352 nm.
Unless otherwise indicated, all reagents must conform to the specifications established by the Committee on Analytical Reagents of the American Chemical Society. Where such specifications are not available, use the best available grade.
7.1 Sample Collection. The following reagents are required for sample collection:
7.1.1 Water. Deionized distilled to conform to ASTM Specification D 1193-77 or 91 Type 3 (incorporated by reference – see § 60.17). The KMnO
7.1.2 Isopropanol, 80 Percent by Volume. Mix 80 ml of isopropanol with 20 ml of water.
7.1.2.1 Check each lot of isopropanol for peroxide impurities as follows: Shake 10 ml of isopropanol with 10 ml of freshly prepared 10 percent potassium iodide solution. Prepare a blank by similarly treating 10 ml of water. After 1 minute, read the absorbance at 352 nm on a spectrophotometer using a 1-cm path length. If absorbance exceeds 0.1, reject alcohol for use.
7.1.2.2 Peroxides may be removed from isopropanol by redistilling or by passage through a column of activated alumina; however, reagent grade isopropanol with suitably low peroxide levels may be obtained from commercial sources. Rejection of contaminated lots may, therefore, be a more efficient procedure.
7.1.3 Hydrogen Peroxide (H
7.1.4 Potassium Iodide Solution, 10 Percent Weight by Volume (w/v). Dissolve 10.0 g of KI in water, and dilute to 100 ml. Prepare when needed.
7.2 Sample Recovery. The following reagents are required for sample recovery:
7.2.1 Water. Same as in section 7.1.1.
7.2.2 Isopropanol, 80 Percent by Volume. Same as in section 7.1.2.
7.3 Sample Analysis. The following reagents and standards are required for sample analysis:
7.3.1 Water. Same as in section 7.1.1.
7.3.2 Isopropanol, 100 Percent.
7.3.3 Thorin Indicator. 1-(o-arsonophenylazo)-2-naphthol-3,6-disulfonic acid, disodium salt, or equivalent. Dissolve 0.20 g in 100 ml of water.
7.3.4 Barium Standard Solution, 0.0100 N. Dissolve 1.95 g of barium perchlorate trihydrate [Ba(ClO
7.3.5 Sulfuric Acid Standard, 0.0100 N. Purchase or standardize to ±0.0002 N against 0.0100 N NaOH which has previously been standardized against potassium acid phthalate (primary standard grade).
8.1 Preparation of Sampling Train. Measure 15 ml of 80 percent isopropanol into the midget bubbler and 15 ml of 3 percent H
8.2 Sampling Train Leak-Check Procedure. A leak-check prior to the sampling run is recommended, but not required. A leak-check after the sampling run is mandatory. The leak-check procedure is as follows:
8.2.1 Temporarily attach a suitable (e.g., 0- to 40- ml/min) rotameter to the outlet of the DGM, and place a vacuum gauge at or near the probe inlet. Plug the probe inlet, pull a vacuum of at least 250 mm Hg (10 in. Hg), and note the flow rate as indicated by the rotameter. A leakage rate in excess of 2 percent of the average sampling rate is not acceptable.
Carefully (i.e., slowly) release the probe inlet plug before turning off the pump.
8.2.2 It is suggested (not mandatory) that the pump be leak-checked separately, either prior to or after the sampling run. To leak-check the pump, proceed as follows: Disconnect the drying tube from the probe-impinger assembly. Place a vacuum gauge at the inlet to either the drying tube or the pump, pull a vacuum of 250 mm Hg (10 in. Hg), plug or pinch off the outlet of the flow meter, and then turn off the pump. The vacuum should remain stable for at least 30 seconds.
If performed prior to the sampling run, the pump leak-check shall precede the leak-check of the sampling train described immediately above; if performed after the sampling run, the pump leak-check shall follow the sampling train leak-check.
8.2.3 Other leak-check procedures may be used, subject to the approval of the Administrator.
8.3 Sample Collection.
8.3.1 Record the initial DGM reading and barometric pressure. To begin sampling, position the tip of the probe at the sampling point, connect the probe to the bubbler, and start the pump. Adjust the sample flow to a constant rate of approximately 1.0 liter/min as indicated by the rate meter. Maintain this constant rate (±10 percent) during the entire sampling run.
8.3.2 Take readings (DGM volume, temperatures at DGM and at impinger outlet, and rate meter flow rate) at least every 5 minutes. Add more ice during the run to keep the temperature of the gases leaving the last impinger at 20 °C (68 °F) or less.
8.3.3 At the conclusion of each run, turn off the pump, remove the probe from the stack, and record the final readings. Conduct a leak-check as described in section 8.2. (This leak-check is mandatory.) If a leak is detected, void the test run or use procedures acceptable to the Administrator to adjust the sample volume for the leakage.
8.3.4 Drain the ice bath, and purge the remaining part of the train by drawing clean ambient air through the system for 15 minutes at the sampling rate. Clean ambient air can be provided by passing air through a charcoal filter or through an extra midget impinger containing 15 ml of 3 percent H
8.4 Sample Recovery. Disconnect the impingers after purging. Discard the contents of the midget bubbler. Pour the contents of the midget impingers into a leak-free polyethylene bottle for shipment. Rinse the three midget impingers and the connecting tubes with water, and add the rinse to the same storage container. Mark the fluid level. Seal and identify the sample container.
| Section | Quality control measure | Effect |
|---|---|---|
| 7.1.2 | Isopropanol check | Ensure acceptable level of peroxide impurities in isopropanol. |
| 8.2, 10.1-10.4 | Sampling equipment leak-check and calibration | Ensure accurate measurement of stack gas flow rate, sample volume. |
| 10.5 | Barium standard solution standardization | Ensure precision of normality determination |
| 11.2.3 | Replicate titrations | Ensure precision of titration determinations. |
10.1 Volume Metering System.
10.1.1 Initial Calibration.
10.1.1.1 Before its initial use in the field, leak-check the metering system (drying tube, needle valve, pump, rate meter, and DGM) as follows: Place a vacuum gauge at the inlet to the drying tube and pull a vacuum of 250 mm Hg (10 in. Hg). Plug or pinch off the outlet of the flow meter, and then turn off the pump. The vacuum must remain stable for at least 30 seconds. Carefully release the vacuum gauge before releasing the flow meter end.
10.1.1.2 Remove the drying tube, and calibrate the metering system (at the sampling flow rate specified by the method) as follows: Connect an appropriately sized wet-test meter (e.g., 1 liter per revolution) to the inlet of the needle valve. Make three independent calibration runs, using at least five revolutions of the DGM per run. Calculate the calibration factor Y (wet-test meter calibration volume divided by the DGM volume, both volumes adjusted to the same reference temperature and pressure) for each run, and average the results (Y
10.1.2 Post-Test Calibration Check. After each field test series, conduct a calibration check using the procedures outlined in section 10.1.1.2, except that three or more revolutions of the DGM may be used, and only two independent runs need be made. If the average of the two post-test calibration factors does not deviate by more than 5 percent from Y
10.1.3 DGM as a Calibration Standard. A DGM may be used as a calibration standard for volume measurements in place of the wet-test meter specified in section 10.1.1.2, provided that it is calibrated initially and recalibrated periodically according to the same procedures outlined in Method 5, section 10.3 with the following exceptions: (a) the DGM is calibrated against a wet-test meter having a capacity of 1 liter/rev (0.035 ft
10.2 Temperature Sensors. Calibrate against mercury-in-glass thermometers. An alternative mercury-free thermometer may be used if the thermometer is, at a minimum, equivalent in terms of performance or suitably effective for the specific temperature measurement application.
10.3 Rate Meter. The rate meter need not be calibrated, but should be cleaned and maintained according to the manufacturer’s instructions.
10.4 Barometer. Calibrate against a mercury barometer or NIST-traceable barometer prior to the field test.
10.5 Barium Standard Solution. Standardize the barium perchlorate or chloride solution against 25 ml of standard sulfuric acid to which 100 ml of 100 percent isopropanol has been added. Run duplicate analyses. Calculate the normality using the average of duplicate analyses where the titrations agree within 1 percent or 0.2 ml, whichever is larger.
11.1 Sample Loss Check. Note level of liquid in container and confirm whether any sample was lost during shipment; note this finding on the analytical data sheet. If a noticeable amount of leakage has occurred, either void the sample or use methods, subject to the approval of the Administrator, to correct the final results.
11.2 Sample Analysis.
11.2.1 Transfer the contents of the storage container to a 100-ml volumetric flask, dilute to exactly 100 ml with water, and mix the diluted sample.
11.2.2 Pipette a 20-ml aliquot of the diluted sample into a 250-ml Erlenmeyer flask and add 80 ml of 100 percent isopropanol plus two to four drops of thorin indicator. While stirring the solution, titrate to a pink endpoint using 0.0100 N barium standard solution.
11.2.3 Repeat the procedures in section 11.2.2, and average the titration volumes. Run a blank with each series of samples. Replicate titrations must agree within 1 percent or 0.2 ml, whichever is larger.
Protect the 0.0100 N barium standard solution from evaporation at all times.
Carry out calculations, retaining at least one extra significant figure beyond that of the acquired data. Round off figures after final calculation.
12.2 Dry Sample Gas Volume, Corrected to Standard Conditions.
12.3 SO
13.1 Range. The minimum detectable limit of the method has been determined to be 3.4 mg SO
16.1 Nomenclature. Same as section 12.1, with the following additions:
V
16.2 Critical Orifices for Volume and Rate Measurements. A critical orifice may be used in place of the DGM specified in section 6.1.1.10, provided that it is selected, calibrated, and used as follows:
16.2.1 Preparation of Sampling Train. Assemble the sampling train as shown in Figure 6-2. The rate meter and surge tank are optional but are recommended in order to detect changes in the flow rate.
The critical orifices can be adapted to a Method 6 type sampling train as follows: Insert sleeve type, serum bottle stoppers into two reducing unions. Insert the needle into the stoppers as shown in Figure 6-3.
16.2.2 Selection of Critical Orifices.
16.2.2.1 The procedure that follows describes the use of hypodermic needles and stainless steel needle tubings, which have been found suitable for use as critical orifices. Other materials and critical orifice designs may be used provided the orifices act as true critical orifices, (i.e., a critical vacuum can be obtained) as described in this section. Select a critical orifice that is sized to operate at the desired flow rate. The needle sizes and tubing lengths shown in Table 6-1 give the following approximate flow rates.
16.2.2.2 Determine the suitability and the appropriate operating vacuum of the critical orifice as follows: If applicable, temporarily attach a rate meter and surge tank to the outlet of the sampling train, if said equipment is not present (see section 16.2.1). Turn on the pump and adjust the valve to give an outlet vacuum reading corresponding to about half of the atmospheric pressure. Observe the rate meter reading. Slowly increase the vacuum until a stable reading is obtained on the rate meter. Record the critical vacuum, which is the outlet vacuum when the rate meter first reaches a stable value. Orifices that do not reach a critical value must not be used.
16.2.3 Field Procedures.
16.2.3.1 Leak-Check Procedure. A leak-check before the sampling run is recommended, but not required. The leak-check procedure is as follows: Temporarily attach a suitable (e.g., 0-40 ml/min) rotameter and surge tank, or a soap bubble meter and surge tank to the outlet of the pump. Plug the probe inlet, pull an outlet vacuum of at least 250 mm Hg (10 in. Hg), and note the flow rate as indicated by the rotameter or bubble meter. A leakage rate in excess of 2 percent of the average sampling rate (Q
16.2.3.2 Moisture Determination. At the sampling location, prior to testing, determine the percent moisture of the ambient air using the wet and dry bulb temperatures or, if appropriate, a relative humidity meter.
16.2.3.3 Critical Orifice Calibration. At the sampling location, prior to testing, calibrate the entire sampling train (i.e., determine the flow rate of the sampling train when operated at critical conditions). Attach a 500-ml soap bubble meter to the inlet of the probe, and operate the sampling train at an outlet vacuum of 25 to 50 mm Hg (1 to 2 in. Hg) above the critical vacuum. Record the information listed in Figure 6-4. Calculate the standard volume of air measured by the soap bubble meter and the volumetric flow rate using the equations below:
16.2.3.4 Sampling.
16.2.3.4.1 Operate the sampling train for sample collection at the same vacuum used during the calibration run. Start the watch and pump simultaneously. Take readings (temperature, rate meter, inlet vacuum, and outlet vacuum) at least every 5 minutes. At the end of the sampling run, stop the watch and pump simultaneously.
16.2.3.4.2 Conduct a post-test calibration run using the calibration procedure outlined in section 16.2.3.3. If the Q
16.2.3.4.3 If the percent difference between the molecular weight of the ambient air at saturated conditions and the sample gas is more that ±3 percent, then the molecular weight of the gas sample must be considered in the calculations using the following equation:
A post-test leak-check is not necessary because the post-test calibration run results will indicate whether there is any leakage.
16.2.3.4.4 Drain the ice bath, and purge the sampling train using the procedure described in section 8.3.4.
16.3 Elimination of Ammonia Interference. The following alternative procedures must be used in addition to those specified in the method when sampling at sources having ammonia emissions.
16.3.1 Sampling. The probe shall be maintained at 275 °C (527 °F) and equipped with a high-efficiency in-stack filter (glass fiber) to remove particulate matter. The filter material shall be unreactive to SO
16.3.2 Sample Recovery. Recover the sample according to section 8.4 except for discarding the contents of the midget bubbler. Add the bubbler contents, including the rinsings of the bubbler with water, to a separate polyethylene bottle from the rest of the sample. Under normal testing conditions where sulfur trioxide will not be present significantly, the tester may opt to delete the midget bubbler from the sampling train. If an approximation of the sulfur trioxide concentration is desired, transfer the contents of the midget bubbler to a separate polyethylene bottle.
16.3.3 Sample Analysis. Follow the procedures in sections 11.1 and 11.2, except add 0.5 ml of 0.1 N HCl to the Erlenmeyer flask and mix before adding the indicator. The following analysis procedure may be used for an approximation of the sulfur trioxide concentration. The accuracy of the calculated concentration will depend upon the ammonia to SO
1. Atmospheric Emissions from Sulfuric Acid Manufacturing Processes. U.S. DHEW, PHS, Division of Air Pollution. Public Health Service Publication No. 999-AP-13. Cincinnati, OH. 1965.
2. Corbett, P.F. The Determination of SO
3. Matty, R.E., and E.K. Diehl. Measuring Flue-Gas SO
4. Patton, W.F., and J.A. Brink, Jr. New Equipment and Techniques for Sampling Chemical Process Gases. J. Air Pollution Control Association. 13:162. 1963.
5. Rom, J.J. Maintenance, Calibration, and Operation of Isokinetic Source Sampling Equipment. Office of Air Programs, U.S. Environmental Protection Agency. Research Triangle Park, NC. APTD-0576. March 1972.
6. Hamil, H.F., and D.E. Camann. Collaborative Study of Method for the Determination of Sulfur Dioxide Emissions from Stationary Sources (Fossil-Fuel Fired Steam Generators). U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA-650/4-74-024. December 1973.
7. Annual Book of ASTM Standards. Part 31; Water, Atmospheric Analysis. American Society for Testing and Materials. Philadelphia, PA. 1974. pp. 40-42.
8. Knoll, J.E., and M.R. Midgett. The Application of EPA Method 6 to High Sulfur Dioxide Concentrations. U.S. Environmental Protection Agency. Research Triangle Park, NC. EPA-600/4-76-038. July 1976.
9. Westlin, P.R., and R.T. Shigehara. Procedure for Calibrating and Using Dry Gas Volume Meters as Calibration Standards. Source Evaluation Society Newsletter. 3(1):17-30. February 1978.
10. Yu, K.K. Evaluation of Moisture Effect on Dry Gas Meter Calibration. Source Evaluation Society Newsletter. 5(1):24-28. February 1980.
11. Lodge, J.P., Jr., et al. The Use of Hypodermic Needles as Critical Orifices in Air Sampling. J. Air Pollution Control Association. 16:197-200. 1966.
12. Shigehara, R.T., and C.B. Sorrell. Using Critical Orifices as Method 5 CalibrationStandards. Source Evaluation Society Newsletter. 10:4-15. August 1985.
13. Curtis, F., Analysis of Method 6 Samples in the Presence of Ammonia. Source Evaluation Society Newsletter. 13(1):9-15 February 1988.
Table 6-1 – Approximate Flow Rates for Various Needle Sizes
| Needle size (gauge) | Needle length (cm) | Flow rate (ml/min) |
|---|---|---|
| 21 | 7.6 | 1,100 |
| 22 | 2.9 | 1,000 |
| 22 | 3.8 | 900 |
| 23 | 3.8 | 500 |
| 23 | 5.1 | 450 |
| 24 | 3.2 | 400 |
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 2, Method 3, Method 5, Method 6, and Method 19.
1.1 Analytes.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| SO | 7449-09-05 | 3.4 mg SO 3 (2.12 × 10 3) |
| CO | 124-38-9 | N/A |
| H | 7732-18-5 | N/A |
1.2 Applicability. This method is applicable for the determination of sulfur dioxide (SO
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 A gas sample is extracted from a sampling point in the stack. The SO
Same as Method 6, section 4.0.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method.
5.2 Corrosive reagents. Same as Method 6, section 5.2.
6.1 Sample Collection. Same as Method 6, section 6.1, with the exception of the following:
6.1.1 Sampling Train. A schematic of the sampling train used in this method is shown in Figure 6A-1.
6.1.1.1 Impingers and Bubblers. Two 30 = ml midget impingers with a 1 = mm restricted tip and two 30 = ml midget bubblers with unrestricted tips. Other types of impingers and bubblers (e.g., Mae West for SO
6.1.1.2 CO
For applications downstream of wet scrubbers, a heated out-of-stack filter (either borosilicate glass wool or glass fiber mat) is necessary.
6.2 Sample Recovery. Same as Method 6, section 6.2.
6.3 Sample Analysis. Same as Method 6, section 6.3, with the addition of a balance to measure within 0.05 g.
Unless otherwise indicated, all reagents must conform to the specifications established by the Committee on Analytical Reagents of the American Chemical Society. Where such specifications are not available, use the best available grade.
7.1 Sample Collection. Same as Method 6, section 7.1, with the addition of the following:
7.1.1 Drierite. Anhydrous calcium sulfate (CaSO
Do not use silica gel or similar desiccant in this application.
7.1.2 CO
7.2 Sample Recovery and Analysis. Same as Method 6, sections 7.2 and 7.3, respectively.
8.1 Preparation of Sampling Train.
8.1.1 Measure 15 ml of 80 percent isopropanol into the first midget bubbler and 15 ml of 3 percent hydrogen peroxide into each of the two midget impingers (the second and third vessels in the train) as described in Method 6, section 8.1. Insert the glass wool into the top of the isopropanol bubbler as shown in Figure 6A-1. Place about 25 g of Drierite into the second midget bubbler (the fourth vessel in the train). Clean the outside of the bubblers and impingers and allow the vessels to reach room temperature. Weigh the four vessels simultaneously to the nearest 0.1 g, and record this initial weight (m
8.1.2 With one end of the CO
8.1.3 Assemble the train as shown in figure 6A-1. Adjust the probe heater to a temperature sufficient to prevent condensation (see note in section 6.1). Place crushed ice and water around the impingers and bubblers. Mount the CO
8.2 Sampling Train Leak-Check Procedure and Sample Collection. Same as Method 6, sections 8.2 and 8.3, respectively.
8.3 Sample Recovery.
8.3.1 Moisture Measurement. Disconnect the isopropanol bubbler, the SO
8.3.2 Peroxide Solution. Discard the contents of the isopropanol bubbler and pour the contents of the midget impingers into a leak-free polyethylene bottle for shipping. Rinse the two midget impingers and connecting tubes with water, and add the washing to the same storage container.
8.3.3 CO
Same as Method 6, section 9.0.
Same as Method 6, section 10.0.
11.1 Sample Analysis. The sample analysis procedure for SO
Same as Method 6, section 12.0, with the addition of the following:
12.1 Nomenclature.
12.2 CO
12.3 Moisture Volume Collected, Corrected to Standard Conditions.
12.4 SO
12.5 CO
12.6 Moisture Concentration.
13.1 Range and Precision. The minimum detectable limit and the upper limit for the measurement of SO
If the only emission measurement desired is in terms of emission rate of SO
16.1 Sampling Train. The sampling train is the same as that shown in Figure 6A-1 and as described in section 6.1, except that the dry gas meter is not needed.
16.2 Preparation of the Sampling Train. Follow the same procedure as in section 8.1, except do not weigh the isopropanol bubbler, the SO
16.3 Sampling Train Leak-Check Procedure and Sample Collection. Leak-check and operate the sampling train as described in section 8.2, except that dry gas meter readings, barometric pressure, and dry gas meter temperatures need not be recorded during sampling.
16.4 Sample Recovery. Follow the procedure in section 8.3, except do not weigh the isopropanol bubbler, the SO
16.5 Sample Analysis. Analysis of the peroxide solution is the same as that described in section 11.1.
16.6 Calculations.
16.6.1 SO
16.6.2 Sulfur Dioxide Emission Rate.
Same as Method 6, section 17.0, References 1 through 8, with the addition of the following:
1. Stanley, Jon and P.R. Westlin. An Alternate Method for Stack Gas Moisture Determination. Source Evaluation Society Newsletter. 3(4). November 1978.
2. Whittle, Richard N. and P.R. Westlin. Air Pollution Test Report: Development and Evaluation of an Intermittent Integrated SO
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 2, Method 3, Method 5, Method 6, and Method 6A.
1.1 Analytes.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Sulfur dioxide (SO | 7449-09-05 | 3.4 mg SO 3 (2.12 × 10 3) |
| Carbon dioxide (CO | 124-38-9 | N/A |
1.2 Applicability. This method is applicable for the determination of SO
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 A gas sample is extracted from the sampling point in the stack intermittently over a 24-hour or other specified time period. The SO
Same as Method 6, section 4.0.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method.
5.2 Corrosive Reagents. Same as Method 6, section 5.2.
Same as Method 6A, section 6.0, with the following exceptions and additions:
6.1 The isopropanol bubbler is not used. An empty bubbler for the collection of liquid droplets, that does not allow direct contact between the collected liquid and the gas sample, may be included in the sampling train.
6.2 For intermittent operation, include an industrial timer-switch designed to operate in the “on” position at least 2 minutes continuously and “off” the remaining period over a repeating cycle. The cycle of operation is designated in the applicable regulation. At a minimum, the sampling operation should include at least 12, equal, evenly-spaced periods per 24 hours.
6.3 Stainless steel sampling probes, type 316, are not recommended for use with Method 6B because of potential sample contamination due to corrosion. Glass probes or other types of stainless steel, e.g., Hasteloy or Carpenter 20, are recommended for long-term use.
For applications downstream of wet scrubbers, a heated out-of-stack filter (either borosilicate glass wool or glass fiber mat) is necessary. Probe and filter heating systems capable of maintaining a sample gas temperature of between 20 and 120 °C (68 and 248 °F) at the filter are also required in these cases. The electric supply for these heating systems should be continuous and separate from the timed operation of the sample pump.
Same as Method 6A, section 7.0, with the following exceptions:
7.1 Isopropanol is not used for sampling.
7.2 The hydrogen peroxide absorbing solution shall be diluted to no less than 6 percent by volume, instead of 3 percent as specified in Methods 6 and 6A.
7.3 If the Method 6B sampling train is to be operated in a low sample flow condition (less than 100 ml/min or 0.21 ft
8.1 Preparation of Sampling Train. Same as Method 6A, section 8.1, with the addition of the following:
8.1.1 The sampling train is assembled as shown in Figure 6A-1 of Method 6A, except that the isopropanol bubbler is not included.
8.1.2 Adjust the timer-switch to operate in the “on” position from 2 to 4 minutes on a 2-hour repeating cycle or other cycle specified in the applicable regulation. Other timer sequences may be used with the restriction that the total sample volume collected is between 25 and 60 liters (0.9 and 2.1 ft
8.1.3 Add cold water to the tank until the impingers and bubblers are covered at least two-thirds of their length. The impingers and bubbler tank must be covered and protected from intense heat and direct sunlight. If freezing conditions exist, the impinger solution and the water bath must be protected.
Sampling may be conducted continuously if a low flow-rate sample pump [20 to 40 ml/min (0.04 to 0.08 ft
8.2 Sampling Train Leak-Check Procedure. Same as Method 6, section 8.2.
8.3 Sample Collection.
8.3.1 The probe and filter (either in-stack, out-of-stack, or both) must be heated to a temperature sufficient to prevent water condensation.
8.3.2 Record the initial dry gas meter reading. To begin sampling, position the tip of the probe at the sampling point, connect the probe to the first impinger (or filter), and start the timer and the sample pump. Adjust the sample flow to a constant rate of approximately 1.0 liter/min (0.035 cfm) as indicated by the rotameter. Observe the operation of the timer, and determine that it is operating as intended (i.e., the timer is in the “on” position for the desired period, and the cycle repeats as required).
8.3.3 One time between 9 a.m. and 11 a.m. during the 24-hour sampling period, record the dry gas meter temperature (T
8.3.4 At the conclusion of the run, turn off the timer and the sample pump, remove the probe from the stack, and record the final gas meter volume reading. Conduct a leak-check as described in section 8.2. If a leak is found, void the test run or use procedures acceptable to the Administrator to adjust the sample volume for leakage. Repeat the steps in sections 8.3.1 to 8.3.4 for successive runs.
8.4 Sample Recovery. The procedures for sample recovery (moisture measurement, peroxide solution, and CO
Same as Method 6, section 9.0., with the exception of the isopropanol-check.
Same as Method 6, section 10.0, with the addition of the following:
10.1 Periodic Calibration Check. After 30 days of operation of the test train, conduct a calibration check according to the same procedures as the post-test calibration check (Method 6, section 10.1.2). If the deviation between initial and periodic calibration factors exceeds 5 percent, use the smaller of the two factors in calculations for the preceding 30 days of data, but use the most recent calibration factor for succeeding test runs.
11.1 Sample Loss Check and Analysis. Same as Method 6, sections 11.1 and 11.2, respectively.
Same as Method 6A, section 12.0, except that P
13.1 Range.
13.1.1 Sulfur Dioxide. Same as Method 6.
13.1.2 Carbon Dioxide. Not determined.
13.2 Repeatability and Reproducibility. EPA-sponsored collaborative studies were undertaken to determine the magnitude of repeatability and reproducibility achievable by qualified testers following the procedures in this method. The results of the studies evolve from 145 field tests including comparisons with Methods 3 and 6. For measurements of emission rates from wet, flue gas desulfurization units in (ng/J), the repeatability (intra-laboratory precision) is 8.0 percent and the reproducibility (inter-laboratory precision) is 11.1 percent.
Same as Method 6A, section 16.0, except that the timer is needed and is operated as outlined in this method.
Same as Method 6A, section 17.0, with the addition of the following:
1. Butler, Frank E., et. al. The Collaborative Test of Method 6B: Twenty-Four-Hour Analysis of SO
Method 6C is a procedure for measuring sulfur dioxide (SO
This method does not completely describe all equipment, supplies, and sampling and analytical procedures you will need but refers to other methods for some of the details. Therefore, to obtain reliable results, you should also have a thorough knowledge of these additional test methods which are found in appendix A to this part:
(a) Method 1 – Sample and Velocity Traverses for Stationary Sources.
(b) Method 4 – Determination of Moisture Content in Stack Gases.
(c) Method 6 – Determination of Sulfur Dioxide Emissions from Stationary Sources.
(d) Method 7E – Determination of Nitrogen Oxides Emissions from Stationary Sources (Instrumental Analyzer Procedure).
1.1 Analytes. What does this method determine? This method measures the concentration of sulfur dioxide.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| SO | 7446-09-5 | Typically |
1.2 Applicability. When is this method required? The use of Method 6C may be required by specific New Source Performance Standards, Clean Air Marketing rules, State Implementation Plans, and permits where SO
1.3 Data Quality Objectives. How good must my collected data be? Refer to section 1.3 of Method 7E.
In this method, you continuously sample the effluent gas and convey the sample to an analyzer that measures the concentration of SO
Refer to section 3.0 of Method 7E for the applicable definitions.
Refer to Section 4.0 of Method 7E.
Refer to section 5.0 of Method 7E.
Figure 7E-1 of Method 7E is a schematic diagram of an acceptable measurement system.
6.1 What do I need for the measurement system? The essential components of the measurement system are the same as those in sections 6.1 and 6.2 of Method 7E, except that the SO
6.2 What analyzer must I use? You may use an instrument that uses an ultraviolet, non-dispersive infrared, fluorescence, or other detection principle to continuously measure SO
7.1 Calibration Gas. What calibration gases do I need? Refer to section 7.1 of Method 7E for the calibration gas requirements. Example calibration gas mixtures are listed below.
(a) SO
(b) SO
(c) SO
(d) SO
(e) SO
(f) CO
(g) CO
7.2 Interference Check. What additional reagents do I need for the interference check? The test gases for the interference check are listed in Table 7E-3 of Method 7E. For the alternative interference check, you must use the reagents described in section 7.0 of Method 6.
8.1 Sampling Site and Sampling Points. You must follow the procedures of section 8.1 of Method 7E.
8.2 Initial Measurement System Performance Tests. You must follow the procedures in section 8.2 of Method 7E. If a dilution-type measurement system is used, the special considerations in section 8.3 of Method 7E also apply.
8.3 Interference Check. You must follow the procedures of section 8.2.7 of Method 7E to conduct an interference check, substituting SO
8.4 Sample Collection. You must follow the procedures of section 8.4 of Method 7E.
8.5 Post-Run System Bias Check and Drift Assessment. You must follow the procedures of section 8.5 of Method 7E.
Follow quality control procedures in section 9.0 of Method 7E.
Follow the procedures for calibration and standardization in section 10.0 of Method 7E.
Because sample collection and analysis are performed together (see section 8), additional discussion of the analytical procedure is not necessary.
You must follow the applicable procedures for calculations and data analysis in section 12.0 of Method 7E as applicable, substituting SO
13.1 The specifications for the applicable performance checks are the same as in section 13.0 of Method 7E.
13.2 Alternative Interference Check. The results are acceptable if the difference between the Method 6C result and the modified Method 6 result is less than 7.0 percent of the Method 6 result for each of the three test runs. For the purposes of comparison, the Method 6 and 6C results must be expressed in the same units of measure.
16.1 Alternative Interference Check. You may perform an alternative interference check consisting of at least three comparison runs between Method 6C and Method 6. This check validates the Method 6C results at each particular source category (type of facility) where the check is performed. When testing under conditions of low concentrations ( The procedure described below applies to non-dilution sampling systems only. If this alternative interference check is used for a dilution sampling system, use a standard Method 6 sampling train and extract the sample directly from the exhaust stream at points collocated with the Method 6C sample probe.
a. Build the modified Method 6 sampling train (flow control valve, two midget impingers containing 3 percent hydrogen peroxide, and dry gas meter) shown in Figure 6C-1. Connect the sampling train to the sample bypass discharge vent. Record the dry gas meter reading before you begin sampling. Simultaneously collect modified Method 6 and Method 6C samples. Open the flow control valve in the modified Method 6 train as you begin to sample with Method 6C. Adjust the Method 6 sampling rate to 1 liter per minute (.10 percent). The sampling time per run must be the same as for Method 6 plus twice the average measurement system response time. If your modified Method 6 train does not include a pump, you risk biasing the results high if you over-pressurize the midget impingers and cause a leak. You can reduce this risk by cautiously increasing the flow rate as sampling begins.
b. After completing a run, record the final dry gas meter reading, meter temperature, and barometric pressure. Recover and analyze the contents of the midget impingers using the procedures in Method 6. Determine the average gas concentration reported by Method 6C for the run.
1. “EPA Traceability Protocol for Assay and Certification of Gaseous Calibration Standards” September 1997 as amended, EPA-600/R-97/121
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1 and Method 5.
1.1 Analytes.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Nitrogen oxides (NO | ||
| Nitric oxide (NO) | 10102-43-9 | |
| Nitrogen dioxide (NO | 10102-44-0 | 2-400 mg/dscm |
1.2 Applicability. This method is applicable for the measurement of nitrogen oxides (NO
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sample methods.
A grab sample is collected in an evacuated flask containing a dilute sulfuric acid-hydrogen peroxide absorbing solution, and the nitrogen oxides, except nitrous oxide, are measured colorimetrically using the phenoldisulfonic acid (PDS) procedure.
Biased results have been observed when sampling under conditions of high sulfur dioxide concentrations. At or above 2100 ppm SO
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to performing this test method.
5.2 Corrosive Reagents. The following reagents are hazardous. Personal protective equipment and safe procedures are useful in preventing chemical splashes. If contact occurs, immediately flush with copious amounts of water for at least 15 minutes. Remove clothing under shower and decontaminate. Treat residual chemical burns as thermal burns.
5.2.1 Hydrogen Peroxide (H
5.2.2 Phenoldisulfonic Acid. Irritating to eyes and skin.
5.2.3 Sodium Hydroxide (NaOH). Causes severe damage to eyes and skin. Inhalation causes irritation to nose, throat, and lungs. Reacts exothermically with limited amounts of water.
5.2.4 Sulfuric Acid (H
5.2.5 Phenol. Poisonous and caustic. Do not handle with bare hands as it is absorbed through the skin.
6.1 Sample Collection. A schematic of the sampling train used in performing this method is shown in Figure 7-1. Other grab sampling systems or equipment, capable of measuring sample volume to within 2.0 percent and collecting a sufficient sample volume to allow analytical reproducibility to within 5 percent, will be considered acceptable alternatives, subject to the approval of the Administrator. The following items are required for sample collection:
6.1.1 Probe. Borosilicate glass tubing, sufficiently heated to prevent water condensation and equipped with an in-stack or heated out-of-stack filter to remove particulate matter (a plug of glass wool is satisfactory for this purpose). Stainless steel or Teflon tubing may also be used for the probe. Heating is not necessary if the probe remains dry during the purging period.
6.1.2 Collection Flask. Two-liter borosilicate, round bottom flask, with short neck and 24/40 standard taper opening, protected against implosion or breakage.
6.1.3 Flask Valve. T-bore stopcock connected to a 24/40 standard taper joint.
6.1.4 Temperature Gauge. Dial-type thermometer, or other temperature gauge, capable of measuring 1 °C (2 °F) intervals from −5 to 50 °C (23 to 122 °F).
6.1.5 Vacuum Line. Tubing capable of withstanding a vacuum of 75 mm (3 in.) Hg absolute pressure, with “T” connection and T-bore stopcock.
6.1.6 Vacuum Gauge. U-tube manometer, 1 meter (39 in.), with 1 mm (0.04 in.) divisions, or other gauge capable of measuring pressure to within 2.5 mm (0.10 in.) Hg.
6.1.7 Pump. Capable of evacuating the collection flask to a pressure equal to or less than 75 mm (3 in.) Hg absolute.
6.1.8 Squeeze Bulb. One-way.
6.1.9 Volumetric Pipette. 25-ml.
6.1.10 Stopcock and Ground Joint Grease. A high-vacuum, high-temperature chlorofluorocarbon grease is required. Halocarbon 25-5S has been found to be effective.
6.1.11 Barometer. Mercury, aneroid, or other barometer capable of measuring atmospheric pressure to within 2.5 mm (0.1 in.) Hg. See note in Method 5, section 6.1.2.
6.2 Sample Recovery. The following items are required for sample recovery:
6.2.1 Graduated Cylinder. 50-ml with 1 ml divisions.
6.2.2 Storage Containers. Leak-free polyethylene bottles.
6.2.3 Wash Bottle. Polyethylene or glass.
6.2.4 Glass Stirring Rod.
6.2.5 Test Paper for Indicating pH. To cover the pH range of 7 to 14.
6.3 Analysis. The following items are required for analysis:
6.3.1 Volumetric Pipettes. Two 1-ml, two 2-ml, one 3-ml, one 4-ml, two 10-ml, and one 25-ml for each sample and standard.
6.3.2 Porcelain Evaporating Dishes. 175- to 250-ml capacity with lip for pouring, one for each sample and each standard. The Coors No. 45006 (shallowform, 195-ml) has been found to be satisfactory. Alternatively, polymethyl pentene beakers (Nalge No. 1203, 150-ml), or glass beakers (150-ml) may be used. When glass beakers are used, etching of the beakers may cause solid matter to be present in the analytical step; the solids should be removed by filtration.
6.3.3 Steam Bath. Low-temperature ovens or thermostatically controlled hot plates kept below 70 °C (160 °F) are acceptable alternatives.
6.3.4 Dropping Pipette or Dropper. Three required.
6.3.5 Polyethylene Policeman. One for each sample and each standard.
6.3.6 Graduated Cylinder. 100-ml with 1-ml divisions.
6.3.7 Volumetric Flasks. 50-ml (one for each sample and each standard), 100-ml (one for each sample and each standard, and one for the working standard KNO
6.3.8 Spectrophotometer. To measure at 410 nm.
6.3.9 Graduated Pipette. 10-ml with 0.1-ml divisions.
6.3.10 Test Paper for Indicating pH. To cover the pH range of 7 to 14.
6.3.11 Analytical Balance. To measure to within 0.1 mg.
Unless otherwise indicated, it is intended that all reagents conform to the specifications established by the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available; otherwise, use the best available grade.
7.1 Sample Collection. The following reagents are required for sampling:
7.1.1 Water. Deionized distilled to conform to ASTM D 1193-77 or 91 Type 3 (incorporated by reference – see § 60.17). The KMnO
7.1.2 Absorbing Solution. Cautiously add 2.8 ml concentrated H
7.2 Sample Recovery. The following reagents are required for sample recovery:
7.2.1 Water. Same as in 7.1.1.
7.2.2 Sodium Hydroxide, 1 N. Dissolve 40 g NaOH in water, and dilute to 1 liter.
7.3 Analysis. The following reagents and standards are required for analysis:
7.3.1 Water. Same as in 7.1.1.
7.3.2 Fuming Sulfuric Acid. 15 to 18 percent by weight free sulfur trioxide. HANDLE WITH CAUTION.
7.3.3 Phenol. White solid.
7.3.4 Sulfuric Acid. Concentrated, 95 percent minimum assay.
7.3.5 Potassium Nitrate (KNO
7.3.6 Standard KNO
7.3.7 Working Standard KNO
7.3.8 Phenoldisulfonic Acid Solution. Dissolve 25 g of pure white phenol solid in 150 ml concentrated sulfuric acid on a steam bath. Cool, add 75 ml fuming sulfuric acid (15 to 18 percent by weight free sulfur trioxide – HANDLE WITH CAUTION), and heat at 100 °C (212 °F) for 2 hours. Store in a dark, stoppered bottle.
7.3.9 Concentrated Ammonium Hydroxide.
8.1 Sample Collection.
8.1.1 Flask Volume. The volume of the collection flask and flask valve combination must be known prior to sampling. Assemble the flask and flask valve, and fill with water to the stopcock. Measure the volume of water to ±10 ml. Record this volume on the flask.
8.1.2 Pipette 25 ml of absorbing solution into a sample flask, retaining a sufficient quantity for use in preparing the calibration standards. Insert the flask valve stopper into the flask with the valve in the “purge” position. Assemble the sampling train as shown in Figure 7-1, and place the probe at the sampling point. Make sure that all fittings are tight and leak-free, and that all ground glass joints have been greased properly with a high-vacuum, high temperature chlorofluorocarbon-based stopcock grease. Turn the flask valve and the pump valve to their “evacuate” positions. Evacuate the flask to 75 mm (3 in.) Hg absolute pressure, or less. Evacuation to a pressure approaching the vapor pressure of water at the existing temperature is desirable. Turn the pump valve to its “vent” position, and turn off the pump. Check for leakage by observing the manometer for any pressure fluctuation. (Any variation greater than 10 mm (0.4 in.) Hg over a period of 1 minute is not acceptable, and the flask is not to be used until the leakage problem is corrected. Pressure in the flask is not to exceed 75 mm (3 in.) Hg absolute at the time sampling is commenced.) Record the volume of the flask and valve (V
8.1.3 Shake the flask for at least 5 minutes.
8.1.4 If the gas being sampled contains insufficient oxygen for the conversion of NO to NO
8.2 Sample Recovery. Let the flask sit for a minimum of 16 hours, and then shake the contents for 2 minutes.
8.2.1 Connect the flask to a mercury filled U-tube manometer. Open the valve from the flask to the manometer, and record the flask temperature (T
| Section | Quality control measure | Effect |
|---|---|---|
| 10.1 | Spectrophotometer calibration | Ensure linearity of spectrophotometer response to standards. |
10.1 Spectrophotometer.
10.1.1 Optimum Wavelength Determination.
10.1.1.1 Calibrate the wavelength scale of the spectrophotometer every 6 months. The calibration may be accomplished by using an energy source with an intense line emission such as a mercury lamp, or by using a series of glass filters spanning the measuring range of the spectrophotometer. Calibration materials are available commercially and from the National Institute of Standards and Technology. Specific details on the use of such materials should be supplied by the vendor; general information about calibration techniques can be obtained from general reference books on analytical chemistry. The wavelength scale of the spectrophotometer must read correctly within 5 nm at all calibration points; otherwise, repair and recalibrate the spectrophotometer. Once the wavelength scale of the spectrophotometer is in proper calibration, use 410 nm as the optimum wavelength for the measurement of the absorbance of the standards and samples.
10.1.1.2 Alternatively, a scanning procedure may be employed to determine the proper measuring wavelength. If the instrument is a double-beam spectrophotometer, scan the spectrum between 400 and 415 nm using a 200 µg NO
10.1.2 Determination of Spectrophotometer Calibration Factor K
10.1.3 Spectrophotometer Calibration Quality Control. Multiply the absorbance value obtained for each standard by the K
10.2 Barometer. Calibrate against a mercury barometer or NIST-traceable barometer prior to the field test.
10.3 Temperature Gauge. Calibrate dial thermometers against mercury-in-glass thermometers. An alternative mercury-free thermometer may be used if the thermometer is, at a minimum, equivalent in terms of performance or suitably effective for the specific temperature measurement application.
10.4 Vacuum Gauge. Calibrate mechanical gauges, if used, against a mercury manometer such as that specified in section 6.1.6.
10.5 Analytical Balance. Calibrate against standard weights.
11.1 Sample Loss Check. Note the level of the liquid in the container, and confirm whether any sample was lost during shipment. Note this on the analytical data sheet. If a noticeable amount of leakage has occurred, either void the sample or use methods, subject to the approval of the Administrator, to correct the final results.
11.2 Sample Preparation. Immediately prior to analysis, transfer the contents of the shipping container to a 50 ml volumetric flask, and rinse the container twice with 5 ml portions of water. Add the rinse water to the flask, and dilute to mark with water; mix thoroughly. Pipette a 25-ml aliquot into the porcelain evaporating dish. Return any unused portion of the sample to the polyethylene storage bottle. Evaporate the 25-ml aliquot to dryness on a steam bath, and allow to cool. Add 2 ml phenoldisulfonic acid solution to the dried residue, and triturate thoroughly with a polyethylene policeman. Make sure the solution contacts all the residue. Add 1 ml water and 4 drops of concentrated sulfuric acid. Heat the solution on a steam bath for 3 minutes with occasional stirring. Allow the solution to cool, add 20 ml water, mix well by stirring, and add concentrated ammonium hydroxide, dropwise, with constant stirring, until the pH is 10 (as determined by pH paper). If the sample contains solids, these must be removed by filtration (centrifugation is an acceptable alternative, subject to the approval of the Administrator) as follows: Filter through Whatman No. 41 filter paper into a 100-ml volumetric flask. Rinse the evaporating dish with three 5-ml portions of water. Filter these three rinses. Wash the filter with at least three 15-ml portions of water. Add the filter washings to the contents of the volumetric flask, and dilute to the mark with water. If solids are absent, the solution can be transferred directly to the 100-ml volumetric flask and diluted to the mark with water.
11.3 Sample Analysis. Mix the contents of the flask thoroughly, and measure the absorbance at the optimum wavelength used for the standards (section 10.1.1), using the blank solution as a zero reference. Dilute the sample and the blank with equal volumes of water if the absorbance exceeds A
Carry out the calculations, retaining at least one extra significant figure beyond that of the acquired data. Round off figures after final calculations.
12.1 12.1 Nomenclature
12.2 Spectrophotometer Calibration Factor.
12.3 Sample Volume, Dry Basis, Corrected to Standard Conditions.
12.4 Total µg NO
If other than a 25-ml aliquot is used for analysis, the factor 2 must be replaced by a corresponding factor.
12.5 Sample Concentration, Dry Basis, Corrected to Standard Conditions.
13.1 Range. The analytical range of the method has been determined to be 2 to 400 milligrams NO
1. Standard Methods of Chemical Analysis. 6th ed. New York, D. Van Nostrand Co., Inc. 1962. Vol. 1, pp. 329-330.
2. Standard Method of Test for Oxides of Nitrogen in Gaseous Combustion Products (Phenoldisulfonic Acid Procedure). In: 1968 Book of ASTM Standards, Part 26. Philadelphia, PA. 1968. ASTM Designation D 1608-60, pp. 725-729.
3. Jacob, M.B. The Chemical Analysis of Air Pollutants. New York. Interscience Publishers, Inc. 1960. Vol. 10, pp. 351-356.
4. Beatty, R.L., L.B. Berger, and H.H. Schrenk. Determination of Oxides of Nitrogen by the Phenoldisulfonic Acid Method. Bureau of Mines, U.S. Dept. of Interior. R.I. 3687. February 1943.
5. Hamil, H.F. and D.E. Camann. Collaborative Study of Method for the Determination of Nitrogen Oxide Emissions from Stationary Sources (Fossil Fuel-Fired Steam Generators). Southwest Research Institute Report for Environmental Protection Agency. Research Triangle Park, NC. October 5, 1973.
6. Hamil, H.F. and R.E. Thomas. Collaborative Study of Method for the Determination of Nitrogen Oxide Emissions from Stationary Sources (Nitric Acid Plants). Southwest Research Institute Report for Environmental Protection Agency. Research Triangle Park, NC. May 8, 1974.
7. Stack Sampling Safety Manual (Draft). U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards, Research Triangle Park, NC. September 1978.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 3, Method 5, and Method 7.
1.1 Analytes.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Nitrogen oxides (NO | ||
| Nitric oxide (NO) | 10102-43-9 | |
| Nitrogen dioxide (NO | 10102-44-0 | 65-655 ppmv |
1.2 Applicability. This method is applicable for the determination of NO
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
A grab sample is collected in an evacuated flask containing a dilute sulfuric acid-hydrogen peroxide absorbing solution. The nitrogen oxides, excluding nitrous oxide (N
Biased results have been observed when sampling under conditions of high sulfur dioxide concentrations. At or above 2100 ppm SO
5.1 This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to performing this test method.
5.2 Corrosive reagents. The following reagents are hazardous. Personal protective equipment and safe procedures are useful in preventing chemical splashes. If contact occurs, immediately flush with copious amounts of water at least 15 minutes. Remove clothing under shower and decontaminate. Treat residual chemical burns as thermal burns.
5.2.1 Hydrogen Peroxide (H
5.2.2 Sulfuric Acid (H
6.1 Sample Collection. Same as in Method 7, section 6.1.
6.2 Sample Recovery. Same as in Method 7, section 6.2, except the stirring rod and pH paper are not needed.
6.3 Analysis. For the analysis, the following equipment and supplies are required. Alternative instrumentation and procedures will be allowed provided the calibration precision requirement in section 10.1.2 can be met.
6.3.1 Volumetric Pipets. Class A;1-, 2-, 4-, 5-ml (two for the set of standards and one per sample), 6-, 10-, and graduated 5-ml sizes.
6.3.2 Volumetric Flasks. 50-ml (two per sample and one per standard), 200-ml, and 1-liter sizes.
6.3.3 Analytical Balance. To measure to within 0.1 mg.
6.3.4 Ion Chromatograph. The ion chromatograph should have at least the following components:
6.3.4.1 Columns. An anion separation or other column capable of resolving the nitrate ion from sulfate and other species present and a standard anion suppressor column (optional). Suppressor columns are produced as proprietary items; however, one can be produced in the laboratory using the resin available from BioRad Company, 32nd and Griffin Streets, Richmond, California. Peak resolution can be optimized by varying the eluent strength or column flow rate, or by experimenting with alternative columns that may offer more efficient separation. When using guard columns with the stronger reagent to protect the separation column, the analyst should allow rest periods between injection intervals to purge possible sulfate buildup in the guard column.
6.3.4.2 Pump. Capable of maintaining a steady flow as required by the system.
6.3.4.3 Flow Gauges. Capable of measuring the specified system flow rate.
6.3.4.4 Conductivity Detector.
6.3.4.5 Recorder. Compatible with the output voltage range of the detector.
Unless otherwise indicated, it is intended that all reagents conform to the specifications established by the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available; otherwise, use the best available grade.
7.1 Sample Collection. Same as Method 7, section 7.1.
7.2 Sample Recovery. Same as Method 7, section 7.1.1.
7.3 Analysis. The following reagents and standards are required for analysis:
7.3.1 Water. Same as Method 7, section 7.1.1.
7.3.2 Stock Standard Solution, 1 mg NO
7.3.3 Working Standard Solution, 25 µg/ml. Dilute 5 ml of the standard solution to 200 ml with water in a volumetric flask, and mix well.
7.3.4 Eluent Solution. Weigh 1.018 g of sodium carbonate (Na
8.1 Sampling. Same as in Method 7, section 8.1.
8.2 Sample Recovery. Same as in Method 7, section 8.2, except delete the steps on adjusting and checking the pH of the sample. Do not store the samples more than 4 days between collection and analysis.
| Section | Quality control measure | Effect |
|---|---|---|
| 10.1 | Ion chromatographn calibration | Ensure linearity of ion chromatograph response to standards. |
10.1 Ion Chromatograph.
10.1.1 Determination of Ion Chromatograph Calibration Factor S. Prepare a series of five standards by adding 1.0, 2.0, 4.0, 6.0, and 10.0 ml of working standard solution (25 µg/ml) to a series of five 50-ml volumetric flasks. (The standard masses will equal 25, 50, 100, 150, and 250 µg.) Dilute each flask to the mark with water, and mix well. Analyze with the samples as described in section 11.2, and subtract the blank from each value. Prepare or calculate a linear regression plot of the standard masses in µg (x-axis) versus their peak height responses in millimeters (y-axis). (Take peak height measurements with symmetrical peaks; in all other cases, calculate peak areas.) From this curve, or equation, determine the slope, and calculate its reciprocal to denote as the calibration factor, S.
10.1.2 Ion Chromatograph Calibration Quality Control. If any point on the calibration curve deviates from the line by more than 7 percent of the concentration at that point, remake and reanalyze that standard. This deviation can be determined by multiplying S times the peak height response for each standard. The resultant concentrations must not differ by more than 7 percent from each known standard mass (i.e., 25, 50, 100, 150, and 250 µg).
10.2 Conductivity Detector. Calibrate according to manufacturer’s specifications prior to initial use.
10.3 Barometer. Calibrate against a mercury barometer.
10.4 Temperature Gauge. Calibrate dial thermometers against mercury-in-glass thermometers. An alternative mercury-free thermometer may be used if the thermometer is, at a minimum, equivalent in terms of performance or suitably effective for the specific temperature measurement application.
10.5 Vacuum Gauge. Calibrate mechanical gauges, if used, against a mercury manometer such as that specified in section 6.1.6 of Method 7.
10.6 Analytical Balance. Calibrate against standard weights.
11.1 Sample Preparation.
11.1.1 Note on the analytical data sheet, the level of the liquid in the container, and whether any sample was lost during shipment. If a noticeable amount of leakage has occurred, either void the sample or use methods, subject to the approval of the Administrator, to correct the final results. Immediately before analysis, transfer the contents of the shipping container to a 50-ml volumetric flask, and rinse the container twice with 5 ml portions of water. Add the rinse water to the flask, and dilute to the mark with water. Mix thoroughly.
11.1.2 Pipet a 5-ml aliquot of the sample into a 50-ml volumetric flask, and dilute to the mark with water. Mix thoroughly. For each set of determinations, prepare a reagent blank by diluting 5 ml of absorbing solution to 50 ml with water. (Alternatively, eluent solution may be used instead of water in all sample, standard, and blank dilutions.)
11.2 Analysis.
11.2.1 Prepare a standard calibration curve according to section 10.1.1. Analyze the set of standards followed by the set of samples using the same injection volume for both standards and samples. Repeat this analysis sequence followed by a final analysis of the standard set. Average the results. The two sample values must agree within 5 percent of their mean for the analysis to be valid. Perform this duplicate analysis sequence on the same day. Dilute any sample and the blank with equal volumes of water if the concentration exceeds that of the highest standard.
11.2.2 Document each sample chromatogram by listing the following analytical parameters: injection point, injection volume, nitrate and sulfate retention times, flow rate, detector sensitivity setting, and recorder chart speed.
Carry out the calculations, retaining at least one extra significant figure beyond that of the acquired data. Round off figures after final calculations.
12.1 Sample Volume. Calculate the sample volume Vsc (in ml), on a dry basis, corrected to standard conditions, using Equation 7-2 of Method 7.
12.2 Sample Concentration of NO
12.2.1 Calculate the sample concentration C (in mg/dscm) as follows:
12.2.2 If desired, the concentration of NO
13.1 Range. The analytical range of the method is from 125 to 1250 mg NO
1. Mulik, J.D., and E. Sawicki. Ion Chromatographic Analysis of Environmental Pollutants. Ann Arbor, Ann Arbor Science Publishers, Inc. Vol. 2, 1979.
2. Sawicki, E., J.D. Mulik, and E. Wittgenstein. Ion Chromatographic Analysis of Environmental Pollutants. Ann Arbor, Ann Arbor Science Publishers, Inc. Vol. 1. 1978.
3. Siemer, D.D. Separation of Chloride and Bromide from Complex Matrices Prior to Ion Chromatographic Determination. Anal. Chem. 52(12):1874-1877. October 1980.
4. Small, H., T.S. Stevens, and W.C. Bauman. Novel Ion Exchange Chromatographic Method Using Conductimetric Determination. Anal. Chem. 47(11):1801. 1975.
5. Yu, K.K., and P.R. Westlin. Evaluation of Reference Method 7 Flask Reaction Time. Source Evaluation Society Newsletter. 4(4). November 1979. 10 pp.
6. Stack Sampling Safety Manual (Draft). U.S. Environmental Protection Agency, Office of Air Quality Planning and Standard, Research Triangle Park, NC. September 1978.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 5, and Method 7.
1.1 Analytes.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Nitrogen oxides (NO | ||
| Nitric oxide (NO) | 10102-43-9 | |
| Nitrogen dioxide (NO | 10102-44-0 | 30-786 ppmv |
1.2 Applicability. This method is applicable for the determination of NO
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 A grab sample is collected in an evacuated flask containing a dilute sulfuric acid-hydrogen peroxide absorbing solution; the NO
5.1 This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to performing this test method.
5.2 Corrosive reagents. The following reagents are hazardous. Personal protective equipment and safe procedures are useful in preventing chemical splashes. If contact occurs, immediately flush with copious amounts of water at least 15 minutes. Remove clothing under shower and decontaminate. Treat residual chemical burn as thermal burn.
5.2.1 Hydrogen Peroxide (H
5.2.2 Sodium Hydroxide (NaOH). Causes severe damage to eyes and skin. Inhalation causes irritation to nose, throat, and lungs. Reacts exothermically with limited amounts of water.
5.2.3 Sulfuric Acid (H
6.1 Sample Collection. Same as Method 7, section 6.1.
6.2 Sample Recovery. The following items are required for sample recovery:
6.2.1 Wash Bottle. Polyethylene or glass.
6.2.2 Volumetric Flasks. 100-ml (one for each sample).
6.3 Analysis. The following items are required for analysis:
6.3.1 Volumetric Pipettes. 5-, 10-, 15-, and 20-ml to make standards and sample dilutions.
6.3.2 Volumetric Flasks. 1000- and 100-ml for preparing standards and dilution of samples.
6.3.3 Spectrophotometer. To measure ultraviolet absorbance at 210 nm.
6.3.4 Analytical Balance. To measure to within 0.1 mg.
Unless otherwise indicated, all reagents are to conform to the specifications established by the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available. Otherwise, use the best available grade.
7.1 Sample Collection. Same as Method 7, section 7.1. It is important that the amount of hydrogen peroxide in the absorbing solution not be increased. Higher concentrations of peroxide may interfere with sample analysis.
7.2 Sample Recovery. Same as Method 7, section 7.2.
7.3 Analysis. Same as Method 7, sections 7.3.1, 7.3.3, and 7.3.4, with the addition of the following:
7.3.1 Working Standard KNO
8.1 Sample Collection. Same as Method 7, section 8.1.
8.2 Sample Recovery.
8.2.1 Let the flask sit for a minimum of 16 hours, and then shake the contents for 2 minutes.
8.2.2 Connect the flask to a mercury filled U-tube manometer. Open the valve from the flask to the manometer, and record the flask temperature (T
8.2.3 Transfer the contents of the flask to a leak-free wash bottle. Rinse the flask three times with 10-ml portions of water, and add to the bottle. Mark the height of the liquid level so that the container can be checked for leakage after transport. Label the container to identify clearly its contents. Seal the container for shipping.
| Section | Quality control measure | Effect |
|---|---|---|
| 10.1 | Spectrophotometer calibration | Ensures linearity of spectrophotometer response to standards. |
Same as Method 7, sections 10.2 through 10.5, with the addition of the following:
10.1 Determination of Spectrophotometer Standard Curve. Add 0 ml, 5 ml, 10 ml, 15 ml, and 20 ml of the KNO
If other than a 20-ml aliquot of sample is used for analysis, then the amount of absorbing solution in the blank and standards must be adjusted such that the same amount of absorbing solution is in the blank and standards as is in the aliquot of sample used.
10.1.1 Calculate the spectrophotometer calibration factor as follows:
10.1.2 For the set of calibration standards specified here, Equation 7B-1 simplifies to the following:
10.2 Spectrophotometer Calibration Quality Control. Multiply the absorbance value obtained for each standard by the K
11.1 Sample Loss Check. Note the level of the liquid in the container, and confirm whether any sample was lost during shipment. Note this on the analytical data sheet. If a noticeable amount of leakage has occurred, either void the sample or use methods, subject to the approval of the Administrator, to correct the final results.
11.2 Sample Preparation. Immediately prior to analysis, transfer the contents of the shipping container to a 100-ml volumetric flask, and rinse the container twice with 5-ml portions of water. Add the rinse water to the flask, and dilute to mark with water.
11.3 Sample Analysis. Mix the contents of the flask thoroughly and pipette a 20 ml-aliquot of sample into a 100-ml volumetric flask. Dilute to the mark with water. Using the blank as zero reference, read the absorbance of the sample at 210 nm.
11.4 Audit Sample Analysis. Same as Method 7, section 11.4, except that a set of audit samples must be analyzed with each set of compliance samples or once per analysis day, or once per week when averaging continuous samples.
Same as Method 7, section 12.0, except replace section 12.3 with the following:
12.1 Total µg NO
If other than a 20-ml aliquot is used for analysis, the factor 5 must be replaced by a corresponding factor.
13.1 Range. The analytical range of the method as outlined has been determined to be 57 to 1500 milligrams NO
1. National Institute for Occupational Safety and Health. Recommendations for Occupational Exposure to Nitric Acid. In: Occupational Safety and Health Reporter. Washington, D.C. Bureau of National Affairs, Inc. 1976. p. 149.
2. Rennie, P.J., A.M. Sumner, and F.B. Basketter. Determination of Nitrate in Raw, Potable, and Waste Waters by Ultraviolet Spectrophotometry. Analyst. 104:837. September 1979.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 3, Method 6 and Method 7.
1.1 Analytes.
| Analyte | CAS no. | Sensitivity |
|---|---|---|
| Nitrogen oxides (NO | ||
| Nitric oxide (NO) | 10102-43-9 | |
| Nitrogen dioxide (NO | 10102-44-07 | ppmv |
1.2 Applicability. This method applies to the measurement of NO
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
An integrated gas sample is extracted from the stack and passed through impingers containing an alkaline potassium permanganate solution; NO
Possible interferents are sulfur dioxides (SO
4.1 High concentrations of SO
4.2 Ammonia (NH
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to performing this test method.
5.2 Corrosive Reagents. The following reagents are hazardous. Personal protective equipment and safe procedures are useful in preventing chemical splashes. If contact occurs, immediately flush with copious amounts of water for at least 15 minutes. Remove clothing under shower and decontaminate. Treat residual chemical burns as thermal burns.
5.2.1 Hydrochloric Acid (HCl). Highly toxic and corrosive. Causes severe damage to skin. Vapors are highly irritating to eyes, skin, nose, and lungs, causing severe damage. May cause bronchitis, pneumonia, or edema of lungs. Exposure to vapor concentrations of 0.13 to 0.2 percent can be lethal in minutes. Will react with metals, producing hydrogen.
5.2.2 Oxalic Acid (COOH)
5.2.3 Sodium Hydroxide (NaOH). Causes severe damage to eye tissues and to skin. Inhalation causes irritation to nose, throat, and lungs. Reacts exothermically with small amounts of water.
5.2.4 Potassium Permanganate (KMnO
6.1 Sample Collection and Sample Recovery. A schematic of the Method 7C sampling train is shown in Figure 7C-1, and component parts are discussed below. Alternative apparatus and procedures are allowed provided acceptable accuracy and precision can be demonstrated to the satisfaction of the Administrator.
6.1.1 Probe. Borosilicate glass tubing, sufficiently heated to prevent water condensation and equipped with an in-stack or heated out-of-stack filter to remove particulate matter (a plug of glass wool is satisfactory for this purpose). Stainless steel or Teflon tubing may also be used for the probe.
6.1.2 Impingers. Three restricted-orifice glass impingers, having the specifications given in Figure 7C-2, are required for each sampling train. The impingers must be connected in series with leak-free glass connectors. Stopcock grease may be used, if necessary, to prevent leakage. (The impingers can be fabricated by a glass blower if not available commercially.)
6.1.3 Glass Wool, Stopcock Grease, Drying Tube, Valve, Pump, Barometer, and Vacuum Gauge and Rotameter. Same as in Method 6, sections 6.1.1.3, 6.1.1.4, 6.1.1.6, 6.1.1.7, 6.1.1.8, 6.1.2, and 6.1.3, respectively.
6.1.4 Rate Meter. Rotameter, or equivalent, accurate to within 2 percent at the selected flow rate of between 400 and 500 ml/min (0.014 to 0.018 cfm). For rotameters, a range of 0 to 1 liter/min (0 to 0.035 cfm) is recommended.
6.1.5 Volume Meter. Dry gas meter (DGM) capable of measuring the sample volume under the sampling conditions of 400 to 500 ml/min (0.014 to 0.018 cfm) for 60 minutes within an accuracy of 2 percent.
6.1.6 Filter. To remove NO
6.1.7 Polyethylene Bottles. 1-liter, for sample recovery.
6.1.8 Funnel and Stirring Rods. For sample recovery.
6.2 Sample Preparation and Analysis.
6.2.1 Hot Plate. Stirring type with 50- by 10-mm Teflon-coated stirring bars.
6.2.2 Beakers. 400-, 600-, and 1000-ml capacities.
6.2.3 Filtering Flask. 500-ml capacity with side arm.
6.2.4 Buchner Funnel. 75-mm ID, with spout equipped with a 13-mm ID by 90-mm long piece of Teflon tubing to minimize possibility of aspirating sample solution during filtration.
6.2.5 Filter Paper. Whatman GF/C, 7.0-cm diameter.
6.2.6 Stirring Rods.
6.2.7 Volumetric Flasks. 100-, 200- or 250-, 500-, and 1000-ml capacity.
6.2.8 Watch Glasses. To cover 600- and 1000-ml beakers.
6.2.9 Graduated Cylinders. 50- and 250-ml capacities.
6.2.10 Pipettes. Class A.
6.2.11 pH Meter. To measure pH from 0.5 to 12.0.
6.2.12 Burette. 50-ml with a micrometer type stopcock. (The stopcock is Catalog No. 8225-t-05, Ace Glass, Inc., Post Office Box 996, Louisville, Kentucky 50201.) Place a glass wool plug in bottom of burette. Cut off burette at a height of 43 cm (17 in.) from the top of plug, and have a blower attach a glass funnel to top of burette such that the diameter of the burette remains essentially unchanged. Other means of attaching the funnel are acceptable.
6.2.13 Glass Funnel. 75-mm ID at the top.
6.2.14 Spectrophotometer. Capable of measuring absorbance at 540 nm; 1-cm cells are adequate.
6.2.15 Metal Thermometers. Bimetallic thermometers, range 0 to 150 °C (32 to 300 °F).
6.2.16 Culture Tubes. 20-by 150-mm, Kimax No. 45048.
6.2.17 Parafilm “M.” Obtained from American Can Company, Greenwich, Connecticut 06830.
6.2.18 CO
Unless otherwise indicated, it is intended that all reagents conform to the specifications established by the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available; otherwise, use the best available grade.
7.1 Sample Collection.
7.1.1 Water. Deionized distilled to conform to ASTM Specification D 1193-77 or 91 Type 3 (incorporated by reference – see § 60.17).
7.1.2 Potassium Permanganate, 4.0 Percent (w/w), Sodium Hydroxide, 2.0 Percent (w/w) solution (KMnO
7.2 Sample Preparation and Analysis.
7.2.1 Water. Same as in section 7.1.1.
7.2.2 Oxalic Acid Solution. Dissolve 48 g of oxalic acid [(COOH)
7.2.3 Sodium Hydroxide, 0.5 N. Dissolve 20 g of NaOH in water, and dilute to 1 liter.
7.2.4 Sodium Hydroxide, 10 N. Dissolve 40 g of NaOH in water, and dilute to 100 ml.
7.2.5 Ethylenediamine Tetraacetic Acid (EDTA) Solution, 6.5 percent (w/v). Dissolve 6.5 g of EDTA (disodium salt) in water, and dilute to 100 ml. Dissolution is best accomplished by using a magnetic stirrer.
7.2.6 Column Rinse Solution. Add 20 ml of 6.5 percent EDTA solution to 960 ml of water, and adjust the pH to between 11.7 and 12.0 with 0.5 N NaOH.
7.2.7 Hydrochloric Acid (HCl), 2 N. Add 86 ml of concentrated HCl to a 500 ml-volumetric flask containing water, dilute to volume, and mix well. Store in a glass-stoppered bottle.
7.2.8 Sulfanilamide Solution. Add 20 g of sulfanilamide (melting point 165 to 167 °C (329 to 333 °F)) to 700 ml of water. Add, with mixing, 50 ml concentrated phosphoric acid (85 percent), and dilute to 1000 ml. This solution is stable for at least 1 month, if refrigerated.
7.2.9 N-(1-Naphthyl)-Ethylenediamine Dihydrochloride (NEDA) Solution. Dissolve 0.5 g of NEDA in 500 ml of water. An aqueous solution should have one absorption peak at 320 nm over the range of 260 to 400 nm. NEDA that shows more than one absorption peak over this range is impure and should not be used. This solution is stable for at least 1 month if protected from light and refrigerated.
7.2.10 Cadmium. Obtained from Matheson Coleman and Bell, 2909 Highland Avenue, Norwood, Ohio 45212, as EM Laboratories Catalog No. 2001. Prepare by rinsing in 2 N HCl for 5 minutes until the color is silver-grey. Then rinse the cadmium with water until the rinsings are neutral when tested with pH paper. CAUTION: H
7.2.11 Sodium Nitrite (NaNO
7.2.12 Potassium Nitrate (KNO
7.2.13 Spiking Solution. Pipette 7 ml of the KNO
7.2.14 Blank Solution. Dissolve 2.4 g of KMnO
8.1 Preparation of Sampling Train. Add 200 ml of KMnO
8.2 Leak-Checks. Same as in Method 6, section 8.2.
8.3 Sample Collection.
8.3.1 Record the initial DGM reading and barometric pressure. Determine the sampling point or points according to the appropriate regulations (e.g., § 60.46(b)(5) of 40 CFR Part 60). Position the tip of the probe at the sampling point, connect the probe to the first impinger, and start the pump. Adjust the sample flow to a value between 400 and 500 ml/min (0.014 and 0.018 cfm). CAUTION: DO NOT EXCEED THESE FLOW RATES. Once adjusted, maintain a constant flow rate during the entire sampling run. Sample for 60 minutes. For relative accuracy (RA) testing of continuous emission monitors, the minimum sampling time is 1 hour, sampling 20 minutes at each traverse point.
When the SO
8.3.2 Record the DGM temperature, and check the flow rate at least every 5 minutes. At the conclusion of each run, turn off the pump, remove the probe from the stack, and record the final readings. Divide the sample volume by the sampling time to determine the average flow rate. Conduct the mandatory post-test leak-check. If a leak is found, void the test run, or use procedures acceptable to the Administrator to adjust the sample volume for the leakage.
8.4 CO
8.5 Sample Recovery. Disconnect the impingers. Pour the contents of the impingers into a 1-liter polyethylene bottle using a funnel and a stirring rod (or other means) to prevent spillage. Complete the quantitative transfer by rinsing the impingers and connecting tubes with water until the rinsings are clear to light pink, and add the rinsings to the bottle. Mix the sample, and mark the solution level. Seal and identify the sample container.
| Section | Quality control measure | Effect |
|---|---|---|
| 8.2, 10.1-10.3 | Sampling equipment leak-check and calibration | Ensure accurate measurement of sample volume. |
| 10.4 | Spectrophotometer calibration | Ensure linearity of spectrophotometer response to standards |
| 11.3 | Spiked sample analysis. | Ensure reduction efficiency of column. |
10.1 Volume Metering System. Same as Method 6, section 10.1. For detailed instructions on carrying out these calibrations, it is suggested that section 3.5.2 of Reference 4 of section 16.0 be consulted.
10.2 Temperature Sensors and Barometer. Same as in Method 6, sections 10.2 and 10.4, respectively.
10.3 Check of Rate Meter Calibration Accuracy (Optional). Disconnect the probe from the first impinger, and connect the filter. Start the pump, and adjust the rate meter to read between 400 and 500 ml/min (0.014 and 0.018 cfm). After the flow rate has stabilized, start measuring the volume sampled, as recorded by the dry gas meter and the sampling time. Collect enough volume to measure accurately the flow rate. Then calculate the flow rate. This average flow rate must be less than 500 ml/min (0.018 cfm) for the sample to be valid; therefore, it is recommended that the flow rate be checked as above prior to each test.
10.4 Spectrophotometer.
10.4.1 Dilute 5.0 ml of the NaNO
10.4.2 Measure the absorbance of the standards and a water blank as instructed in section 11.5. Plot the net absorbance vs. µg NO
11.1 Sample Stability. Collected samples are stable for at least four weeks; thus, analysis must occur within 4 weeks of collection.
11.2 Sample Preparation.
11.2.1 Prepare a cadmium reduction column as follows: Fill the burette with water. Add freshly prepared cadmium slowly, with tapping, until no further settling occurs. The height of the cadmium column should be 39 cm (15 in). When not in use, store the column under rinse solution.
The column should not contain any bands of cadmium fines. This may occur if regenerated cadmium is used and will greatly reduce the column lifetime.
11.2.2 Note the level of liquid in the sample container, and determine whether any sample was lost during shipment. If a noticeable amount of leakage has occurred, the volume lost can be determined from the difference between initial and final solution levels, and this value can then be used to correct the analytical result. Quantitatively transfer the contents to a 1-liter volumetric flask, and dilute to volume.
11.2.3 Take a 100-ml aliquot of the sample and blank (unexposed KMnO
11.2.4 Allow the samples to cool to near room temperature, being sure that the samples are still clear. Adjust the pH to between 11.7 and 12.0 with 10 N NaOH. Quantitatively transfer the mixture to a Buchner funnel containing GF/C filter paper, and filter the precipitate. Filter the mixture into a 500-ml filtering flask. Wash the solid material four times with water. When filtration is complete, wash the Teflon tubing, quantitatively transfer the filtrate to a 500-ml volumetric flask, and dilute to volume. The samples are now ready for cadmium reduction. Pipette a 50-ml aliquot of the sample into a 150-ml beaker, and add a magnetic stirring bar. Pipette in 1.0 ml of 6.5 percent EDTA solution, and mix.
11.3 Determine the correct stopcock setting to establish a flow rate of 7 to 9 ml/min of column rinse solution through the cadmium reduction column. Use a 50-ml graduated cylinder to collect and measure the solution volume. After the last of the rinse solution has passed from the funnel into the burette, but before air entrapment can occur, start adding the sample, and collect it in a 250-ml graduated cylinder. Complete the quantitative transfer of the sample to the column as the sample passes through the column. After the last of the sample has passed from the funnel into the burette, start adding 60 ml of column rinse solution, and collect the rinse solution until the solution just disappears from the funnel. Quantitatively transfer the sample to a 200-ml volumetric flask (a 250-ml flask may be required), and dilute to volume. The samples are now ready for NO
Two spiked samples should be run with every group of samples passed through the column. To do this, prepare two additional 50-ml aliquots of the sample suspected to have the highest NO
11.5 Sample Analysis. Pipette 10 ml of sample into a culture tube. Pipette in 10 ml of sulfanilamide solution and 1.4 ml of NEDA solution. Cover the culture tube with parafilm, and mix the solution. Prepare a blank in the same manner using the sample from treatment of the unexposed KMnO
Some test tubes give a high blank NO
11.6 Audit Sample Analysis. Same as in Method 7, section 11.4.
Carry out calculations, retaining at least one extra significant figure beyond that of the acquired data. Round off figures after final calculation.
12.1 Nomenclature.
12.2 NO
12.3 NO
12.4 Sample Volume, Dry Basis, Corrected to Standard Conditions.
12.5 Efficiency of Cadmium Reduction Column. Calculate this value as follows:
12.6 Total µg NO
12.7 Sample Concentration.
13.1 Precision. The intra-laboratory relative standard deviation for a single measurement is 2.8 and 2.9 percent at 201 and 268 ppm NO
13.2 Bias. The method does not exhibit any bias relative to Method 7.
13.3 Range. The lower detectable limit is 13 mg NO
1. Margeson, J.H., W.J. Mitchell, J.C. Suggs, and M.R. Midgett. Integrated Sampling and Analysis Methods for Determining NO
2. Memorandum and attachment from J.H. Margeson, Source Branch, Quality Assurance Division, Environmental Monitoring Systems Laboratory, to The Record, EPA. March 30, 1983. NH
3. Margeson, J.H., J.C. Suggs, and M.R. Midgett. Reduction of Nitrate to Nitrite with Cadmium. Anal. Chem. 52:1955-57. 1980.
4. Quality Assurance Handbook for Air Pollution Measurement Systems. Volume III – Stationary Source Specific Methods. U.S. Environmental Protection Agency. Research Triangle Park, NC. Publication No. EPA-600/4-77-027b. August 1977.
5. Margeson, J.H., et al. An Integrated Method for Determining NO
This method is not inclusive with respect to specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 3, Method 6, Method 7, and Method 7C.
1.1 Analytes.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Nitrogen oxides (NO | ||
| Nitric oxide (NO) | 10102-43-9 | |
| Nitrogen dioxide (NO | 10102-44-0 | 7 ppmv |
1.2 Applicability. This method applies to the measurement of NO
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
An integrated gas sample is extracted from the stack and passed through impingers containing an alkaline-potassium permanganate solution; NO
Same as in Method 7C, section 4.0.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to performing this test method.
5.2 Corrosive reagents. The following reagents are hazardous. Personal protective equipment and safe procedures are useful in preventing chemical splashes. If contact occurs, immediately flush with copious amounts of water for at least 15 minutes. Remove clothing under shower and decontaminate. Treat residual chemical burns as thermal burns.
5.2.1 Hydrogen Peroxide (H
5.2.2 Sodium Hydroxide (NaOH). Causes severe damage to eye tissues and to skin. Inhalation causes irritation to nose, throat, and lungs. Reacts exothermically with limited amounts of water.
5.2.3 Potassium Permanganate (KMnO
6.1 Sample Collection and Sample Recovery. Same as Method 7C, section 6.1. A schematic of the sampling train used in performing this method is shown in Figure 7C-1 of Method 7C.
6.2 Sample Preparation and Analysis.
6.2.1 Magnetic Stirrer. With 25- by 10-mm Teflon-coated stirring bars.
6.2.2 Filtering Flask. 500-ml capacity with sidearm.
6.2.3 Buchner Funnel. 75-mm ID, with spout equipped with a 13-mm ID by 90-mm long piece of Teflon tubing to minimize possibility of aspirating sample solution during filtration.
6.2.4 Filter Paper. Whatman GF/C, 7.0-cm diameter.
6.2.5 Stirring Rods.
6.2.6 Volumetric Flask. 250-ml.
6.2.7 Pipettes. Class A.
6.2.8 Erlenmeyer Flasks. 250-ml.
6.2.9 Ion Chromatograph. Equipped with an anion separator column to separate NO
Unless otherwise indicated, it is intended that all reagents conform to the specifications established by the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available; otherwise, use the best available grade.
7.1 Sample Collection.
7.1.1 Water. Deionized distilled to conform to ASTM specification D 1193-77 or 91 Type 3 (incorporated by reference – see § 60.17).
7.1.2 Potassium Permanganate, 4.0 Percent (w/w), Sodium Hydroxide, 2.0 Percent (w/w). Dissolve 40.0 g of KMnO
7.2 Sample Preparation and Analysis.
7.2.1 Water. Same as in section 7.1.1.
7.2.2 Hydrogen Peroxide (H
7.2.3 Blank Solution. Dissolve 2.4 g of KMnO
7.2.4 KNO
7.2.5 Eluent, 0.003 M NaHCO
8.1 Sampling. Same as in Method 7C, section 8.1.
8.2 Sample Recovery. Same as in Method 7C, section 8.2.
8.3 Sample Preparation for Analysis.
Samples must be analyzed within 28 days of collection.
8.3.1 Note the level of liquid in the sample container, and determine whether any sample was lost during shipment. If a noticeable amount of leakage has occurred, the volume lost can be determined from the difference between initial and final solution levels, and this value can then be used to correct the analytical result. Quantitatively transfer the contents to a 1-liter volumetric flask, and dilute to volume.
8.3.2 Sample preparation can be started 36 hours after collection. This time is necessary to ensure that all NO
The faster the stirring rate, the less volume of H
| Section | Quality control measure | Effect |
|---|---|---|
| 8.2, 10.1-10.3 | Sampling equipment leak-check and calibration | Ensure accurate measurement of sample volume. |
| 10.4 | Spectrophotometer calibration | Ensure linearity of spectrophotometer response to standards. |
| 11.3 | Spiked sample analysis | Ensure reduction efficiency of column. |
10.1 Dry Gas Meter (DGM) System.
10.1.1 Initial Calibration. Same as in Method 6, section 10.1.1. For detailed instructions on carrying out this calibration, it is suggested that section 3.5.2 of Citation 4 in section 16.0 of Method 7C be consulted.
10.1.2 Post-Test Calibration Check. Same as in Method 6, section 10.1.2.
10.2 Thermometers for DGM and Barometer. Same as in Method 6, sections 10.2 and 10.4, respectively.
10.3 Ion Chromatograph.
10.3.1 Dilute a given volume (1.0 ml or greater) of the KNO
10.3.2 Do not force the curve through zero. Draw a smooth curve through the points. The curve should be linear. With the linear curve, use linear regression to determine the calibration equation.
11.1 The following chromatographic conditions are recommended: 0.003 M NaHCO
11.2 Establish a stable baseline. Inject a sample of water, and determine whether any NO
Carry out calculations, retaining at least one extra significant figure beyond that of the acquired data. Round off figures after final calculation.
12.1 Nomenclature. Same as in Method 7C, section 12.1.
12.2 NO
12.3 Sample Volume, Dry Basis, Corrected to Standard Conditions. Same as in Method 7C, section 12.4.
12.4 Total µg NO
12.5 Sample Concentration. Same as in Method 7C, section 12.7.
13.1 Precision. The intra-laboratory relative standard deviation for a single measurement is approximately 6 percent at 200 to 270 ppm NO
13.2 Bias. The method does not exhibit any bias relative to Method 7.
13.3 Range. The lower detectable limit is similar to that of Method 7C. No upper limit has been established; however, when using the recommended sampling conditions, the method has been found to collect NO
Same as Method 7C, section 16.0, References 1, 2, 4, and 5.
Method 7E is a procedure for measuring nitrogen oxides (NO
(a) Method 1 – Sample and Velocity Traverses for Stationary Sources.
(b) Method 4 – Determination of Moisture Content in Stack Gases.
1.1 Analytes. What does this method determine? This method measures the concentration of nitrogen oxides as NO
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Nitric oxide (NO) | 10102-43-9 | Typically |
| Nitrogen dioxide (NO | 10102-44-0 | Calibration Span. |
1.2 Applicability. When is this method required? The use of Method 7E may be required by specific New Source Performance Standards, Clean Air Marketing rules, State Implementation Plans, and permits where measurement of NO
1.3 Data Quality Objectives (DQO). How good must my collected data be? Method 7E is designed to provide high-quality data for determining compliance with Federal and State emission standards and for relative accuracy testing of CEMS. In these and other applications, the principal objective is to ensure the accuracy of the data at the actual emission levels encountered. To meet this objective, the use of EPA traceability protocol calibration gases and measurement system performance tests are required.
1.4 Data Quality Assessment for Low Emitters. Is performance relief granted when testing low-emission units? Yes. For low-emitting sources, there are alternative performance specifications for analyzer calibration error, system bias, drift, and response time. Also, the alternative dynamic spiking procedure in section 16 may provide performance relief for certain low-emitting units.
In this method, a sample of the effluent gas is continuously sampled and conveyed to the analyzer for measuring the concentration of NO
3.1 Analyzer Calibration Error, for non-dilution systems, means the difference between the manufacturer certified concentration of a calibration gas and the measured concentration of the same gas when it is introduced into the analyzer in direct calibration mode.
3.2 Calibration Curve means the relationship between an analyzer’s response to the injection of a series of calibration gases and the actual concentrations of those gases.
3.3 Calibration Gas means the gas mixture containing NO
3.3.1 Low-Level Gas means a calibration gas with a concentration that is less than 20 percent of the calibration span and may be a zero gas.
3.3.2 Mid-Level Gas means a calibration gas with a concentration that is 40 to 60 percent of the calibration span.
3.3.3 High-Level Gas means a calibration gas with a concentration that is equal to the calibration span.
3.4 Calibration Span means the upper limit of the analyzer’s calibration that is set by the choice of high-level calibration gas. No valid run average concentration may exceed the calibration span. To the extent practicable, the measured emissions should be between 20 to 100 percent of the selected calibration span. This may not be practicable in some cases of low-concentration measurements or testing for compliance with an emission limit when emissions are substantially less than the limit. In such cases, calibration spans that are practicable to achieving the data quality objectives without being excessively high should be chosen.
3.5 Centroidal Area means the central area of the stack or duct that is no greater than 1 percent of the stack or duct cross section. This area has the same geometric shape as the stack or duct.
3.6 Converter Efficiency Gas means a calibration gas with a known NO or NO
3.7 Data Recorder means the equipment that permanently records the concentrations reported by the analyzer.
3.8 Direct Calibration Mode means introducing the calibration gases directly into the analyzer (or into the assembled measurement system at a point downstream of all sample conditioning equipment) according to manufacturer’s recommended calibration procedure. This mode of calibration applies to non-dilution-type measurement systems.
3.9 Drift means the difference between the pre- and post-run system bias (or system calibration error) checks at a specific calibration gas concentration level (i.e. low-, mid- or high-).
3.10 Gas Analyzer means the equipment that senses the gas being measured and generates an output proportional to its concentration.
3.11 Interference Check means the test to detect analyzer responses to compounds other than the compound of interest, usually a gas present in the measured gas stream, that is not adequately accounted for in the calibration procedure and may cause measurement bias.
3.12 Low-Concentration Analyzer means any analyzer that operates with a calibration span of 20 ppm NO
3.13 Measurement System means all of the equipment used to determine the NO
3.14 Response Time means the time it takes the measurement system to respond to a change in gas concentration occurring at the sampling point when the system is operating normally at its target sample flow rate or dilution ratio.
3.15 Run means a series of gas samples taken successively from the stack or duct. A test normally consists of a specific number of runs.
3.16 System Bias means the difference between a calibration gas measured in direct calibration mode and in system calibration mode. System bias is determined before and after each run at the low- and mid- or high-concentration levels. For dilution-type systems, pre- and post-run system calibration error is measured rather than system bias.
3.17 System Calibration Error applies to dilution-type systems and means the difference between the measured concentration of low-, mid-, or high-level calibration gas and the certified concentration for each gas when introduced in system calibration mode. For dilution-type systems, a 3-point system calibration error test is conducted in lieu of the analyzer calibration error test, and 2-point system calibration error tests are conducted in lieu of system bias tests.
3.18 System Calibration Mode means introducing the calibration gases into the measurement system at the probe, upstream of the filter and all sample conditioning components.
3.19 Test refers to the series of runs required by the applicable regulation.
Note that interferences may vary among instruments and that instrument-specific interferences must be evaluated through the interference test.
What safety measures should I consider when using this method? This method may require you to work with hazardous materials and in hazardous conditions. We encourage you to establish safety procedures before using the method. Among other precautions, you should become familiar with the safety recommendations in the gas analyzer user’s manual. Occupational Safety and Health Administration (OSHA) regulations concerning cylinder and noxious gases may apply. Nitric oxide and NO
The performance criteria in this method will be met or exceeded if you are properly using equipment designed for this application.
6.1 What do I need for the measurement system? You may use any equipment and supplies meeting the following specifications:
(1) Sampling system components that are not evaluated in the system bias or system calibration error test must be glass, Teflon, or stainless steel. Other materials are potentially acceptable, subject to approval by the Administrator.
(2) The interference, calibration error, and system bias criteria must be met.
(3) Sample flow rate must be maintained within 10 percent of the flow rate at which the system response time was measured.
(4) All system components (excluding sample conditioning components, if used) must maintain the sample temperature above the moisture dew point. Ensure minimal contact between any condensate and the sample gas. Section 6.2 provides example equipment specifications for a NO
6.2 Measurement System Components
6.2.1 Sample Probe. Glass, stainless steel, or other approved material, of sufficient length to traverse the sample points.
6.2.2 Particulate Filter. An in-stack or out-of-stack filter. The filter must be made of material that is non-reactive to the gas being sampled. The filter media for out-of-stack filters must be included in the system bias test. The particulate filter requirement may be waived in applications where no significant particulate matter is expected (e.g., for emission testing of a combustion turbine firing natural gas).
6.2.3 Sample Line. The sample line from the probe to the conditioning system/sample pump should be made of Teflon or other material that does not absorb or otherwise alter the sample gas. For a dry-basis measurement system (as shown in Figure 7E-1), the temperature of the sample line must be maintained at a sufficiently high level to prevent condensation before the sample conditioning components. For wet-basis measurement systems, the temperature of the sample line must be maintained at a sufficiently high level to prevent condensation before the analyzer.
6.2.4 Conditioning Equipment. For dry basis measurements, a condenser, dryer or other suitable device is required to remove moisture continuously from the sample gas. Any equipment needed to heat the probe or sample line to avoid condensation prior to the sample conditioning component is also required.
For wet basis systems, you must keep the sample above its dew point either by: (1) Heating the sample line and all sample transport components up to the inlet of the analyzer (and, for hot-wet extractive systems, also heating the analyzer) or (2) by diluting the sample prior to analysis using a dilution probe system. The components required to do either of the above are considered to be conditioning equipment.
6.2.5 Sampling Pump. For systems similar to the one shown in Figure 7E-1, a leak-free pump is needed to pull the sample gas through the system at a flow rate sufficient to minimize the response time of the measurement system. The pump may be constructed of any material that is non-reactive to the gas being sampled. For dilution-type measurement systems, an ejector pump (eductor) is used to create a vacuum that draws the sample through a critical orifice at a constant rate.
6.2.6 Calibration Gas Manifold. Prepare a system to allow the introduction of calibration gases either directly to the gas analyzer in direct calibration mode or into the measurement system, at the probe, in system calibration mode, or both, depending upon the type of system used. In system calibration mode, the system should be able to flood the sampling probe and vent excess gas. Alternatively, calibration gases may be introduced at the calibration valve following the probe. Maintain a constant pressure in the gas manifold. For in-stack dilution-type systems, a gas dilution subsystem is required to transport large volumes of purified air to the sample probe and a probe controller is needed to maintain the proper dilution ratio.
6.2.7 Sample Gas Manifold. For the type of system shown in Figure 7E-1, the sample gas manifold diverts a portion of the sample to the analyzer, delivering the remainder to the by-pass discharge vent. The manifold should also be able to introduce calibration gases directly to the analyzer (except for dilution-type systems). The manifold must be made of material that is non-reactive to the gas sampled or the calibration gas and be configured to safely discharge the bypass gas.
6.2.8 NO
6.2.8.1 Dual Range Analyzers. For certain applications, a wide range of gas concentrations may be encountered, necessitating the use of two measurement ranges. Dual-range analyzers are readily available for these applications. These analyzers are often equipped with automated range-switching capability, so that when readings exceed the full-scale of the low measurement range, they are recorded on the high range. As an alternative to using a dual-range analyzer, you may use two segments of a single, large measurement scale to serve as the low and high ranges. In all cases, when two ranges are used, you must quality-assure both ranges using the proper sets of calibration gases. You must also meet the interference, calibration error, system bias, and drift checks. However, we caution that when you use two segments of a large measurement scale for dual range purposes, it may be difficult to meet the performance specifications on the low range due to signal-to-noise ratio considerations.
6.2.8.2 Low Concentration Analyzer. When an analyzer is routinely calibrated with a calibration span of 20 ppmv or less, the manufacturer’s stability test (MST) is required. See Table 7E-5 for test parameters.
6.2.9 Data Recording. A strip chart recorder, computerized data acquisition system, digital recorder, or data logger for recording measurement data may be used.
7.1 Calibration Gas. What calibration gases do I need? Your calibration gas must be NO in N
7.1.1 High-Level Gas. This concentration is chosen to set the calibration span as defined in Section 3.4.
7.1.2 Mid-Level Gas. 40 to 60 percent of the calibration span.
7.1.3 Low-Level Gas. Less than 20 percent of the calibration span.
7.1.4 Converter Efficiency Gas. What reagents do I need for the converter efficiency test? The converter efficiency gas is a manufacturer-certified gas with a concentration sufficient to show NO
7.2 Interference Check. What reagents do I need for the interference check? Use the appropriate test gases listed in Table 7E-3 or others not listed that can potentially interfere (as indicated by the test facility type, instrument manufacturer, etc.) to conduct the interference check. These gases should be manufacturer certified but do not have to be prepared by the EPA traceability protocol.
Since you are allowed to choose different options to comply with some of the performance criteria, it is your responsibility to identify the specific options you have chosen, to document that the performance criteria for that option have been met, and to identify any deviations from the method.
8.1 What sampling site and sampling points do I select?
8.1.1 Unless otherwise specified in an applicable regulation or by the Administrator, when this method is used to determine compliance with an emission standard, conduct a stratification test as described in section 8.1.2 to determine the sampling traverse points to be used. For performance testing of continuous emission monitoring systems, follow the sampling site selection and traverse point layout procedures described in the appropriate performance specification or applicable regulation (e.g., Performance Specification 2 in appendix B to this part).
8.1.2 Determination of Stratification. Perform a stratification test at each test site to determine the appropriate number of sample traverse points. If testing for multiple pollutants or diluents at the same site, a stratification test using only one pollutant or diluent satisfies this requirement. A stratification test is not required for small stacks that are less than 4 inches in diameter. To test for stratification, use a probe of appropriate length to measure the NO
8.2 Initial Measurement System Performance Tests. What initial performance criteria must my system meet before I begin collecting samples? Before measuring emissions, perform the following procedures:
(a) Calibration gas verification,
(b) Measurement system preparation,
(c) Calibration error test,
(d) NO
(e) System bias check,
(f) System response time test, and
(g) Interference check
8.2.1 Calibration Gas Verification. How must I verify the concentrations of my calibration gases? Obtain a certificate from the gas manufacturer documenting the quality of the gas. Confirm that the manufacturer certification is complete and current. Ensure that your calibration gas certifications have not expired. This documentation should be available on-site for inspection. To the extent practicable, select a high-level gas concentration that will result in the measured emissions being between 20 and 100 percent of the calibration span.
8.2.2 Measurement System Preparation. How do I prepare my measurement system? Assemble, prepare, and precondition the measurement system according to your standard operating procedure. Adjust the system to achieve the correct sampling rate or dilution ratio (as applicable).
8.2.3 Calibration Error Test. How do I confirm my analyzer calibration is correct? After you have assembled, prepared and calibrated your sampling system and analyzer, you must conduct a 3-point analyzer calibration error test (or a 3-point system calibration error test for dilution systems) before the first run and again after any failed system bias test (or 2-point system calibration error test for dilution systems) or failed drift test. Introduce the low-, mid-, and high-level calibration gases sequentially. For non-dilution-type measurement systems, introduce the gases in direct calibration mode. For dilution-type measurement systems, introduce the gases in system calibration mode.
(1) For non-dilution systems, you may adjust the system to maintain the correct flow rate at the analyzer during the test, but you may not make adjustments for any other purpose. For dilution systems, you must operate the measurement system at the appropriate dilution ratio during all system calibration error checks, and may make only the adjustments necessary to maintain the proper ratio.
(2) Record the analyzer’s response to each calibration gas on a form similar to Table 7E-1. For each calibration gas, calculate the analyzer calibration error using Equation 7E-1 in section 12.2 or the system calibration error using Equation 7E-3 in section 12.4 (as applicable). The calibration error specification in section 13.1 must be met for the low-, mid-, and high-level gases. If the calibration error specification is not met, take corrective action and repeat the test until an acceptable 3-point calibration is achieved.
8.2.4 NO
8.2.4.1 Introduce NO
8.2.4.2 Alternatively, either of the procedures for determining conversion efficiency using NO in section 16.2 may be used.
8.2.5 Initial System Bias and System Calibration Error Checks. Before sampling begins, determine whether the high-level or mid-level calibration gas best approximates the emissions and use it as the upscale gas. Introduce the upscale gas at the probe upstream of all sample conditioning components in system calibration mode. Record the time it takes for the measured concentration to increase to a value that is at least 95 percent or within 0.5 ppm (whichever is less restrictive) of a stable response for both the low-level and upscale gases. Continue to observe the gas concentration reading until it has reached a final, stable value. Record this value on a form similar to Table 7E-2.
(1) Next, introduce the low-level gas in system calibration mode and record the time required for the concentration response to decrease to a value that is within 5.0 percent or 0.5 ppm (whichever is less restrictive) of the certified low-range gas concentration. If the low-level gas is a zero gas, use the procedures described above and observe the change in concentration until the response is 0.5 ppm or 5.0 percent of the upscale gas concentration (whichever is less restrictive).
(2) Continue to observe the low-level gas reading until it has reached a final, stable value and record the result on a form similar to Table 7E-2. Operate the measurement system at the normal sampling rate during all system bias checks. Make only the adjustments necessary to achieve proper calibration gas flow rates at the analyzer.
(3) From these data, calculate the measurement system response time (see section 8.2.6) and then calculate the initial system bias using Equation 7E-2 in section 12.3. For dilution systems, calculate the system calibration error in lieu of system bias using equation 7E-3 in section 12.4. See section 13.2 for acceptable performance criteria for system bias and system calibration error. If the initial system bias (or system calibration error) specification is not met, take corrective action. Then, you must repeat the applicable calibration error test from section 8.2.3 and the initial system bias (or 2-point system calibration error) check until acceptable results are achieved, after which you may begin sampling.
(
8.2.6 Measurement System Response Time. As described in section 8.2.5, you must determine the measurement system response time during the initial system bias (or 2-point system calibration error) check. Observe the times required to achieve 95 percent of a stable response for both the low-level and upscale gases. The longer interval is the response time.
8.2.7 Interference Check. Conduct an interference response test of the gas analyzer prior to its initial use in the field. If you have multiple analyzers of the same make and model, you need only perform this alternative interference check on one analyzer. You may also meet the interference check requirement if the instrument manufacturer performs this or a similar check on an analyzer of the same make and model of the analyzer that you use and provides you with documented results.
(1) You may introduce the appropriate interference test gases (that are potentially encountered during a test; see examples in Table 7E-3) into the analyzer separately or as mixtures. Test the analyzer with the interference gas alone at the highest concentration expected at a test source and again with the interference gas and NO
(2) A copy of this data, including the date completed and signed certification, must be available for inspection at the test site and included with each test report. This interference test is valid for the life of the instrument unless major analytical components (e.g., the detector) are replaced with different model parts. If major components are replaced with different model parts, the interference gas check must be repeated before returning the analyzer to service. If major components are replaced, the interference gas check must be repeated before returning the analyzer to service. The tester must ensure that any specific technology, equipment, or procedures that are intended to remove interference effects are operating properly during testing.
8.3 Dilution-Type Systems – Special Considerations. When a dilution-type measurement system is used, there are three important considerations that must be taken into account to ensure the quality of the emissions data. First, the critical orifice size and dilution ratio must be selected properly so that the sample dew point will be below the sample line and analyzer temperatures. Second, a high-quality, accurate probe controller must be used to maintain the dilution ratio during the test. The probe controller should be capable of monitoring the dilution air pressure, eductor vacuum, and sample flow rates. Third, differences between the molecular weight of calibration gas mixtures and the stack gas molecular weight must be addressed because these can affect the dilution ratio and introduce measurement bias.
8.4 Sample Collection.
(1) Position the probe at the first sampling point. Purge the system for at least two times the response time before recording any data. Then, traverse all required sampling points, sampling at each point for an equal length of time and maintaining the appropriate sample flow rate or dilution ratio (as applicable). You must record at least one valid data point per minute during the test run.
(2) Each time the probe is removed from the stack and replaced, you must recondition the sampling system for at least two times the system response time prior to your next recording. If the average of any run exceeds the calibration span value, that run is invalid.
(3) You may satisfy the multipoint traverse requirement by sampling sequentially using a single-hole probe or a multi-hole probe designed to sample at the prescribed points with a flow within 10 percent of mean flow rate. Notwithstanding, for applications under part 75 of this chapter, the use of multi-hole probes is subject to the approval of the Administrator.
8.5 Post-Run System Bias Check and Drift Assessment.
How do I confirm that each sample I collect is valid? After each run, repeat the system bias check or 2-point system calibration error check (for dilution systems) to validate the run. Do not make adjustments to the measurement system (other than to maintain the target sampling rate or dilution ratio) between the end of the run and the completion of the post-run system bias or system calibration error check. Note that for all post-run system bias or 2-point system calibration error checks, you may inject the low-level gas first and the upscale gas last, or vice-versa. If conducting a relative accuracy test or relative accuracy test audit, consisting of nine runs or more, you may risk sampling for up to three runs before performing the post-run bias or system calibration error check provided you pass this test at the conclusion of the group of three runs. A failed post-run bias or system calibration error check in this case will invalidate all runs subsequent to the last passed check. When conducting a performance or compliance test, you must perform a post-run system bias or system calibration error check after each individual test run.
(1) If you do not pass the post-run system bias (or system calibration error) check, then the run is invalid. You must diagnose and fix the problem and pass another calibration error test (Section 8.2.3) and system bias (or 2-point system calibration error) check (Section 8.2.5) before repeating the run. Record the system bias (or system calibration error) results on a form similar to Table 7E-2.
(2) After each run, calculate the low-level and upscale drift, using Equation 7E-4 in section 12.5. If the post-run low- and upscale bias (or 2-point system calibration error) checks are passed, but the low-or upscale drift exceeds the specification in section 13.3, the run data are valid, but a 3-point calibration error test and a system bias (or 2-point system calibration error) check must be performed and passed before any more test runs are done.
(3) For dilution systems, data from a 3-point system calibration error test may be used to met the pre-run 2-point system calibration error requirement for the first run in a test sequence. Also, the post-run bias (or 2-point calibration error) check data may be used as the pre-run data for the next run in the test sequence at the discretion of the tester.
8.6 Alternative Interference and System Bias Checks (Dynamic Spike Procedure). If I want to use the dynamic spike procedure to validate my data, what procedure should I follow? Except for applications under part 75 of this chapter, you may use the dynamic spiking procedure and requirements provided in section 16.1 during each test as an alternative to the interference check and the pre- and post-run system bias checks. The calibration error test is still required under this option. Use of the dynamic spiking procedure for Part 75 applications is subject to the approval of the Administrator.
8.7 Moisture correction. You must determine the moisture content of the flue gas and correct the measured gas concentrations to a dry basis using Method 4 or other appropriate methods, subject to the approval of the Administrator, when the moisture basis (wet or dry) of the measurements made with this method is different from the moisture basis of either: (1) The applicable emissions limit; or (2) the CEMS being evaluated for relative accuracy. Moisture correction is also required if the applicable limit is in lb/mmBtu and the moisture basis of the Method 7E NO
The following table is a summary of the mandatory, suggested, and alternative quality assurance and quality control measures and the associated frequency and acceptance criteria. All of the QC data, along with the sample run data, must be documented and included in the test report.
Summary Table of AQ/QC
| Status | Process or element | QA/QC specification | Acceptance criteria | Checking frequency |
|---|---|---|---|---|
| S | Identify Data User | Regulatory Agency or other primary end user of data | Before designing test. | |
| S | Analyzer Design | Analyzer resolution or sensitivity | Manufacturer design. | |
| M | Interference gas check | Sum of responses ≤2.5% of calibration span Alternatively, sum of responses: | ||
| ≤0.5 ppmv for calibration spans of 5 to 10 ppmv | ||||
| ≤0.2 ppmv for calibration spans | ||||
| See Table 7E-3 | ||||
| M | Calibration Gases | Traceability protocol (G1, G2) | Valid certificate required Uncertainty ≤2.0% of tag value | |
| M | High-level gas | Equal to the calibration span | Each test. | |
| M | Mid-level gas | 40 to 60% of calibration span | Each test. | |
| M | Low-level gas | Each test. | ||
| S | Data Recorder Design | Data resolution | ≤0.5% of full-scale range | Manufacturer design. |
| S | Sample Extraction | Probe material | SS or quartz if stack >500 °F | East test. |
| M | Sample Extraction | Probe, filter and sample line temperature | For dry-basis analyzers, keep sample above the dew point by heating, prior to sample conditioning | Each run. |
| For wet-basis analyzers, keep sample above dew point at all times, by heating or dilution | ||||
| S | Sample Extraction | Calibration valve material | SS | Each test. |
| S | Sample Extraction | Sample pump material | Inert to sample constituents | Each test. |
| S | Sample Extraction | Manifolding material | Inert to sample constituents | Each test. |
| S | Moisture Removal | Equipment efficiency | Verified through system bias check. | |
| S | Particulate Removal | Filter inertness | Pass system bias check | Each bias check. |
| M | Analyzer & Calibration Gas Performance | Analyzer calibration error (of 3-point system calibration error for dilution systems) | Within ±2.0 percent of the calibration span of the analyzer for the low-, mid-, and high-level calibration gases | Before initial run and after a failed system bias test or drift test. |
| Alternative specification: ≤0.5 ppmv absolute difference | ||||
| M | System Performance | System bias (or pre- and post-run 2-point system calibration error for dilution (Systems) | Within ±5.0% of the analyzer calibration span for low-sacle and upscale calibration gases | Before and after each run. |
| Alternative specification: ≤0.5 ppmv absolute difference | ||||
| M | System Performance | System response time | Determines minimum sampling time per point | During initial sampling system bias test. |
| M | System Performance | Drift | ≤3.0% of calibration span for low-level and mid- or high-level gases | After each test run. |
| Alternative specification: ≤0.5 ppmv absolute difference | ||||
| M | System Performance | NO | ≥90% of certified test gas concentration | Before or after each test. |
| M | System Performance | Purge time | ≥2 times system response time | Before starting the first run and when probe is removed from and re-inserted into the stack. |
| M | System Performance | Minimum sample time at each point | Two times the system response time | Each sample point. |
| M | System Performance | Stable sample flow rate (surrogate for maintaining system response time) | Within 10% of flow rate established during system response time check | Each run. |
| M | Sample Point Selection | Stratification test | All points within: | Prior to first run. |
| ±5% of mean for 1-point sampling | ||||
| ±10% of mean for 3-point | ||||
| Alternatively, all points within: | ||||
| ±0.5 ppm of mean for 1-point sampling | ||||
| ±1.0 ppm of mean for 3-point sampling | ||||
| A | Multiple sample points simultaneously | No. of openings in probe | Multi-hole probe with verifiable constant flow through all holes within 10% of mean flow rate (requires Administrative approval for Part 75) | Each run. |
| M | Data Recording | Frequency | ≤1 minute average | During run. |
| S | Data Parameters | Sample concentration range | All 1-minute averages within calibration span | Each run. |
| M | Date Parameters | Average concentration for the run | Run average ≤calibration span | Each run. |
S = Suggest.
M = Mandatory.
A = Alternative.
Agency.
(1) The initial 3-point calibration error test as described in section 8.2.3 and the system bias (or system calibration error) checks described in section 8.2.5 are required and must meet the specifications in section 13 before you start the test. Make all necessary adjustments to calibrate the gas analyzer and data recorder. Then, after the test commences, the system bias or system calibration error checks described in section 8.5 are required before and after each run. Your analyzer must be calibrated for all species of NO
(2) You must include a copy of the manufacturer’s certification of the calibration gases used in the testing as part of the test report. This certification must include the 13 documentation requirements in the EPA Traceability Protocol For Assay and Certification of Gaseous Calibration Standards, September 1997, as amended August 25, 1999. When Method 205 is used to produce diluted calibration gases, you must document that the specifications for the gas dilution system are met for the test. You must also include the date of the most recent dilution system calibration against flow standards and the name of the person or manufacturer who carried out the calibration in the test report.
Because sample collection and analysis are performed together (see section 8), additional discussion of the analytical procedure is not necessary.
You must follow the procedures for calculations and data analysis listed in this section.
12.1 Nomenclature. The terms used in the equations are defined as follows:
12.2 Analyzer Calibration Error. For non-dilution systems, use Equation 7E-1 to calculate the analyzer calibration error for the low-, mid-, and high-level calibration gases.
12.3 System Bias. For non-dilution systems, use Equation 7E-2 to calculate the system bias separately for the low-level and upscale calibration gases.
12.4 System Calibration Error. Use Equation 7E-3 to calculate the system calibration error for dilution systems. Equation 7E-3 applies to both the initial 3-point system calibration error test and the subsequent 2-point calibration error checks between test runs. In this equation, the term “C
12.5 Drift Assessment. Use Equation 7E-4 to separately calculate the low-level and upscale drift over each test run. For dilution systems, replace “SB
12.6 Effluent Gas Concentration. For each test run, calculate C
12.7 NO
12.8 NO
12.9 Alternative NO
12.10 Moisture Correction. Use Equation 7E-10 if your measurements need to be corrected to a dry basis.
12.11 Calculated Spike Gas Concentration and Spike Recovery for the Example Alternative Dynamic Spiking Procedure in section 16.1.3. Use Equation 7E-11 to determine the calculated spike gas concentration. Use Equation 7E-12 to calculate the spike recovery.
13.1 Calibration Error. This specification is applicable to both the analyzer calibration error and the 3-point system calibration error tests described in section 8.2.3. At each calibration gas level (low, mid, and high) the calibration error must either be within ±2.0 percent of the calibration span. Alternatively, the results are acceptable if |C
13.2 System Bias. This specification is applicable to both the system bias and 2-point system calibration error tests described in section 8.2.5 and 8.5. The pre- and post-run system bias (or system calibration error) must be within ±5.0 percent of the calibration span for the low-level and upscale calibration gases. Alternatively, the results are acceptable if | C
13.3 Drift. For each run, the low-level and upscale drift must be less than or equal to 3.0 percent of the calibration span. The drift is also acceptable if the pre- and post-run bias (or the pre- and post-run system calibration error) responses do not differ by more than 0.5 ppmv at each gas concentration (i.e. | C
13.4 Interference Check. The total interference response (i.e., the sum of the interference responses of all tested gaseous components) must not be greater than 2.50 percent of the calibration span for the analyzer tested. In summing the interferences, use the larger of the absolute values obtained for the interferent tested with and without the pollutant present. The results are also acceptable if the sum of the responses does not exceed 0.5 ppmv for a calibration span of 5 to 10 ppmv, or 0.2 ppmv for a calibration span
13.5 NO
13.6 Alternative Dynamic Spike Procedure. Recoveries of both pre-test spikes and post-test spikes must be within 100 ±10 percent. If the absolute difference between the calculated spike value and measured spike value is equal to or less than 0.20 ppmv, then the requirements of the ADSC are met.
16.1 Dynamic Spike Procedure. Except for applications under part 75 of this chapter, you may use a dynamic spiking procedure to validate your test data for a specific test matrix in place of the interference check and pre- and post-run system bias checks. For part 75 applications, use of this procedure is subject to the approval of the Administrator. Best results are obtained for this procedure when source emissions are steady and not varying. Fluctuating emissions may render this alternative procedure difficult to pass. To use this alternative, you must meet the following requirements.
16.1.1 Procedure Documentation. You must detail the procedure you followed in the test report, including how the spike was measured, added, verified during the run, and calculated after the test.
16.1.2 Spiking Procedure Requirements. The spikes must be prepared from EPA Traceability Protocol gases. Your procedure must be designed to spike field samples at two target levels both before and after the test. Your target spike levels should bracket the average sample NO
16.1.3 Example Spiking Procedure. Determine the NO concentration needed to generate concentrations that are 50 and 150 percent of the anticipated NO
(1) Prepare the measurement system and conduct the analyzer calibration error test as described in sections 8.2.2 and 8.2.3. Following the sampling procedures in section 8.1, determine the stack NO
(2) Conduct the number of runs required for the test. Then repeat the above procedure for the post-test spike evaluation. The last run of the test may serve as the average stack concentration for the post-test spike test calculations. The results of the post-test spikes must meet the limits in section 13.6.
16.2 Alternative NO
16.2.1 The procedure for determining conversion efficiency using NO in 40 CFR 86.123-78.
16.2.2 Bag Procedure. Perform the analyzer calibration error test to document the calibration (both NO and NO
(1) Immediately attach the bag to the inlet of the NO
(2) [Reserved]
16.3 Manufacturer’s Stability Test. A manufacturer’s stability test is required for all analyzers that routinely measure emissions below 20 ppmv and is optional but recommended for other analyzers. This test evaluates each analyzer model by subjecting it to the tests listed in Table 7E-5 following procedures similar to those in 40 CFR 53.23 for thermal stability and insensitivity to supply voltage variations. If the analyzer will be used under temperature conditions that are outside the test conditions in Table B-4 of Part 53.23, alternative test temperatures that better reflect the analyzer field environment should be used. Alternative procedures or documentation that establish the analyzer’s stability over the appropriate line voltages and temperatures are acceptable.
1. “ERA Traceability Protocol for Assay and Certification of Gaseous Calibration Standards” September 1997 as amended, ERA-600/R-97/121.
Table 7E-3 – Example Interference Check Gas Concentrations
| Potential interferent gas 1 | Concentrations 2 sample conditioning type | |
|---|---|---|
| Hot wet | Dried | |
| CO | 5 and 15% | 5 and 15% |
| H | 25% | 1% |
| NO | 15 ppmv | 15 ppmv |
| NO | 15 ppmv | 15 ppmv |
| N | 10 ppmv | 10 ppmv |
| CO | 50 ppmv | 50 ppmv |
| NH | 10 ppmv | 10 ppmv |
| CH | 50 ppmv | 50 ppmv |
| SO | 20 ppmv | 20 ppmv |
| H | 50 ppmv | 50 ppmv |
| HCl | 10 ppmv | 10 ppmv |
1 Any applicable gas may be eliminated or tested at a reduced level if the manufacturer has provided reliable means for limiting or scrubbing that gas to a specified level.
2 As practicable, gas concentrations should be the highest expected at test sites.
| Test gas type | Concentration (ppm) | Analyzer response |
|---|---|---|
| Sum of Responses | ||
| % of Calibration Span | ||
Table 7E-5 – Manufacturer Stability Test
| Test description | Acceptance criteria (note 1) |
|---|---|
| Thermal Stability | Temperature range when drift does not exceed 3.0% of analyzer range over a 12-hour run when measured with NO |
| Fault Conditions | Identify conditions which, when they occur, result in performance which is not in compliance with the Manufacturer’s Stability Test criteria. These are to be indicated visually or electrically to alert the operator of the problem. |
| Insensitivity to Supply Voltage Variations | ±10.0% (or manufacturers alternative) variation from nominal voltage must produce a drift of ≤2.0% of calibration span for either zero or concentration ≥80% NO |
| Analyzer Calibration Error | For a low-, medium-, and high-calibration gas, the difference between the manufacturer certified value and the analyzer response in direct calibration mode, no more than 2.0% of calibration span. |
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 2, Method 3, Method 5, and Method 6.
1.1 Analytes.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Sulfuric acid, including: Sulfuric acid (H | 7664-93-9, 7449-11-9 | 0.05 mg/m 3 (0.03 × 10 3). |
| Sulfur dioxide (SO | 7449-09-5 | 1.2 mg/m 3 (3 × 10 3). |
1.2 Applicability. This method is applicable for the determination of H
Filterable particulate matter may be determined along with H
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
A gas sample is extracted isokinetically from the stack. The H
4.1 Possible interfering agents of this method are fluorides, free ammonia, and dimethyl aniline. If any of these interfering agents is present (this can be determined by knowledge of the process), alternative methods, subject to the approval of the Administrator, are required.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method.
5.2 Corrosive reagents. Same as Method 6, section 5.2.
6.1 Sample Collection. Same as Method 5, section 6.1, with the following additions and exceptions:
6.1.1 Sampling Train. A schematic of the sampling train used in this method is shown in Figure 8-1; it is similar to the Method 5 sampling train, except that the filter position is different, and the filter holder does not have to be heated. See Method 5, section 6.1.1, for details and guidelines on operation and maintenance.
6.1.1.1 Probe Nozzle. Borosilicate or quartz glass with a sharp, tapered leading edge and coupled to the probe liner using a polytetrafluoroethylene (PTFE) or glass-lined union (e.g., fused silica, Slico, or equivalent). When the stack temperature exceeds 210 °C (410 °F), a leak-free ground glass fitting or other leak free, non-contaminating fitting must be used to couple the nozzle to the probe liner. It is also acceptable to use a one-piece glass nozzle/liner assembly. The angle of the taper shall be ≤30°, and the taper shall be on the outside to preserve a constant internal diameter. The probe nozzle shall be of the button-hook or elbow design, unless otherwise specified by the Administrator. Other materials of construction may be used, subject to the approval of the Administrator. A range of nozzle sizes suitable for isokinetic sampling should be available. Typical nozzle sizes range from 0.32 to 1.27 cm (
6.1.1.2 Probe Liner. Borosilicate or quartz glass, with a heating system to prevent visible condensation during sampling. Do not use metal probe liners.
6.1.1.3 Filter Holder. Borosilicate glass, with a glass frit filter support and a silicone rubber gasket. Other gasket materials (e.g., Teflon or Viton) may be used, subject to the approval of the Administrator. The holder design shall provide a positive seal against leakage from the outside or around the filter. The filter holder shall be placed between the first and second impingers. Do not heat the filter holder.
6.1.1.4 Impingers. Four, of the Greenburg-Smith design, as shown in Figure 8-1. The first and third impingers must have standard tips. The second and fourth impingers must be modified by replacing the insert with an approximately 13-mm (
6.1.1.5 Temperature Sensor. Thermometer, or equivalent, to measure the temperature of the gas leaving the impinger train to within 1 °C (2 °F).
6.2 Sample Recovery. The following items are required for sample recovery:
6.2.1 Wash Bottles. Two polyethylene or glass bottles, 500-ml.
6.2.2 Graduated Cylinders. Two graduated cylinders (volumetric flasks may be used), 250-ml, 1-liter.
6.2.3 Storage Bottles. Leak-free polyethylene bottles, 1-liter size (two for each sampling run).
6.2.4 Trip Balance. 500-g capacity, to measure to ±0.5 g (necessary only if a moisture content analysis is to be done).
6.3 Analysis. The following items are required for sample analysis:
6.3.1 Pipettes. Volumetric 10-ml, 100-ml.
6.3.2 Burette. 50-ml.
6.3.3 Erlenmeyer Flask. 250-ml (one for each sample, blank, and standard).
6.3.4 Graduated Cylinder. 100-ml.
6.3.5 Dropping Bottle. To add indicator solution, 125-ml size.
Unless otherwise indicated, all reagents are to conform to the specifications established by the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available. Otherwise, use the best available grade.
7.1 Sample Collection. The following reagents are required for sample collection:
7.1.1 Filters and Silica Gel. Same as in Method 5, sections 7.1.1 and 7.1.2, respectively.
7.1.2 Water. Same as in Method 6, section 7.1.1.
7.1.3 Isopropanol, 80 Percent by Volume. Mix 800 ml of isopropanol with 200 ml of water.
Check for peroxide impurities using the procedure outlined in Method 6, section 7.1.2.1.
7.1.4 Hydrogen Peroxide (H
7.1.5 Crushed Ice.
7.2 Sample Recovery. The reagents and standards required for sample recovery are:
7.2.1 Water. Same as in section 7.1.2.
7.2.2 Isopropanol, 80 Percent. Same as in section 7.1.3.
7.3 Sample Analysis. Same as Method 6, section 7.3.
8.1 Pretest Preparation. Same as Method 5, section 8.1, except that filters should be inspected but need not be desiccated, weighed, or identified. If the effluent gas can be considered dry (i.e., moisture-free), the silica gel need not be weighed.
8.2 Preliminary Determinations. Same as Method 5, section 8.2.
8.3 Preparation of Sampling Train. Same as Method 5, section 8.3, with the following exceptions:
8.3.1 Use Figure 8-1 instead of Figure 5-1.
8.3.2 Replace the second sentence of Method 5, section 8.3.1 with: Place 100 ml of 80 percent isopropanol in the first impinger, 100 ml of 3 percent H
8.3.3 Ignore any other statements in section 8.3 of Method 5 that are obviously not applicable to the performance of Method 8.
If moisture content is to be determined by impinger analysis, weigh each of the first three impingers (plus absorbing solution) to the nearest 0.5 g, and record these weights. Weigh also the silica gel (or silica gel plus container) to the nearest 0.5 g, and record.)
8.4 Metering System Leak-Check Procedure. Same as Method 5, section 8.4.1.
8.5 Pretest Leak-Check Procedure. Follow the basic procedure in Method 5, section 8.4.2, noting that the probe heater shall be adjusted to the minimum temperature required to prevent condensation, and also that verbage such as “* * * plugging the inlet to the filter holder * * * ” found in section 8.4.2.2 of Method 5 shall be replaced by “ * * * plugging the inlet to the first impinger * * * ”. The pretest leak-check is recommended, but is not required.
8.6 Sampling Train Operation. Follow the basic procedures in Method 5, section 8.5, in conjunction with the following special instructions:
8.6.1 Record the data on a sheet similar to that shown in Figure 8-2 (alternatively, Figure 5-2 in Method 5 may be used). The sampling rate shall not exceed 0.030 m
8.6.2 After turning off the pump and recording the final readings at the conclusion of each run, remove the probe from the stack. Conduct a post-test (mandatory) leak-check as outlined in section 8.4.4 of Method 5 (with appropriate modifications), and record the leak rate. If the post-test leakage rate exceeds the specified acceptable rate, either correct the sample volume, as outlined in section 12.3 of Method 5, or void the run.
8.6.3 Drain the ice bath and, with the probe disconnected, purge the remaining part of the train by drawing clean ambient air through the system for 15 minutes at the average flow rate used for sampling.
Clean ambient air can be provided by passing air through a charcoal filter. Alternatively, ambient air (without cleaning) may be used.
8.7 Calculation of Percent Isokinetic. Same as Method 5, section 8.6.
8.8 Sample Recovery. Proper cleanup procedure begins as soon as the probe is removed from the stack at the end of the sampling period. Allow the probe to cool. Treat the samples as follows:
8.8.1 Container No. 1.
8.8.1.1 If a moisture content analysis is to be performed, clean and weigh the first impinger (plus contents) to the nearest 0.5 g, and record this weight.
8.8.1.2 Transfer the contents of the first impinger to a 250-ml graduated cylinder. Rinse the probe, first impinger, all connecting glassware before the filter, and the front half of the filter holder with 80 percent isopropanol. Add the isopropanol rinse solution to the cylinder. Dilute the contents of the cylinder to 225 ml with 80 percent isopropanol, and transfer the cylinder contents to the storage container. Rinse the cylinder with 25 ml of 80 percent isopropanol, and transfer the rinse to the storage container. Add the filter to the solution in the storage container and mix. Seal the container to protect the solution against evaporation. Mark the level of liquid on the container, and identify the sample container.
8.8.2 Container No. 2.
8.8.2.1 If a moisture content analysis is to be performed, clean and weigh the second and third impingers (plus contents) to the nearest 0.5 g, and record the weights. Also, weigh the spent silica gel (or silica gel plus impinger) to the nearest 0.5 g, and record the weight.
8.8.2.2 Transfer the solutions from the second and third impingers to a 1-liter graduated cylinder. Rinse all connecting glassware (including back half of filter holder) between the filter and silica gel impinger with water, and add this rinse water to the cylinder. Dilute the contents of the cylinder to 950 ml with water. Transfer the solution to a storage container. Rinse the cylinder with 50 ml of water, and transfer the rinse to the storage container. Mark the level of liquid on the container. Seal and identify the sample container.
9.1 Miscellaneous Quality Control Measures.
| Section | Quality control measure | Effect |
|---|---|---|
| 7.1.3 | Isopropanol check | Ensure acceptable level of peroxide impurities in isopropanol. |
| 8.4, 8.5, 10.1 | Sampling equipment leak-check and calibration | Ensure accurate measurement of stack gas flow rate, sample volume. |
| 10.2 | Barium standard solution standardization | Ensure normality determination. |
| 11.2 | Replicate titrations | Ensure precision of titration determinations. |
9.2 Volume Metering System Checks. Same as Method 5, section 9.2.
10.1 Sampling Equipment. Same as Method 5, section 10.0.
10.2 Barium Standard Solution. Same as Method 6, section 10.5.
11.1. Sample Loss. Same as Method 6, section 11.1.
11.2. Sample Analysis.
11.2.1 Container No. 1. Shake the container holding the isopropanol solution and the filter. If the filter breaks up, allow the fragments to settle for a few minutes before removing a sample aliquot. Pipette a 100-ml aliquot of this solution into a 250-ml Erlenmeyer flask, add 2 to 4 drops of thorin indicator, and titrate to a pink endpoint using 0.0100 N barium standard solution. Repeat the titration with a second aliquot of sample, and average the titration values. Replicate titrations must agree within 1 percent or 0.2 ml, whichever is greater.
11.2.2 Container No. 2. Thoroughly mix the solution in the container holding the contents of the second and third impingers. Pipette a 10-ml aliquot of sample into a 250-ml Erlenmeyer flask. Add 40 ml of isopropanol, 2 to 4 drops of thorin indicator, and titrate to a pink endpoint using 0.0100 N barium standard solution. Repeat the titration with a second aliquot of sample, and average the titration values. Replicate titrations must agree within 1 percent or 0.2 ml, whichever is greater.
11.2.3 Blanks. Prepare blanks by adding 2 to 4 drops of thorin indicator to 100 ml of 80 percent isopropanol. Titrate the blanks in the same manner as the samples.
Carry out calculations retaining at least one extra significant figure beyond that of the acquired data. Round off figures after final calculation.
12.1 Nomenclature. Same as Method 5, section 12.1, with the following additions and exceptions:
12.2 Average Dry Gas Meter Temperature and Average Orifice Pressure Drop. See data sheet (Figure 8-2).
12.3 Dry Gas Volume. Same as Method 5, section 12.3.
12.4 Volume of Water Vapor Condensed and Moisture Content. Calculate the volume of water vapor using Equation 5-2 of Method 5; the weight of water collected in the impingers and silica gel can be converted directly to milliliters (the specific gravity of water is 1 g/ml). Calculate the moisture content of the stack gas (B
12.5 Sulfuric Acid Mist (Including SO
12.6 Sulfur Dioxide Concentration.
12.7 Isokinetic Variation. Same as Method 5, section 12.11.
12.8 Stack Gas Velocity and Volumetric Flow Rate. Calculate the average stack gas velocity and volumetric flow rate, if needed, using data obtained in this method and the equations in sections 12.6 and 12.7 of Method 2.
13.1 Analytical Range. Collaborative tests have shown that the minimum detectable limits of the method are 0.06 mg/m
Same as section 17.0 of Methods 5 and 6.
Many stationary sources discharge visible emissions into the atmosphere; these emissions are usually in the shape of a plume. This method involves the determination of plume opacity by qualified observers. The method includes procedures for the training and certification of observers, and procedures to be used in the field for determination of plume opacity. The appearance of a plume as viewed by an observer depends upon a number of variables, some of which may be controllable and some of which may not be controllable in the field. Variables which can be controlled to an extent to which they no longer exert a significant influence upon plume appearance include: Angle of the observer with respect to the plume; angle of the observer with respect to the sun; point of observation of attached and detached steam plume; and angle of the observer with respect to a plume emitted from a rectangular stack with a large length to width ratio. The method includes specific criteria applicable to these variables.
Other variables which may not be controllable in the field are luminescence and color contrast between the plume and the background against which the plume is viewed. These variables exert an influence upon the appearance of a plume as viewed by an observer, and can affect the ability of the observer to accurately assign opacity values to the observed plume. Studies of the theory of plume opacity and field studies have demonstrated that a plume is most visible and presents the greatest apparent opacity when viewed against a contrasting background. It follows from this, and is confirmed by field trials, that the opacity of a plume, viewed under conditions where a contrasting background is present can be assigned with the greatest degree of accuracy. However, the potential for a positive error is also the greatest when a plume is viewed under such contrasting conditions. Under conditions presenting a less contrasting background, the apparent opacity of a plume is less and approaches zero as the color and luminescence contrast decrease toward zero. As a result, significant negative bias and negative errors can be made when a plume is viewed under less contrasting conditions. A negative bias decreases rather than increases the possibility that a plant operator will be cited for a violation of opacity standards due to observer error.
Studies have been undertaken to determine the magnitude of positive errors which can be made by qualified observers while reading plumes under contrasting conditions and using the procedures set forth in this method. The results of these studies (field trials) which involve a total of 769 sets of 25 readings each are as follows:
(1) For black plumes (133 sets at a smoke generator), 100 percent of the sets were read with a positive error
(2) For white plumes (170 sets at a smoke generator, 168 sets at a coal-fired power plant, 298 sets at a sulfuric acid plant), 99 percent of the sets were read with a positive error of less than 7.5 percent opacity; 95 percent were read with a positive error of less than 5 percent opacity.
The positive observational error associated with an average of twenty-five readings is therefore established. The accuracy of the method must be taken into account when determining possible violations of applicable opacity standards.
1.1 Principle. The opacity of emissions from stationary sources is determined visually by a qualified observer.
1.2 Applicability. This method is applicable for the determination of the opacity of emissions from stationary sources pursuant to § 60.11(b) and for qualifying observers for visually determining opacity of emissions.
The observer qualified in accordance with section 3 of this method shall use the following procedures for visually determining the opacity of emissions:
2.1 Position. The qualified observer shall stand at a distance sufficient to provide a clear view of the emissions with the sun oriented in the 140° sector to his back. Consistent with maintaining the above requirement, the observer shall, as much as possible, make his observations from a position such that his line of vision is approximately perpendicular to the plume direction, and when observing opacity of emissions from rectangular outlets (e.g., roof monitors, open baghouses, noncircular stacks), approximately perpendicular to the longer axis of the outlet. The observer’s line of sight should not include more than one plume at a time when multiple stacks are involved, and in any case the observer should make his observations with his line of sight perpendicular to the longer axis of such a set of multiple stacks (e.g., stub stacks on baghouses).
2.2 Field Records. The observer shall record the name of the plant, emission location, type facility, observer’s name and affiliation, a sketch of the observer’s position relative to the source, and the date on a field data sheet (Figure 9-1). The time, estimated distance to the emission location, approximate wind direction, estimated wind speed, description of the sky condition (presence and color of clouds), and plume background are recorded on a field data sheet at the time opacity readings are initiated and completed.
2.3 Observations. Opacity observations shall be made at the point of greatest opacity in that portion of the plume where condensed water vapor is not present. The observer shall not look continuously at the plume, but instead shall observe the plume momentarily at 15-second intervals.
2.3.1 Attached Steam Plumes. When condensed water vapor is present within the plume as it emerges from the emission outlet, opacity observations shall be made beyond the point in the plume at which condensed water vapor is no longer visible. The observer shall record the approximate distance from the emission outlet to the point in the plume at which the observations are made.
2.3.2 Detached Steam Plume. When water vapor in the plume condenses and becomes visible at a distinct distance from the emission outlet, the opacity of emissions should be evaluated at the emission outlet prior to the condensation of water vapor and the formation of the steam plume.
2.4 Recording Observations. Opacity observations shall be recorded to the nearest 5 percent at 15-second intervals on an observational record sheet. (See Figure 9-2 for an example.) A minimum of 24 observations shall be recorded. Each momentary observation recorded shall be deemed to represent the average opacity of emissions for a 15-second period.
2.5 Data Reduction. Opacity shall be determined as an average of 24 consecutive observations recorded at 15-second intervals. Divide the observations recorded on the record sheet into sets of 24 consecutive observations. A set is composed of any 24 consecutive observations. Sets need not be consecutive in time and in no case shall two sets overlap. For each set of 24 observations, calculate the average by summing the opacity of the 24 observations and dividing this sum by 24. If an applicable standard specifies an averaging time requiring more than 24 observations, calculate the average for all observations made during the specified time period. Record the average opacity on a record sheet. (See Figure 9-1 for an example.)
3.1 Certification Requirements. To receive certification as a qualified observer, a candidate must be tested and demonstrate the ability to assign opacity readings in 5 percent increments to 25 different black plumes and 25 different white plumes, with an error not to exceed 15 percent opacity on any one reading and an average error not to exceed 7.5 percent opacity in each category. Candidates shall be tested according to the procedures described in section 3.2. Smoke generators used pursuant to section 3.2 shall be equipped with a smoke meter which meets the requirements of section 3.3.
The certification shall be valid for a period of 6 months, at which time the qualification procedure must be repeated by any observer in order to retain certification.
3.2 Certification Procedure. The certification test consists of showing the candidate a complete run of 50 plumes – 25 black plumes and 25 white plumes – generated by a smoke generator. Plumes within each set of 25 black and 25 white runs shall be presented in random order. The candidate assigns an opacity value to each plume and records his observation on a suitable form. At the completion of each run of 50 readings, the score of the candidate is determined. If a candidate fails to qualify, the complete run of 50 readings must be repeated in any retest. The smoke test may be administered as part of a smoke school or training program, and may be preceded by training or familiarization runs of the smoke generator during which candidates are shown black and white plumes of known opacity.
3.3 Smoke Generator Specifications. Any smoke generator used for the purposes of section 3.2 shall be equipped with a smoke meter installed to measure opacity across the diameter of the smoke generator stack. The smoke meter output shall display instack opacity based upon a pathlength equal to the stack exit diameter, on a full 0 to 100 percent chart recorder scale. The smoke meter optical design and performance shall meet the specifications shown in Table 9-1. The smoke meter shall be calibrated as prescribed in section 3.3.1 prior to the conduct of each smoke reading test. At the completion of each test, the zero and span drift shall be checked and if the drift exceeds ±1 percent opacity, the condition shall be corrected prior to conducting any subsequent test runs. The smoke meter shall be demonstrated, at the time of installation, to meet the specifications listed in Table 9-1. This demonstration shall be repeated following any subsequent repair or replacement of the photocell or associated electronic circuitry including the chart recorder or output meter, or every 6 months, whichever occurs first.
Table 9-1 – Smoke Meter Design and Performance Specifications
| Parameter | Specification |
|---|---|
| a. Light source | Incandescent lamp operated at nominal rated voltage. |
| b. Spectral response of photocell | Photopic (daylight spectral response of the human eye – Citation 3). |
| c. Angle of view | 15° maximum total angle. |
| d. Angle of projection | 15° maximum total angle. |
| e. Calibration error | ±3% opacity, maximum. |
| f. Zero and span drift | ±1% opacity, 30 minutes. |
| g. Response time | 5 seconds. |
3.3.1 Calibration. The smoke meter is calibrated after allowing a minimum of 30 minutes warmup by alternately producing simulated opacity of 0 percent and 100 percent. When stable response at 0 percent or 100 percent is noted, the smoke meter is adjusted to produce an output of 0 percent or 100 percent, as appropriate. This calibration shall be repeated until stable 0 percent and 100 percent readings are produced without adjustment. Simulated 0 percent and 100 percent opacity values may be produced by alternately switching the power to the light source on and off while the smoke generator is not producing smoke.
3.3.2 Smoke Meter Evaluation. The smoke meter design and performance are to be evaluated as follows:
3.3.2.1 Light Source. Verify from manufacturer’s data and from voltage measurements made at the lamp, as installed, that the lamp is operated within ±5 percent of the nominal rated voltage.
3.3.2.2 Spectral Response of Photocell. Verify from manufacturer’s data that the photocell has a photopic response; i.e., the spectral sensitivity of the cell shall closely approximate the standard spectral-luminosity curve for photopic vision which is referenced in (b) of Table 9-1.
Figure 9-2 – Observation Record
Page ____ of ____
| Company | Observer | |
| Location | Type facility | |
| Test Number | Point of emissions | |
| Date |
| Hr. | Min. | Seconds | Steam plume (check if applicable) | Comments | ||||
|---|---|---|---|---|---|---|---|---|
| 0 | 15 | 30 | 45 | Attached | Detached | |||
| 0 | ||||||||
| 1 | ||||||||
| 2 | ||||||||
| 3 | ||||||||
| 4 | ||||||||
| 5 | ||||||||
| 6 | ||||||||
| 7 | ||||||||
| 8 | ||||||||
| 9 | ||||||||
| 10 | ||||||||
| 11 | ||||||||
| 12 | ||||||||
| 13 | ||||||||
| 14 | ||||||||
| 15 | ||||||||
| 16 | ||||||||
| 17 | ||||||||
| 18 | ||||||||
| 19 | ||||||||
| 20 | ||||||||
| 21 | ||||||||
| 22 | ||||||||
| 23 | ||||||||
| 24 | ||||||||
| 25 | ||||||||
| 26 | ||||||||
| 27 | ||||||||
| 28 | ||||||||
| 29 | ||||||||
Figure 9-2 – Observation Record (Continued)
Page ____ of ____
| Company | Observer | |
| Location | Type facility | |
| Test Number | Point of emissions | |
| Date |
| Hr. | Min. | Seconds | Steam plume (check if applicable) | Comments | ||||
|---|---|---|---|---|---|---|---|---|
| 0 | 15 | 30 | 45 | Attached | Detached | |||
| 30 | ||||||||
| 31 | ||||||||
| 32 | ||||||||
| 33 | ||||||||
| 34 | ||||||||
| 35 | ||||||||
| 36 | ||||||||
| 37 | ||||||||
| 38 | ||||||||
| 39 | ||||||||
| 40 | ||||||||
| 41 | ||||||||
| 42 | ||||||||
| 43 | ||||||||
| 44 | ||||||||
| 45 | ||||||||
| 46 | ||||||||
| 47 | ||||||||
| 48 | ||||||||
| 49 | ||||||||
| 50 | ||||||||
| 51 | ||||||||
| 52 | ||||||||
| 53 | ||||||||
| 54 | ||||||||
| 55 | ||||||||
| 56 | ||||||||
| 57 | ||||||||
| 58 | ||||||||
| 59 | ||||||||
3.3.2.3 Angle of View. Check construction geometry to ensure that the total angle of view of the smoke plume, as seen by the photocell, does not exceed 15°. The total angle of view may be calculated from: θ = 2 tan
3.3.2.4 Angle of Projection. Check construction geometry to ensure that the total angle of projection of the lamp on the smoke plume does not exceed 15°. The total angle of projection may be calculated from: θ = 2 tan
3.3.2.5 Calibration Error. Using neutral-density filters of known opacity, check the error between the actual response and the theoretical linear response of the smoke meter. This check is accomplished by first calibrating the smoke meter according to 3.3.1 and then inserting a series of three neutral-density filters of nominal opacity of 20, 50, and 75 percent in the smoke meter pathlength. Filters calibrated within ±2 percent shall be used. Care should be taken when inserting the filters to prevent stray light from affecting the meter. Make a total of five nonconsecutive readings for each filter. The maximum error on any one reading shall be 3 percent opacity.
3.3.2.6 Zero and Span Drift. Determine the zero and span drift by calibrating and operating the smoke generator in a normal manner over a 1-hour period. The drift is measured by checking the zero and span at the end of this period.
3.3.2.7 Response Time. Determine the response time by producing the series of five simulated 0 percent and 100 percent opacity values and observing the time required to reach stable response. Opacity values of 0 percent and 100 percent may be simulated by alternately switching the power to the light source off and on while the smoke generator is not operating.
1. Air Pollution Control District Rules and Regulations, Los Angeles County Air Pollution Control District, Regulation IV, Prohibitions, Rule 50.
2. Weisburd, Melvin I., Field Operations and Enforcement Manual for Air, U.S. Environmental Protection Agency, Research Triangle Park, NC. APTD-1100, August 1972, pp. 4.1-4.36.
3. Condon, E.U., and Odishaw, H., Handbook of Physics, McGraw-Hill Co., New York, NY, 1958, Table 3.1, p. 6-52.
This alternate method provides the quantitative determination of the opacity of an emissions plume remotely by a mobile lidar system (laser radar; Light Detection and Ranging). The method includes procedures for the calibration of the lidar and procedures to be used in the field for the lidar determination of plume opacity. The lidar is used to measure plume opacity during either day or nighttime hours because it contains its own pulsed light source or transmitter. The operation of the lidar is not dependent upon ambient lighting conditions (light, dark, sunny or cloudy).
The lidar mechanism or technique is applicable to measuring plume opacity at numerous wavelengths of laser radiation. However, the performance evaluation and calibration test results given in support of this method apply only to a lidar that employs a ruby (red light) laser [Reference 5.1].
1.1 Principle. The opacity of visible emissions from stationary sources (stacks, roof vents, etc.) is measured remotely by a mobile lidar (laser radar).
1.2 Applicability. This method is applicable for the remote measurement of the opacity of visible emissions from stationary sources during both nighttime and daylight conditions, pursuant to 40 CFR § 60.11(b). It is also applicable for the calibration and performance verification of the mobile lidar for the measurement of the opacity of emissions. A performance/design specification for a basic lidar system is also incorporated into this method.
1.3 Definitions.
Azimuth angle: The angle in the horizontal plane that designates where the laser beam is pointed. It is measured from an arbitrary fixed reference line in that plane.
Backscatter: The scattering of laser light in a direction opposite to that of the incident laser beam due to reflection from particulates along the beam’s atmospheric path which may include a smoke plume.
Backscatter signal: The general term for the lidar return signal which results from laser light being backscattered by atmospheric and smoke plume particulates.
Convergence distance: The distance from the lidar to the point of overlap of the lidar receiver’s field-of-view and the laser beam.
Elevation angle: The angle of inclination of the laser beam referenced to the horizontal plane.
Far region: The region of the atmosphere’s path along the lidar line-of-sight beyond or behind the plume being measured.
Lidar: Acronym for Light Detection and Ranging.
Lidar range: The range or distance from the lidar to a point of interest along the lidar line-of-sight.
Near region: The region of the atmospheric path along the lidar line-of-sight between the lidar’s convergence distance and the plume being measured.
Opacity: One minus the optical transmittance of a smoke plume, screen target, etc.
Pick interval: The time or range intervals in the lidar backscatter signal whose minimum average amplitude is used to calculate opacity. Two pick intervals are required, one in the near region and one in the far region.
Plume: The plume being measured by lidar.
Plume signal: The backscatter signal resulting from the laser light pulse passing through a plume.
1/R
Reference signal: The backscatter signal resulting from the laser light pulse passing through ambient air.
Sample interval: The time period between successive samples for a digital signal or between successive measurements for an analog signal.
Signal spike: An abrupt, momentary increase and decrease in signal amplitude.
Source: The source being tested by lidar.
Time reference: The time (t
The mobile lidar calibrated in accordance with Paragraph 3 of this method shall use the following procedures for remotely measuring the opacity of stationary source emissions:
2.1 Lidar Position. The lidar shall be positioned at a distance from the plume sufficient to provide an unobstructed view of the source emissions. The plume must be at a range of at least 50 meters or three consecutive pick intervals (whichever is greater) from the lidar’s transmitter/receiver convergence distance along the line-of-sight. The maximum effective opacity measurement distance of the lidar is a function of local atmospheric conditions, laser beam diameter, and plume diameter. The test position of the lidar shall be selected so that the diameter of the laser beam at the measurement point within the plume shall be no larger than three-fourths the plume diameter. The beam diameter is calculated by Equation (AM1-1):
When there is more than one source of emissions in the immediate vicinity of the plume, the lidar shall be positioned so that the laser beam passes through only a single plume, free from any interference of the other plumes for a minimum of 50 meters or three consecutive pick intervals (whichever is greater) in each region before and beyond the plume along the line-of-sight (determined from the backscatter signals). The lidar shall initially be positioned so that its line-of-sight is approximately perpendicular to the plume.
When measuring the opacity of emissions from rectangular outlets (e.g., roof monitors, open baghouses, noncircular stacks, etc.), the lidar shall be placed in a position so that its line-of-sight is approximately perpendicular to the longer (major) axis of the outlet.
2.2 Lidar Operational Restrictions. The lidar receiver shall not be aimed within an angle of ±15° (cone angle) of the sun.
This method shall not be used to make opacity measurements if thunderstorms, snowstorms, hail storms, high wind, high-ambient dust levels, fog or other atmospheric conditions cause the reference signals to consistently exceed the limits specified in section 2.3.
2.3 Reference Signal Requirements. Once placed in its proper position for opacity measurement, the laser is aimed and fired with the line-of-sight near the outlet height and rotated horizontally to a position clear of the source structure and the associated plume. The backscatter signal obtained from this position is called the ambient-air or reference signal. The lidar operator shall inspect this signal [Section V of Reference 5.1] to: (1) determine if the lidar line-of-sight is free from interference from other plumes and from physical obstructions such as cables, power lines, etc., for a minimum of 50 meters or three consecutive pick intervals (whichever is greater) in each region before and beyond the plume, and (2) obtain a qualitative measure of the homogeneity of the ambient air by noting any signal spikes.
Should there be any signal spikes on the reference signal within a minimum of 50 meters or three consecutive pick intervals (whichever is greater) in each region before and beyond the plume, the laser shall be fired three more times and the operator shall inspect the reference signals on the display. If the spike(s) remains, the azimuth angle shall be changed and the above procedures conducted again. If the spike(s) disappears in all three reference signals, the lidar line-of-sight is acceptable if there is shot-to-shot consistency and there is no interference from other plumes.
Shot-to-shot consistency of a series of reference signals over a period of twenty seconds is verified in either of two ways. (1) The lidar operator shall observe the reference signal amplitudes. For shot-to-shot consistency the ratio of R
If a set of reference signals fails to meet the requirements of this section, then all plume signals [Section 2.4] from the last set of acceptable reference signals to the failed set shall be discarded.
2.3.1 Initial and Final Reference Signals. Three reference signals shall be obtained within a 90-second time period prior to any data run. A final set of three reference signals shall be obtained within three (3) minutes after the completion of the same data run.
2.3.2 Temporal Criterion for Additional Reference Signals. An additional set of reference signals shall be obtained during a data run if there is a change in wind direction or plume drift of 30° or more from the direction that was prevalent when the last set of reference signals was obtained. An additional set of reference signals shall also be obtained if there is an increase in value of S
2.4 Plume Signal Requirements. Once properly aimed, the lidar is placed in operation with the nominal pulse or firing rate of six pulses/minute (1 pulse/10 seconds). The lidar operator shall observe the plume backscatter signals to determine the need for additional reference signals as required by section 2.3.2. The plume signals are recorded from lidar start to stop and are called a data run. The length of a data run is determined by operator discretion. Short-term stops of the lidar to record additional reference signals do not constitute the end of a data run if plume signals are resumed within 90 seconds after the reference signals have been recorded, and the total stop or interrupt time does not exceed 3 minutes.
2.4.1 Non-hydrated Plumes. The laser shall be aimed at the region of the plume which displays the greatest opacity. The lidar operator must visually verify that the laser is aimed clearly above the source exit structure.
2.4.2 Hydrated Plumes. The lidar will be used to measure the opacity of hydrated or so-called steam plumes. As listed in the reference method, there are two types, i.e., attached and detached steam plumes.
2.4.2.1 Attached Steam Plumes. When condensed water vapor is present within a plume, lidar opacity measurements shall be made at a point within the residual plume where the condensed water vapor is no longer visible. The laser shall be aimed into the most dense region (region of highest opacity) of the residual plume.
During daylight hours the lidar operator locates the most dense portion of the residual plume visually. During nighttime hours a high-intensity spotlight, night vision scope, or low light level TV, etc., can be used as an aid to locate the residual plume. If visual determination is ineffective, the lidar may be used to locate the most dense region of the residual plume by repeatedly measuring opacity, along the longitudinal axis or center of the plume from the emissions outlet to a point just beyond the steam plume. The lidar operator should also observe color differences and plume reflectivity to ensure that the lidar is aimed completely within the residual plume. If the operator does not obtain a clear indication of the location of the residual plume, this method shall not be used.
Once the region of highest opacity of the residual plume has been located, aiming adjustments shall be made to the laser line-of-sight to correct for the following: movement to the region of highest opacity out of the lidar line-of-sight (away from the laser beam) for more than 15 seconds, expansion of the steam plume (air temperature lowers and/or relative humidity increases) so that it just begins to encroach on the field-of-view of the lidar’s optical telescope receiver, or a decrease in the size of the steam plume (air temperature higher and/or relative humidity decreases) so that regions within the residual plume whose opacity is higher than the one being monitored, are present.
2.4.2.2 Detached Steam Plumes. When the water vapor in a hydrated plume condenses and becomes visible at a finite distance from the stack or source emissions outlet, the opacity of the emissions shall be measured in the region of the plume clearly above the emissions outlet and below condensation of the water vapor.
During daylight hours the lidar operators can visually determine if the steam plume is detached from the stack outlet. During nighttime hours a high-intensity spotlight, night vision scope, low light level TV, etc., can be used as an aid in determining if the steam plume is detached. If visual determination is ineffective, the lidar may be used to determine if the steam plume is detached by repeatedly measuring plume opacity from the outlet to the steam plume along the plume’s longitudinal axis or center line. The lidar operator should also observe color differences and plume reflectivity to detect a detached plume. If the operator does not obtain a clear indication of the location of the detached plume, this method shall not be used to make opacity measurements between the outlet and the detached plume.
Once the determination of a detached steam plume has been confirmed, the laser shall be aimed into the region of highest opacity in the plume between the outlet and the formation of the steam plume. Aiming adjustments shall be made to the lidar’s line-of-sight within the plume to correct for changes in the location of the most dense region of the plume due to changes in wind direction and speed or if the detached steam plume moves closer to the source outlet encroaching on the most dense region of the plume. If the detached steam plume should move too close to the source outlet for the lidar to make interference-free opacity measurements, this method shall not be used.
2.5 Field Records. In addition to the recording recommendations listed in other sections of this method the following records should be maintained. Each plume measured should be uniquely identified. The name of the facility, type of facility, emission source type, geographic location of the lidar with respect to the plume, and plume characteristics should be recorded. The date of the test, the time period that a source was monitored, the time (to the nearest second) of each opacity measurement, and the sample interval should also be recorded. The wind speed, wind direction, air temperature, relative humidity, visibility (measured at the lidar’s position), and cloud cover should be recorded at the beginning and end of each time period for a given source. A small sketch depicting the location of the laser beam within the plume should be recorded.
If a detached or attached steam plume is present at the emissions source, this fact should be recorded. Figures AM1-I and AM1-II are examples of logbook forms that may be used to record this type of data. Magnetic tape or paper tape may also be used to record data.
2.6 Opacity Calculation and Data Analysis. Referring to the reference signal and plume signal in Figure AM1-III, the measured opacity (O
The 1/R
The first step in selecting the pick intervals for Equation AM1-2 is to divide the plume signal amplitude by the reference signal amplitude at the same respective ranges to obtain a “normalized” signal. The pick intervals selected using this normalized signal, are a minimum of 15 m (100 nanoseconds) in length and consist of at least 5 contiguous sample intervals. In addition, the following criteria, listed in order of importance, govern pick interval selection. (1) The intervals shall be in a region of the normalized signal where the reference signal meets the requirements of section 2.3 and is everywhere greater than zero. (2) The intervals (near and far) with the minimum average amplitude are chosen. (3) If more than one interval with the same minimum average amplitude is found, the interval closest to the plume is chosen. (4) The standard deviation, S
If S
The reference signal pick intervals, R
The average amplitudes for each of the pick intervals, I
Similarly, the amplitudes for I
The standard deviation, S
Similarly, the standard deviations S
The calculated values of I
2.6.1 Azimuth Angle Correction. If the azimuth angle correction to opacity specified in this section is performed, then the elevation angle correction specified in section 2.6.2 shall not be performed. When opacity is measured in the residual region of an attached steam plume, and the lidar line-of-sight is not perpendicular to the plume, it may be necessary to correct the opacity measured by the lidar to obtain the opacity that would be measured on a path perpendicular to the plume. The following method, or any other method which produces equivalent results, shall be used to determine the need for a correction, to calculate the correction, and to document the point within the plume at which the opacity was measured.
Figure AM1-IV(b) shows the geometry of the opacity correction. L′ is the path through the plume along which the opacity measurement is made. P′ is the path perpendicular to the plume at the same point. The angle ε is the angle between L′ and the plume center line. The angle (π/2-ε), is the angle between the L′ and P′. The measured opacity, O
Figure AM1-IV(a) shows the geometry used to calculate ε and the position in the plume at which the lidar measurement is made. This analysis assumes that for a given lidar measurement, the range from the lidar to the plume, the elevation angle of the lidar from the horizontal plane, and the azimuth angle of the lidar from an arbitrary fixed reference in the horizontal plane can all be obtained directly.
The correction angle ε shall be determined using Equation AM1-10.
*Obtained directly from lidar. These values should be recorded.
R≤, the distance from the source to the opacity measurement point projected in the horizontal plane, shall be determined using Equation AM1-11.
2.6.2 Elevation Angle Correction. An individual lidar-measured opacity, O
The values for β
2.6.3 Determination of Actual Plume Opacity. Actual opacity of the plume shall be determined by Equation AM1-15.
2.6.4 Calculation of Average Actual Plume Opacity. The average of the actual plume opacity, O
The lidar shall be subjected to two types of performance verifications that shall be performed in the field. The annual calibration, conducted at least once a year, shall be used to directly verify operation and performance of the entire lidar system. The routine verification, conducted for each emission source measured, shall be used to insure proper performance of the optical receiver and associated electronics.
3.1 Annual Calibration Procedures. Either a plume from a smoke generator or screen targets shall be used to conduct this calibration.
If the screen target method is selected, five screens shall be fabricated by placing an opaque mesh material over a narrow frame (wood, metal extrusion, etc.). The screen shall have a surface area of at least one square meter. The screen material should be chosen for precise optical opacities of about 10, 20, 40, 60, and 80%. Opacity of each target shall be optically determined and should be recorded. If a smoke generator plume is selected, it shall meet the requirements of section 3.3 of Reference Method 9. This calibration shall be performed in the field during calm (as practical) atmospheric conditions. The lidar shall be positioned in accordance with section 2.1.
The screen targets must be placed perpendicular to and coincident with the lidar line-of-sight at sufficient height above the ground (suggest about 30 ft) to avoid ground-level dust contamination. Reference signals shall be obtained just prior to conducting the calibration test.
The lidar shall be aimed through the center of the plume within 1 stack diameter of the exit, or through the geometric center of the screen target selected. The lidar shall be set in operation for a 6-minute data run at a nominal pulse rate of 1 pulse every 10 seconds. Each backscatter return signal and each respective opacity value obtained from the smoke generator transmissometer, shall be obtained in temporal coincidence. The data shall be analyzed and reduced in accordance with section 2.6 of this method. This calibration shall be performed for 0% (clean air), and at least five other opacities (nominally 10, 20, 40, 60, and 80%).
The average of the lidar opacity values obtained during a 6-minute calibration run shall be calculated and should be recorded. Also the average of the opacity values obtained from the smoke generator transmissometer for the same 6-minute run shall be calculated and should be recorded.
Alternate calibration procedures that do not meet the above requirements but produce equivalent results may be used.
3.2 Routine Verification Procedures. Either one of two techniques shall be used to conduct this verification. It shall be performed at least once every 4 hours for each emission source measured. The following parameters shall be directly verified.
1) The opacity value of 0% plus a minimum of 5 (nominally 10, 20, 40, 60, and 80%) opacity values shall be verified through the PMT detector and data processing electronics.
2) The zero-signal level (receiver signal with no optical signal from the source present) shall be inspected to insure that no spurious noise is present in the signal. With the entire lidar receiver and analog/digital electronics turned on and adjusted for normal operating performance, the following procedures shall be used for Techniques 1 and 2, respectively.
3.2.1 Procedure for Technique 1. This test shall be performed with no ambient or stray light reaching the PMT detector. The narrow band filter (694.3 nanometers peak) shall be removed from its position in front of the PMT detector. Neutral density filters of nominal opacities of 10, 20, 40, 60, and 80% shall be used. The recommended test configuration is depicted in Figure AM1-VI.
The zero-signal level shall be measured and should be recorded, as indicated in Figure AM1-VI(a). This simulated clear-air or 0% opacity value shall be tested in using the selected light source depicted in Figure AM1-VI(b).
The light source either shall be a continuous wave (CW) laser with the beam mechanically chopped or a light emitting diode controlled with a pulse generator (rectangular pulse). (A laser beam may have to be attenuated so as not to saturate the PMT detector). This signal level shall be measured and should be recorded. The opacity value is calculated by taking two pick intervals [Section 2.6] about 1 microsecond apart in time and using Equation (AM1-2) setting the ratio R
The simulated clear-air signal level is also employed in the optical test using the neutral density filters. Using the test configuration in Figure AM1-VI(c), each neutral density filter shall be separately placed into the light path from the light source to the PMT detector. The signal level shall be measured and should be recorded. The opacity value for each filter is calculated by taking the signal level for that respective filter (I
The neutral density filters used for Technique 1 shall be calibrated for actual opacity with accuracy of ±2% or better. This calibration shall be done monthly while the filters are in use and the calibrated values should be recorded.
3.2.2 Procedure for Technique 2. An optical generator (built-in calibration mechanism) that contains a light-emitting diode (red light for a lidar containing a ruby laser) is used. By injecting an optical signal into the lidar receiver immediately ahead of the PMT detector, a backscatter signal is simulated. With the entire lidar receiver electronics turned on and adjusted for normal operating performance, the optical generator is turned on and the simulation signal (corrected for 1/R
The opacity values of 0% and the other five values are selected one at a time in any order. The simulated return signal data should be recorded. The opacity value shall be calculated. This measurement/calculation shall be performed at least three times for each selected opacity value. While the order is not important, each of the opacity values from the optical generator shall be verified. The calibrated optical generator opacity value for each selection should be recorded.
The optical generator used for Technique 2 shall be calibrated for actual opacity with an accuracy of ±1% or better. This calibration shall be done monthly while the generator is in use and calibrated value should be recorded.
Alternate verification procedures that do not meet the above requirements but produce equivalent results may be used.
3.3 Deviation. The permissible error for the annual calibration and routine verification are:
3.3.1 Annual Calibration Deviation.
3.3.1.1 Smoke Generator. If the lidar-measured average opacity for each data run is not within ±5% (full scale) of the respective smoke generator’s average opacity over the range of 0% through 80%, then the lidar shall be considered out of calibration.
3.3.1.2 Screens. If the lidar-measured average opacity for each data run is not within ±3% (full scale) of the laboratory-determined opacity for each respective simulation screen target over the range of 0% through 80%, then the lidar shall be considered out of calibration.
3.3.2 Routine Verification Error. If the lidar-measured average opacity for each neutral density filter (Technique 1) or optical generator selection (Technique 2) is not within ±3% (full scale) of the respective laboratory calibration value then the lidar shall be considered non-operational.
4.1 Lidar Design Specification. The essential components of the basic lidar system are a pulsed laser (transmitter), optical receiver, detector, signal processor, recorder, and an aiming device that is used in aiming the lidar transmitter and receiver. Figure AM1-VII shows a functional block diagram of a basic lidar system.
4.2 Performance Evaluation Tests. The owner of a lidar system shall subject such a lidar system to the performance verification tests described in section 3, prior to first use of this method. The annual calibration shall be performed for three separate, complete runs and the results of each should be recorded. The requirements of section 3.3.1 must be fulfilled for each of the three runs.
Once the conditions of the annual calibration are fulfilled the lidar shall be subjected to the routine verification for three separate complete runs. The requirements of section 3.3.2 must be fulfilled for each of the three runs and the results should be recorded. The Administrator may request that the results of the performance evaluation be submitted for review.
5.1 The Use of Lidar for Emissions Source Opacity Determination, U.S. Environmental Protection Agency, National Enforcement Investigations Center, Denver, CO. EPA-330/1-79-003-R, Arthur W. Dybdahl, current edition [NTIS No. PB81-246662].
5.2 Field Evaluation of Mobile Lidar for the Measurement of Smoke Plume Opacity, U.S. Environmental Protection Agency, National Enforcement Investigations Center, Denver, CO. EPA/NEIC-TS-128, February 1976.
5.3 Remote Measurement of Smoke Plume Transmittance Using Lidar, C. S. Cook, G. W. Bethke, W. D. Conner (EPA/RTP). Applied Optics 11, pg 1742. August 1972.
5.4 Lidar Studies of Stack Plumes in Rural and Urban Environments, EPA-650/4-73-002, October 1973.
5.5 American National Standard for the Safe Use of Lasers ANSI Z 136.1-176, March 8, 1976.
5.6 U.S. Army Technical Manual TB MED 279, Control of Hazards to Health from Laser Radiation, February 1969.
5.7 Laser Institute of America Laser Safety Manual, 4th Edition.
5.8 U.S. Department of Health, Education and Welfare, Regulations for the Administration and Enforcement of the Radiation Control for Health and Safety Act of 1968, January 1976.
5.9 Laser Safety Handbook, Alex Mallow, Leon Chabot, Van Nostrand Reinhold Co., 1978.
Method 10 is a procedure for measuring carbon monoxide (CO) in stationary source emissions using a continuous instrumental analyzer. Quality assurance and quality control requirements are included to assure that you, the tester, collect data of known quality. You must document your adherence to these specific requirements for equipment, supplies, sample collection and analysis, calculations, and data analysis. This method does not completely describe all equipment, supplies, and sampling and analytical procedures you will need but refers to other methods for some of the details. Therefore, to obtain reliable results, you should also have a thorough knowledge of these additional test methods which are found in appendix A to this part:
(a) Method 1 – Sample and Velocity Traverses for Stationary Sources.
(b) Method 4 – Determination of Moisture Content in Stack Gases.
(c) Method 7E – Determination of Nitrogen Oxides Emissions from Stationary Sources (Instrumental Analyzer Procedure).
1.1 Analytes. What does this method determine? This method measures the concentration of carbon monoxide.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| CO | 630-08-0 | Typically |
1.2 Applicability. When is this method required? The use of Method 10 may be required by specific New Source Performance Standards, State Implementation Plans, and permits where CO concentrations in stationary source emissions must be measured, either to determine compliance with an applicable emission standard or to conduct performance testing of a continuous emission monitoring system (CEMS). Other regulations may also require the use of Method 10.
1.3 Data Quality Objectives. Refer to section 1.3 of Method 7E.
In this method, you continuously or intermittently sample the effluent gas and convey the sample to an analyzer that measures the concentration of CO. You must meet the performance requirements of this method to validate your data.
Refer to section 3.0 of Method 7E for the applicable definitions.
Substances having a strong absorption of infrared energy may interfere to some extent in some analyzers. Instrumental correction may be used to compensate for the interference. You may also use silica gel and ascarite traps to eliminate the interferences. If this option is used, correct the measured gas volume for the carbon dioxide (CO
Refer to section 5.0 of Method 7E.
6.1 Continuous Sampling. Figure 7E-1 of Method 7E is a schematic diagram of an acceptable measurement system. The components are the same as those in sections 6.1 and 6.2 of Method 7E, except that the CO analyzer described in section 6.2 of this method must be used instead of the analyzer described in section 6.2 of Method 7E. You must follow the noted specifications in section 6.1 of Method 7E except that the requirements to use stainless steel, Teflon, or non-reactive glass filters do not apply. Also, a heated sample line is not required to transport dry gases or for systems that measure the CO concentration on a dry basis.
6.2 Integrated Sampling.
6.2.1 Air-Cooled Condenser or Equivalent. To remove any excess moisture.
6.2.2 Valve. Needle valve, or equivalent, to adjust flow rate.
6.2.3 Pump. Leak-free diaphragm type, or equivalent, to transport gas.
6.2.4 Rate Meter. Rotameter, or equivalent, to measure a flow range from 0 to 1.0 liter per minute (0.035 cfm).
6.2.5 Flexible Bag. Tedlar, or equivalent, with a capacity of 60 to 90 liters (2 to 3 ft
6.2.6 Sample Tank. Stainless steel or aluminum tank equipped with a pressure indicator with a minimum volume of 4 liters.
6.3 What analyzer must I use? You must use an instrument that continuously measures CO in the gas stream and meets the specifications in section 13.0. The dual-range analyzer provisions in section 6.2.8.1 of Method 7E apply.
7.1 Calibration Gas. What calibration gases do I need? Refer to section 7.1 of Method 7E for the calibration gas requirements.
7.2 Interference Check. What additional reagents do I need for the interference check? Use the appropriate test gases listed in Table 7E-3 of Method 7E (i.e., potential interferents, as identified by the instrument manufacturer) to conduct the interference check.
8.1 Sampling Site and Sampling Points. You must follow section 8.1 of Method 7E.
8.2 Initial Measurement System Performance Tests. You must follow the procedures in section 8.2 of Method 7E. If a dilution-type measurement system is used, the special considerations in section 8.3 of Method 7E also apply.
8.3 Interference Check. You must follow the procedures of section 8.2.7 of Method 7E.
8.4 Sample Collection.
8.4.1 Continuous Sampling. You must follow the procedures of section 8.4 of Method 7E.
8.4.2 Integrated Sampling. Evacuate the flexible bag or sample tank. Set up the equipment as shown in Figure 10-1 with the bag disconnected. Place the probe in the stack and purge the sampling line. Connect the bag, making sure that all connections are leak-free. Sample at a rate proportional to the stack velocity. If needed, the CO
8.5 Post-Run System Bias Check, Drift Assessment, and Alternative Dynamic Spike Procedure. You must follow the procedures in sections 8.5 and 8.6 of Method 7E.
Follow the quality control procedures in section 9.0 of Method 7E.
Follow the procedures for calibration and standardization in section 10.0 of Method 7E.
Because sample collection and analysis are performed together (see section 8), additional discussion of the analytical procedure is not necessary.
You must follow the procedures for calculations and data analysis in section 12.0 of Method 7E, as applicable, substituting CO for NO
12.1 Concentration Correction for CO
The specifications for analyzer calibration error, system bias, drift, interference check, and alternative dynamic spike procedure are the same as in section 13.0 of Method 7E.
The dynamic spike procedure and the manufacturer stability test are the same as in sections 16.1 and 16.3 of Method 7E
1. “EPA Traceability Protocol for Assay and Certification of Gaseous Calibration Standards – September 1997 as amended, EPA-600/R-97/121
Table 10-1 – Field Data
[Integrated sampling]
| Location: Date: | ||
| Test: Operator: | ||
| Clock Time | Rotameter Reading liters/min (cfm) | Comments |
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 4, and Method 5.
1.1 Analytes.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Carbon monoxide (CO) | 630-08-0 | 3 ppmv |
1.2 Applicability. This method is applicable for the determination of CO emissions at petroleum refineries. This method serves as the reference method in the relative accuracy test for nondispersive infrared (NDIR) CO continuous emission monitoring systems (CEMS) that are required to be installed in petroleum refineries on fluid catalytic cracking unit catalyst regenerators (§ 60.105(a)(2) of this part).
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
An integrated gas sample is extracted from the stack, passed through an alkaline permanganate solution to remove sulfur oxides and nitrogen oxides, and collected in a Tedlar or equivalent bag. (Verify through the manufacturer that the Tedlar alternative is suitable for NO and make this verified information available for inspection.) The CO concentration in the sample is measured spectrophotometrically using the reaction of CO with p-sulfaminobenzoic acid.
Sulfur oxides, nitric oxide, and other acid gases interfere with the colorimetric reaction. They are removed by passing the sampled gas through an alkaline potassium permanganate scrubbing solution. Carbon dioxide (CO
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method. The analyzer users manual should be consulted for specific precautions to be taken with regard to the analytical procedure.
5.2 Corrosive reagents. The following reagents are hazardous. Personal protective equipment and safe procedures are useful in preventing chemical splashes. If contact occurs, immediately flush with copious amounts of water for at least 15 minutes. Remove clothing under shower and decontaminate. Treat residual chemical burns as thermal burns.
5.2.1 Sodium Hydroxide (NaOH). Causes severe damage to eyes and skin. Inhalation causes irritation to nose, throat, and lungs. Reacts exothermically with limited amounts of water.
6.1 Sample Collection. The sampling train shown in Figure 10A-1 is required for sample collection. Component parts are described below:
6.1.1 Probe. Stainless steel, sheathed Pyrex glass, or equivalent, equipped with a glass wool plug to remove particulate matter.
6.1.2 Sample Conditioning System. Three Greenburg-Smith impingers connected in series with leak-free connections.
6.1.3 Pump. Leak-free pump with stainless steel and Teflon parts to transport sample at a flow rate of 300 ml/min (0.01 ft
6.1.4 Surge Tank. Installed between the pump and the rate meter to eliminate the pulsation effect of the pump on the rate meter.
6.1.5 Rate Meter. Rotameter, or equivalent, to measure flow rate at 300 ml/min (0.01 ft
6.1.6 Flexible Bag. Tedlar, or equivalent, with a capacity of 10 liters (0.35 ft
6.1.7 Sample Tank. Stainless steel or aluminum tank equipped with a pressure indicator with a minimum volume of 10 liters.
6.1.8 Valves. Stainless-steel needle valve to adjust flow rate, and stainless-steel 3-way valve, or equivalent.
6.1.9 CO
6.1.10 Volume Meter. Dry gas meter, capable of measuring the sample volume under calibration conditions of 300 ml/min (0.01 ft
6.1.11 Pressure Gauge. A water filled U-tube manometer, or equivalent, of about 30 cm (12 in.) to leak-check the flexible bag.
6.2 Sample Analysis.
6.2.1 Spectrophotometer. Single- or double-beam to measure absorbance at 425 and 600 nm. Slit width should not exceed 20 nm.
6.2.2 Spectrophotometer Cells. 1-cm pathlength.
6.2.3 Vacuum Gauge. U-tube mercury manometer, 1 meter (39 in.), with 1-mm divisions, or other gauge capable of measuring pressure to within 1 mm Hg.
6.2.4 Pump. Capable of evacuating the gas reaction bulb to a pressure equal to or less than 40 mm Hg absolute, equipped with coarse and fine flow control valves.
6.2.5 Barometer. Mercury, aneroid, or other barometer capable of measuring atmospheric pressure to within 1 mm Hg.
6.2.6 Reaction Bulbs. Pyrex glass, 100-ml with Teflon stopcock (Figure 10A-2), leak-free at 40 mm Hg, designed so that 10 ml of the colorimetric reagent can be added and removed easily and accurately. Commercially available gas sample bulbs such as Supelco Catalog No. 2-2161 may also be used.
6.2.7 Manifold. Stainless steel, with connections for three reaction bulbs and the appropriate connections for the manometer and sampling bag as shown in Figure 10A-3.
6.2.8 Pipets. Class A, 10-ml size.
6.2.9 Shaker Table. Reciprocating-stroke type such as Eberbach Corporation, Model 6015. A rocking arm or rotary-motion type shaker may also be used. The shaker must be large enough to accommodate at least six gas sample bulbs simultaneously. It may be necessary to construct a table top extension for most commercial shakers to provide sufficient space for the needed bulbs (Figure 10A-4).
6.2.10 Valve. Stainless steel shut-off valve.
6.2.11 Analytical Balance. Capable of weighing to 0.1 mg.
Unless otherwise indicated, all reagents shall conform to the specifications established by the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available; otherwise, the best available grade shall be used.
7.1 Sample Collection.
7.1.1 Water. Deionized distilled, to conform to ASTM D 1193-77 or 91, Type 3 (incorporated by reference – see § 60.17). If high concentrations of organic matter are not expected to be present, the potassium permanganate test for oxidizable organic matter may be omitted.
7.1.2 Alkaline Permanganate Solution, 0.25 M KMnO
7.2 Sample Analysis.
7.2.1 Water. Same as in section 7.1.1.
7.2.2 1 M Sodium Hydroxide Solution. Dissolve 40 g NaOH in approximately 900 ml of water, cool, and dilute to 1 liter.
7.2.3 0.1 M NaOH Solution. Dilute 50 ml of the 1 M NaOH solution prepared in section 7.2.2 to 500 ml.
7.2.4 0.1 M Silver Nitrate (AgNO
7.2.5 0.1 M Para-Sulfaminobenzoic Acid (p-SABA) Solution. Dissolve 10.0 g p-SABA in 0.1 M NaOH, and dilute to 500 ml with 0.1 M NaOH.
7.2.6 Colorimetric Solution. To a flask, add 100 ml of 0.1 M p-SABA solution and 100 ml of 0.1 M AgNO
7.2.7 Standard Gas Mixtures. Traceable to National Institute of Standards and Technology (NIST) standards and containing between 50 and 1000 ppm CO in nitrogen. At least two concentrations are needed to span each calibration range used (Section 10.3). The calibration gases must be certified by the manufacturer to be within 2 percent of the specified concentrations.
8.1 Sample Bag or Tank Leak-Checks. While a leak-check is required after bag or sample tank use, it should also be done before the bag or sample tank is used for sample collection. The tank should be leak-checked according to the procedure specified in section 8.1.2 of Method 25. The bag should be leak-checked in the inflated and deflated condition according to the following procedure:
8.1.1 Connect the bag to a water manometer, and pressurize the bag to 5 to 10 cm H
8.1.2 Evacuate the bag with a leakless pump that is connected to the downstream side of a flow indicating device such as a 0- to 100-ml/min rotameter or an impinger containing water. When the bag is completely evacuated, no flow should be evident if the bag is leak-free.
8.2 Sample Collection.
8.2.1 Evacuate and leak check the sample bag or tank as specified in section 8.1. Assemble the apparatus as shown in Figure 10A-1. Loosely pack glass wool in the tip of the probe. Place 400 ml of alkaline permanganate solution in the first two impingers and 250 ml in the third. Connect the pump to the third impinger, and follow this with the surge tank, rate meter, and 3-way valve. Do not connect the bag or sample tank to the system at this time.
8.2.2 Leak-check the sampling system by plugging the probe inlet, opening the 3-way valve, and pulling a vacuum of approximately 250 mm Hg on the system while observing the rate meter for flow. If flow is indicated on the rate meter, do not proceed further until the leak is found and corrected.
8.2.3 Purge the system with sample gas by inserting the probe into the stack and drawing the sample gas through the system at 300 ml/min ±10 percent for 5 minutes. Connect the evacuated bag or sample tank to the system, record the starting time, and sample at a rate of 300 ml/min for 30 minutes, or until the bag is nearly full, or the sample tank reaches ambient pressure. Record the sampling time, the barometric pressure, and the ambient temperature. Purge the system as described above immediately before each sample.
8.2.4 The scrubbing solution is adequate for removing sulfur oxides and nitrogen oxides from 50 liters (1.8 ft
8.3 Carbon Dioxide Measurement. Measure the CO
9.1 Miscellaneous Quality Control Measures.
| Section | Quality control measure | Effect |
|---|---|---|
| 8.1 | Sampling equipment leak-checks and calibration | Ensure accuracy and precision of sampling measurements. |
| 10.3 | Spectrophotometer calibration | Ensure linearity of spectrophotometer response to standards. |
9.2 Volume Metering System Checks. Same as Method 5, section 9.2.
Maintain a laboratory log of all calibrations.
10.1 Gas Bulb Calibration. Weigh the empty bulb to the nearest 0.1 g. Fill the bulb to the stopcock with water, and again weigh to the nearest 0.1 g. Subtract the tare weight, and calculate the volume in liters to three significant figures using the density of water at the measurement temperature. Record the volume on the bulb. Alternatively, mark an identification number on the bulb, and record the volume in a notebook.
10.2 Rate Meter Calibration. Assemble the system as shown in Figure 10A-1 (the impingers may be removed), and attach a volume meter to the probe inlet. Set the rotameter at 300 ml/min, record the volume meter reading, start the pump, and pull ambient air through the system for 10 minutes. Record the final volume meter reading. Repeat the procedure and average the results to determine the volume of gas that passed through the system.
10.3 Spectrophotometer Calibration Curve.
10.3.1 Collect the standards as described in section 8.2. Prepare at least two sets of three bulbs as standards to span the 0 to 400 or 400 to 1000 ppm range. If any samples span both concentration ranges, prepare a calibration curve for each range using separate reagent blanks. Prepare a set of three bulbs containing colorimetric reagent but no CO to serve as a reagent blank. Analyze each standard and blank according to the sample analysis procedure of section 11.0 Reject the standard set where any of the individual bulb absorbances differs from the set mean by more than 10 percent.
10.3.2 Calculate the average absorbance for each set (3 bulbs) of standards using Equation 10A-1 and Table 10A-1. Construct a graph of average absorbance for each standard against its corresponding concentration. Draw a smooth curve through the points. The curve should be linear over the two concentration ranges discussed in section 13.3.
11.1 Assemble the system shown in Figure 10A-3, and record the information required in Table 10A-1 as it is obtained. Pipet 10.0 ml of the colorimetric reagent into each gas reaction bulb, and attach the bulbs to the system. Open the stopcocks to the reaction bulbs, but leave the valve to the bag closed. Turn on the pump, fully open the coarse-adjust flow valve, and slowly open the fine-adjust valve until the pressure is reduced to at least 40 mm Hg. Now close the coarse adjust valve, and observe the manometer to be certain that the system is leak-free. Wait a minimum of 2 minutes. If the pressure has increased less than 1 mm Hg, proceed as described below. If a leak is present, find and correct it before proceeding further.
11.2 Record the vacuum pressure (P
11.3 Immediately after shaking, measure the absorbance (A) of each bulb sample at 425 nm if the concentration is less than or equal to 400 ppm CO or at 600 nm if the concentration is above 400 ppm.
This may be accomplished with multiple bulb sets by sequentially collecting sets and adding to the shaker at staggered intervals, followed by sequentially removing sets from the shaker for absorbance measurement after the two-hour designated intervals have elapsed.
11.4 Use a small portion of the sample to rinse a spectrophotometer cell several times before taking an aliquot for analysis. If one cell is used to analyze multiple samples, rinse the cell with deionized distilled water several times between samples. Prepare and analyze standards and a reagent blank as described in section 10.3. Use water as the reference. Reject the analysis if the blank absorbance is greater than 0.1. All conditions should be the same for analysis of samples and standards. Measure the absorbances as soon as possible after shaking is completed.
11.5 Determine the CO concentration of each bag sample using the calibration curve for the appropriate concentration range as discussed in section 10.3.
Carry out calculations retaining at least one extra decimal figure beyond that of the acquired data. Round off figures after final calculation.
12.1 Nomenclature.
12.2 Average Sample Absorbance per Liter. Calculate A
A and A
12.3 CO Concentration in the Bag. Calculate C
12.4 CO Concentration in the Stack.
13.1 Precision. The estimated intralaboratory standard deviation of the method is 3 percent of the mean for gas samples analyzed in duplicate in the concentration range of 39 to 412 ppm. The interlaboratory precision has not been established.
13.2 Accuracy. The method contains no significant biases when compared to an NDIR analyzer calibrated with NIST standards.
13.3 Range. Approximately 3 to 1800 ppm CO. Samples having concentrations below 400 ppm are analyzed at 425 nm, and samples having concentrations above 400 ppm are analyzed at 600 nm.
13.4 Sensitivity. The detection limit is 3 ppmv based on a change in concentration equal to three times the standard deviation of the reagent blank solution.
13.5 Stability. The individual components of the colorimetric reagent are stable for at least one month. The colorimetric reagent must be used within two days after preparation to avoid excessive blank correction. The samples in the bag should be stable for at least one week if the bags are leak-free.
1. Butler, F.E., J.E. Knoll, and M.R. Midgett. Development and Evaluation of Methods for Determining Carbon Monoxide Emissions. U.S. Environmental Protection Agency, Research Triangle Park, N.C. June 1985. 33 pp.
2. Ferguson, B.B., R.E. Lester, and W.J. Mitchell. Field Evaluation of Carbon Monoxide and Hydrogen Sulfide Continuous Emission Monitors at an Oil Refinery. U.S. Environmental Protection Agency, Research Triangle Park, N.C. Publication No. EPA-600/4-82-054. August 1982. 100 pp.
3. Lambert, J.L., and R.E. Weins. Induced Colorimetric Method for Carbon Monoxide. Analytical Chemistry. 46(7):929-930. June 1974.
4. Levaggi, D.A., and M. Feldstein. The Colorimetric Determination of Low Concentrations of Carbon Monoxide. Industrial Hygiene Journal. 25:64-66. January-February 1964.
5. Repp, M. Evaluation of Continuous Monitors For Carbon Monoxide in Stationary Sources. U.S. Environmental Protection Agency. Research Triangle Park, N.C. Publication No. EPA-600/2-77-063. March 1977. 155 pp.
6. Smith, F., D.E. Wagoner, and R.P. Donovan. Guidelines for Development of a Quality Assurance Program: Volume VIII – Determination of CO Emissions from Stationary Sources by NDIR Spectrometry. U.S. Environmental Protection Agency. Research Triangle Park, N.C. Publication No. EPA-650/4-74-005-h. February 1975. 96 pp.
Table 10A-1 – Data Recording Sheet for Samples Analyzed in Triplicate
| Sample No./type | Room temp °C | Stack %CO | Bulb No. | Bulb vol. liters | Reagent vol. in bulb, liter | Partial pressure of gas in bulb, mm Hg | P mm Hg | Shaking time, min | Abs versus water | A-A | A | Avg A |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| blank | ||||||||||||
| Std. 1 | ||||||||||||
| Std. 2 | ||||||||||||
| Sample 1 | ||||||||||||
| Sample 2 | ||||||||||||
| Sample 3 |
Table 10A-2 – Moisture Correction
| Temperature °C | Vapor pressure of H | Temperature °C | Vapor pressure of H |
|---|---|---|---|
| 4 | 6.1 | 18 | 15.5 |
| 6 | 7.0 | 20 | 17.5 |
| 8 | 8.0 | 22 | 19.8 |
| 10 | 9.2 | 24 | 22.4 |
| 12 | 10.5 | 26 | 25.2 |
| 14 | 12.0 | 28 | 28.3 |
| 16 | 13.6 | 30 | 31.8 |
This method is not inclusive with respect to specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 4, Method 10A, and Method 25.
1.1 Analytes.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Carbon monoxide (CO) | 630-08-0 | Not determined. |
1.2 Applicability. This method applies to the measurement of CO emissions at petroleum refineries and from other sources when specified in an applicable subpart of the regulations.
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 An integrated gas sample is extracted from the sampling point, passed through a conditioning system to remove interferences, and collected in a Tedlar or equivalent bag. (Verify through the manufacturer that the Tedlar alternative is suitable for NO and make this verifying information available for inspection.) The CO is separated from the sample by gas chromatography (GC) and catalytically reduced to methane (CH
4.1 Carbon dioxide (CO
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method. The analyzer users manual should be consulted for specific precautions concerning the analytical procedure.
6.1 Sample Collection. Same as in Method 10A, section 6.1 (paragraphs 6.1.1 through 6.1.11).
6.2 Sample Analysis. A GC/FID analyzer, capable of quantifying CO in the sample and consisting of at least the following major components, is required for sample analysis. [Alternatively, complete Method 25 analytical systems (Method 25, section 6.3) are acceptable alternatives when calibrated for CO and operated in accordance with the Method 25 analytical procedures (Method 25, section 11.0).]
6.2.1 Separation Column. A column capable of separating CO from CO
6.2.2 Reduction Catalyst. Same as in Method 25, section 6.3.1.2.
6.2.3 Sample Injection System. Same as in Method 25, Section 6.3.1.4, equipped to accept a sample line from the bag.
6.2.4 Flame Ionization Detector. Meeting the linearity specifications of section 10.3 and having a minimal instrument range of 10 to 1,000 ppm CO.
6.2.5 Data Recording System. Analog strip chart recorder or digital integration system, compatible with the FID, for permanently recording the analytical results.
7.1 Sample Collection. Same as in Method 10A, section 7.1.
7.2 Sample Analysis.
7.2.1 Carrier, Fuel, and Combustion Gases. Same as in Method 25, sections 7.2.1, 7.2.2, and 7.2.3, respectively.
7.2.2 Calibration Gases. Three standard gases with nominal CO concentrations of 20, 200, and 1,000 ppm CO in nitrogen. The calibration gases shall be certified by the manufacturer to be ±2 percent of the specified concentrations.
7.2.3 Reduction Catalyst Efficiency Check Calibration Gas. Standard CH
Same as in Method 10A, section 8.0.
| Section | Quality control measure | Effect |
|---|---|---|
| 8.0 | Sample bag/sampling system leak-checks | Ensures that negative bias introduced through leakage is minimized. |
| 10.1 | Carrier gas blank check | Ensures that positive bias introduced by contamination of carrier gas is less than 5 ppmv. |
| 10.2 | Reduction catalyst efficiency check | Ensures that negative bias introduced by inefficient reduction catalyst is less than 5 percent. |
| 10.3 | Analyzer calibration | Ensures linearity of analyzer response to standards. |
| 11.2 | Triplicate sample analyses | Ensures precision of analytical results. |
10.1 Carrier Gas Blank Check. Analyze each new tank of carrier gas with the GC analyzer according to section 11.2 to check for contamination. The corresponding concentration must be less than 5 ppm for the tank to be acceptable for use.
10.2 Reduction Catalyst Efficiency Check. Prior to initial use, the reduction catalyst shall be tested for reduction efficiency. With the heated reduction catalyst bypassed, make triplicate injections of the 1,000 ppm CH
10.3 Analyzer Calibration. Perform this test before the system is first placed into operation. With the reduction catalyst in operation, conduct a linearity check of the analyzer using the standards specified in section 7.2.2. Make triplicate injections of each calibration gas, and then calculate the average response factor (area/ppm) for each gas, as well as the overall mean of the response factor values. The instrument linearity is acceptable if the average response factor of each calibration gas is within 2.5 percent of the overall mean value and if the relative standard deviation (calculated in section 12.8 of Method 25) for each set of triplicate injections is less than 2 percent. Record the overall mean of the response factor values as the calibration response factor (R).
11.1 Preparation for Analysis. Before putting the GC analyzer into routine operation, conduct the calibration procedures listed in section 10.0. Establish an appropriate carrier flow rate and detector temperature for the specific instrument used.
11.2 Sample Analysis. Purge the sample loop with sample, and then inject the sample. Analyze each sample in triplicate, and calculate the average sample area (A). Determine the bag CO concentration according to section 12.2.
Carry out calculations retaining at least one extra significant figure beyond that of the acquired data. Round off results only after the final calculation.
12.1 Nomenclature.
12.2 CO Concentration in the Bag. Calculate C
12.3 CO Concentration in the Stack
Same as in Method 25, section 16.0, with the addition of the following:
1. Butler, F.E, J.E. Knoll, and M.R. Midgett. Development and Evaluation of Methods for Determining Carbon Monoxide Emissions. Quality Assurance Division, Environmental Monitoring Systems Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC. June 1985. 33 pp.
Appendix A-5 to Part 60 – Test Methods 11 through 15A
The test methods in this appendix are referred to in § 60.8 (Performance Tests) and § 60.11 (Compliance With Standards and Maintenance Requirements) of 40 CFR part 60, subpart A (General Provisions). Specific uses of these test methods are described in the standards of performance contained in the subparts, beginning with Subpart D.
Within each standard of performance, a section title “Test Methods and Procedures” is provided to: (1) Identify the test methods to be used as reference methods to the facility subject to the respective standard and (2) identify any special instructions or conditions to be followed when applying a method to the respective facility. Such instructions (for example, establish sampling rates, volumes, or temperatures) are to be used either in addition to, or as a substitute for procedures in a test method. Similarly, for sources subject to emission monitoring requirements, specific instructions pertaining to any use of a test method as a reference method are provided in the subpart or in Appendix B.
Inclusion of methods in this appendix is not intended as an endorsement or denial of their applicability to sources that are not subject to standards of performance. The methods are potentially applicable to other sources; however, applicability should be confirmed by careful and appropriate evaluation of the conditions prevalent at such sources.
The approach followed in the formulation of the test methods involves specifications for equipment, procedures, and performance. In concept, a performance specification approach would be preferable in all methods because this allows the greatest flexibility to the user. In practice, however, this approach is impractical in most cases because performance specifications cannot be established. Most of the methods described herein, therefore, involve specific equipment specifications and procedures, and only a few methods in this appendix rely on performance criteria.
Minor changes in the test methods should not necessarily affect the validity of the results and it is recognized that alternative and equivalent methods exist. section 60.8 provides authority for the Administrator to specify or approve (1) equivalent methods, (2) alternative methods, and (3) minor changes in the methodology of the test methods. It should be clearly understood that unless otherwise identified all such methods and changes must have prior approval of the Administrator. An owner employing such methods or deviations from the test methods without obtaining prior approval does so at the risk of subsequent disapproval and retesting with approved methods.
Within the test methods, certain specific equipment or procedures are recognized as being acceptable or potentially acceptable and are specifically identified in the methods. The items identified as acceptable options may be used without approval but must be identified in the test report. The potentially approvable options are cited as “subject to the approval of the Administrator” or as “or equivalent.” Such potentially approvable techniques or alternatives may be used at the discretion of the owner without prior approval. However, detailed descriptions for applying these potentially approvable techniques or alternatives are not provided in the test methods. Also, the potentially approvable options are not necessarily acceptable in all applications. Therefore, an owner electing to use such potentially approvable techniques or alternatives is responsible for: (1) assuring that the techniques or alternatives are in fact applicable and are properly executed; (2) including a written description of the alternative method in the test report (the written method must be clear and must be capable of being performed without additional instruction, and the degree of detail should be similar to the detail contained in the test methods); and (3) providing any rationale or supporting data necessary to show the validity of the alternative in the particular application. Failure to meet these requirements can result in the Administrator’s disapproval of the alternative.
1.1 Analytes.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Hydrogen sulfide (H | 7783-06-4 | 8 mg/m 3 – 740 mg/m 3, (6 ppm – 520 ppm). |
1.2 Applicability. This method is applicable for the determination of the H
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 A sample is extracted from a source and passed through a series of midget impingers containing a cadmium sulfate (CdSO
4.1 Any compound that reduces iodine (I
4.2 Entrained H
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method.
5.2 Corrosive reagents. The following reagents are hazardous. Personal protective equipment and safe procedures are useful in preventing chemical splashes. If contact occurs, immediately flush with copious amounts of water for at least 15 minutes. Remove clothing under shower and decontaminate. Treat residual chemical burns as thermal burns.
5.2.1 Hydrogen Peroxide. Irritating to eyes, skin, nose, and lungs. 30% H
5.2.2 Hydrochloric Acid. Highly toxic. Vapors are highly irritating to eyes, skin, nose, and lungs, causing severe damage. May cause bronchitis, pneumonia, or edema of lungs. Exposure to concentrations of 0.13 to 0.2 percent can be lethal in minutes. Will react with metals, producing hydrogen.
6.1 Sample Collection. The following items are needed for sample collection:
6.1.1 Sampling Line. Teflon tubing, 6- to 7- mm (
6.1.2 Impingers. Five midget impingers, each with 30-ml capacity. The internal diameter of the impinger tip must be 1 mm ±0.05 mm. The impinger tip must be positioned 4 to 6 mm from the bottom of the impinger.
6.1.3 Tubing. Glass or Teflon connecting tubing for the impingers.
6.1.4 Ice Water Bath. To maintain absorbing solution at a low temperature.
6.1.5 Drying Tube. Tube packed with 6- to 16- mesh indicating-type silica gel, or equivalent, to dry the gas sample and protect the meter and pump. If the silica gel has been used previously, dry at 175 °C (350 °F) for 2 hours. New silica gel may be used as received. Alternatively, other types of desiccants (equivalent or better) may be used, subject to approval of the Administrator.
Do not use more than 30 g of silica gel. Silica gel adsorbs gases such as propane from the fuel gas stream, and use of excessive amounts of silica gel could result in errors in the determination of sample volume.
6.1.6 Sampling Valve. Needle valve, or equivalent, to adjust gas flow rate. Stainless steel or other corrosion-resistant material.
6.1.7 Volume Meter. Dry gas meter (DGM), sufficiently accurate to measure the sample volume within 2 percent, calibrated at the selected flow rate (about 1.0 liter/min) and conditions actually encountered during sampling. The meter shall be equipped with a temperature sensor (dial thermometer or equivalent) capable of measuring temperature to within 3 °C (5.4 °F). The gas meter should have a petcock, or equivalent, on the outlet connector which can be closed during the leak-check. Gas volume for one revolution of the meter must not be more than 10 liters.
6.1.8 Rate Meter. Rotameter, or equivalent, to measure flow rates in the range from 0.5 to 2 liters/min (1 to 4 ft
6.1.9 Graduated Cylinder. 25-ml size.
6.1.10 Barometer. Mercury, aneroid, or other barometer capable of measuring atmospheric pressure to within 2.5 mm Hg (0.1 in. Hg). In many cases, the barometric reading may be obtained from a nearby National Weather Service station, in which case, the station value (which is the absolute barometric pressure) shall be requested and an adjustment for elevation differences between the weather station and the sampling point shall be applied at a rate of minus 2.5 mm Hg (0.1 in Hg) per 30 m (100 ft) elevation increase or vice-versa for elevation decrease.
6.1.11 U-tube Manometer. 0-; to 30-cm water column, for leak-check procedure.
6.1.12 Rubber Squeeze Bulb. To pressurize train for leak-check.
6.1.13 Tee, Pinchclamp, and Connecting Tubing. For leak-check.
6.1.14 Pump. Diaphragm pump, or equivalent. Insert a small surge tank between the pump and rate meter to minimize the pulsation effect of the diaphragm pump on the rate meter. The pump is used for the air purge at the end of the sample run; the pump is not ordinarily used during sampling, because fuel gas streams are usually sufficiently pressurized to force sample gas through the train at the required flow rate. The pump need not be leak-free unless it is used for sampling.
6.1.15 Needle Valve or Critical Orifice. To set air purge flow to 1 liter/min.
6.1.16 Tube Packed with Active Carbon. To filter air during purge.
6.1.17 Volumetric Flask. One 1000-ml.
6.1.18 Volumetric Pipette. One 15-ml.
6.1.19 Pressure-Reduction Regulator. Depending on the sampling stream pressure, a pressure-reduction regulator may be needed to reduce the pressure of the gas stream entering the Teflon sample line to a safe level.
6.1.20 Cold Trap. If condensed water or amine is present in the sample stream, a corrosion-resistant cold trap shall be used immediately after the sample tap. The trap shall not be operated below 0 °C (32 °F) to avoid condensation of C
6.2 Sample Recovery. The following items are needed for sample recovery:
6.2.1 Sample Container. Iodine flask, glass-stoppered, 500-ml size.
6.2.2 Volumetric Pipette. One 50-ml.
6.2.3 Graduated Cylinders. One each 25- and 250-ml.
6.2.4 Erlenmeyer Flasks. 125-ml.
6.2.5 Wash Bottle.
6.2.6 Volumetric Flasks. Three 1000-ml.
6.3 Sample Analysis. The following items are needed for sample analysis:
6.3.1 Flask. Glass-stoppered iodine flask, 500-ml.
6.3.2 Burette. 50-ml.
6.3.3 Erlenmeyer Flask. 125-ml.
6.3.4 Volumetric Pipettes. One 25-ml; two each 50- and 100-ml.
6.3.5 Volumetric Flasks. One 1000-ml; two 500-ml.
6.3.6 Graduated Cylinders. One each 10- and 100-ml.
Unless otherwise indicated, it is intended that all reagents conform to the specifications established by the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available. Otherwise, use the best available grade.
7.1 Sample Collection. The following reagents are required for sample collection:
7.1.1 CdSO
7.1.2 Hydrogen Peroxide, 3 Percent. Dilute 30 percent H
7.1.3 Water. Deionized distilled to conform to ASTM D 1193-77 or 91, Type 3 (incorporated by reference – see § 60.17). The KMnO
7.2 Sample Recovery. The following reagents are needed for sample recovery:
7.2.1 Water. Same as section 7.1.3.
7.2.2 Hydrochloric Acid (HCl) Solution, 3 M. Add 240 ml of concentrated HCl (specific gravity 1.19) to 500 ml of water in a 1-liter volumetric flask. Dilute to 1 liter with water. Mix thoroughly.
7.2.3 Iodine (I
7.2.4 Standard I
7.3 Sample Analysis. The following reagents and standards are needed for sample analysis:
7.3.1 Water. Same as in section 7.1.3.
7.3.2 Standard Sodium Thiosulfate Solution, 0.1 N. Dissolve 24.8 g of sodium thiosulfate pentahydrate (Na
7.3.3 Standard Sodium Thiosulfate Solution, 0.01 N. Pipette 50.0 ml of the standard 0.1 N Na
A 0.01 N phenylarsine oxide (C
7.3.4 Standard Phenylarsine Oxide Solution, 0.01 N. Dissolve 1.80 g of (C
7.3.5 Starch Indicator Solution. Suspend 10 g of soluble starch in 100 ml of water, and add 15 g of potassium hydroxide (KOH) pellets. Stir until dissolved, dilute with 900 ml of water, and let stand for 1 hour. Neutralize the alkali with concentrated HCl, using an indicator paper similar to Alkacid test ribbon, then add 2 ml of glacial acetic acid as a preservative.
Test starch indicator solution for decomposition by titrating with 0.01 N I
8.1 Sampling Train Preparation. Assemble the sampling train as shown in Figure 11-1, connecting the five midget impingers in series. Place 15 ml of 3 percent H
8.2 Leak-Check Procedure.
8.2.1 Connect the rubber bulb and manometer to the first impinger, as shown in Figure 11-1. Close the petcock on the DGM outlet. Pressurize the train to 25 cm water with the bulb, and close off the tubing connected to the rubber bulb. The train must hold 25 cm water pressure with not more than a 1 cm drop in pressure in a 1-minute interval. Stopcock grease is acceptable for sealing ground glass joints.
8.2.2 If the pump is used for sampling, it is recommended, but not required, that the pump be leak-checked separately, either prior to or after the sampling run. To leak-check the pump, proceed as follows: Disconnect the drying tube from the impinger assembly. Place a vacuum gauge at the inlet to either the drying tube or the pump, pull a vacuum of 250 mm Hg (10 in. Hg), plug or pinch off the outlet of the flow meter, and then turn off the pump. The vacuum should remain stable for at least 30 seconds. If performed prior to the sampling run, the pump leak-check should precede the leak-check of the sampling train described immediately above; if performed after the sampling run, the pump leak-check should follow the sampling train leak-check.
8.3 Purge the connecting line between the sampling valve and the first impinger by disconnecting the line from the first impinger, opening the sampling valve, and allowing process gas to flow through the line for one to two minutes. Then, close the sampling valve, and reconnect the line to the impinger train. Open the petcock on the dry gas meter outlet. Record the initial DGM reading.
8.4 Open the sampling valve, and then adjust the valve to obtain a rate of approximately 1 liter/min (0.035 cfm). Maintain a constant (±10 percent) flow rate during the test. Record the DGM temperature.
8.5 Sample for at least 10 minutes. At the end of the sampling time, close the sampling valve, and record the final volume and temperature readings. Conduct a leak-check as described in Section 8.2. A yellow color in the final cadmium sulfate impinger indicates depletion of the absorbing solution. An additional cadmium sulfate impinger should be added for subsequent samples and the sample with yellow color in the final impinger should be voided.
8.6 Disconnect the impinger train from the sampling line. Connect the charcoal tube and the pump as shown in Figure 11-1. Purge the train [at a rate of 1 liter/min (0.035 ft
8.7 Sample Recovery.
8.7.1 Discard the contents of the H
The impingers normally have only a thin film of CdS remaining after a water rinse. If Antifoam B was not used or if significant quantities of yellow CdS remain in the impingers, the alternative recovery procedure in section 11.2 must be used.
8.7.2 Proceed to section 11 for the analysis.
| Section | Quality control measure | Effect |
|---|---|---|
| 8.2, 10.1 | Sampling equipment leak-check and calibration | Ensure accurate measurement of sample volume. |
| 11.2 | Replicate titrations of blanks | Ensure precision of titration determinations. |
Maintain a log of all calibrations.
10.1 Calibration. Calibrate the sample collection equipment as follows.
10.1.1 Dry Gas Meter.
10.1.1.1 Initial Calibration. The DGM shall be calibrated before its initial use in the field. Proceed as follows: First, assemble the following components in series: Drying tube, needle valve, pump, rotameter, and DGM. Then, leak-check the metering system as follows: Place a vacuum gauge (at least 760 mm Hg) at the inlet to the drying tube, and pull a vacuum of 250 mm Hg (10 in. Hg); plug or pinch off the outlet of the flow meter, and then turn off the pump. The vacuum shall remain stable for at least 30 seconds. Carefully release the vacuum gauge before releasing the flow meter end. Next, calibrate the DGM (at the sampling flow rate specified by the method) as follows: Connect an appropriately sized wet-test meter (e.g., 1 liter per revolution) to the inlet of the drying tube. Make three independent calibration runs, using at least five revolutions of the DGM per run. Calculate the calibration factor, Y (wet-test meter calibration volume divided by the DGM volume, both volumes adjusted to the same reference temperature and pressure), for each run, and average the results. If any Y value deviates by more than 2 percent from the average, the DGM is unacceptable for use. Otherwise, use the average as the calibration factor for subsequent test runs.
10.1.1.2 Post-Test Calibration Check. After each field test series, conduct a calibration check as in section 10.1.1.1, above, except for the following two variations: (a) three or more revolutions of the DGM may be used and (b) only two independent runs need be made. If the calibration factor does not deviate by more than 5 percent from the initial calibration factor (determined in section 10.1.1.1), then the DGM volumes obtained during the test series are acceptable. If the calibration factor deviates by more than 5 percent, recalibrate the DGM as in section 10.1.1.1, and for the calculations, use the calibration factor (initial or recalibration) that yields the lower gas volume for each test run.
10.1.2 Temperature Sensors. Calibrate against mercury-in-glass thermometers. An alternative mercury-free thermometer may be used if the thermometer is at a minimum equivalent in terms of performance or suitably effective for the specific temperature measurement application.
10.1.3 Rate Meter. The rate meter need not be calibrated, but should be cleaned and maintained according to the manufacturer’s instructions.
10.1.4 Barometer. Calibrate against a mercury barometer.
10.2 Standardization.
10.2.1 Iodine Solution Standardization. Standardize the 0.01 N I
10.2.2 Sodium Thiosulfate Solution Standardization. Standardize the 0.1 N Na
10.2.3 Phenylarsine Oxide Solution Standardization. Standardize the 0.01 N C
Conduct the titration analyses in a clean area away from direct sunlight.
11.1 Pipette exactly 50 ml of 0.01 N I
11.2 Use these alternative procedures if Antifoam B was not used or if significant quantities of yellow CdS remain in the impingers. Extract the remaining CdS from the third, fourth, and fifth impingers using the acidified I
11.3 Allow the iodine flask to stand about 30 minutes in the dark for absorption of the H
Iodine evaporates from acidified I
11.4 Prepare a blank by adding 45 ml of CdSO
The blank must be handled by exactly the same procedure as that used for the samples.
11.5 Using 0.01 N Na
11.6 Titrate the blanks in the same manner as the samples. Run blanks each day until replicate values agree within 0.05 ml. Average the replicate titration values which agree within 0.05 ml.
Carry out calculations, retaining at least one extra significant figure beyond that of the acquired data. Round off figures only after the final calculation.
12.1 Nomenclature.
12.2 Normality of the Standard (≃0.1 N) Sodium Thiosulfate Solution.
12.3 Normality of Standard Phenylarsine Oxide Solution (if applicable).
12.4 Normality of Standard Iodine Solution.
If C
12.5 Dry Gas Volume. Correct the sample volume measured by the DGM to standard conditions (20 °C and 760 mm Hg).
12.6 Concentration of H
If C
13.1 Precision. Collaborative testing has shown the intra-laboratory precision to be 2.2 percent and the inter-laboratory precision to be 5 percent.
13.2 Bias. The method bias was shown to be −4.8 percent when only H
1. Determination of Hydrogen Sulfide, Ammoniacal Cadmium Chloride Method. API Method 772-54. In: Manual on Disposal of Refinery Wastes, Vol. V: Sampling and Analysis of Waste Gases and Particulate Matter. American Petroleum Institute, Washington, D.C. 1954.
2. Tentative Method of Determination of Hydrogen Sulfide and Mercaptan Sulfur in Natural Gas. Natural Gas Processors Association, Tulsa, OK. NGPA Publication No. 2265-65. 1965.
3. Knoll, J.D., and M.R. Midgett. Determination of Hydrogen Sulfide in Refinery Fuel Gases. Environmental Monitoring Series, Office of Research and Development, USEPA. Research Triangle Park, NC 27711. EPA 600/4-77-007.
4. Scheil, G.W., and M.C. Sharp. Standardization of Method 11 at a Petroleum Refinery. Midwest Research Institute Draft Report for USEPA. Office of Research and Development. Research Triangle Park, NC 27711. EPA Contract No. 68-02-1098. August 1976. EPA 600/4-77-088a (Volume 1) and EPA 600/4-77-088b (Volume 2).
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 2, Method 3, and Method 5.
1.1 Analytes.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Inorganic Lead Compounds as lead (Pb) | 7439-92-1 | see section 13.3. |
1.2 Applicability. This method is applicable for the determination of inorganic lead emissions from stationary sources, only as specified in an applicable subpart of the regulations.
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 Particulate and gaseous Pb emissions are withdrawn isokinetically from the source and are collected on a filter and in dilute nitric acid. The collected samples are digested in acid solution and are analyzed by atomic absorption spectrophotometry using an air/acetylene flame.
4.1 Copper. High concentrations of copper may interfere with the analysis of Pb at 217.0 nm. This interference can be avoided by analyzing the samples at 283.3 nm.
4.2 Matrix Effects. Analysis for Pb by flame atomic absorption spectrophotometry is sensitive to the chemical composition and to the physical properties (e.g., viscosity, pH) of the sample. The analytical procedure requires the use of the Method of Standard Additions to check for these matrix effects, and requires sample analysis using the Method of Standard Additions if significant matrix effects are found to be present.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to performing this test method.
5.2 Corrosive Reagents. The following reagents are hazardous. Personal protective equipment and safe procedures are useful in preventing chemical splashes. If contact occurs, immediately flush with copious amounts of water at least 15 minutes. Remove clothing under shower and decontaminate. Treat residual chemical burn as thermal burn.
5.2.1 Hydrogen Peroxide (H
5.2.2 Nitric Acid (HNO
6.1 Sample Collection. A schematic of the sampling train used in performing this method is shown in Figure 12-1 in section 18.0; it is similar to the Method 5 train. The following items are needed for sample collection:
6.1.1 Probe Nozzle, Probe Liner, Pitot Tube, Differential Pressure Gauge, Filter Holder, Filter Heating System, Temperature Sensor, Metering System, Barometer, and Gas Density Determination Equipment. Same as Method 5, sections 6.1.1.1 through 6.1.1.7, 6.1.1.9, 6.1.2, and 6.1.3, respectively.
6.1.2 Impingers. Four impingers connected in series with leak-free ground glass fittings or any similar leak-free noncontaminating fittings are needed. For the first, third, and fourth impingers, use the Greenburg-Smith design, modified by replacing the tip with a 1.3 cm (
6.1.3 Temperature Sensor. Place a temperature sensor, capable of measuring temperature to within 1 °C (2 °F) at the outlet of the fourth impinger for monitoring purposes.
6.2 Sample Recovery. The following items are needed for sample recovery:
6.2.1 Probe-Liner and Probe-Nozzle Brushes, Petri Dishes, Graduated Cylinder and/or Balance, Plastic Storage Containers, and Funnel and Rubber Policeman. Same as Method 5, sections 6.2.1 and 6.2.4 through 6.2.7, respectively.
6.2.2 Wash Bottles. Glass (2).
6.2.3 Sample Storage Containers. Chemically resistant, borosilicate glass bottles, for 0.1 N nitric acid (HNO
6.2.4 Funnel. Glass, to aid in sample recovery.
6.3 Sample Analysis. The following items are needed for sample analysis:
6.3.1 Atomic Absorption Spectrophotometer. With lead hollow cathode lamp and burner for air/acetylene flame.
6.3.2 Hot Plate.
6.3.3 Erlenmeyer Flasks. 125-ml, 24/40 standard taper.
6.3.4 Membrane Filters. Millipore SCWPO 4700, or equivalent.
6.3.5 Filtration Apparatus. Millipore vacuum filtration unit, or equivalent, for use with the above membrane filter.
6.3.6 Volumetric Flasks. 100-ml, 250-ml, and 1000-ml.
Unless otherwise indicated, it is intended that all reagents conform to the specifications established by the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available; otherwise, use the best available grade.
7.1 Sample Collection. The following reagents are needed for sample collection:
7.1.1 Filter. Gelman Spectro Grade, Reeve Angel 934 AH, MSA 1106 BH, all with lot assay for Pb, or other high-purity glass fiber filters, without organic binder, exhibiting at least 99.95 percent efficiency (
7.1.2 Silica Gel and Crushed Ice. Same as Method 5, sections 7.1.2 and 7.1.4, respectively.
7.1.3 Water. Deionized distilled, to conform to ASTM D 1193-77 or 91, Type 3 (incorporated by reference – see § 60.17). If high concentrations of organic matter are not expected to be present, the potassium permanganate test for oxidizable organic matter may be omitted.
7.1.4 Nitric Acid, 0.1 N. Dilute 6.5 ml of concentrated HNO
7.2 Sample Recovery. 0.1 N HNO
7.3 Sample Analysis. The following reagents and standards are needed for sample analysis:
7.3.1 Water. Same as in section 7.1.3.
7.3.2 Nitric Acid, Concentrated.
7.3.3 Nitric Acid, 50 Percent (v/v). Dilute 500 ml of concentrated HNO
7.3.4 Stock Lead Standard Solution, 1000 µg Pb/ml. Dissolve 0.1598 g of lead nitrate [Pb(NO
7.3.5 Working Lead Standards. Pipet 0.0, 1.0, 2.0, 3.0, 4.0, and 5.0 ml of the stock lead standard solution (Section 7.3.4) into 250-ml volumetric flasks. Add 5 ml of concentrated HNO
7.3.6 Air. Suitable quality for atomic absorption spectrophotometry.
7.3.7 Acetylene. Suitable quality for atomic absorption spectrophotometry.
7.3.8 Hydrogen Peroxide, 3 Percent (v/v). Dilute 10 ml of 30 percent H
8.1 Pretest Preparation. Follow the same general procedure given in Method 5, section 8.1, except that the filter need not be weighed.
8.2 Preliminary Determinations. Follow the same general procedure given in Method 5, section 8.2.
8.3 Preparation of Sampling Train. Follow the same general procedure given in Method 5, section 8.3, except place 100 ml of 0.1 N HNO
8.4 Leak-Check Procedures. Same as Method 5, section 8.4.
8.5 Sampling Train Operation. Same as Method 5, section 8.5.
8.6 Calculation of Percent Isokinetic. Same as Method 5, section 8.6.
8.7 Sample Recovery. Same as Method 5, sections 8.7.1 through 8.7.6.1, with the addition of the following:
8.7.1 Container No. 2 (Probe).
8.7.1.1 Taking care that dust on the outside of the probe or other exterior surfaces does not get into the sample, quantitatively recover sample matter and any condensate from the probe nozzle, probe fitting, probe liner, and front half of the filter holder by washing these components with 0.1 N HNO
8.7.1.2 Carefully remove the probe nozzle, and rinse the inside surfaces with 0.1 N HNO
8.7.1.3 Brush and rinse with 0.1 N HNO
8.7.1.4 Rinse the probe liner with 0.1 N HNO
8.7.1.5 It is recommended that two people clean the probe to minimize loss of sample. Between sampling runs, keep brushes clean and protected from contamination.
8.7.1.6 Brush and rinse with 0.1 N HNO
8.7.2 Container No. 3 (Silica Gel). Note the color of the indicating silica gel to determine if it has been completely spent, and make a notation of its condition. Transfer the silica gel from the fourth impinger to the original container, and seal. A funnel may be used to pour the silica gel from the impinger and a rubber policeman may be used to remove the silica gel from the impinger. It is not necessary to remove the small amount of particles that may adhere to the walls and are difficult to remove. Since the gain in weight is to be used for moisture calculations, do not use any water or other liquids to transfer the silica gel. If a balance is available in the field, follow the procedure for Container No. 3 in section 11.4.2.
8.7.3 Container No. 4 (Impingers). Due to the large quantity of liquid involved, the impinger solutions may be placed in several containers. Clean each of the first three impingers and connecting glassware in the following manner:
8.7.3.1 Cap the impinger ball joints.
8.7.3.2 Rotate and agitate each impinger, so that the impinger contents might serve as a rinse solution.
8.7.3.3 Treat the impingers as follows: Make a notation of any color or film in the liquid catch. Measure the liquid that is in the first three impingers by weighing it to within 0.5 g at a minimum by using a balance. Record the weight of liquid present. The liquid weight is needed, along with the silica gel data, to calculate the stack gas moisture content (see Method 5, Figure 5-6).
8.7.3.4 Transfer the contents to Container No. 4.
In sections 8.7.3.5 and 8.7.3.6, measure and record the total amount of 0.1 N HNO
8.7.3.5 Pour approximately 30 ml of 0.1 N HNO
8.7.3.6 Rinse the insides of each piece of connecting glassware for the impingers twice with 0.1 N HNO
8.8 Blanks.
8.8.1 Nitric Acid. Save 200 ml of the 0.1 N HNO
8.8.2 Filter. Save two filters from each lot of filters used in sampling. Place these filters in a container labeled “filter blank.”
9.1 Miscellaneous Quality Control Measures.
| Section | Quality control measure | Effect |
|---|---|---|
| 8.4, 10.1 | Sampling equipment leak-checks and calibration | Ensure accuracy and precision of sampling measurements. |
| 10.2 | Spectrophotometer calibration | Ensure linearity of spectrophotometer response to standards. |
| 11.5 | Check for matrix effects | Eliminate matrix effects. |
9.2 Volume Metering System Checks. Same as Method 5, section 9.2.
Maintain a laboratory log of all calibrations.
10.1 Sampling Equipment. Same as Method 5, section 10.0.
10.2 Spectrophotometer.
10.2.1 Measure the absorbance of the standard solutions using the instrument settings recommended by the spectrophotometer manufacturer. Repeat until good agreement (±3 percent) is obtained between two consecutive readings. Plot the absorbance (y-axis) versus concentration in µg Pb/ml (x-axis). Draw or compute a straight line through the linear portion of the curve. Do not force the calibration curve through zero, but if the curve does not pass through the origin or at least lie closer to the origin than ±0.003 absorbance units, check for incorrectly prepared standards and for curvature in the calibration curve.
10.2.2 To determine stability of the calibration curve, run a blank and a standard after every five samples, and recalibrate as necessary.
11.1 Sample Loss Check. Prior to analysis, check the liquid level in Containers Number 2 and Number 4. Note on the analytical data sheet whether leakage occurred during transport. If a noticeable amount of leakage occurred, either void the sample or take steps, subject to the approval of the Administrator, to adjust the final results.
11.2 Sample Preparation.
11.2.1 Container No. 1 (Filter). Cut the filter into strips and transfer the strips and all loose particulate matter into a 125-ml Erlenmeyer flask. Rinse the petri dish with 10 ml of 50 percent HNO
If the total volume required in section 11.2.3 is expected to exceed 80 ml, use a 250-ml flask in place of the 125-ml flask.
11.2.2 Containers No. 2 and No. 4 (Probe and Impingers). Combine the contents of Containers No. 2 and No. 4, and evaporate to dryness on a hot plate.
11.2.3 Sample Extraction for Lead.
11.2.3.1 Based on the approximate stack gas particulate concentration and the total volume of stack gas sampled, estimate the total weight of particulate sample collected. Next, transfer the residue from Containers No. 2 and No. 4 to the 125-ml Erlenmeyer flask that contains the sampling filter using a rubber policeman and 10 ml of 50 percent HNO
11.2.3.2 Place the Erlenmeyer flask on a hot plate, and heat with periodic stirring for 30 minutes at a temperature just below boiling. If the sample volume falls below 15 ml, add more 50 percent HNO
11.2.4 Filter Blank. Cut each filter into strips, and place each filter in a separate 125-ml Erlenmeyer flask. Add 15 ml of 50 percent HNO
11.2.5 Nitric Acid Blank, 0.1 N. Take the entire 200 ml of 0.1 N HNO
11.3 Spectrophotometer Preparation. Turn on the power; set the wavelength, slit width, and lamp current; and adjust the background corrector as instructed by the manufacturer’s manual for the particular atomic absorption spectrophotometer. Adjust the burner and flame characteristics as necessary.
11.4 Analysis.
11.4.1 Lead Determination. Calibrate the spectrophotometer as outlined in section 10.2, and determine the absorbance for each source sample, the filter blank, and 0.1 N HNO
11.4.2 Container No. 3 (Silica Gel). This step may be conducted in the field. Weigh the spent silica gel (or silica gel plus impinger) to the nearest 0.5 g; record this weight.
11.5 Check for Matrix Effects. Use the Method of Standard Additions as follows to check at least one sample from each source for matrix effects on the Pb results:
11.5.1 Add or spike an equal volume of standard solution to an aliquot of the sample solution.
11.5.2 Measure the absorbance of the resulting solution and the absorbance of an aliquot of unspiked sample.
11.5.3 Calculate the Pb concentration C
Volume corrections will not be required if the solutions as analyzed have been made to the same final volume. Therefore, C
Method of Standard Additions procedures described on pages 9-4 and 9-5 of the section entitled “General Information” of the Perkin Elmer Corporation Atomic Absorption Spectrophotometry Manual, Number 303-0152 (Reference 1 in section 17.0) may also be used. In any event, if the results of the Method of Standard Additions procedure used on the single source sample do not agree to within ±5 percent of the value obtained by the routine atomic absorption analysis, then reanalyze all samples from the source using the Method of Standard Additions procedure.
12.1 Nomenclature.
A
A
A
B
C
C
C
I = Percent of isokinetic sampling.
L
L
L
L
m
M
P
P
P
R = Ideal gas constant, 0.06236 [(mm Hg) (m
T
T
v
V
V
V
Y = Dry gas meter calibration factor.
ΔH = Average pressure differential across the orifice meter (see Figure 5-3 of Method 5), mm H
θ = Total sampling time, min.
θ
θ
θ
12.2 Average Dry Gas Meter Temperatures (T
12.3 Dry Gas Volume, Volume of Water Vapor Condensed, and Moisture Content. Using data obtained in this test, calculate V
12.4 Total Lead in Source Sample. For each source sample, correct the average absorbance for the contribution of the filter blank and the 0.1 N HNO
12.5 Sample Lead Concentration. Calculate the Pb concentration of the sample using the following equation:
12.6 Lead Concentration. Calculate the stack gas Pb concentration C
12.7 Stack Gas Velocity and Volumetric Flow Rate. Calculate the average stack gas velocity and volumetric flow rate using data obtained in this method and the equations in sections 12.2 and 12.3 of Method 2.
12.8 Isokinetic Variation. Same as Method 5, section 12.11.
13.1 Precision. The within-laboratory precision, as measured by the coefficient of variation, ranges from 0.2 to 9.5 percent relative to a run-mean concentration. These values were based on tests conducted at a gray iron foundry, a lead storage battery manufacturing plant, a secondary lead smelter, and a lead recovery furnace of an alkyl lead manufacturing plant. The concentrations encountered during these tests ranged from 0.61 to 123.3 mg Pb/m
13.2 Analytical Range. For a minimum analytical accuracy of ±10 percent, the lower limit of the range is 100 µg. The upper limit can be extended considerably by dilution.
13.3 Analytical Sensitivity. Typical sensitivities for a 1-percent change in absorption (0.0044 absorbance units) are 0.2 and 0.5 µg Pb/ml for the 217.0 and 283.3 nm lines, respectively.
16.1 Simultaneous Determination of Particulate Matter and Lead Emissions. Method 12 may be used to simultaneously determine Pb and particulate matter provided:
(1) A glass fiber filter with a low Pb background is used and this filter is checked, desiccated and weighed per section 8.1 of Method 5,
(2) An acetone rinse, as specified by Method 5, sections 7.2 and 8.7.6.2, is used to remove particulate matter from the probe and inside of the filter holder prior to and kept separate from the 0.1 N HNO
(3) The recovered filter, the acetone rinse, and an acetone blank (Method 5, section 7.2) are subjected to the gravimetric analysis of Method 5, sections 6.3 and 11.0 prior to the analysis for Pb as described below, and
(4) The entire train contents, including the 0.1 N HNO
16.2 Filter Location. A filter may be used between the third and fourth impingers provided the filter is included in the analysis for Pb.
16.3 In-Stack Filter. An in-stack filter may be used provided: (1) A glass-lined probe and at least two impingers, each containing 100 ml of 0.1 N HNO
16.4 Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) Analysis. ICP-AES may be used as an alternative to atomic absorption analysis provided the following conditions are met:
16.4.1 Sample collection/recovery, sample loss check, and sample preparation procedures are as defined in sections 8.0, 11.1, and 11.2, respectively, of this method.
16.4.2 Analysis shall be conducted following Method 6010D of SW-846 (incorporated by reference, see § 60.17). The limit of detection for the ICP-AES must be demonstrated according to section 15.0 of Method 301 in appendix A of part 63 of this chapter and must be no greater than one-third of the applicable emission limit. Perform a check for matrix effects according to section 11.5 of this method.
16.5 Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) Analysis. ICP-MS may be used as an alternative to atomic absorption analysis provided the following conditions are met:
16.5.1 Sample collection/recovery, sample loss check, and sample preparation procedures are as defined in sections 8.0, 11.1, and 11.2, respectively of this method.
16.5.2 Analysis shall be conducted following Method 6020B of SW-846 (incorporated by reference, see § 60.17). The limit of detection for the ICP-MS must be demonstrated according to section 15.0 of Method 301 in appendix A to part 63 of this chapter and must be no greater than one-third of the applicable emission limit. Use the multipoint calibration curve option in section 10.4 of Method 6020B and perform a check for matrix effects according to section 11.5 of this method.
Same as Method 5, section 17.0, References 2, 3, 4, 5, and 7, with the addition of the following:
1. Perkin Elmer Corporation. Analytical Methods for Atomic Absorption Spectrophotometry. Norwalk, Connecticut. September 1976.
2. American Society for Testing and Materials. Annual Book of ASTM Standards, Part 31: Water, Atmospheric Analysis. Philadelphia, PA 1974. p. 40-42.
3. Kelin, R., and C. Hach. Standard Additions – Uses and Limitations in Spectrophotometric Analysis. Amer. Lab. 9:21-27. 1977.
4. Mitchell, W.J., and M.R. Midgett. Determining Inorganic and Alkyl Lead Emissions from Stationary Sources. U.S. Environmental Protection Agency. Emission Monitoring and Support Laboratory. Research Triangle Park, NC. (Presented at National APCA Meeting, Houston. June 26, 1978).
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 2, Method 3, and Method 5.
1.1 Analytes.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Total fluorides as Fluorine | 7782-41-4 | Not determined. |
1.2 Applicability. This method is applicable for the determination of fluoride (F
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
Gaseous and particulate F
4.1 Chloride. Large quantities of chloride will interfere with the analysis, but this interference can be prevented by adding silver sulfate into the distillation flask (see section 11.3). If chloride ion is present, it may be easier to use the specific ion electrode method of analysis (Method 13B).
4.2 Grease. Grease on sample-exposed surfaces may cause low F
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to performing this test method.
5.2 Corrosive Reagents. The following reagents are hazardous. Personal protective equipment and safe procedures are useful in preventing chemical splashes. If contact occurs, immediately flush with copious amounts of water at least 15 minutes. Remove clothing under shower and decontaminate. Treat residual chemical burn as thermal burn.
5.2.1 Hydrochloric Acid (HCl). Highly toxic. Vapors are highly irritating to eyes, skin, nose, and lungs, causing severe damage. May cause bronchitis, pneumonia, or edema of lungs. Exposure to concentrations of 0.13 to 0.2 percent can be lethal in minutes. Will react with metals, producing hydrogen.
5.2.2 Sodium Hydroxide (NaOH). Causes severe damage to eye tissues and to skin. Inhalation causes irritation to nose, throat, and lungs. Reacts exothermically with limited amounts of water.
5.2.3 Sulfuric Acid (H
6.1 Sample Collection. A schematic of the sampling train used in performing this method is shown in Figure 13A-1; it is similar to the Method 5 sampling train except that the filter position is interchangeable. The sampling train consists of the following components:
6.1.1 Probe Nozzle, Pitot Tube, Differential Pressure Gauge, Filter Heating System, Temperature Sensor, Metering System, Barometer, and Gas Density Determination Equipment. Same as Method 5, sections 6.1.1.1, 6.1.1.3 through 6.1.1.7, 6.1.1.9, 6.1.2, and 6.1.3, respectively. The filter heating system and temperature sensor are needed only when moisture condensation is a problem.
6.1.2 Probe Liner. Borosilicate glass or 316 stainless steel. When the filter is located immediately after the probe, a probe heating system may be used to prevent filter plugging resulting from moisture condensation, but the temperature in the probe shall not be allowed to exceed 120 ±14 °C (248 ±25 °F).
6.1.3 Filter Holder. With positive seal against leakage from the outside or around the filter. If the filter is located between the probe and first impinger, use borosilicate glass or stainless steel with a 20-mesh stainless steel screen filter support and a silicone rubber gasket; do not use a glass frit or a sintered metal filter support. If the filter is located between the third and fourth impingers, borosilicate glass with a glass frit filter support and a silicone rubber gasket may be used. Other materials of construction may be used, subject to the approval of the Administrator.
6.1.4 Impingers. Four impingers connected as shown in Figure 13A-1 with ground-glass (or equivalent), vacuum-tight fittings. For the first, third, and fourth impingers, use the Greenburg-Smith design, modified by replacing the tip with a 1.3-cm (
6.2 Sample Recovery. The following items are needed for sample recovery:
6.2.1 Probe-liner and Probe-Nozzle Brushes, Wash Bottles, Graduated Cylinder and/or Balance, Plastic Storage Containers, Funnel and Rubber Policeman, and Funnel. Same as Method 5, sections 6.2.1, 6.2.2 and 6.2.5 to 6.2.8, respectively.
6.2.2 Sample Storage Container. Wide-mouth, high-density polyethylene bottles for impinger water samples, 1 liter.
6.3 Sample Preparation and Analysis. The following items are needed for sample preparation and analysis:
6.3.1 Distillation Apparatus. Glass distillation apparatus assembled as shown in Figure 13A-2.
6.3.2 Bunsen Burner.
6.3.3 Electric Muffle Furnace. Capable of heating to 600 °C (1100 °F).
6.3.4 Crucibles. Nickel, 75- to 100-ml.
6.3.5 Beakers. 500-ml and 1500-ml.
6.3.6 Volumetric Flasks. 50-ml.
6.3.7 Erlenmeyer Flasks or Plastic Bottles. 500-ml.
6.3.8 Constant Temperature Bath. Capable of maintaining a constant temperature of ±1.0 °C at room temperature conditions.
6.3.9 Balance. 300-g capacity, to measure to ±0.5 g.
6.3.10 Spectrophotometer. Instrument that measures absorbance at 570 nm and provides at least a 1-cm light path.
6.3.11 Spectrophotometer Cells. 1-cm path length.
Unless otherwise indicated, all reagents are to conform to the specifications established by the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available. Otherwise, use the best available grade.
7.1 Sample Collection. The following reagents are needed for sample collection:
7.1.1 Filters.
7.1.1.1 If the filter is located between the third and fourth impingers, use a Whatman No. 1 filter, or equivalent, sized to fit the filter holder.
7.1.1.2 If the filter is located between the probe and first impinger, use any suitable medium (e.g., paper, organic membrane) that can withstand prolonged exposure to temperatures up to 135 °C (275 °F), and has at least 95 percent collection efficiency (− blank value (−/cm
7.1.2 Water. Deionized distilled, to conform to ASTM D 1193-77 or 91, Type 3 (incorporated by reference – see § 60.17). If high concentrations of organic matter are not expected to be present, the potassium permanganate test for oxidizable organic matter may be deleted.
7.1.3 Silica Gel, Crushed Ice, and Stopcock Grease. Same as Method 5, sections 7.1.2, 7.1.4, and 7.1.5, respectively.
7.2 Sample Recovery. Water, as described in section 7.1.2, is needed for sample recovery.
7.3 Sample Preparation and Analysis. The following reagents and standards are needed for sample preparation and analysis:
7.3.1 Calcium Oxide (CaO). Certified grade containing 0.005 percent F
7.3.2 Phenolphthalein Indicator. Dissolve 0.1 g of phenolphthalein in a mixture of 50 ml of 90 percent ethanol and 50 ml of water.
7.3.3 Silver Sulfate (Ag
7.3.4 Sodium Hydroxide (NaOH), Pellets.
7.3.5 Sulfuric Acid (H
7.3.6 Sulfuric Acid, 25 Percent (v/v). Mix 1 part of concentrated H
7.3.7 Filters. Whatman No. 541, or equivalent.
7.3.8 Hydrochloric Acid (HCl), Concentrated.
7.3.9 Water. Same as in section 7.1.2.
7.3.10 Fluoride Standard Solution, 0.01 mg F
7.3.11 SPADNS Solution [4,5 Dihydroxyl-3-(p-Sulfophenylazo)-2,7-Naphthalene-Disulfonic Acid Trisodium Salt]. Dissolve 0.960 ±0.010 g of SPADNS reagent in 500 ml water. If stored in a well-sealed bottle protected from the sunlight, this solution is stable for at least 1 month.
7.3.12 Spectrophotometer Zero Reference Solution. Add 10 ml of SPADNS solution to 100 ml water, and acidify with a solution prepared by diluting 7 ml of concentrated HCl to 10 ml with deionized, distilled water. Prepare daily.
7.3.13 SPADNS Mixed Reagent. Dissolve 0.135 ±0.005 g of zirconyl chloride octahydrate (ZrOCl
8.1 Pretest Preparation. Follow the general procedure given in Method 5, section 8.1, except that the filter need not be weighed.
8.2 Preliminary Determinations. Follow the general procedure given in Method 5, section 8.2, except that the nozzle size must be selected such that isokinetic sampling rates below 28 liters/min (1.0 cfm) can be maintained.
8.3 Preparation of Sampling Train. Follow the general procedure given in Method 5, section 8.3, except for the following variation: Assemble the train as shown in Figure 13A-1 with the filter between the third and fourth impingers. Alternatively, if a 20-mesh stainless steel screen is used for the filter support, the filter may be placed between the probe and first impinger. A filter heating system to prevent moisture condensation may be used, but shall not allow the temperature to exceed 120 ±14 °C (248 ±25 °F). Record the filter location on the data sheet (see section 8.5).
8.4 Leak-Check Procedures. Follow the leak-check procedures given in Method 5, section 8.4.
8.5 Sampling Train Operation. Follow the general procedure given in Method 5, section 8.5, keeping the filter and probe temperatures (if applicable) at 120 ±14 °C (248 ±25 °F) and isokinetic sampling rates below 28 liters/min (1.0 cfm). For each run, record the data required on a data sheet such as the one shown in Method 5, Figure 5-3.
8.6 Sample Recovery. Proper cleanup procedure begins as soon as the probe is removed from the stack at the end of the sampling period. Allow the probe to cool.
8.6.1 When the probe can be safely handled, wipe off all external particulate matter near the tip of the probe nozzle, and place a cap over it to keep from losing part of the sample. Do not cap off the probe tip tightly while the sampling train is cooling down as this would create a vacuum in the filter holder, thus drawing water from the impingers into the filter holder.
8.6.2 Before moving the sample train to the cleanup site, remove the probe from the sample train, wipe off any silicone grease, and cap the open outlet of the probe. Be careful not to lose any condensate that might be present. Remove the filter assembly, wipe off any silicone grease from the filter holder inlet, and cap this inlet. Remove the umbilical cord from the last impinger, and cap the impinger. After wiping off any silicone grease, cap off the filter holder outlet and any open impinger inlets and outlets. Ground-glass stoppers, plastic caps, or serum caps may be used to close these openings.
8.6.3 Transfer the probe and filter-impinger assembly to the cleanup area. This area should be clean and protected from the wind so that the chances of contaminating or losing the sample will be minimized.
8.6.4 Inspect the train prior to and during disassembly, and note any abnormal conditions. Treat the samples as follows:
8.6.4.1 Container No. 1 (Probe, Filter, and Impinger Catches).
8.6.4.1.1 Using a graduated cylinder, measure to the nearest ml, and record the volume of the water in the first three impingers; include any condensate in the probe in this determination. Transfer the impinger water from the graduated cylinder into a polyethylene container. Add the filter to this container. (The filter may be handled separately using procedures subject to the Administrator’s approval.) Taking care that dust on the outside of the probe or other exterior surfaces does not get into the sample, clean all sample-exposed surfaces (including the probe nozzle, probe fitting, probe liner, first three impingers, impinger connectors, and filter holder) with water. Use less than 500 ml for the entire wash. Add the washings to the sample container. Perform the water rinses as follows:
8.6.4.1.2 Carefully remove the probe nozzle and rinse the inside surface with water from a wash bottle. Brush with a Nylon bristle brush, and rinse until the rinse shows no visible particles, after which make a final rinse of the inside surface. Brush and rinse the inside parts of the Swagelok fitting with water in a similar way.
8.6.4.1.3 Rinse the probe liner with water. While squirting the water into the upper end of the probe, tilt and rotate the probe so that all inside surfaces will be wetted with water. Let the water drain from the lower end into the sample container. A funnel (glass or polyethylene) may be used to aid in transferring the liquid washes to the container. Follow the rinse with a probe brush. Hold the probe in an inclined position, and squirt water into the upper end as the probe brush is being pushed with a twisting action through the probe. Hold the sample container underneath the lower end of the probe, and catch any water and particulate matter that is brushed from the probe. Run the brush through the probe three times or more. With stainless steel or other metal probes, run the brush through in the above prescribed manner at least six times since metal probes have small crevices in which particulate matter can be entrapped. Rinse the brush with water, and quantitatively collect these washings in the sample container. After the brushing, make a final rinse of the probe as described above.
8.6.4.1.4 It is recommended that two people clean the probe to minimize sample losses. Between sampling runs, keep brushes clean and protected from contamination.
8.6.4.1.5 Rinse the inside surface of each of the first three impingers (and connecting glassware) three separate times. Use a small portion of water for each rinse, and brush each sample-exposed surface with a Nylon bristle brush, to ensure recovery of fine particulate matter. Make a final rinse of each surface and of the brush.
8.6.4.1.6 After ensuring that all joints have been wiped clean of the silicone grease, brush and rinse with water the inside of the filter holder (front-half only, if filter is positioned between the third and fourth impingers). Brush and rinse each surface three times or more if needed. Make a final rinse of the brush and filter holder.
8.6.4.1.7 After all water washings and particulate matter have been collected in the sample container, tighten the lid so that water will not leak out when it is shipped to the laboratory. Mark the height of the fluid level to transport. Label the container clearly to identify its contents.
8.6.4.2 Container No. 2 (Sample Blank). Prepare a blank by placing an unused filter in a polyethylene container and adding a volume of water equal to the total volume in Container No. 1. Process the blank in the same manner as for Container No. 1.
8.6.4.3 Container No. 3 (Silica Gel). Note the color of the indicating silica gel to determine whether it has been completely spent, and make a notation of its condition. Transfer the silica gel from the fourth impinger to its original container, and seal. A funnel may be used to pour the silica gel and a rubber policeman to remove the silica gel from the impinger. It is not necessary to remove the small amount of dust particles that may adhere to the impinger wall and are difficult to remove. Since the gain in weight is to be used for moisture calculations, do not use any water or other liquids to transfer the silica gel. If a balance is available in the field, follow the analytical procedure for Container No. 3 in section 11.4.2.
9.1 Miscellaneous Quality Control Measures.
| Section | Quality control measure | Effect |
|---|---|---|
| 8.4, 10.1 | Sampling equipment leak-check and calibration | Ensure accurate measurement of stack gas flow rate and sample volume. |
| 10.2 | Spectrophotometer calibration | Evaluate analytical technique, preparation of standards. |
| 11.3.3 | Interference/recovery efficiency check during distillation | Minimize negative effects of used acid. |
9.2 Volume Metering System Checks. Same as Method 5, section 9.2.
Maintain a laboratory log of all calibrations.
10.1 Sampling Equipment. Calibrate the probe nozzle, pitot tube, metering system, probe heater, temperature sensors, and barometer according to the procedures outlined in Method 5, sections 10.1 through 10.6. Conduct the leak-check of the metering system according to the procedures outlined in Method 5, section 8.4.1.
10.2 Spectrophotometer.
10.2.1 Prepare the blank standard by adding 10 ml of SPADNS mixed reagent to 50 ml of water.
10.2.2 Accurately prepare a series of standards from the 0.01 mg F
10.2.3 After mixing, place the blank and calibration standards in a constant temperature bath for 30 minutes before reading the absorbance with the spectrophotometer. Adjust all samples to this same temperature before analyzing.
10.2.4 With the spectrophotometer at 570 nm, use the blank standard to set the absorbance to zero. Determine the absorbance of the standards.
10.2.5 Prepare a calibration curve by plotting µg F
11.1 Sample Loss Check. Note the liquid levels in Containers No. 1 and No. 2, determine whether leakage occurred during transport, and note this finding on the analytical data sheet. If noticeable leakage has occurred, either void the sample or use methods, subject to the approval of the Administrator, to correct the final results.
11.2 Sample Preparation. Treat the contents of each sample container as described below:
11.2.1 Container No. 1 (Probe, Filter, and Impinger Catches). Filter this container’s contents, including the sampling filter, through Whatman No. 541 filter paper, or equivalent, into a 1500-ml beaker.
11.2.1.1 If the filtrate volume exceeds 900 ml, make the filtrate basic (red to phenolphthalein) with NaOH, and evaporate to less than 900 ml.
11.2.1.2 Place the filtered material (including sampling filter) in a nickel crucible, add a few ml of water, and macerate the filters with a glass rod.
11.2.1.2.1 Add 100 mg CaO to the crucible, and mix the contents thoroughly to form a slurry. Add two drops of phenolphthalein indicator. Place the crucible in a hood under infrared lamps or on a hot plate at low heat. Evaporate the water completely. During the evaporation of the water, keep the slurry basic (red to phenolphthalein) to avoid loss of F
11.2.1.2.2 After evaporation of the water, place the crucible on a hot plate under a hood, and slowly increase the temperature until the Whatman No. 541 and sampling filters char. It may take several hours to char the filters completely.
11.2.1.2.3 Place the crucible in a cold muffle furnace. Gradually (to prevent smoking) increase the temperature to 600 °C (1100 °F), and maintain this temperature until the contents are reduced to an ash. Remove the crucible from the furnace, and allow to cool.
11.2.1.2.4 Add approximately 4 g of crushed NaOH to the crucible, and mix. Return the crucible to the muffle furnace, and fuse the sample for 10 minutes at 600 °C.
11.2.1.2.5 Remove the sample from the furnace, and cool to ambient temperature. Using several rinsings of warm water, transfer the contents of the crucible to the beaker containing the filtrate. To ensure complete sample removal, rinse finally with two 20-ml portions of 25 percent H
11.2.2 Container No. 2 (Sample Blank). Treat in the same manner as described in section 11.2.1 above.
11.2.3 Adjustment of Acid/Water Ratio in Distillation Flask. Place 400 ml of water in the distillation flask, and add 200 ml of concentrated H
11.3 Distillation.
11.3.1 Cool the contents of the distillation flask to below 80 °C (180 °F). Pipet an aliquot of sample containing less than 10.0 mg F
If the sample contains chloride, add 5 mg of Ag
11.3.2 Place a 250-ml volumetric flask at the condenser exit. Heat the flask as rapidly as possible with a Bunsen burner, and collect all the distillate up to 175 °C (347 °F). During heatup, play the burner flame up and down the side of the flask to prevent bumping. Conduct the distillation as rapidly as possible (15 minutes or less). Slow distillations have been found to produce low F
11.3.3 The acid in the distillation flask may be used until there is carry-over of interferences or poor F
11.4 Sample Analysis.
11.4.1 Containers No. 1 and No. 2.
11.4.1.1 After distilling suitable aliquots from Containers No. 1 and No. 2 according to section 11.3, dilute the distillate in the volumetric flasks to exactly 250 ml with water, and mix thoroughly. Pipet a suitable aliquot of each sample distillate (containing 10 to 40 µg F
11.4.1.2 After mixing, place the sample in a constant-temperature bath containing the standard solutions for 30 minutes before reading the absorbance on the spectrophotometer.
After the sample and colorimetric reagent are mixed, the color formed is stable for approximately 2 hours. Also, a 3 °C (5.4 °F) temperature difference between the sample and standard solutions produces an error of approximately 0.005 mg F
11.4.1.3 Set the spectrophotometer to zero absorbance at 570 nm with the zero reference solution (Section 7.3.12), and check the spectrophotometer calibration with the standard solution (Section 7.3.10). Determine the absorbance of the samples, and determine the concentration from the calibration curve. If the concentration does not fall within the range of the calibration curve, repeat the procedure using a different size aliquot.
11.4.2 Container No. 3 (Silica Gel). Weigh the spent silica gel (or silica gel plus impinger) to the nearest 0.5 g using a balance. This step may be conducted in the field.
Carry out calculations, retaining at least one extra significant figure beyond that of the acquired data. Round off figures after final calculation. Other forms of the equations may be used, provided that they yield equivalent results.
12.1 Nomenclature.
12.2 Average DGM Temperature and Average Orifice Pressure Drop (see Figure 5-3 of Method 5).
12.3 Dry Gas Volume. Calculate V
12.4 Volume of Water Vapor and Moisture Content. Calculate V
12.5 Total Fluoride in Sample. Calculate the amount of F
12.6 Fluoride Concentration in Stack Gas. Determine the F
12.7 Isokinetic Variation. Same as Method 5, section 12.11.
The following estimates are based on a collaborative test done at a primary aluminum smelter. In the test, six laboratories each sampled the stack simultaneously using two sampling trains for a total of 12 samples per sampling run. Fluoride concentrations encountered during the test ranged from 0.1 to 1.4 mg F
13.1 Precision. The intra- and inter-laboratory standard deviations, which include sampling and analysis errors, were 0.044 mg F
13.2 Bias. The collaborative test did not find any bias in the analytical method.
13.3 Range. The range of this method is 0 to 1.4 µg F
16.1 Compliance with ASTM D 3270-73T, 80, 91, or 95 (incorporated by reference – see § 60.17) “Analysis of Fluoride Content of the Atmosphere and Plant Tissues (Semiautomated Method) is an acceptable alternative for the requirements specified in sections 11.2, 11.3, and 11.4.1 when applied to suitable aliquots of Containers 1 and 2 samples.
1. Bellack, Ervin. Simplified Fluoride Distillation Method. J. of the American Water Works Association. 50:5306. 1958.
2. Mitchell, W.J., J.C. Suggs, and F.J. Bergman. Collaborative Study of EPA Method 13A and Method 13B. Publication No. EPA-300/4-77-050. U.S. Environmental Protection Agency, Research Triangle Park, NC. December 1977.
3. Mitchell, W.J., and M.R. Midgett. Adequacy of Sampling Trains and Analytical Procedures Used for Fluoride. Atm. Environ. 10:865-872. 1976.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 2, Method 3, Method 5, and Method 13A.
1.1 Analytes.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Total fluorides as Fluorine | 7782-41-4 | Not determined. |
1.2 Applicability. This method is applicable for the determination of fluoride (F
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
Gaseous and particulate F
Grease on sample-exposed surfaces may cause low F
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to performing this test method.
5.2 Corrosive Reagents. The following reagents are hazardous. Personal protective equipment and safe procedures are useful in preventing chemical splashes. If contact occurs, immediately flush with copious amounts of water at least 15 minutes. Remove clothing under shower and decontaminate. Treat residual chemical burn as thermal burn.
5.2.1 Sodium Hydroxide (NaOH). Causes severe damage to eye tissues and to skin. Inhalation causes irritation to nose, throat, and lungs. Reacts exothermically with limited amounts of water.
5.2.2 Sulfuric Acid (H
6.1 Sample Collection and Sample Recovery. Same as Method 13A, sections 6.1 and 6.2, respectively.
6.2 Sample Preparation and Analysis. The following items are required for sample preparation and analysis:
6.2.1 Distillation Apparatus, Bunsen Burner, Electric Muffle Furnace, Crucibles, Beakers, Volumetric Flasks, Erlenmeyer Flasks or Plastic Bottles, Constant Temperature Bath, and Balance. Same as Method 13A, sections 6.3.1 to 6.3.9, respectively.
6.2.2 Fluoride Ion Activity Sensing Electrode.
6.2.3 Reference Electrode. Single junction, sleeve type.
6.2.4 Electrometer. A pH meter with millivolt-scale capable of ±0.1-mv resolution, or a specific ion meter made specifically for specific ion electrode use.
6.2.5 Magnetic Stirrer and Tetrafluoroethylene (TFE) Fluorocarbon-Coated Stirring Bars.
6.2.6 Beakers. Polyethylene, 100-ml.
Unless otherwise indicated, all reagents are to conform to the specifications established by the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available. Otherwise, use the best available grade.
7.1 Sample Collection and Sample Recovery. Same as Method 13A, sections 7.1 and 7.2, respectively.
7.2 Sample Preparation and Analysis. The following reagents and standards are required for sample analysis:
7.2.1 Calcium Oxide (CaO). Certified grade containing 0.005 percent F
7.2.2 Phenolphthalein Indicator. Dissolve 0.1 g phenolphthalein in a mixture of 50 ml of 90 percent ethanol and 50 ml water.
7.2.3 Sodium Hydroxide (NaOH), Pellets.
7.2.4 Sulfuric Acid (H
7.2.5 Filters. Whatman No. 541, or equivalent.
7.2.6 Water. Same as section 7.1.2 of Method 13A.
7.2.7 Sodium Hydroxide, 5 M. Dissolve 20 g of NaOH in 100 ml of water.
7.2.8 Sulfuric Acid, 25 Percent (v/v). Mix 1 part of concentrated H
7.2.9 Total Ionic Strength Adjustment Buffer (TISAB). Place approximately 500 ml of water in a 1-liter beaker. Add 57 ml of glacial acetic acid, 58 g of sodium chloride, and 4 g of cyclohexylene dinitrilo tetraacetic acid. Stir to dissolve. Place the beaker in a water bath and cool to 20 °C (68 °F). Slowly add 5 M NaOH to the solution, measuring the pH continuously with a calibrated pH/reference electrode pair, until the pH is 5.3. Pour into a 1-liter volumetric flask, and dilute to volume with deionized, distilled water. Commercially prepared TISAB may be substituted for the above.
7.2.10 Fluoride Standard Solution, 0.1 M. Oven dry approximately 10 g of sodium fluoride (NaF) for a minimum of 2 hours at 110 °C (230 °F), and store in a desiccator. Then add 4.2 g of NaF to a 1-liter volumetric flask, and add enough water to dissolve. Dilute to volume with water.
Same as Method 13A, section 8.0.
9.1 Miscellaneous Quality Control Measures.
| Section | Quality control measure | Effect |
|---|---|---|
| 8.0, 10.1 | Sampling equipment leak-check and calibration | Ensure accurate measurement of stack gas flow rate and sample volume. |
| 10.2 | Fluoride electrode | Evaluate analytical technique, preparation of standards. |
| 11.1 | Interference/recovery efficiency-check during distillation | Minimize negative effects of used acid. |
9.2 Volume Metering System Checks. Same as Method 5, section 9.2.
Maintain a laboratory log of all calibrations.
10.1 Sampling Equipment. Same as Method 13A, section 10.1.
10.2 Fluoride Electrode. Prepare fluoride standardizing solutions by serial dilution of the 0.1 M fluoride standard solution. Pipet 10 ml of 0.1 M fluoride standard solution into a 100-ml volumetric flask, and make up to the mark with water for a 10
10.2.1 Pipet 50 ml of each standard into a separate beaker. Add 50 ml of TISAB to each beaker. Place the electrode in the most dilute standard solution. When a steady millivolt reading is obtained, plot the value on the linear axis of semilog graph paper versus concentration on the log axis. Plot the nominal value for concentration of the standard on the log axis, (e.g., when 50 ml of 10
10.2.2 Between measurements, soak the fluoride sensing electrode in water for 30 seconds, and then remove and blot dry. Analyze the standards going from dilute to concentrated standards. A straight-line calibration curve will be obtained, with nominal concentrations of 10
10.2.3 Calibrate the fluoride electrode daily, and check it hourly. Prepare fresh fluoride standardizing solutions daily (10
Certain specific ion meters have been designed specifically for fluoride electrode use and give a direct readout of fluoride ion concentration. These meters may be used in lieu of calibration curves for fluoride measurements over a narrow concentration ranges. Calibrate the meter according to the manufacturer’s instructions.
11.1 Sample Loss Check, Sample Preparation, and Distillation. Same as Method 13A, sections 11.1 through 11.3, except that the note following section 11.3.1 is not applicable.
11.2 Analysis.
11.2.1 Containers No. 1 and No. 2. Distill suitable aliquots from Containers No. 1 and No. 2. Dilute the distillate in the volumetric flasks to exactly 250 ml with water, and mix thoroughly. Pipet a 25-ml aliquot from each of the distillate into separate beakers. Add an equal volume of TISAB, and mix. The sample should be at the same temperature as the calibration standards when measurements are made. If ambient laboratory temperature fluctuates more than ±2 °C from the temperature at which the calibration standards were measured, condition samples and standards in a constant-temperature bath before measurement. Stir the sample with a magnetic stirrer during measurement to minimize electrode response time. If the stirrer generates enough heat to change solution temperature, place a piece of temperature insulating material, such as cork, between the stirrer and the beaker. Hold dilute samples (below 10
11.2.2 Insert the fluoride and reference electrodes into the solution. When a steady millivolt reading is obtained, record it. This may take several minutes. Determine concentration from the calibration curve. Between electrode measurements, rinse the electrode with water.
11.2.3 Container No. 3 (Silica Gel). Same as in Method 13A, section 11.4.2.
Carry out calculations, retaining at least one extra significant figure beyond that of the acquired data. Round off figures after final calculation.
12.1 Nomenclature. Same as Method 13A, section 12.1, with the addition of the following:
12.2 Average DGM Temperature and Average Orifice Pressure Drop, Dry Gas Volume, Volume of Water Vapor and Moisture Content, Fluoride Concentration in Stack Gas, and Isokinetic Variation. Same as Method 13A, sections 12.2 to 12.4, 12.6, and 12.7, respectively.
12.3 Total Fluoride in Sample. Calculate the amount of F
The following estimates are based on a collaborative test done at a primary aluminum smelter. In the test, six laboratories each sampled the stack simultaneously using two sampling trains for a total of 12 samples per sampling run. Fluoride concentrations encountered during the test ranged from 0.1 to 1.4 mg F
13.1 Precision. The intra-laboratory and inter-laboratory standard deviations, which include sampling and analysis errors, are 0.037 mg F
13.2 Bias. The collaborative test did not find any bias in the analytical method.
13.3 Range. The range of this method is 0.02 to 2,000 µg F
16.1 Compliance with ASTM D 3270-73T, 91, 95 “Analysis for Fluoride Content of the Atmosphere and Plant Tissues (Semiautomated Method)” is an acceptable alternative for the distillation and analysis requirements specified in sections 11.1 and 11.2 when applied to suitable aliquots of Containers 1 and 2 samples.
Same as Method 13A, section 16.0, References 1 and 2, with the following addition:
1. MacLeod, Kathryn E., and Howard L. Crist. Comparison of the SPADNS-Zirconium Lake and Specific Ion Electrode Methods of Fluoride Determination in Stack Emission Samples. Analytical Chemistry. 45:1272-1273. 1973.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 2, Method 3, Method 5, Method 13A, and Method 13B.
1.1 Analytes.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Total fluorides as Fluorine | 7782-41-4 | Not determined. |
1.2 Applicability. This method is applicable for the determination of fluoride emissions from roof monitors at primary aluminum reduction plant potroom groups.
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 Gaseous and particulate fluoride roof monitor emissions are drawn into a permanent sampling manifold through several large nozzles. The sample is transported from the sampling manifold to ground level through a duct. The fluoride content of the gas in the duct is determined using either Method 13A or Method 13B. Effluent velocity and volumetric flow rate are determined using anemometers located in the roof monitor.
Potroom means a building unit which houses a group of electrolytic cells in which aluminum is produced.
Potroom group means an uncontrolled potroom, a potroom which is controlled individually, or a group of potrooms or potroom segments ducted to a common control system.
Roof monitor means that portion of the roof of a potroom where gases not captured at the cell exit from the potroom.
Same as section 4.0 of either Method 13A or Method 13B, with the addition of the following:
4.1 Magnetic Field Effects. Anemometer readings can be affected by potroom magnetic field effects. section 6.1 provides for minimization of this interference through proper shielding or encasement of anemometer components.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to performing this test method.
5.2 Corrosive Reagents. Same as section 5.2 of either Method 13A or Method 13B.
Same as section 6.0 of either Method 13A or Method 13B, as applicable, with the addition of the following:
6.1 Velocity Measurement Apparatus.
6.1.1 Anemometer Specifications. Propeller anemometers, or equivalent. Each anemometer shall meet the following specifications:
6.1.1.1 Its propeller shall be made of polystyrene, or similar material of uniform density. To ensure uniformity of performance among propellers, it is desirable that all propellers be made from the same mold.
6.1.1.2 The propeller shall be properly balanced, to optimize performance.
6.1.1.3 When the anemometer is mounted horizontally, its threshold velocity shall not exceed 15 m/min (50 ft/min).
6.1.1.4 The measurement range of the anemometer shall extend to at least 600 m/min (2,000 ft/min).
6.1.1.5 The anemometer shall be able to withstand prolonged exposure to dusty and corrosive environments; one way of achieving this is to purge the bearings of the anemometer continuously with filtered air during operation.
6.1.1.6 All anemometer components shall be properly shielded or encased, such that the performance of the anemometer is uninfluenced by potroom magnetic field effects.
6.1.1.7 A known relationship shall exist between the electrical output signal from the anemometer generator and the propeller shaft rpm (see section 10.2.1). Anemometers having other types of output signals (e.g., optical) may be used, subject to the approval of the Administrator. If other types of anemometers are used, there must be a known relationship between output signal and shaft rpm (see section 10.2.2).
6.1.1.8 Each anemometer shall be equipped with a suitable readout system (see section 6.1.3).
6.1.2 Anemometer Installation Requirements.
6.1.2.1 Single, Isolated Potroom. If the affected facility consists of a single, isolated potroom (or potroom segment), install at least one anemometer for every 85 m (280 ft) of roof monitor length. If the length of the roof monitor divided by 85 m (280 ft) is not a whole number, round the fraction to the nearest whole number to determine the number of anemometers needed. For monitors that are less than 130 m (430 ft) in length, use at least two anemometers. Divide the monitor cross-section into as many equal areas as anemometers, and locate an anemometer at the centroid of each equal area. See exception in section 6.1.2.3.
6.1.2.2 Two or More Potrooms. If the affected facility consists of two or more potrooms (or potroom segments) ducted to a common control device, install anemometers in each potroom (or segment) that contains a sampling manifold. Install at least one anemometer for every 85 m (280 ft) of roof monitor length of the potroom (or segment). If the potroom (or segment) length divided by 85 m (280 ft) is not a whole number, round the fraction to the nearest whole number to determine the number of anemometers needed. If the potroom (or segment) length is less than 130 m (430 ft), use at least two anemometers. Divide the potroom (or segment) monitor cross-section into as many equal areas as anemometers, and locate an anemometer at the centroid of each equal area. See exception in section 6.1.2.3.
6.1.2.3 Placement of Anemometer at the Center of Manifold. At least one anemometer shall be installed in the immediate vicinity (i.e., within 10 m (33 ft)) of the center of the manifold (see section 6.2.1). For its placement in relation to the width of the monitor, there are two alternatives. The first is to make a velocity traverse of the width of the roof monitor where an anemometer is to be placed and install the anemometer at a point of average velocity along this traverse. The traverse may be made with any suitable low velocity measuring device, and shall be made during normal process operating conditions. The second alternative is to install the anemometer half-way across the width of the roof monitor. In this latter case, the velocity traverse need not be conducted.
6.1.3 Recorders. Recorders that are equipped with suitable auxiliary equipment (e.g., transducers) for converting the output signal from each anemometer to a continuous recording of air flow velocity or to an integrated measure of volumetric flowrate shall be used. A suitable recorder is one that allows the output signal from the propeller anemometer to be read to within 1 percent when the velocity is between 100 and 120 m/min (330 and 390 ft/min). For the purpose of recording velocity, “continuous” shall mean one readout per 15-minute or shorter time interval. A constant amount of time shall elapse between readings. Volumetric flow rate may be determined by an electrical count of anemometer revolutions. The recorders or counters shall permit identification of the velocities or flowrates measured by each individual anemometer.
6.1.4 Pitot Tube. Standard-type pitot tube, as described in section 6.7 of Method 2, and having a coefficient of 0.99 ±0.01.
6.1.5 Pitot Tube (Optional). Isolated, Type S pitot, as described in section 6.1 of Method 2, and having a known coefficient, determined as outlined in section 4.1 of Method 2.
6.1.6 Differential Pressure Gauge. Inclined manometer, or equivalent, as described in section 6.1.2 of Method 2.
6.2 Roof Monitor Air Sampling System.
6.2.1 Manifold System and Ductwork. A minimum of one manifold system shall be installed for each potroom group. The manifold system and ductwork shall meet the following specifications:
6.2.1.1 The manifold system and connecting duct shall be permanently installed to draw an air sample from the roof monitor to ground level. A typical installation of a duct for drawing a sample from a roof monitor to ground level is shown in Figure 14-1 in section 17.0. A plan of a manifold system that is located in a roof monitor is shown in Figure 14-2. These drawings represent a typical installation for a generalized roof monitor. The dimensions on these figures may be altered slightly to make the manifold system fit into a particular roof monitor, but the general configuration shall be followed.
6.2.1.2 There shall be eight nozzles, each having a diameter of 0.40 to 0.50 m.
6.2.1.3 The length of the manifold system from the first nozzle to the eighth shall be 35 m (115 ft) or eight percent of the length of the potroom (or potroom segment) roof monitor, whichever is greater. Deviation from this requirement is subject to the approval of the Administrator.
6.2.1.4 The duct leading from the roof monitor manifold system shall be round with a diameter of 0.30 to 0.40 m (1.0 to 1.3 ft). All connections in the ductwork shall be leak-free.
6.2.1.5 As shown in Figure 14-2, each of the sample legs of the manifold shall have a device, such as a blast gate or valve, to enable adjustment of the flow into each sample nozzle.
6.2.1.6 The manifold system shall be located in the immediate vicinity of one of the propeller anemometers (see section 8.1.1.4) and as close as possible to the midsection of the potroom (or potroom segment). Avoid locating the manifold system near the end of a potroom or in a section where the aluminum reduction pot arrangement is not typical of the rest of the potroom (or potroom segment). The sample nozzles shall be centered in the throat of the roof monitor (see Figure 14-1).
6.2.1.7 All sample-exposed surfaces within the nozzles, manifold, and sample duct shall be constructed with 316 stainless steel. Alternatively, aluminum may be used if a new ductwork is conditioned with fluoride-laden roof monitor air for a period of six weeks before initial testing. Other materials of construction may be used if it is demonstrated through comparative testing, to the satisfaction of the Administrator, that there is no loss of fluorides in the system.
6.2.1.8 Two sample ports shall be located in a vertical section of the duct between the roof monitor and the exhaust fan (see section 6.2.2). The sample ports shall be at least 10 duct diameters downstream and three diameters upstream from any flow disturbance such as a bend or contraction. The two sample ports shall be situated 90° apart. One of the sample ports shall be situated so that the duct can be traversed in the plane of the nearest upstream duct bend.
6.2.2 Exhaust Fan. An industrial fan or blower shall be attached to the sample duct at ground level (see Figure 14-1). This exhaust fan shall have a capacity such that a large enough volume of air can be pulled through the ductwork to maintain an isokinetic sampling rate in all the sample nozzles for all flow rates normally encountered in the roof monitor. The exhaust fan volumetric flow rate shall be adjustable so that the roof monitor gases can be drawn isokinetically into the sample nozzles. This control of flow may be achieved by a damper on the inlet to the exhauster or by any other workable method.
6.3 Temperature Measurement Apparatus. To monitor and record the temperature of the roof monitor effluent gas, and consisting of the following:
6.3.1 Temperature Sensor. A temperature sensor shall be installed in the roof monitor near the sample duct. The temperature sensor shall conform to the specifications outlined in Method 2, section 6.3.
6.3.2 Signal Transducer. Transducer, to change the temperature sensor voltage output to a temperature readout.
6.3.3 Thermocouple Wire. To reach from roof monitor to signal transducer and recorder.
6.3.4 Recorder. Suitable recorder to monitor the output from the thermocouple signal transducer.
Same as section 7.0 of either Method 13A or Method 13B, as applicable.
8.1 Roof Monitor Velocity Determination.
8.1.1 Velocity Estimate(s) for Setting Isokinetic Flow. To assist in setting isokinetic flow in the manifold sample nozzles, the anticipated average velocity in the section of the roof monitor containing the sampling manifold shall be estimated before each test run. Any convenient means to make this estimate may be used (e.g., the velocity indicated by the anemometer in the section of the roof monitor containing the sampling manifold may be continuously monitored during the 24-hour period before the test run). If there is question as to whether a single estimate of average velocity is adequate for an entire test run (e.g., if velocities are anticipated to be significantly different during different potroom operations), the test run may be divided into two or more “sub-runs,” and a different estimated average velocity may be used for each sub-run (see section 8.4.2).
8.1.2 Velocity Determination During a Test Run. During the actual test run, record the velocity or volumetric flowrate readings of each propeller anemometer in the roof monitor. Readings shall be taken from each anemometer at equal time intervals of 15 minutes or less (or continuously).
8.2 Temperature Recording. Record the temperature of the roof monitor effluent gases at least once every 2 hours during the test run.
8.3 Pretest Ductwork Conditioning. During the 24-hour period immediately preceding the test run, turn on the exhaust fan, and draw roof monitor air through the manifold system and ductwork. Adjust the fan to draw a volumetric flow through the duct such that the velocity of gas entering the manifold nozzles approximates the average velocity of the air exiting the roof monitor in the vicinity of the sampling manifold.
8.4 Manifold Isokinetic Sample Rate Adjustment(s).
8.4.1 Initial Adjustment. Before the test run (or first sub-run, if applicable; see sections 8.1.1 and 8.4.2), adjust the fan such that air enters the manifold sample nozzles at a velocity equal to the appropriate estimated average velocity determined under section 8.1.1. Use Equation 14-1 (Section 12.2.2) to determine the correct stream velocity needed in the duct at the sampling location, in order for sample gas to be drawn isokinetically into the manifold nozzles. Next, verify that the correct stream velocity has been achieved, by performing a pitot tube traverse of the sample duct (using either a standard or Type S pitot tube); use the procedure outlined in Method 2.
8.4.2 Adjustments During Run. If the test run is divided into two or more “sub-runs” (see section 8.1.1), additional isokinetic rate adjustment(s) may become necessary during the run. Any such adjustment shall be made just before the start of a sub-run, using the procedure outlined in section 8.4.1 above.
Isokinetic rate adjustments are not permissible during a sub-run.
8.5 Pretest Preparation, Preliminary Determinations, Preparation of Sampling Train, Leak-Check Procedures, Sampling Train Operation, and Sample Recovery. Same as Method 13A, sections 8.1 through 8.6, with the exception of the following:
8.5.1 A single train shall be used for the entire sampling run. Alternatively, if two or more sub-runs are performed, a separate train may be used for each sub-run; note, however, that if this option is chosen, the area of the sampling nozzle shall be the same (±2 percent) for each train. If the test run is divided into sub-runs, a complete traverse of the duct shall be performed during each sub-run.
8.5.2 Time Per Run. Each test run shall last 8 hours or more; if more than one run is to be performed, all runs shall be of approximately the same (±10 percent) length. If questions exist as to the representativeness of an 8-hour test, a longer period should be selected. Conduct each run during a period when all normal operations are performed underneath the sampling manifold. For most recently-constructed plants, 24 hours are required for all potroom operations and events to occur in the area beneath the sampling manifold. During the test period, all pots in the potroom group shall be operated such that emissions are representative of normal operating conditions in the potroom group.
9.1 Miscellaneous Quality Control Measures.
| Section | Quality Control Measure | Effect |
|---|---|---|
| 8.0, 10.0 | Sampling equipment leak-check and calibration | Ensure accurate measurement of gas flow rate in duct and of sample volume. |
| 10.3, 10.4 | Initial and periodic performance checks of roof monitor effluent gas characterization apparatus | Ensure accurate and precise measurement of roof monitor effluent gas temperature and flow rate. |
| 11.0 | Interference/recovery efficiency check during distillation | Minimize negative effects of used acid. |
9.2 Volume Metering System Checks. Same as Method 5, section 9.2.
Same as section 10.0 of either Method 13A or Method 13B, as applicable, with the addition of the following:
10.1 Manifold Intake Nozzles. The manifold intake nozzles shall be calibrated when the manifold system is installed or, alternatively, the manifold may be preassembled and the nozzles calibrated on the ground prior to installation. The following procedures shall be observed:
10.1.1 Adjust the exhaust fan to draw a volumetric flow rate (refer to Equation 14-1) such that the entrance velocity into each manifold nozzle approximates the average effluent velocity in the roof monitor.
10.1.2 Measure the velocity of the air entering each nozzle by inserting a standard pitot tube into a 2.5 cm or less diameter hole (see Figure 14-2) located in the manifold between each blast gate (or valve) and nozzle. Note that a standard pitot tube is used, rather than a type S, to eliminate possible velocity measurement errors due to cross-section blockage in the small (0.13 m diameter) manifold leg ducts. The pitot tube tip shall be positioned at the center of each manifold leg duct. Take care to ensure that there is no leakage around the pitot tube, which could affect the indicated velocity in the manifold leg.
10.1.3 If the velocity of air being drawn into each nozzle is not the same, open or close each blast gate (or valve) until the velocity in each nozzle is the same. Fasten each blast gate (or valve) so that it will remain in position, and close the pitot port holes.
10.2 Initial Calibration of Propeller Anemometers.
10.2.1 Anemometers that meet the specifications outlined in section 6.1.1 need not be calibrated, provided that a reference performance curve relating anemometer signal output to air velocity (covering the velocity range of interest) is available from the manufacturer. If a reference performance curve is not available from the manufacturer, such a curve shall be generated.
For the purpose of this method, a “reference” performance curve is defined as one that has been derived from primary standard calibration data, with the anemometer mounted vertically. “Primary standard” data are obtainable by: (a) direct calibration of one or more of the anemometers by the National Institute of Standards and Technology (NIST); (b) NIST-traceable calibration; or (c) Calibration by direct measurement of fundamental parameters such as length and time (e.g., by moving the anemometers through still air at measured rates of speed, and recording the output signals).
10.2.2 Anemometers having output signals other than electrical (e.g., optical) may be used, subject to the approval of the Administrator. If other types of anemometers are used, a reference performance curve shall be generated, using procedures subject to the approval of the Administrator.
10.2.3 The reference performance curve shall be derived from at least the following three points: 60 ±15, 900 ±100, and 1800 ±100 rpm.
10.3 Initial Performance Checks. Conduct these checks within 60 days before the first performance test.
10.3.1 Anemometers. A performance-check shall be conducted as outlined in sections 10.3.1.1 through 10.3.1.3. Alternatively, any other suitable method that takes into account the signal output, propeller condition, and threshold velocity of the anemometer may be used, subject to the approval of the Administrator.
10.3.1.1 Check the signal output of the anemometer by using an accurate rpm generator (see Figure 14-3) or synchronous motors to spin the propeller shaft at each of the three rpm settings described in section 10.2.3, and measuring the output signal at each setting. If, at each setting, the output signal is within 5 percent of the manufacturer’s value, the anemometer can be used. If the anemometer performance is unsatisfactory, the anemometer shall either be replaced or repaired.
10.3.1.2 Check the propeller condition, by visually inspecting the propeller, making note of any significant damage or warpage; damaged or deformed propellers shall be replaced.
10.3.1.3 Check the anemometer threshold velocity as follows: With the anemometer mounted as shown in Figure 14-4(A), fasten a known weight (a straight-pin will suffice) to the anemometer propeller at a fixed distance from the center of the propeller shaft. This will generate a known torque; for example, a 0.1-g weight, placed 10 cm from the center of the shaft, will generate a torque of 1.0 g-cm. If the known torque causes the propeller to rotate downward, approximately 90° [see Figure 14-4(B)], then the known torque is greater than or equal to the starting torque; if the propeller fails to rotate approximately 90°, the known torque is less than the starting torque. By trying different combinations of weight and distance, the starting torque of a particular anemometer can be satisfactorily estimated. Once an estimate of the starting torque has been obtained, the threshold velocity of the anemometer (for horizontal mounting) can be estimated from a graph such as Figure 14-5 (obtained from the manufacturer). If the horizontal threshold velocity is acceptable [
10.3.2 Recorders and Counters. Check the calibration of each recorder and counter (see section 6.1.2) at a minimum of three points, approximately spanning the expected range of velocities. Use the calibration procedures recommended by the manufacturer, or other suitable procedures (subject to the approval of the Administrator). If a recorder or counter is found to be out of calibration by an average amount greater than 5 percent for the three calibration points, replace or repair the system; otherwise, the system can be used.
10.3.3 Temperature Measurement Apparatus. Check the calibration of the Temperature Measurement Apparatus, using the procedures outlined in section 10.3 of Method 2, at temperatures of 0, 100, and 150 °C (32, 212, and 302 °F). If the calibration is off by more than 5 °C (9 °F) at any of the temperatures, repair or replace the apparatus; otherwise, the apparatus can be used.
10.4 Periodic Performance Checks. Repeat the procedures outlined in section 10.3 no more than 12 months after the initial performance checks. If the above systems pass the performance checks (i.e., if no repair or replacement of any component is necessary), continue with the performance checks on a 12-month interval basis. However, if any of the above systems fail the performance checks, repair or replace the system(s) that failed, and conduct the periodic performance checks on a 3-month interval basis, until sufficient information (to the satisfaction of the Administrator) is obtained to establish a modified performance check schedule and calculation procedure.
If any of the above systems fails the 12-month periodic performance checks, the data for the past year need not be recalculated.
Same as section 11.0 of either Method 13A or Method 13B.
Same as section 12.0 of either Method 13A or Method 13B, as applicable, with the following additions and exceptions:
12.1 Nomenclature.
12.2 Isokinetic Sampling Check.
12.2.1 Calculate the arithmetic mean of the roof monitor effluent gas velocity readings (v
12.2.2 Calculate the expected average velocity (v
12.2.3 Calculate the actual average velocity (v
12.2.4 Express each vs value from section 12.2.3 as a percentage of the corresponding v
12.2.4.1 If vs is less than or equal to 120 percent of v
12.2.4.2 If v
12.3 Average Velocity of Roof Monitor Effluent Gas. Calculate the arithmetic mean roof monitor effluent gas velocity (v
12.4 Average Temperature of Roof Monitor Effluent Gas. Calculate the arithmetic mean roof monitor effluent gas temperature (T
12.5 Concentration of Fluorides in Roof Monitor Effluent Gas.
12.5.1 If a single sampling train was used throughout the run, calculate the average fluoride concentration for the roof monitor using Equation 13A-2 of Method 13A.
12.5.2 If two or more sampling trains were used (i.e., one per sub-run), calculate the average fluoride concentration for the run using Equation 14-3:
12.6 Mole Fraction of Dry Gas.
12.7 Average Volumetric Flow Rate of Roof Monitor Effluent Gas. Calculate the arithmetic mean volumetric flow rate of the roof monitor effluent gases using Equation 14-5.
Same as section 16.0 of either Method 13A or Method 13B, as applicable, with the addition of the following:
1. Shigehara, R.T. A Guideline for Evaluating Compliance Test Results (Isokinetic Sampling Rate Criterion). U.S. Environmental Protection Agency, Emission Measurement Branch, Research Triangle Park, NC. August 1977.
This method does not include all the specifications (e.g., equipment and supplies) and procedures (e.g., sampling) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 5, Methods 13A and 13B, and Method 14 of this appendix.
1.1 Analytes.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Total fluorides | None assigned | Not determined. |
| Includes hydrogen fluoride | 007664-39-3 | Not determined. |
1.2 Applicability. This method is applicable for the determination of total fluorides (TF) emissions from sources specified in the applicable regulation. This method was developed by consensus with the Aluminum Association and the U.S. Environmental Protection Agency (EPA).
2.1 Total fluorides, in the form of solid and gaseous fluorides, are withdrawn from the ascending air stream inside of an aluminum reduction potroom and, prior to exiting the potroom roof monitor, into a specific cassette arrangement. The cassettes are connected by tubing to flowmeters and a manifold system that allows for the equal distribution of volume pulled through each cassette, and finally to a dry gas meter. The cassettes have a specific internal arrangement of one unaltered cellulose filter and support pad in the first section of the cassette for solid fluoride retention and two cellulose filters with support pads that are impregnated with sodium formate for the chemical absorption of gaseous fluorides in the following two sections of the cassette. A minimum of eight cassettes shall be used for a potline and shall be strategically located at equal intervals across the potroom roof so as to encompass a minimum of 8 percent of the total length of the potroom. A greater number of cassettes may be used should the regulated facility choose to do so. The mass flow rate of pollutants is determined with anemometers and temperature sensing devices located immediately below the opening of the roof monitor and spaced evenly within the cassette group.
3.1 Cassette. A segmented, styrene acrylonitrile cassette configuration with three separate segments and a base, for the purpose of this method, to capture and retain fluoride from potroom gases.
3.2 Cassette arrangement. The cassettes, tubing, manifold system, flowmeters, dry gas meter, and any other related equipment associated with the actual extraction of the sample gas stream.
3.3 Cassette group. That section of the potroom roof monitor where a distinct group of cassettes is located.
3.4 Potline. A single, discrete group of electrolytic reduction cells electrically connected in series, in which alumina is reduced to form aluminum.
3.5 Potroom. A building unit that houses a group of electrolytic reduction cells in which aluminum is produced.
3.6 Potroom group. An uncontrolled potroom, a potroom that is controlled individually, or a group of potrooms or potroom segments ducted to a common primary control system.
3.7 Primary control system. The equipment used to capture the gases and particulate matter generated during the reduction process and the emission control device(s) used to remove pollutants prior to discharge of the cleaned gas to the atmosphere.
3.8 Roof monitor. That portion of the roof of a potroom building where gases, not captured at the cell, exit from the potroom.
3.9 Total fluorides (TF). Elemental fluorine and all fluoride compounds as measured by Methods 13A or 13B of this appendix or by an approved alternative method.
4.1 There are two principal categories of limitations that must be addressed when using this method. The first category is sampling bias and the second is analytical bias. Biases in sampling can occur when there is an insufficient number of cassettes located along the roof monitor of a potroom or if the distribution of those cassettes is spatially unequal. Known sampling biases also can occur when there are leaks within the cassette arrangement and if anemometers and temperature devices are not providing accurate data. Applicable instruments must be properly calibrated to avoid sampling bias. Analytical biases can occur when instrumentation is not calibrated or fails calibration and the instrument is used out of proper calibration. Additionally, biases can occur in the laboratory if fusion crucibles retain residual fluorides over lengthy periods of use. This condition could result in falsely elevated fluoride values. Maintaining a clean work environment in the laboratory is crucial to producing accurate values.
4.2 Biases during sampling can be avoided by properly spacing the appropriate number of cassettes along the roof monitor, conducting leak checks of the cassette arrangement, calibrating the dry gas meter every 30 days, verifying the accuracy of individual flowmeters (so that there is no more than 5 percent difference in the volume pulled between any two flowmeters), and calibrating or replacing anemometers and temperature sensing devices as necessary to maintain true data generation.
4.3 Analytical biases can be avoided by calibrating instruments according to the manufacturer’s specifications prior to conducting any analyses, by performing internal and external audits of up to 10 percent of all samples analyzed, and by rotating individual crucibles as the “blank” crucible to detect any potential residual fluoride carry-over to samples. Should any contamination be discovered in the blank crucible, the crucible shall be thoroughly cleaned to remove any detected residual fluorides and a “blank” analysis conducted again to evaluate the effectiveness of the cleaning. The crucible shall remain in service as long as no detectable residual fluorides are present.
5.1 This method may involve the handling of hazardous materials in the analytical phase. This method does not purport to address all of the potential safety hazards associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method.
5.2 Corrosive reagents. The following reagents are hazardous. Personal protective equipment and safe procedures are useful in preventing chemical splashes. If contact occurs, immediately flush with copious amounts of water for at least 15 minutes. Remove clothing under shower and decontaminate. Treat residual chemical burn as thermal burn.
5.3 Sodium Hydroxide (NaOH). Causes severe damage to eyes and skin. Inhalation causes irritation to nose, throat, and lungs. Reacts exothermically with limited amounts of water.
5.4 Perchloric Acid (HClO
6.1 Sampling.
6.1.1 Cassette arrangement. The cassette itself is a three-piece, styrene acrylonitrile cassette unit (a Gelman Sciences product), 37 millimeter (mm), with plastic connectors. In the first section (the intake section), an untreated Gelman Sciences 37 mm, 0.8 micrometer (µm) DM-800 metricel membrane filter and cellulose support pad, or equivalent, is situated. In the second and third segments of the cassette there is placed one each of Gelman Sciences 37 mm, 5 µm GLA-5000 low-ash PVC filter with a cellulose support pad or equivalent product. Each of these two filters and support pads shall have been immersed in a solution of 10 percent sodium formate (volume/volume in an ethyl alcohol solution). The impregnated pads shall be placed in the cassette segments while still wet and heated at 50 °C (122 °F) until the pad is completely dry. It is important to check for a proper fit of the filter and support pad to the cassette segment to ensure that there are no areas where gases could bypass the filter. Once all of the cassette segments have been prepared, the cassette shall be assembled and a plastic plug shall be inserted into the exhaust hole of the cassette. Prior to placing the cassette into service, the space between each segment shall be taped with an appropriately durable tape to prevent the infiltration of gases through the points of connection, and an aluminum nozzle shall be inserted into the intake hole of the cassette. The aluminum nozzle shall have a short section of tubing placed over the opening of the nozzle, with the tubing plugged to prevent dust from entering the nozzle and to prepare the nozzle for the cassette arrangement leak check. An alternate nozzle type can be used if historical results or scientific demonstration of applicability can be shown.
6.1.2 Anemometers and temperature sensing devices. To calculate the mass flow rate of TF from the roof monitor under standard conditions, anemometers that meet the specifications in section 2.1.1 in Method 14 of this appendix or an equivalent device yielding equivalent information shall be used. A recording mechanism capable of accurately recording the exit gas temperature at least every 2 hours shall be used.
6.1.3 Barometer. To correct the volumetric flow from the potline roof monitor to standard conditions, a mercury (Hg), aneroid, or other barometer capable of measuring atmospheric pressure to within 2.5 mm [0.1 inch (in)] Hg shall be used.
The barometric reading may be obtained from a nearby National Weather Service Station. In this case, the station value (which is absolute barometric pressure) shall be requested and an adjustment for elevation differences between the weather station and the sampling point shall be made at a rate of minus 2.5 mm (0.1 in) Hg per 30 meters (m) [100 feet (ft)] elevation increase or plus 2.5 mm (0.1 in) Hg per 30 m (100 ft) elevation decrease.
6.2 Sample recovery.
6.2.1 Hot plate.
6.2.2 Muffle furnace.
6.2.3 Nickel crucible.
6.2.4 Stirring rod. Teflon.
6.2.5 Volumetric flask. 50-milliliter (ml).
6.2.6 Plastic vial. 50-ml.
6.3 Analysis.
6.3.1 Primary analytical method. An automated analyzer having the following components or equivalent: a multichannel proportioning pump, multiposition sampler, voltage stabilizer, colorimeter, instrument recording device, microdistillation apparatus, flexible Teflon ® heating bath, vacuum pump, pulse suppressers and an air flow system.
6.3.2 Secondary analytical method. Specific Ion Electrode (SIE).
7.1 Water. Deionized distilled to conform to ASTM Specification D 1193-77, Type 3 (incorporated by reference in § 60.17(a)(22) of this part). The KMnO
7.2 Calcium oxide.
7.3 Sodium hydroxide (NaOH). Pellets.
7.4 Perchloric acid (HClO
7.5 Audit samples. The audit samples discussed in section 9.1 shall be prepared from reagent grade, water soluble stock reagents, or purchased as an aqueous solution from a commercial supplier. If the audit stock solution is purchased from a commercial supplier, the standard solution must be accompanied by a certificate of analysis or an equivalent proof of fluoride concentration.
8.1 Preparing cassette arrangement for sampling. The cassettes are initially connected to flexible tubing. The tubing is connected to flowmeters and a manifold system. The manifold system is connected to a dry gas meter (Research Appliance Company model 201009 or equivalent). The length of tubing is managed by pneumatically or electrically operated hoists located in the roof monitor, and the travel of the tubing is controlled by encasing the tubing in aluminum conduit. The tubing is lowered for cassette insertion by operating a control box at floor level. Once the cassette has been securely inserted into the tubing and the leak check performed, the tubing and cassette are raised to the roof monitor level using the floor level control box. Arrangements similar to the one described are acceptable if the scientific sample collection principles are followed.
8.2 Test run sampling period. A test run shall comprise a minimum of a 24-hour sampling event encompassing at least eight cassettes per potline (or four cassettes per potroom group). Monthly compliance shall be based on three test runs during the month. Test runs of greater than 24 hours are allowed; however, three such runs shall be conducted during the month.
8.3 Leak-check procedures.
8.3.1 Pretest leak check. A pretest leak-check is recommended; however, it is not required. To perform a pretest leak-check after the cassettes have been inserted into the tubing, isolate the cassette to be leak-checked by turning the valves on the manifold to stop all flows to the other sampling points connected to the manifold and meter. The cassette, with the plugged tubing section securing the intake of the nozzle, is subjected to the highest vacuum expected during the run. If no leaks are detected, the tubing plug can be briefly removed as the dry gas meter is rapidly turned off.
8.3.2 Post-test leak check. A leak check is required at the conclusion of each test run for each cassette. The leak check shall be performed in accordance with the procedure outlined in section 8.3.1 of this method except that it shall be performed at a vacuum greater than the maximum vacuum reached during the test run. If the leakage rate is found to be no greater than 4 percent of the average sampling rate, the results are acceptable. If the leakage rate is greater than 4 percent of the average sampling rate, either record the leakage rate and correct the sampling volume as discussed in section 12.4 of this method or void the test run if the minimum number of cassettes were used. If the number of cassettes used was greater than the minimum required, discard the leaking cassette and use the remaining cassettes for the emission determination.
8.3.3 Anemometers and temperature sensing device placement. Install the recording mechanism to record the exit gas temperature. Anemometers shall be installed as required in section 6.1.2 of Method 14 of this appendix, except replace the word “manifold” with “cassette group” in section 6.1.2.3. These two different instruments shall be located near each other along the roof monitor. See conceptual configurations in Figures 14A-1, 14A-2, and 14A-3 of this method. Fewer temperature devices than anemometers may be used if at least one temperature device is located within the span of the cassette group. Other anemometer location siting scenarios may be acceptable as long as the exit velocity of the roof monitor gases is representative of the entire section of the potline being sampled.
8.4 Sampling. The actual sample run shall begin with the removal of the tubing and plug from the cassette nozzle. Each cassette is then raised to the roof monitor area, the dry gas meter is turned on, and the flowmeters are set to the calibration point, which allows an equal volume of sampled gas to enter each cassette. The dry gas meter shall be set to a range suitable for the specific potroom type being sampled that will yield valid data known from previous experience or a range determined by the use of the calculation in section 12 of this method. Parameters related to the test run that shall be recorded, either during the test run or after the test run if recording devices are used, include: anemometer data, roof monitor exit gas temperature, dry gas meter temperature, dry gas meter volume, and barometric pressure. At the conclusion of the test run, the cassettes shall be lowered, the dry gas meter turned off, and the volume registered on the dry gas meter recorded. The post-test leak check procedures described in section 8.3.2 of this method shall be performed. All data relevant to the test shall be recorded on a field data sheet and maintained on file.
8.5 Sample recovery.
8.5.1 The cassettes shall be brought to the laboratory with the intake nozzle contents protected with the section of plugged tubing previously described. The exterior of cassettes shall carefully be wiped free of any dust or debris, making sure that any falling dust or debris does not present a potential laboratory contamination problem.
8.5.2 Carefully remove all tape from the cassettes and remove the initial filter, support pad, and all loose solids from the first (intake) section of the cassette. Fold the filter and support pad several times and, along with all loose solids removed from the interior of the first section of the cassette, place them into a nickel crucible. Using water, wash the interior of the nozzle into the same nickel crucible. Add 0.1 gram (g) [±0.1 milligram (mg)] of calcium oxide and a sufficient amount of water to make a loose slurry. Mix the contents of the crucible thoroughly with a Teflon” stirring rod. After rinsing any adhering residue from the stirring rod back into the crucible, place the crucible on a hot plate or in a muffle furnace until all liquid is evaporated and allow the mixture to gradually char for 1 hour.
8.5.3 Transfer the crucible to a cold muffle furnace and ash at 600 °C (1,112 °F). Remove the crucible after the ashing phase and, after the crucible cools, add 3.0 g (±0.1 g) of NaOH pellets. Place this mixture in a muffle furnace at 600 °C (1,112 °F) for 3 minutes. Remove the crucible and roll the melt so as to reach all of the ash with the molten NaOH. Let the melt cool to room temperature. Add 10 to 15 ml of water to the crucible and place it on a hot plate at a low temperature setting until the melt is soft or suspended. Transfer the contents of the crucible to a 50-ml volumetric flask. Rinse the crucible with 20 ml of 1:1 perchloric acid or 20 ml of 1:1 sulfuric acid in two (2) 10 ml portions. Pour the acid rinse slowly into the volumetric flask and swirl the flask after each addition. Cool to room temperature. The product of this procedure is particulate fluorides.
8.5.4 Gaseous fluorides can be isolated for analysis by folding the gaseous fluoride filters and support pads to approximately
9.1 Laboratory auditing. Laboratory audits of specific and known concentrations of fluoride shall be submitted to the laboratory with each group of samples submitted for analysis. An auditor shall prepare and present the audit samples as a “blind” evaluation of laboratory performance with each group of samples submitted to the laboratory. The audits shall be prepared to represent concentrations of fluoride that could be expected to be in the low, medium and high range of actual results. Average recoveries of all three audits must equal 90 to 110 percent for acceptable results; otherwise, the laboratory must investigate procedures and instruments for potential problems.
The analytical procedure allows for the analysis of individual or combined filters and pads from the cassettes provided that equal volumes (±10 percent) are sampled through each cassette.
10.1 Equipment evaluations. To ensure the integrity of this method, periodic calibrations and equipment replacements are necessary.
10.1.1 Metering system. At 30-day intervals the metering system shall be calibrated. Connect the metering system inlet to the outlet of a wet test meter that is accurate to 1 percent. Refer to Figure 5-4 of Method 5 of this appendix. The wet-test meter shall have a capacity of 30 liters/revolution [1 cubic foot (ft
10.1.2 Estimating volumes for initial test runs. For a facility’s initial test runs, the regulated facility must have a target or desired volume of gases to be sampled and a target range of volumes to use during the calibration of the dry gas meter. Use Equations 14A-1 and 14A-2 in section 12 of this method to derive the target dry gas meter volume (F
10.1.3 Calibration of anemometers and temperature sensing devices. If the standard anemometers in Method 14 of this appendix are used, the calibration and integrity evaluations in sections 10.3.1.1 through 10.3.1.3 of Method 14 of this appendix shall be used as well as the recording device described in section 2.1.3 of Method 14. The calibrations or complete change-outs of anemometers shall take place at a minimum of once per year. The temperature sensing and recording devices shall be calibrated according to the manufacturer’s specifications.
10.1.4 Calibration of flowmeters. The calibration of flowmeters is necessary to ensure that an equal volume of sampled gas is entering each of the individual cassettes and that no large differences, which could possibly bias the sample, exist between the cassettes.
10.1.4.1 Variable area, 65 mm flowmeters or equivalent shall be used. These flowmeters can be mounted on a common base for convenience. These flowmeters shall be calibrated by attaching a prepared cassette, complete with filters and pads, to the flowmeter and then to the system manifold. This manifold is an aluminum cylinder with valved inlets for connections to the flowmeters/cassettes and one outlet to a dry gas meter. The connection is then made to the wet-test meter and finally to a dry gas meter. All connections are made with tubing.
10.1.4.2 Turn the dry gas meter on for 15 min. in preparation for the calibration. Turn the dry gas meter off and plug the intake hole of the cassette. Turn the dry gas meter back on to evaluate the entire system for leaks. If the dry gas meter shows a leakage rate of less than 0.02 ft
10.1.4.3 With the dry gas meter turned on and the flow indicator ball at a selected flow rate, record the exact amount of gas pulled through the flowmeter by taking measurements from the wet test meter after exactly 10 min. Record the room temperature and barometric pressure. Conduct this test for all flowmeters in the system with all flowmeters set at the same indicator ball reading. When all flowmeters have gone through the procedure above, correct the volume pulled through each flowmeter to standard conditions. The acceptable difference between the highest and lowest flowmeter rate is 5 percent. Should one or more flowmeters be outside of the acceptable limit of 5 percent, repeat the calibration procedure at a lower or higher indicator ball reading until all flowmeters show no more than 5 percent difference among them.
10.1.4.4 This flowmeter calibration shall be conducted at least once per year.
10.1.5 Miscellaneous equipment calibrations. Miscellaneous equipment used such as an automatic recorder/ printer used to measure dry gas meter temperatures shall be calibrated according to the manufacturer’s specifications in order to maintain the accuracy of the equipment.
11.1 The preferred primary analytical determination of the individual isolated samples or the combined particulate and gaseous samples shall be performed by an automated methodology. The analytical method for this technology shall be based on the manufacturer’s instructions for equipment operation and shall also include the analysis of five standards with concentrations in the expected range of the actual samples. The results of the analysis of the five standards shall have a coefficient of correlation of at least 0.99. A check standard shall be analyzed as the last sample of the group to determine if instrument drift has occurred. The acceptable result for the check standard is 95 to 105 percent of the standard’s true value.
11.2 The secondary analytical method shall be by specific ion electrode if the samples are distilled or if a TISAB IV buffer is used to eliminate aluminum interferences. Five standards with concentrations in the expected range of the actual samples shall be analyzed, and a coefficient of correlation of at least 0.99 is the minimum acceptable limit for linearity. An exception for this limit for linearity is a condition when low-level standards in the range of 0.01 to 0.48 µg fluoride/ml are analyzed. In this situation, a minimum coefficient of correlation of 0.97 is required. TISAB II shall be used for low-level analyses.
12.1 Carry out calculations, retaining at least one extra decimal point beyond that of the acquired data. Round off values after the final calculation. Other forms of calculations may be used as long as they give equivalent results.
12.2 Estimating volumes for initial test runs.
12.2.1 Example calculation. Assume that the typical emission rate (R
This is a total of 575.40 ft
12.3 Calculations of TF emissions from field and laboratory data that would yield a production related emission rate can be calculated as follows:
12.3.1 Obtain a standard cubic feet (scf) value for the volume pulled through the dry gas meter for all cassettes by using the field and calibration data and Equation 5-1 of Method 5 of this appendix.
12.3.2 Derive the average quantity of TF per cassette (in µg TF/cassette) by adding all laboratory data for all cassettes and dividing this value by the total number of cassettes used. Divide this average TF value by the corrected dry gas meter volume for each cassette; this value then becomes TF
12.3.3 Calculate the production-based emission rate (R
12.3.4 As an example calculation, assume eight cassettes located in a potline were used to sample for 72 hours during the run. The analysis of all eight cassettes yielded a total of 3,000 µg of TF. The dry gas meter volume was corrected to yield a total of 75 scf per cassette, which yields a value for TF
12.4 Corrections to volumes due to leakage. Should the post-test leak check leakage rate exceed 4 percent as described in section 8.3.2 of this method, correct the volume as detailed in Case I in section 6.3 of Method 5 of this appendix.
This method is not inclusive with respect to specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of gas chromatography techniques.
1.1 Analytes.
| Analyte | CAS No. | Sensitivity (See Sec 13.2) |
|---|---|---|
| Carbon disulfide [CS | 75-15-0 | 0.5 ppmv |
| Carbonyl sulfide [COS] | 463-58-1 | 0.5 ppmv |
| Hydrogen sulfide [H | 7783-06-4 | 0.5 ppmv |
1.2 Applicability.
1.2.1 This method applies to the determination of emissions of reduced sulfur compounds from tail gas control units of sulfur recovery plants, H
1.2.2 The method described below uses the principle of gas chromatographic (GC) separation and flame photometric detection (FPD). Since there are many systems or sets of operating conditions that represent useable methods for determining sulfur emissions, all systems which employ this principle, but differ only in details of equipment and operation, may be used as alternative methods, provided that the calibration precision and sample-line loss criteria are met.
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 A gas sample is extracted from the emission source and diluted with clean dry air (if necessary). An aliquot of the diluted sample is then analyzed for CS
4.1 Moisture Condensation. Moisture condensation in the sample delivery system, the analytical column, or the FPD burner block can cause losses or interferences. This potential is eliminated by heating the probe, filter box, and connections, and by maintaining the SO
4.2 Carbon Monoxide (CO) and Carbon Dioxide (CO
4.3 Elemental Sulfur. The condensation of sulfur vapor in the sampling system can lead to blockage of the particulate filter. This problem can be minimized by observing the filter for buildup and changing as needed.
4.4 Sulfur Dioxide (SO
4.5 Alkali Mist. Alkali mist in the emissions of some control devices may cause a rapid increase in the SO
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test to establish appropriate safety and health practices and determine the applicability of regulatory limitations to performing this test.
6.1 Sample Collection. See Figure 15-1. The sampling train component parts are discussed in the following sections:
6.1.1 Probe. The probe shall be made of Teflon or Teflon-lined stainless steel and heated to prevent moisture condensation. It shall be designed to allow calibration gas to enter the probe at or near the sample point entry. Any portion of the probe that contacts the stack gas must be heated to prevent moisture condensation. The probe described in section 6.1.1 of Method 16A having a nozzle directed away from the gas stream is recommended for sources having particulate or mist emissions. Where very high stack temperatures prohibit the use of Teflon probe components, glass or quartz-lined probes may serve as substitutes.
6.1.2 Particulate Filter. 50-mm Teflon filter holder and a 1- to 2-micron porosity Teflon filter (available through Savillex Corporation, 5325 Highway 101, Minnetonka, Minnesota 55343). The filter holder must be maintained in a hot box at a temperature of at least 120 °C (248 °F).
6.1.3 SO
6.1.4 Sample Line. Teflon, no greater than 13-mm (
6.1.5 Sample Pump. The sample pump shall be a leakless Teflon-coated diaphragm type or equivalent.
6.2 Analysis. The following items are needed for sample analysis:
6.2.1 Dilution System. The dilution system must be constructed such that all sample contacts are made of Teflon, glass, or stainless steel. It must be capable of approximately a 9:1 dilution of the sample.
6.2.2 Gas Chromatograph (see Figure 15-2). The gas chromatograph must have at least the following components:
6.2.2.1 Oven. Capable of maintaining the separation column at the proper operating temperature ±1 °C.
6.2.2.2 Temperature Gauge. To monitor column oven, detector, and exhaust temperature ±1 °C.
6.2.2.3 Flow System. Gas metering system to measure sample, fuel, combustion gas, and carrier gas flows.
6.2.2.4 Flame Photometric Detector.
6.2.2.4.1 Electrometer. Capable of full scale amplification of linear ranges of 10
6.2.2.4.2 Power Supply. Capable of delivering up to 750 volts.
6.2.2.5 Recorder. Compatible with the output voltage range of the electrometer.
6.2.2.6 Rotary Gas Valves. Multiport Teflon-lined valves equipped with sample loop. Sample loop volumes shall be chosen to provide the needed analytical range. Teflon tubing and fittings shall be used throughout to present an inert surface for sample gas. The GC shall be calibrated with the sample loop used for sample analysis.
6.2.2.7 GC Columns. The column system must be demonstrated to be capable of resolving three major reduced sulfur compounds: H
6.3 Calibration System (See Figure 15-3). The calibration system must contain the following components:
6.3.1 Flow System. To measure air flow over permeation tubes within 2 percent. Each flowmeter shall be calibrated after each complete test series with a wet-test meter. If the flow measuring device differs from the wet-test meter by more than 5 percent, the completed test shall be discarded. Alternatively, use the flow data that will yield the lowest flow measurement. Calibration with a wet-test meter before a test is optional. Flow over the permeation device may also be determined using a soap bubble flowmeter.
6.3.2 Constant Temperature Bath. Device capable of maintaining the permeation tubes at the calibration temperature within 0.1 °C.
6.3.3 Temperature Sensor. Thermometer or equivalent to monitor bath temperature within 0.1 °C.
7.1 Fuel. Hydrogen gas (H
7.2 Combustion Gas. Oxygen (O
7.3 Carrier Gas. Prepurified grade or better.
7.4 Diluent. Air containing less than 0.5 ppmv total sulfur compounds and less than 10 ppmv each of moisture and total hydrocarbons.
7.5 Calibration Gases.
7.5.1 Permeation Devices. One each of H
7.5.2 Cylinder Gases. Cylinder gases may be used as alternatives to permeation devices. The gases must be traceable to a primary standard (such as permeation tubes) and not used beyond the certification expiration date.
7.6 Citrate Buffer. Dissolve 300 g of potassium citrate and 41 g of anhydrous citric acid in 1 liter of water. Alternatively, 284 g of sodium citrate may be substituted for the potassium citrate. Adjust the pH to between 5.4 and 5.6 with potassium citrate or citric acid, as required.
8.0 Sample Collection, Preservation, Transport, and Storage
8.1 Pretest Procedures. After the complete measurement system has been set up at the site and deemed to be operational, the following procedures should be completed before sampling is initiated. These procedures are not required, but would be helpful in preventing any problem which might occur later to invalidate the entire test.
8.1.1 Leak-Check. Appropriate leak-check procedures should be employed to verify the integrity of all components, sample lines, and connections. The following procedure is suggested: For components upstream of the sample pump, attach the probe end of the sample line to a manometer or vacuum gauge, start the pump and pull a vacuum greater than 50 mm (2 in.) Hg, close off the pump outlet, and then stop the pump and ascertain that there is no leak for 1 minute. For components after the pump, apply a slight positive pressure and check for leaks by applying a liquid (detergent in water, for example) at each joint. Bubbling indicates the presence of a leak. As an alternative to the initial leak-test, the sample line loss test described in section 8.3.1 may be performed to verify the integrity of components.
8.1.2 System Performance. Since the complete system is calibrated at the beginning and end of each day of testing, the precise calibration of each component is not critical. However, these components should be verified to operate properly. This verification can be performed by observing the response of flowmeters or of the GC output to changes in flow rates or calibration gas concentrations, respectively, and ascertaining the response to be within predicted limits. If any component or the complete system fails to respond in a normal and predictable manner, the source of the discrepancy should be identified and corrected before proceeding.
8.2 Sample Collection and Analysis
8.2.1 After performing the calibration procedures outlined in section 10.0, insert the sampling probe into the test port ensuring that no dilution air enters the stack through the port. Begin sampling and dilute the sample approximately 9:1 using the dilution system. Note that the precise dilution factor is the one determined in section 10.4. Condition the entire system with sample for a minimum of 15 minutes before beginning the analysis. Inject aliquots of the sample into the GC/FPD analyzer for analysis. Determine the concentration of each reduced sulfur compound directly from the calibration curves or from the equation for the least-squares line.
8.2.2 If reductions in sample concentrations are observed during a sample run that cannot be explained by process conditions, the sampling must be interrupted to determine if the probe or filter is clogged with particulate matter. If either is found to be clogged, the test must be stopped and the results up to that point discarded. Testing may resume after cleaning or replacing the probe and filter. After each run, the probe and filter shall be inspected and, if necessary, replaced.
8.2.3 A sample run is composed of 16 individual analyses (injects) performed over a period of not less than 3 hours or more than 6 hours.
8.3 Post-Test Procedures.
8.3.1 Sample Line Loss. A known concentration of H
8.3.2 Determination of Calibration Drift. After each run, or after a series of runs made within a 24-hour period, perform a partial recalibration using the procedures in section 10.0. Only H
| Section | Quality control measure | Effect |
|---|---|---|
| 8.3.1 | Sample line loss check | Ensures that uncorrected negative bias introduced by sample loss is no greater than 20 percent, and provides for correction of bias of 20 percent or less. |
| 8.3.2 | Calibration drift test | Ensures that bias introduced by drift in the measurement system output during the run is no greater than 5 percent. |
| 10.0 | Analytical calibration | Ensures precision of analytical results within 5 percent. |
Prior to any sampling run, calibrate the system using the following procedures. (If more than one run is performed during any 24-hour period, a calibration need not be performed prior to the second and any subsequent runs. However, the calibration drift must be determined as prescribed in section 8.3.2 after the last run is made within the 24-hour period.)
This section outlines steps to be followed for use of the GC/FPD and the dilution system. The calibration procedure does not include detailed instructions because the operation of these systems is complex, and it requires an understanding of the individual system being used. Each system should include a written operating manual describing in detail the operating procedures associated with each component in the measurement system. In addition, the operator should be familiar with the operating principles of the components, particularly the GC/FPD. The references in section 16.0 are recommended for review for this purpose.
10.1 Calibration Gas Permeation Tube Preparation.
10.1.1 Insert the permeation tubes into the tube chamber. Check the bath temperature to assure agreement with the calibration temperature of the tubes within 0.1 °C. Allow 24 hours for the tubes to equilibrate. Alternatively, equilibration may be verified by injecting samples of calibration gas at 1-hour intervals. The permeation tubes can be assumed to have reached equilibrium when consecutive hourly samples agree within 5 percent of their mean.
10.1.2 Vary the amount of air flowing over the tubes to produce the desired concentrations for calibrating the analytical and dilution systems. The air flow across the tubes must at all times exceed the flow requirement of the analytical systems. The concentration in ppmv generated by a tube containing a specific permeant can be calculated using Equation 15-1 in section 12.2.
10.2 Calibration of Analytical System. Generate a series of three or more known concentrations spanning the linear range of the FPD (approximately 0.5 to 10 ppmv for a 1-ml sample) for each of the three major sulfur compounds. Bypassing the dilution system, inject these standards into the GC/FPD and monitor the responses until three consecutive injections for each concentration agree within 5 percent of their mean. Failure to attain this precision indicates a problem in the calibration or analytical system. Any such problem must be identified and corrected before proceeding.
10.3 Calibration Curves. Plot the GC/FPD response in current (amperes) versus their causative concentrations in ppmv on log-log coordinate graph paper for each sulfur compound. Alternatively, a least-squares equation may be generated from the calibration data using concentrations versus the appropriate instrument response units.
10.4 Calibration of Dilution System. Generate a known concentration of H
Sample collection and analysis are concurrent for this method (see section 8.0).
12.1 Nomenclature.
12.2 Permeant Concentration. Calculate the concentration generated by a tube containing a specific permeant (see section 10.1) using the following equation:
12.3 Calculation of SO
12.4 Average SO
13.1 Range. Coupled with a GC system using a 1-ml sample size, the maximum limit of the FPD for each sulfur compound is approximately 10 ppmv. It may be necessary to dilute samples from sulfur recovery plants a hundredfold (99:1), resulting in an upper limit of about 1000 ppmv for each compound.
13.2 Sensitivity. The minimum detectable concentration of the FPD is also dependent on sample size and would be about 0.5 ppmv for a 1-ml sample.
13.3 Calibration Precision. A series of three consecutive injections of the same calibration gas, at any dilution, shall produce results which do not vary by more than 5 percent from the mean of the three injections.
13.4 Calibration Drift. The calibration drift determined from the mean of three injections made at the beginning and end of any run or series of runs within a 24-hour period shall not exceed 5 percent.
1. O’Keeffe, A.E., and G.C. Ortman. “Primary Standards for Trace Gas Analysis.” Anal. Chem. 38,760. 1966.
2. Stevens, R.K., A.E. O’Keeffe, and G.C. Ortman. “Absolute Calibration of a Flame Photometric Detector to Volatile Sulfur Compounds at Sub-Part-Per-Million Levels.” Environmental Science and Technology 3:7. July 1969.
3. Mulik, J.D., R.K. Stevens, and R. Baumgardner. “An Analytical System Designed to Measure Multiple Malodorous Compounds Related to Kraft Mill Activities.” Presented at the 12th Conference on Methods in Air Pollution and Industrial Hygiene Studies, University of Southern California, Los Angeles, CA, April 6-8, 1971.
4. Devonald, R.H., R.S. Serenius, and A.D. McIntyre. “Evaluation of the Flame Photometric Detector for Analysis of Sulfur Compounds.” Pulp and Paper Magazine of Canada, 73,3. March 1972.
5. Grimley, K.W., W.S. Smith, and R.M. Martin. “The Use of a Dynamic Dilution System in the Conditioning of Stack Gases for Automated Analysis by a Mobile Sampling Van.” Presented at the 63rd Annual APCA Meeting in St. Louis, MO. June 14-19, 1970.
6. General Reference. Standard Methods of Chemical Analysis Volume III-A and III-B: Instrumental Analysis. Sixth Edition. Van Nostrand Reinhold Co.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 6, Method 15, and Method 16A.
1.1 Analytes.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Reduced sulfur compounds | None assigned | Not determined. |
1.2 Applicability. This method is applicable for the determination of emissions of reduced sulfur compounds from sulfur recovery plants where the emissions are in a reducing atmosphere, such as in Stretford units.
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 An integrated gas sample is extracted from the stack, and combustion air is added to the oxygen (O
4.1 Reduced sulfur compounds, other than CS
4.2 Calcium and aluminum have been shown to interfere in the Method 6 titration procedure. Since these metals have been identified in particulate matter emissions from Stretford units, a Teflon filter is required to minimize this interference.
4.3 Dilution of the hydrogen peroxide (H
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method.
5.2 Corrosive reagents. The following reagents are hazardous. Personal protective equipment and safe procedures are useful in preventing chemical splashes. If contact occurs, immediately flush with copious amounts of water for at least 15 minutes. Remove clothing under shower and decontaminate. Treat residual chemical burns as thermal burns.
5.2.1 Hydrogen Peroxide (H
5.2.2 Sodium Hydroxide (NaOH). Causes severe damage to eyes and skin. Inhalation causes irritation to nose, throat, and lungs. Reacts exothermically with limited amounts of water.
5.2.3 Sulfuric Acid (H
6.1 Sample Collection. The sampling train used in performing this method is shown in Figure 15A-1, and component parts are discussed below. Modifications to this sampling train are acceptable provided that the system performance check is met.
6.1.1 Probe. 6.4-mm (
6.1.2 Particulate Filter. A 50-mm Teflon filter holder and a 1- to 2-mm porosity Teflon filter (available through Savillex Corporation, 5325 Highway 101, Minnetonka, Minnesota 55345). The filter holder must be maintained in a hot box at a temperature high enough to prevent condensation.
6.1.3 Combustion Air Delivery System. As shown in the schematic diagram in Figure 15A-3. The rate meter should be selected to measure an air flow rate of 0.5 liter/min (0.02 ft
6.1.4 Combustion Tube. Quartz glass tubing with an expanded combustion chamber 2.54 cm (1 in.) in diameter and at least 30.5 cm (12 in.) long. The tube ends should have an outside diameter of 0.6 cm (
6.1.5 Furnace. Of sufficient size to enclose the combustion tube. The furnace must have a temperature regulator capable of maintaining the temperature at 1100 ±50 °C (2,012 ±90 °F). The furnace operating temperature must be checked with a thermocouple to ensure accuracy. Lindberg furnaces have been found to be satisfactory.
6.1.6 Peroxide Impingers, Stopcock Grease, Temperature Sensor, Drying Tube, Valve, Pump, and Barometer. Same as in Method 6, sections 6.1.1.2, 6.1.1.4, 6.1.1.5, 6.1.1.6, 6.1.1.7, 6.1.1.8, and 6.1.2, respectively, except that the midget bubbler of Method 6, section 6.1.1.2 is not required.
6.1.7 Vacuum Gauge and Rate Meter. At least 760 mm Hg (30 in. Hg) gauge and rotameter, or equivalent, capable of measuring flow rate to ±5 percent of the selected flow rate and calibrated as in section 10.2.
6.1.8 Volume Meter. Dry gas meter capable of measuring the sample volume under the particular sampling conditions with an accuracy of 2 percent.
6.1.9 U-tube manometer. To measure the pressure at the exit of the combustion gas dry gas meter.
6.2 Sample Recovery and Analysis. Same as Method 6, sections 6.2 and 6.3, except a 10-ml buret with 0.05-ml graduations is required for titrant volumes of less than 10.0 ml, and the spectrophotometer is not needed.
Unless otherwise indicated, all reagents must conform to the specifications established by the Committee on Analytical Reagents of the American Chemical Society. When such specifications are not available, the best available grade shall be used.
7.1 Sample Collection. The following reagents and standards are required for sample analysis:
7.1.1 Water. Same as Method 6, section 7.1.1.
7.1.2 Hydrogen Peroxide (H
7.1.3 Recovery Check Gas. Carbonyl sulfide in nitrogen [100 parts per million by volume (ppmv) or greater, if necessary] in an aluminum cylinder. Concentration certified by the manufacturer with an accuracy of ±2 percent or better, or verified by gas chromatography where the instrument is calibrated with a COS permeation tube.
7.1.4 Combustion Gas. Air, contained in a gas cylinder equipped with a two-stage regulator. The gas shall contain less than 50 ppb of reduced sulfur compounds and less than 10 ppm total hydrocarbons.
7.2 Sample Recovery and Analysis. Same as Method 6, sections 7.2 and 7.3.
8.1 Preparation of Sampling Train. For the Method 6 part of the train, measure 20 ml of 3 percent H
8.2 Leak-Check Procedure. Assemble the sampling train and leak-check as described in Method 6, section 8.2. Include the combustion air delivery system from the needle valve forward in the leak-check.
8.3 Sample Collection. Adjust the pressure on the second stage of the regulator on the combustion air cylinder to 10 psig. Adjust the combustion air flow rate to 0.5 ±0.05 L/min (1.1 ±0.1 ft
In Method 15, a test run is composed of 16 individual analyses (injects) performed over a period of not less than 3 hours or more than 6 hours. For Method 15A to be consistent with Method 15, the following may be used to obtain a test run: (1) Collect three 60-minute samples or (2) collect one 3-hour sample. (Three test runs constitute a test.)
8.4 Sample Recovery. Recover the hydrogen peroxide-containing impingers as detailed in Method 6, section 8.4.
8.5 System Performance Check.
8.5.1 A system performance check is done (1) to validate the sampling train components and procedure (before testing, optional) and (2) to validate a test run (after a run, mandatory). Perform a check in the field before testing consisting of at least two samples (optional), and perform an additional check after each 3-hour run or after three 1-hour samples (mandatory).
8.5.2 The checks involve sampling a known concentration of COS and comparing the analyzed concentration with the known concentration. Mix the recovery gas with N
8.5.3 The recovery check must be performed in the field before replacing the particulate filter and before cleaning the probe. A sample recovery of 100 ±20 percent must be obtained for the data to be valid and should be reported with the emission data, but should not be used to correct the data. However, if the performance check results do not affect the compliance or noncompliance status of the affected facility, the Administrator may decide to accept the results of the compliance test. Use Equation 15A-5 (see section 12.6) to calculate the recovery efficiency.
| Section | Quality control measure | Effect |
|---|---|---|
| 8.5 | System performance check | Ensures validity of sampling train components and analytical procedure. |
| 8.2, 10.0 | Sampling equipment leak-check and calibration | Ensures accurate measurement of stack gas flow rate, sample volume. |
| 10.0 | Barium standard solution standardization | Ensures precision of normality determination. |
| 11.1 | Replicate titrations | Ensures precision of titration determinations. |
10.1 Metering System, Temperature Sensors, Barometer, and Barium Perchlorate Solution. Same as Method 6, sections 10.1, 10.2, 10.4, and 10.5, respectively.
10.2 Rate Meter. Calibrate with a bubble flow tube.
11.1 Sample Loss Check and Sample Analysis. Same as Method 6, sections 11.1 and 11.2.
In the calculations, retain at least one extra decimal figure beyond that of the acquired data. Round off figures after final calculations.
12.1 Nomenclature.
12.2 Dry Sample Gas Volume, Corrected to Standard Conditions.
12.3 Combustion Air Gas Volume, corrected to Standard Conditions.
Correct P
12.4 Concentration of reduced sulfur compounds as ppm SO
12.5 Concentration of Generated Recovery Gas.
12.6 Recovery Efficiency for the System Performance Check.
13.1 Analytical Range. The lower detectable limit is 0.1 ppmv when sampling at 2 lpm for 3 hours or 0.3 ppmv when sampling at 2 lpm for 1 hour. The upper concentration limit of the method exceeds concentrations of reduced sulfur compounds generally encountered in sulfur recovery plants.
13.2 Precision. Relative standard deviations of 2.8 and 6.9 percent have been obtained when sampling a stream with a reduced sulfur compound concentration of 41 ppmv as SO
13.3 Bias. No analytical bias has been identified. However, results obtained with this method are likely to contain a positive bias relative to emission regulations due to the presence of nonregulated sulfur compounds (that are present in petroleum) in the emissions. The magnitude of this bias varies accordingly, and has not been quantified.
1. American Society for Testing and Materials Annual Book of ASTM Standards. Part 31: Water, Atmospheric Analysis. Philadelphia, Pennsylvania. 1974. pp. 40-42.
2. Blosser, R.O., H.S. Oglesby, and A.K. Jain. A Study of Alternate SO
3. Curtis, F., and G.D. McAlister. Development and Evaluation of an Oxidation/Method 6 TRS Emission Sampling Procedure. Emission Measurement Branch, Emission Standards and Engineering Division, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina. February 1980.
4. Gellman, I. A Laboratory and Field Study of Reduced Sulfur Sampling and Monitoring Systems. National Council of the Paper Industry for Air and Stream Improvement, Inc., New York, New York. Atmospheric Quality Improvement Technical Bulletin No. 81. October 1975.
5. Margeson, J.H., et al. A Manual Method for TRS Determination. Journal of Air Pollution Control Association. 35:1280-1286. December 1985.
Appendix A-6 to Part 60 – Test Methods 16 through 18
The test methods in this appendix are referred to in § 60.8 (Performance Tests) and § 60.11 (Compliance With Standards and Maintenance Requirements) of 40 CFR part 60, subpart A (General Provisions). Specific uses of these test methods are described in the standards of performance contained in the subparts, beginning with Subpart D.
Within each standard of performance, a section title “Test Methods and Procedures” is provided to: (1) Identify the test methods to be used as reference methods to the facility subject to the respective standard and (2) identify any special instructions or conditions to be followed when applying a method to the respective facility. Such instructions (for example, establish sampling rates, volumes, or temperatures) are to be used either in addition to, or as a substitute for procedures in a test method. Similarly, for sources subject to emission monitoring requirements, specific instructions pertaining to any use of a test method as a reference method are provided in the subpart or in Appendix B.
Inclusion of methods in this appendix is not intended as an endorsement or denial of their applicability to sources that are not subject to standards of performance. The methods are potentially applicable to other sources; however, applicability should be confirmed by careful and appropriate evaluation of the conditions prevalent at such sources.
The approach followed in the formulation of the test methods involves specifications for equipment, procedures, and performance. In concept, a performance specification approach would be preferable in all methods because this allows the greatest flexibility to the user. In practice, however, this approach is impractical in most cases because performance specifications cannot be established. Most of the methods described herein, therefore, involve specific equipment specifications and procedures, and only a few methods in this appendix rely on performance criteria.
Minor changes in the test methods should not necessarily affect the validity of the results and it is recognized that alternative and equivalent methods exist. section 60.8 provides authority for the Administrator to specify or approve (1) equivalent methods, (2) alternative methods, and (3) minor changes in the methodology of the test methods. It should be clearly understood that unless otherwise identified all such methods and changes must have prior approval of the Administrator. An owner employing such methods or deviations from the test methods without obtaining prior approval does so at the risk of subsequent disapproval and retesting with approved methods.
Within the test methods, certain specific equipment or procedures are recognized as being acceptable or potentially acceptable and are specifically identified in the methods. The items identified as acceptable options may be used without approval but must be identified in the test report. The potentially approvable options are cited as “subject to the approval of the Administrator” or as “or equivalent.” Such potentially approvable techniques or alternatives may be used at the discretion of the owner without prior approval. However, detailed descriptions for applying these potentially approvable techniques or alternatives are not provided in the test methods. Also, the potentially approvable options are not necessarily acceptable in all applications. Therefore, an owner electing to use such potentially approvable techniques or alternatives is responsible for: (1) assuring that the techniques or alternatives are in fact applicable and are properly executed; (2) including a written description of the alternative method in the test report (the written method must be clear and must be capable of being performed without additional instruction, and the degree of detail should be similar to the detail contained in the test methods); and (3) providing any rationale or supporting data necessary to show the validity of the alternative in the particular application. Failure to meet these requirements can result in the Administrator’s disapproval of the alternative.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 4, Method 15, and Method 16A.
1.1 Analytes.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Dimethyl disulfide [(CH | 62-49-20 | 50 ppb. |
| Dimethyl sulfide [(CH | 75-18-3 | 50 ppb. |
| Hydrogen sulfide [H | 7783-06-4 | 50 ppb. |
| Methyl mercaptan [CH | 74-93-1 | 50 ppb. |
1.2 Applicability. This method is applicable for the determination of total reduced sulfur (TRS) compounds from recovery furnaces, lime kilns, and smelt dissolving tanks at kraft pulp mills and fuel gas combustion devices at petroleum refineries.
The method described below uses the principle of gas chromatographic (GC) separation and flame photometric detection (FPD). Since there are many systems or sets of operating conditions that represent useable methods of determining sulfur emissions, all systems which employ this principle, but differ only in details of equipment and operation, may be used as alternative methods, provided that the calibration precision and sample line loss criteria are met.
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 A gas sample is extracted from the emission source and an aliquot is analyzed for hydrogen sulfide (H
4.1 Moisture. Moisture condensation in the sample delivery system, the analytical column, or the FPD burner block can cause losses or interferences. This is prevented by maintaining the probe, filter box, and connections at a temperature of at least 120 °C (248 °F). Moisture is removed in the SO
4.2 Carbon Monoxide (CO) and Carbon Dioxide (CO
4.3 Particulate Matter. Particulate matter in gas samples can cause interference by eventual clogging of the analytical system. This interference is eliminated by using the Teflon filter after the probe.
4.4 Sulfur Dioxide (SO
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method.
5.2 Hydrogen Sulfide. A flammable, poisonous gas with the odor of rotten eggs. H
6.1. Sample Collection. The following items are needed for sample collection.
6.1.1 Probe. Teflon or Teflon-lined stainless steel. The probe must be heated to prevent moisture condensation. It must be designed to allow calibration gas to enter the probe at or near the sample point entry. Any portion of the probe that contacts the stack gas must be heated to prevent moisture condensation. Figure 16-1 illustrates the probe used in lime kilns and other sources where significant amounts of particulate matter are present. The probe is designed with the deflector shield placed between the sample and the gas inlet holes to reduce clogging of the filter and possible adsorption of sample gas. As an alternative, the probe described in section 6.1.1 of Method 16A having a nozzle directed away from the gas stream may be used at sources having significant amounts of particulate matter.
6.1.2 Particulate Filter. 50-mm Teflon filter holder and a 1- to 2-micron porosity Teflon filter (available through Savillex Corporation, 5325 Highway 101, Minnetonka, Minnesota 55343). The filter holder must be maintained in a hot box at a temperature of at least 120 °C (248 °F).
6.1.3 SO
6.1.4 Sample Line. Teflon, no greater than 1.3 cm (
6.1.5 Sample Pump. The sample pump must be a leakless Teflon-coated diaphragm type or equivalent.
6.2 Analysis. The following items are needed for sample analysis:
6.2.1 Dilution System. Needed only for high sample concentrations. The dilution system must be constructed such that all sample contacts are made of Teflon, glass, or stainless steel.
6.2.2 Gas Chromatograph. The gas chromatograph must have at least the following components:
6.2.2.1 Oven. Capable of maintaining the separation column at the proper operating temperature ±1 °C (2 °F).
6.2.2.2 Temperature Gauge. To monitor column oven, detector, and exhaust temperature ±1 °C (2 °F).
6.2.2.3 Flow System. Gas metering system to measure sample, fuel, combustion gas, and carrier gas flows.
6.2.2.4 Flame Photometric Detector.
6.2.2.4.1 Electrometer. Capable of full scale amplification of linear ranges of 10
6.2.2.4.2 Power Supply. Capable of delivering up to 750 volts.
6.2.2.4.3 Recorder. Compatible with the output voltage range of the electrometer.
6.2.2.4.4 Rotary Gas Valves. Multiport Teflon-lined valves equipped with sample loop. Sample loop volumes must be chosen to provide the needed analytical range. Teflon tubing and fittings must be used throughout to present an inert surface for sample gas. The gas chromatograph must be calibrated with the sample loop used for sample analysis.
6.2.3 Gas Chromatogram Columns. The column system must be demonstrated to be capable of resolving the four major reduced sulfur compounds: H
6.3 Calibration. A calibration system, containing the following components, is required (see Figure 16-2).
6.3.1 Tube Chamber. Chamber of glass or Teflon of sufficient dimensions to house permeation tubes.
6.3.2 Flow System. To measure air flow over permeation tubes at ±2 percent. Flow over the permeation device may also be determined using a soap bubble flowmeter.
6.3.3 Constant Temperature Bath. Device capable of maintaining the permeation tubes at the calibration temperature within 0.1 °C (0.2 °F).
6.3.4 Temperature Gauge. Thermometer or equivalent to monitor bath temperature within 1 °C (2 °F).
7.1 Fuel. Hydrogen (H
7.2 Combustion Gas. Oxygen (O
7.3 Carrier Gas. Prepurified grade or better.
7.4 Diluent (if required). Air containing less than 50 ppb total sulfur compounds and less than 10 ppmv each of moisture and total hydrocarbons.
7.5 Calibration Gases
7.5.1 Permeation tubes, one each of H
7.5.2 Cylinder Gases. Cylinder gases may be used as alternatives to permeation devices. The gases must be traceable to a primary standard (such as permeation tubes) and not used beyond the certification expiration date.
7.6 Citrate Buffer and Sample Line Loss Gas. Same as Method 15, sections 7.6 and 7.7.
Same as Method 15, section 8.0, except that the references to the dilution system may not be applicable.
| Section | Quality control measure | Effect |
|---|---|---|
| 8.0 | Sample line loss check | Ensures that uncorrected negative bias introduced by sample loss is no greater than 20 percent, and provides for correction of bias of 20 percent or less. |
| 8.0 | Calibration drift test | Ensures that bias introduced by drift in the measurement system output during the run is no greater than 5 percent. |
| 10.0 | Analytical calibration | Ensures precision of analytical results within 5 percent. |
Same as Method 15, section 10.0, with the following addition and exceptions:
10.1 Use the four compounds that comprise TRS instead of the three reduced sulfur compounds measured by Method 15.
10.2 Flow Meter. Calibration before each test run is recommended, but not required; calibration following each test series is mandatory. Calibrate each flow meter after each complete test series with a wet-test meter. If the flow measuring device differs from the wet-test meter by 5 percent or more, the completed test runs must be voided. Alternatively, the flow data that yield the lower flow measurement may be used. Flow over the permeation device may also be determined using a soap bubble flowmeter.
Sample collection and analysis are concurrent for this method (see section 8.0).
12.1 Concentration of Reduced Sulfur Compounds. Calculate the average concentration of each of the four analytes (i.e., DMDS, DMS, H
12.2 TRS Concentration. Using Equation 16-2, calculate the TRS concentration for each sample run.
12.3 Average TRS Concentration. Calculate the average TRS concentration for all sample runs performed.
13.1 Analytical Range. The analytical range will vary with the sample loop size. Typically, the analytical range may extend from 0.1 to 100 ppmv using 10- to 0.1-ml sample loop sizes. This eliminates the need for sample dilution in most cases.
13.2 Sensitivity. Using the 10-ml sample size, the minimum detectable concentration is approximately 50 ppb.
1. O’Keeffe, A.E., and G.C. Ortman. “Primary Standards for Trace Gas Analysis.” Analytical Chemical Journal, 38,76. 1966.
2. Stevens, R.K., A.E. O’Keeffe, and G.C. Ortman. “Absolute Calibration of a Flame Photometric Detector to Volatile Sulfur Compounds at Sub-Part-Per-Million Levels.” Environmental Science and Technology, 3:7. July 1969.
3. Mulik, J.D., R.K. Stevens, and R. Baumgardner. “An Analytical System Designed to Measure Multiple Malodorous Compounds Related to Kraft Mill Activities.” Presented at the 12th Conference on Methods in Air Pollution and Industrial Hygiene Studies, University of Southern California, Los Angeles, CA. April 6-8, 1971.
4. Devonald, R.H., R.S. Serenius, and A.D. McIntyre. “Evaluation of the Flame Photometric Detector for Analysis of Sulfur Compounds.” Pulp and Paper Magazine of Canada, 73,3. March 1972.
5. Grimley, K.W., W.S. Smith, and R.M. Martin. “The Use of a Dynamic Dilution System in the Conditioning of Stack Gases for Automated Analysis by a Mobile Sampling Van.” Presented at the 63rd Annual APCA Meeting, St. Louis, MO. June 14-19, 1970.
6. General Reference. Standard Methods of Chemical Analysis, Volumes III-A and III-B Instrumental Methods. Sixth Edition. Van Nostrand Reinhold Co.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 6, and Method 16.
1.1 Analytes.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Total reduced sulfur (TRS) including: | N/A | See section 13.1. |
| Dimethyl disulfide [(CH | 62-49-20 | |
| Dimethyl sulfide [(CH | 75-18-3 | |
| Hydrogen sulfide [H | 7783-06-4 | |
| Methyl mercaptan [CH | 74-93-1 | |
| Reduced sulfur (RS) including: | N/A | |
| H | 7783-06-4 | |
| Carbonyl sulfide [COS] | 463-58-1 | |
| Carbon disulfide [CS | 75-15-0 | |
| Reported as: Sulfur dioxide (SO | 7449-09-5 |
1.2 Applicability. This method is applicable for the determination of TRS emissions from recovery boilers, lime kilns, and smelt dissolving tanks at kraft pulp mills, reduced sulfur compounds (H
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 An integrated gas sample is extracted from the stack. SO
4.1 Reduced sulfur compounds other than those regulated by the emission standards, if present, may be measured by this method. Therefore, carbonyl sulfide, which is partially oxidized to SO
4.2 Particulate matter from the lime kiln stack gas (primarily calcium carbonate) can cause a negative bias if it is allowed to enter the citrate scrubber; the particulate matter will cause the pH to rise and H
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method.
5.2 Corrosive reagents. The following reagents are hazardous. Personal protective equipment and safe procedures are useful in preventing chemical splashes. If contact occurs, immediately flush with copious amounts of water for at least 15 minutes. Remove clothing under shower and decontaminate. Treat residual chemical burns as thermal burns.
5.2.1 Hydrogen Peroxide (H
5.2.2 Sodium Hydroxide (NaOH). Causes severe damage to eyes and skin. Inhalation causes irritation to nose, throat, and lungs. Reacts exothermically with limited amounts of water.
5.2.3 Sulfuric Acid (H
5.3 Hydrogen Sulfide (H
6.1 Sample Collection. The sampling train is shown in Figure 16A-1 and component parts are discussed below. Modifications to this sampling train are acceptable provided the system performance check is met (see section 8.5).
6.1.1 Probe. Teflon tubing, 6.4-mm (
6.1.2 Probe Brush. Nylon bristle brush with handle inserted into a 3.2-mm (
6.1.3 Particulate Filter. 50-mm Teflon filter holder and a 1- to 2-µm porosity, Teflon filter (available through Savillex Corporation, 5325 Highway 101, Minnetonka, Minnesota 55343). The filter holder must be maintained in a hot box at a temperature sufficient to prevent moisture condensation. A temperature of 121 °C (250 °F) was found to be sufficient when testing a lime kiln under sub-freezing ambient conditions.
6.1.4 SO
6.1.5 Combustion Tube. Quartz glass tubing with an expanded combustion chamber 2.54 cm (1 in.) in diameter and at least 30.5 cm (12 in.) long. The tube ends should have an outside diameter of 0.6 cm (
6.1.6 Furnace. A furnace of sufficient size to enclose the combustion chamber of the combustion tube with a temperature regulator capable of maintaining the temperature at 800 ±100 °C (1472 ±180 °F). The furnace operating temperature should be checked with a thermocouple to ensure accuracy.
6.1.7 Peroxide Impingers, Stopcock Grease, Temperature Sensor, Drying Tube, Valve, Pump, and Barometer. Same as Method 6, sections 6.1.1.2, 6.1.1.4, 6.1.1.5, 6.1.1.6, 6.1.1.7, 6.1.1.8, and 6.1.2, respectively, except that the midget bubbler of Method 6, section 6.1.1.2 is not required.
6.1.8 Vacuum Gauge. At least 760 mm Hg (30 in. Hg) gauge.
6.1.9 Rate Meter. Rotameter, or equivalent, accurate to within 5 percent at the selected flow rate of approximately 2 liters/min (4.2 ft
6.1.10 Volume Meter. Dry gas meter capable of measuring the sample volume under the sampling conditions of 2 liters/min (4.2 ft
6.2 Sample Recovery. Polyethylene Bottles, 250-ml (one per sample).
6.3 Sample Preparation and Analysis. Same as Method 6, section 6.3, except a 10-ml buret with 0.05-ml graduations is required, and the spectrophotometer is not needed.
Unless otherwise indicated, all reagents must conform to the specifications established by the Committee on Analytical Reagents of the American Chemical Society. When such specifications are not available, the best available grade must be used.
7.1 Sample Collection. The following reagents are required for sample analysis:
7.1.1 Water. Same as in Method 6, section 7.1.1.
7.1.2 Citrate Buffer. Dissolve 300 g of potassium citrate (or 284 g of sodium citrate) and 41 g of anhydrous citric acid in 1 liter of water (200 ml is needed per test). Adjust the pH to between 5.4 and 5.6 with potassium citrate or citric acid, as required.
7.1.3 Hydrogen Peroxide, 3 percent. Same as in Method 6, section 7.1.3 (40 ml is needed per sample).
7.1.4 Recovery Check Gas. Hydrogen sulfide (100 ppmv or less) in nitrogen, stored in aluminum cylinders. Verify the concentration by Method 11 or by gas chromatography where the instrument is calibrated with an H
Alternatively, hydrogen sulfide recovery gas generated from a permeation device gravimetrically calibrated and certified at some convenient operating temperature may be used. The permeation rate of the device must be such that at a dilution gas flow rate of 3 liters/min (6.4 ft
7.1.5 Combustion Gas. Gas containing less than 50 ppb reduced sulfur compounds and less than 10 ppmv total hydrocarbons. The gas may be generated from a clean-air system that purifies ambient air and consists of the following components: Diaphragm pump, silica gel drying tube, activated charcoal tube, and flow rate measuring device. Flow from a compressed air cylinder is also acceptable.
7.2 Sample Recovery and Analysis. Same as Method 6, sections 7.2.1 and 7.3, respectively.
8.1 Preparation of Sampling Train.
8.1.1 For the SO
8.1.2 For the Method 6 part of the train, measure 20 ml of 3 percent hydrogen peroxide into the first and second midget impingers. Leave the third midget impinger empty, and place silica gel in the fourth midget impinger. Alternatively, a silica gel drying tube may be used in place of the fourth impinger. Maintain the oxidation furnace at 800 ±100 °C (1472 ±180 °F). Place crushed ice and water around all impingers.
8.2 Citrate Scrubber Conditioning Procedure. Condition the citrate buffer scrubbing solution by pulling stack gas through the Teflon impingers and bypassing all other sampling train components. A purge rate of 2 liters/min for 10 minutes has been found to be sufficient to obtain equilibrium. After the citrate scrubber has been conditioned, assemble the sampling train, and conduct (optional) a leak-check as described in Method 6, section 8.2.
8.3 Sample Collection. Same as in Method 6, section 8.3, except the sampling rate is 2 liters/min (±10 percent) for 1 or 3 hours. After the sample is collected, remove the probe from the stack, and conduct (mandatory) a post-test leak-check as described in Method 6, section 8.2. The 15-minute purge of the train following collection should not be performed. After each 3-hour test run (or after three 1-hour samples), conduct one system performance check (see section 8.5) to determine the reduced sulfur recovery efficiency through the sampling train. After this system performance check and before the next test run, rinse and brush the probe with water, replace the filter, and change the citrate scrubber (optional but recommended).
In Method 16, a test run is composed of 16 individual analyses (injects) performed over a period of not less than 3 hours or more than 6 hours. For Method 16A to be consistent with Method 16, the following may be used to obtain a test run: (1) collect three 60-minute samples or (2) collect one 3-hour sample. (Three test runs constitute a test.)
8.4 Sample Recovery. Disconnect the impingers. Quantitatively transfer the contents of the midget impingers of the Method 6 part of the train into a leak-free polyethylene bottle for shipment. Rinse the three midget impingers and the connecting tubes with water and add the washings to the same storage container. Mark the fluid level. Seal and identify the sample container.
8.5 System Performance Check.
8.5.1 A system performance check is done (1) to validate the sampling train components and procedure (prior to testing; optional) and (2) to validate a test run (after a run). Perform a check in the field prior to testing consisting of at least two samples (optional), and perform an additional check after each 3 hour run or after three 1-hour samples (mandatory).
8.5.2 The checks involve sampling a known concentration of H
8.5.3 Collect 30-minute samples, and analyze in the same manner as the emission samples. Collect the sample through the probe of the sampling train using a manifold or some other suitable device that will ensure extraction of a representative sample.
8.5.4 The recovery check must be performed in the field prior to replacing the SO
| Section | Quality control measure | Effect |
|---|---|---|
| 8.5 | System performance check | Ensure validity of sampling train components and analytical procedure. |
| 8.2, 10.0 | Sampling equipment leak-check and calibration | Ensure accurate measurement of stack gas flow rate, sample volume. |
| 10.0 | Barium standard solution standardization | Ensure precision of normality determination. |
| 11.1 | Replicate titrations | Ensure precision of titration determinations. |
Same as Method 6, section 10.0.
11.1 Sample Loss Check and Sample Analysis. Same as Method 6, sections 11.1 and 11.2, respectively, with the following exception: for 1-hour sampling, take a 40-ml aliquot, add 160 ml of 100 percent isopropanol and four drops of thorin.
In the calculations, at least one extra decimal figure should be retained beyond that of the acquired data. Figures should be rounded off after final calculations.
12.1 Nomenclature.
12.2 Dry Sample Gas Volume, Corrected to Standard Conditions.
12.3 Concentration of TRS as ppm SO
12.4 Concentration of Recovery Gas Generated in the System Performance Check.
12.5 Recovery Efficiency for the System Performance Check.
13.1 Analytical Range. The lower detectable limit is 0.1 ppmv SO
13.2 Precision. Relative standard deviations of 2.0 and 2.6 percent were obtained when sampling a recovery boiler for 1 and 3 hours, respectively.
13.3 Bias.
13.3.1 No bias was found in Method 16A relative to Method 16 in a separate study at a recovery boiler.
13.3.2 Comparison of Method 16A with Method 16 at a lime kiln indicated that there was no bias in Method 16A. However, instability of the source emissions adversely affected the comparison. The precision of Method 16A at the lime kiln was similar to that obtained at the recovery boiler (Section 13.2.1).
13.3.3 Relative standard deviations of 2.7 and 7.7 percent have been obtained for system performance checks.
As an alternative to the procedures specified in section 7.1.4, the following procedure may be used to verify the H
16.1 Summary. The H
16.2 Range. The procedure has been examined in the range of 5 to 1500 ppmv.
16.3 Interferences. There are no known interferences to this procedure when used to analyze cylinder gases containing H
16.4 Precision and Bias. Laboratory tests have shown a relative standard deviation of less than 3 percent. The procedure showed no bias when compared to a gas chromatographic method that used gravimetrically certified permeation tubes for calibration.
16.5 Equipment and Supplies.
16.5.1 Sampling Apparatus. The sampling train is shown in Figure 16A-4. Its component parts are discussed in sections 16.5.1.1 through 16.5.2.
16.5.1.1 Sampling Line. Teflon tubing (
16.5.1.2 Needle Valve. Stainless steel or Teflon needle valve to control the flow rate of gases to the impingers.
16.5.1.3 Impingers. Three impingers of approximately 100-ml capacity, constructed to permit the addition of reagents through the gas inlet stem. The impingers shall be connected in series with leak-free glass or Teflon connectors. The impinger bottoms have a standard 24/25 ground-glass fitting. The stems are from standard 6.4-mm (
16.5.1.4 Drying Tube, Rate Meter, and Barometer. Same as Method 11, sections 6.1.5, 6.1.8, and 6.1.10, respectively.
16.5.1.5 Cylinder Gas Regulator. Stainless steel, to reduce the pressure of the gas stream entering the Teflon sampling line to a safe level.
16.5.1.6 Soap Bubble Meter. Calibrated for 100 and 500 ml, or two separate bubble meters.
16.5.1.7 Critical Orifice. For volume and rate measurements. The critical orifice may be fabricated according to section 16.7.3 and must be calibrated as specified in section 16.12.4.
16.5.1.8 Graduated Cylinder. 50-ml size.
16.5.1.9 Volumetric Flask. 1-liter size.
16.5.1.10 Volumetric Pipette. 15-ml size.
16.5.1.11 Vacuum Gauge. Minimum 20 in. Hg capacity.
16.5.1.12 Stopwatch.
16.5.2 Sample Recovery and Analysis.
16.5.2.1 Erlenmeyer Flasks. 125- and 250-ml sizes.
16.5.2.2 Pipettes. 2-, 10-, 20-, and 100-ml volumetric.
16.5.2.3 Burette. 50-ml size.
16.5.2.4 Volumetric Flask. 1-liter size.
16.5.2.5 Graduated Cylinder. 50-ml size.
16.5.2.6 Wash Bottle.
16.5.2.7 Stirring Plate and Bars.
16.6 Reagents and Standards. Unless otherwise indicated, all reagents must conform to the specifications established by the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available. Otherwise, use the best available grade.
16.6.1 Water. Same as Method 11, section 7.1.3.
16.6.2 Zinc Acetate Absorbing Solution. Dissolve 20 g zinc acetate in water, and dilute to 1 liter.
16.6.3 Potassium Bi-iodate [KH(IO
16.6.4 Sodium Thiosulfate (Na
16.6.5 Na
16.6.6 Iodine Solution, 0.1 N. Same as Method 11, section 7.2.3.
16.6.7 Standard Iodine Solution, 0.01 N. Same as in Method 11, section 7.2.4. Standardize according to section 16.12.3.
16.6.8 Hydrochloric Acid (HCl) Solution, 10 Percent by Weight. Add 230 ml concentrated HCl (specific gravity 1.19) to 770 ml water.
16.6.9 Starch Indicator Solution. To 5 g starch (potato, arrowroot, or soluble), add a little cold water, and grind in a mortar to a thin paste. Pour into 1 liter of boiling water, stir, and let settle overnight. Use the clear supernatant. Preserve with 1.25 g salicylic acid, 4 g zinc chloride, or a combination of 4 g sodium propionate and 2 g sodium azide per liter of starch solution. Some commercial starch substitutes are satisfactory.
16.7 Pre-test Procedures.
16.7.1 Selection of Gas Sample Volumes. This procedure has been validated for estimating the volume of cylinder gas sample needed when the H
| Approximate cylinder gas H | Approximate ppm-liters desired |
|---|---|
| 5 to | 650 |
| 30 to | 800 |
| 500 to | 1000 |
16.7.2 Critical Orifice Flow Rate Selection. The following table shows the ranges of sample flow rates that are desirable in order to ensure capture of H
| Cylinder gas H | Critical orifice flow rate (ml/min) |
|---|---|
| 5 to 50 ppmv | 1500 ±500 |
| 50 to 250 ppmv | 500 ±250 |
| 250 to | 200 ±50 |
| >1000 ppmv | 75 ±25 |
16.7.3 Critical Orifice Fabrication. Critical orifice of desired flow rates may be fabricated by selecting an orifice tube of desired length and connecting
| Tube (in. OD) | Tube (in. ID) | Length (in.) | Flowrate (ml/min) | Altech Catalog No. |
|---|---|---|---|---|
| 0.007 | 1.2 | 85 | 301430 | |
| 0.01 | 3.2 | 215 | 300530 | |
| 0.01 | 1.2 | 350 | 300530 | |
| 0.02 | 1.2 | 1400 | 300230 |
16.7.4 Determination of Critical Orifice Approximate Flow Rate. Connect the critical orifice to the sampling system as shown in Figure 16A-4 but without the H
16.7.5 Determination of Approximate Sampling Time. Determine the approximate sampling time for a cylinder of known concentration. Use the optimum sample volume obtained in section 16.7.1.
16.8 Sample Collection.
16.8.1 Connect the Teflon tubing, Teflon tee, and rotameter to the flow control needle valve as shown in Figure 16A-4. Vent the rotameter to an exhaust hood. Plug the open end of the tee. Five to 10 minutes prior to sampling, open the cylinder valve while keeping the flow control needle valve closed. Adjust the delivery pressure to 20 psi. Open the needle valve slowly until the rotameter shows a flow rate approximately 50 to 100 ml above the flow rate of the critical orifice being used in the system.
16.8.2 Place 50 ml of zinc acetate solution in two of the impingers, connect them and the empty third impinger (dropout bottle) and the rest of the equipment as shown in Figure 16A-4. Make sure the ground-glass fittings are tight. The impingers can be easily stabilized by using a small cardboard box in which three holes have been cut, to act as a holder. Connect the Teflon sample line to the first impinger. Cover the impingers with a dark cloth or piece of plastic to protect the absorbing solution from light during sampling.
16.8.3 Record the temperature and barometric pressure. Note the gas flow rate through the rotameter. Open the closed end of the tee. Connect the sampling tube to the tee, ensuring a tight connection. Start the sampling pump and stopwatch simultaneously. Note the decrease in flow rate through the excess flow rotameter. This decrease should equal the known flow rate of the critical orifice being used. Continue sampling for the period determined in section 16.7.5.
16.8.4 When sampling is complete, turn off the pump and stopwatch. Disconnect the sampling line from the tee and plug it. Close the needle valve followed by the cylinder valve. Record the sampling time.
16.9 Blank Analysis. While the sample is being collected, run a blank as follows: To a 250-ml Erlenmeyer flask, add 100 ml of zinc acetate solution, 20.0 ml of 0.01 N iodine solution, and 2 ml HCl solution. Titrate, while stirring, with 0.01 N Na
Iodine titration of zinc acetate solutions is difficult to perform because the solution turns slightly white in color near the end point, and the disappearance of the blue color is hard to recognize. In addition, a blue color may reappear in the solution about 30 to 45 seconds after the titration endpoint is reached. This should not be taken to mean the original endpoint was in error. It is recommended that persons conducting this test perform several titrations to be able to correctly identify the endpoint. The importance of this should be recognized because the results of this analytical procedure are extremely sensitive to errors in titration.
16.10 Sample Analysis. Sample treatment is similar to the blank treatment. Before detaching the stems from the bottoms of the impingers, add 20.0 ml of 0.01 N iodine solution through the stems of the impingers holding the zinc acetate solution, dividing it between the two (add about 15 ml to the first impinger and the rest to the second). Add 2 ml HCl solution through the stems, dividing it as with the iodine. Disconnect the sampling line, and store the impingers for 30 minutes. At the end of 30 minutes, rinse the impinger stems into the impinger bottoms. Titrate the impinger contents with 0.01 N Na
16.11 Post-test Orifice Calibration. Conduct a post-test critical orifice calibration run using the calibration procedures outlined in section 16.12.4. If the Q
16.12 Calibrations and Standardizations.
16.12.1 Rotameter and Barometer. Same as Method 11, sections 10.1.3 and 10.1.4.
16.12.2 Na
16.12.3 Iodine Solution, 0.01 N. Standardize the 0.01 N iodine solution as follows: Pipet 20.0 ml of 0.01 N iodine solution into a 125-ml Erlenmeyer flask. Titrate with standard 0.01 N Na
16.12.4 Critical Orifice. Calibrate the critical orifice using the sampling train shown in Figure 16A-4 but without the H
16.13 Calculations.
16.13.1 Nomenclature.
(For tests carried out in a laboratory where the impinger temperature is 25 °C, M
16.13.2 Normality of Standard Na
16.13.3 Normality of Standard Iodine Solution (0.01 N).
16.13.4 Sample Gas Volume.
16.13.5 Concentration of H
1. American Public Health Association, American Water Works Association, and Water Pollution Control Federation. Standard Methods for the Examination of Water and Wastewater. Washington, DC. American Public Health Association. 1975. pp. 316-317.
2. American Society for Testing and Materials. Annual Book of ASTM Standards. Part 31: Water, Atmospheric Analysis. Philadelphia, PA. 1974. pp. 40-42.
3. Blosser, R.O. A Study of TRS Measurement Methods. National Council of the Paper Industry for Air and Stream Improvement, Inc., New York, NY. Technical Bulletin No. 434. May 1984. 14 pp.
4. Blosser, R.O., H.S. Oglesby, and A.K. Jain. A Study of Alternate SO
5. Curtis, F., and G.D. McAlister. Development and Evaluation of an Oxidation/Method 6 TRS Emission Sampling Procedure. Emission Measurement Branch, Emission Standards and Engineering Division, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711. February 1980.
6. Gellman, I. A Laboratory and Field Study of Reduced Sulfur Sampling and Monitoring Systems. National Council of the Paper Industry for Air and Stream Improvement, Inc., New York, NY. Atmospheric Quality Improvement Technical Bulletin No. 81. October 1975.
7. Margeson, J.H., J.E. Knoll, and M.R. Midgett. A Manual Method for TRS Determination. Source Branch, Quality Assurance Division, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711.
8. National Council of the Paper Industry for Air and Stream Improvement. An Investigation of H
9. National Council of the Paper Industry for Air and Stream Improvement. Wet Chemical Method for Determining the H
10. National Council of the Paper Industry for Air and Stream Improvement. Modified Wet Chemical Method for Determining the H
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a knowledge of at least the following additional test methods: Method 6C, Method 16, and Method 16A.
1.1 Analytes.
| Analyte | CAS No. |
|---|---|
| Total reduced sulfur (TRS) including: | N/A |
| Dimethyl disulfide (DMDS), [(CH | 62-49-20 |
| Dimethyl sulfide (DMS), [(CH | 75-18-3 |
| Hydrogen sulfide (H | 7783-06-4 |
| Methyl mercaptan (MeSH), [CH | 74-93-1 |
| Reported as: Sulfur dioxide (SO | 7449-09-5 |
1.2 Applicability. This method is applicable for determining TRS emissions from recovery furnaces (boilers), lime kilns, and smelt dissolving tanks at kraft pulp mills, and from other sources when specified in an applicable subpart of the regulations. The flue gas must contain at least 1 percent oxygen for complete oxidation of all TRS to SO
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 A gas sample is extracted from the stack. The SO
4.1 Reduced sulfur compounds other than those regulated by the emission standards, if present, may be measured by this method. Therefore, carbonyl sulfide, which is partially oxidized to SO
4.2 Particulate matter from the lime kiln stack gas (primarily calcium carbonate) can cause a negative bias if it is allowed to enter the citrate scrubber; the particulate matter will cause the pH to rise and H
4.3 Carbon monoxide (CO) and carbon dioxide (CO
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method.
5.2 Hydrogen Sulfide (H
6.1 Sample Collection. The sampling train is shown in Figure 16B-1. Modifications to the apparatus are accepted provided the system performance check in section 8.3.1 is met.
6.1.1 Probe, Probe Brush, Particulate Filter, SO
6.1.2 Sampling Pump. Leakless Teflon-coated diaphragm type or equivalent.
6.2 Analysis.
6.2.1 Dilution System (optional), Gas Chromatograph, Oven, Temperature Gauges, Flow System, Flame Photometric Detector, Electrometer, Power Supply, Recorder, Calibration System, Tube Chamber, Flow System, and Constant Temperature Bath. Same as in Method 16, sections 6.2.1, 6.2.2, and 6.3.
6.2.2 Gas Chromatograph Columns. Same as in Method 16, section 6.2.3. Other columns with demonstrated ability to resolve SO
Same as in Method 16, section 7.0, except for the following:
7.1 Calibration Gas. SO
7.2 Recovery Check Gas.
7.2.1 Hydrogen sulfide [100 parts per million by volume (ppmv) or less] in nitrogen, stored in aluminum cylinders. Verify the concentration by Method 11, the procedure discussed in section 16.0 of Method 16A, or gas chromatography where the instrument is calibrated with an H
7.2.2 Hydrogen sulfide recovery gas generated from a permeation device gravimetrically calibrated and certified at some convenient operation temperature may be used. The permeation rate of the device must be such that at a dilution gas flow rate of 3 liters/min (64 ft
7.3 Combustion Gas. Gas containing less than 50 ppbv reduced sulfur compounds and less than 10 ppmv total hydrocarbons. The gas may be generated from a clean-air system that purifies ambient air and consists of the following components: diaphragm pump, silica gel drying tube, activated charcoal tube, and flow rate measuring device. Gas from a compressed air cylinder is also acceptable.
8.1 Pretest Procedures. Same as in Method 15, section 8.1.
8.2 Sample Collection. Before any source sampling is performed, conduct a system performance check as detailed in section 8.3.1 to validate the sampling train components and procedures. Although this test is optional, it would significantly reduce the possibility of rejecting tests as a result of failing the post-test performance check. At the completion of the pretest system performance check, insert the sampling probe into the test port making certain that no dilution air enters the stack though the port. Condition the entire system with sample for a minimum of 15 minutes before beginning analysis. If the sample is diluted, determine the dilution factor as in section 10.4 of Method 15.
8.3. Post-Test Procedures
8.3.1 System Performance Check. Same as in Method 16A, section 8.5. A sufficient number of sample injections should be made so that the precision requirements of section 13.2 are satisfied.
8.3.2 Determination of Calibration Drift. Same as in Method 15, section 8.3.2.
| Section | Quality control measure | Effect |
|---|---|---|
| 8.2, 8.3 | System performance check | Ensure validity of sampling train components and analytical procedure. |
| 8.1 | Sampling equipment leak-check and calibration | Ensure accurate measurement of stack gas flow rate, sample volume. |
| 10.0 | Analytical calibration | Ensure precision of analytical results within 5 percent. |
Same as in Method 16, section 10, except SO
11.1 Analysis. Inject aliquots of the sample into the GC/FPD analyzer for analysis. Determine the concentration of SO
11.2 Perform analysis of a minimum of three aliquots or one every 15 minutes, whichever is greater, spaced evenly over the test period.
12.0 Data Analysis and Calculations
12.2 SO
12.3 TRS Concentration.
12.4 Average TRS Concentration
13.1 Range and Sensitivity. Coupled with a GC using a 1-ml sample size, the maximum limit of the FPD for SO
13.2 GC/FPD Calibration and Precision. A series of three consecutive injections of the sample calibration gas, at any dilution, must produce results which do not vary by more than 5 percent from the mean of the three injections.
13.3 Calibration Drift. The calibration drift determined from the mean of the three injections made at the beginning and end of any run or series of runs within a 24-hour period must not exceed 5 percent.
13.4 System Calibration Accuracy. Losses through the sample transport system must be measured and a correction factor developed to adjust the calibration accuracy to 100 percent.
13.5 Field tests between this method and Method 16A showed an average difference of less than 4.0 percent. This difference was not determined to be significant.
1. Same as in Method 16, section 16.0.
2. National Council of the Paper Industry for Air and Stream Improvement, Inc, A Study of TRS Measurement Methods. Technical Bulletin No. 434. New York, NY. May 1984. 12p.
3. Margeson, J.H., J.E. Knoll, and M.R. Midgett. A Manual Method for TRS Determination. Draft available from the authors. Source Branch, Quality Assurance Division, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711.
Method 16C is a procedure for measuring total reduced sulfur (TRS) in stationary source emissions using a continuous instrumental analyzer. Quality assurance and quality control requirements are included to assure that you, the tester, collect data of known quality. You must document your adherence to these specific requirements for equipment, supplies, sample collection and analysis, calculations, and data analysis. This method does not completely describe all equipment, supplies, and sampling and analytical procedures you will need but refers to other methods for some of the details. Therefore, to obtain reliable results, you should also have a thorough knowledge of these additional test methods which are found in appendix A to this part:
(a) Method 6C – Determination of Sulfur Dioxide Emissions from Stationary Sources (Instrumental Analyzer Procedure)
(b) Method 7E – Determination of Nitrogen Oxides Emissions from Stationary Sources (Instrumental Analyzer Procedure)
(c) Method 16A – Determination of Total Reduced Sulfur Emissions from Stationary Sources (Impinger Technique)
1.1 Analytes. What does Method 16C determine?
| Analyte | CAS No. |
|---|---|
| Total reduced sulfur including: | N/A |
| Dimethyl disulfide (DMDS), [(CH | 62-49-20 |
| Dimethyl sulfide (DMS), [(CH | 75-18-3 |
| Hydrogen sulfide (H | 7783-06-4 |
| Methyl mercaptan (MeSH), (CH | 74-93-1 |
| Reported as: Sulfur dioxide (SO | 7449-09-5 |
1.2 Applicability. This method is applicable for determining TRS emissions from recovery furnaces (boilers), lime kilns, and smelt dissolving tanks at kraft pulp mills, and from other sources when specified in an applicable subpart of the regulations.
1.3 Data Quality Objectives. Adherence to the requirements described in Method 16C will enhance the quality of the data obtained.
2.1 An integrated gas sample is extracted from the stack. The SO
Analyzer calibration error, Calibration curve, Calibration gas, Low-level gas, Mid-level gas, High-level gas, Calibration drift, Calibration span, Data recorder, Direct calibration mode, Gas analyzer, Interference check, Measurement system, Response time, Run, System calibration mode, System performance check, and Test are the same as used in Methods 16A and 6C.
4.1 Reduced sulfur compounds other than those defined as TRS, if present, may be measured by this method. Compounds like carbonyl sulfide, which is partially oxidized to SO
4.2 Particulate matter from the lime kiln stack gas (primarily calcium carbonate) can cause a negative bias if it is allowed to enter the citrate scrubber; the particulate matter will cause the pH to rise and H
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user to establish appropriate safety and health practices before performing this test method.
5.2 Hydrogen Sulfide. Hydrogen sulfide is a flammable, poisonous gas with the odor of rotten eggs. Hydrogen sulfide is extremely hazardous and can cause collapse, coma, and death within a few seconds of one or two inhalations at sufficient concentrations. Low concentrations irritate the mucous membranes and may cause nausea, dizziness, and headache after exposure. It is the responsibility of the user of this test method to establish appropriate safety and health practices.
The measurement system is similar to those applicable components in Methods 16A and 6C. Modifications to the apparatus are accepted provided the performance criteria in section 13.0 are met.
6.1 Probe. Teflon tubing, 6.4-mm (
6.2 Probe Brush. Nylon bristle brush with handle inserted into a 3.2-mm (
6.3 Particulate Filter. 50-mm Teflon filter holder and a 1- to 2-µm porosity, Teflon filter (may be available through Savillex Corporation, 5325 Highway 101, Minnetonka, Minnesota 55343, or other suppliers of filters). The filter holder must be maintained in a hot box at a temperature sufficient to prevent moisture condensation. A temperature of 121 °C (250 °F) was found to be sufficient when testing a lime kiln under sub-freezing ambient conditions.
6.4 SO
6.5 Combustion Tube. Quartz glass tubing with an expanded combustion chamber 2.54 cm (1 in.) in diameter and at least 30.5 cm (12 in.) long. The tube ends should have an outside diameter of 0.6 cm (
6.6 Furnace. A furnace of sufficient size to enclose the combustion chamber of the combustion tube with a temperature regulator capable of maintaining the temperature at 800 ±100 °C (1472 ±180 °F). The furnace operating temperature should be checked with a thermocouple to ensure accuracy.
6.7 Sampling Pump. A leak-free pump is required to pull the sample gas through the system at a flow rate sufficient to minimize the response time of the measurement system and must be constructed of material that is non-reactive to the gas it contacts. For dilution-type measurement systems, an eductor pump may be used to create a vacuum that draws the sample through a critical orifice at a constant rate.
6.8 Calibration Gas Manifold. The calibration gas manifold must allow the introduction of calibration gases either directly to the gas analyzer in direct calibration mode or into the measurement system, at the probe, in system calibration mode, or both, depending upon the type of system used. In system calibration mode, the system must be able to flood the sampling probe and vent excess gas. Alternatively, calibration gases may be introduced at the calibration valve following the probe. Maintain a constant pressure in the gas manifold. For in-stack dilution-type systems, a gas dilution subsystem is required to transport large volumes of purified air to the sample probe, and a probe controller is needed to maintain the proper dilution ratio.
6.9 Sample Gas Manifold. The sample gas manifold diverts a portion of the sample to the analyzer, delivering the remainder to the by-pass discharge vent. The manifold should also be able to introduce calibration gases directly to the analyzer. The manifold must be made of material that is non-reactive to SO
6.10 SO
6.11 Data Recording. A strip chart recorder, computerized data acquisition system, digital recorder, or data logger for recording measurement data must be used.
Unless otherwise indicated, all reagents must conform to the specifications established by the Committee on Analytical Reagents of the American Chemical Society. When such specifications are not available, the best available grade must be used.
7.1 Water. Deionized distilled water must conform to ASTM Specification D 1193-77 or 91 Type 3 (incorporated by reference – see § 60.17). The KMnO
7.2 Citrate Buffer. Dissolve 300 g of potassium citrate (or 284 g of sodium citrate) and 41 g of anhydrous citric acid in 1 liter of water (200 ml is needed per test). Adjust the pH to between 5.4 and 5.6 with potassium citrate or citric acid, as required.
7.3 Calibration Gas. Refer to section 7.1 of Method 7E (as applicable) for the calibration gas requirements. Example calibration gas mixtures are listed below.
(a) SO
(b) SO
(c) SO
(d) SO
(e) SO
(f) CO
(g) CO
7.4 System Performance Check Gas. You must use H
Alternatively, H
7.5 Interference Check. Examples of test gases for the interference check are listed in Table 7E-3 of Method 7E.
8.1 Pre-sampling Tests. Before measuring emissions, perform the following procedures:
(a) Calibration gas verification,
(b) Calibration error test,
(c) System performance check,
(d) Verification that the interference check has been satisfied.
8.1.1 Calibration Gas Verification. Obtain a certificate from the gas manufacturer documenting the quality of the gas. Confirm that the manufacturer certification is complete and current. Ensure that your calibration gas certifications have not expired. This documentation should be available on-site for inspection. To the extent practicable, select a high-level gas concentration that will result in the measured emissions being between 20 and 100 percent of the calibration span.
8.1.2 Analyzer Calibration Error Test. After you have assembled, prepared, and calibrated your sampling system and analyzer, you must conduct a 3-point analyzer calibration error test before the first run and again after any failed system performance check or failed drift test to ensure the calibration is acceptable. Introduce the low-, mid-, and high-level calibration gases sequentially to the analyzer in direct calibration mode. For each calibration gas, calculate the analyzer calibration error using Equation 16C-1 in section 12.2. The calibration error for the low-, mid-, and high-level gases must not exceed 5.0 percent or 0.5 ppmv. If the calibration error specification is not met, take corrective action and repeat the test until an acceptable 3-point calibration is achieved.
8.1.3 System Performance Check. A system performance check is done (1) to validate the sampling train components and procedure (prior to testing), and (2) to validate a test run (after a run). You must conduct a performance check in the field prior to testing, and after each 3-hour run or after three 1-hour runs. A performance check consists of sampling and analyzing a known concentration of H
8.1.4 Interference Check. Same as in Method 7E, section 8.2.7.
8.2 Measurement System Preparation.
8.2.1 For the SO
8.2.2 Citrate Scrubber Conditioning Procedure. Condition the citrate buffer scrubbing solution by pulling stack gas through the Teflon impingers as described in section 8.4.1.
8.3 Pretest Procedures. After the complete measurement system has been set up at the site and deemed to be operational, the following procedures must be completed before sampling is initiated.
8.3.1 Leak-Check. Appropriate leak-check procedures must be employed to verify the integrity of all components, sample lines, and connections. For components upstream of the sample pump, attach the probe end of the sample line to a manometer or vacuum gauge, start the pump and pull a vacuum greater than 50 mm (2 in.) Hg, close off the pump outlet, and then stop the pump and ascertain that there is no leak for 1 minute. For components after the pump, apply a slight positive pressure and check for leaks by applying a liquid (detergent in water, for example) at each joint. Bubbling indicates the presence of a leak.
8.3.2 Initial System Performance Check. A system performance check using the test gas (Section 7.4) is performed prior to testing to validate the sampling train components and procedure.
8.4 Sample Collection and Analysis.
8.4.1 After performing the required pretest procedures described in section 8.1, insert the sampling probe into the test port ensuring that no dilution air enters the stack through the port. Condition the sampling system and citrate buffer solution for a minimum of 15 minutes before beginning analysis. Begin sampling and analysis. A source test consists of three test runs. A test run shall consist of a single sample collected over a 3-hour period or three separate 1-hour samples collected over a period not to exceed six hours.
8.5 Post-Run Evaluations.
8.5.1 System Performance Check. Perform a post-run system performance check before replacing the citrate buffer solution and particulate filter and before the probe is cleaned. The check results must not exceed the 100 ±20 percent limit set forth in section 13.2. If this limit is exceeded, the intervening run is considered invalid. However, if the recovery efficiency is not in the 100 ±20 percent range, but the results do not affect the compliance or noncompliance status of the affected facility, the Administrator may decide to accept the results of the compliance test.
8.5.2 Calibration Drift. After a run or series of runs, not to exceed a 24-hour period after initial calibration, perform a calibration drift test using a calibration gas (preferably the level that best approximates the sample concentration) in direct calibration mode. This drift must not differ from the initial calibration error percent by more than 3.0 percent or 0.5 ppm. If the drift exceeds this limit, the intervening run or runs are considered valid, but a new analyzer calibration error test must be performed and passed before continuing sampling.
| Section | Quality control measure | Effect |
|---|---|---|
| 8.1.2 | Analyzer calibration error test | Establishes initial calibration accuracy within 5.0%. |
| 8.1.3, 8.5.1 | System performance check | Ensures accuracy of sampling/analytical procedure to 100 ±20%. |
| 8.5.2 | Calibration drift test | Ensures calibration drift is within 3.0%. |
| 8.1.4 | Interference check | Checks for analytical interferences. |
| 8.3 | Sampling equipment leak-check | Ensures accurate measurement of sample gas flow rate, sample volume. |
10.1 Calibrate the system using the gases described in section 7.3. Perform the initial 3-point calibration error test as described in section 8.1.2 before you start the test. The specification in section 13 must be met. Conduct an initial system performance test described in section 8.1.3 as well before the test to validate the sampling components and procedures before sampling. After the test commences, a system performance check is required after each run. You must include a copy of the manufacturer’s certification of the calibration gases used in the testing as part of the test report. This certification must include the 13 documentation requirements in the EPA Traceability Protocol for Assay and Certification of Gaseous Calibration Standards, September 1997, as amended August 25, 1999.
Because sample collection and analysis are performed together (see section 8.0), additional discussion of the analytical procedure is not necessary.
12.1 Nomenclature.
12.2 Analyzer Calibration Error. For non-dilution systems, use Equation 16C-1 to calculate the analyzer calibration error for the low-, mid-, and high-level calibration gases.
12.3 System Performance Check. Use Equation 16C-2 to calculate the system performance.
12.4 Calibration Drift. Use Equation 16C-3 to calculate the calibration drift at a single concentration level after a run or series of runs (not to exceed a 24-hr period) from initial calibration. Compare the single-level calibration gas error (ACE
12.5 TRS Concentration as SO
13.1 Analyzer Calibration Error. At each calibration gas level (low, mid, and high), the calibration error must either not exceed 5.0 percent of the calibration span or |C
13.2 System Performance. Each system performance check must not deviate from the system performance gas concentration by more than 20 percent. Alternatively, the results are acceptable if |C
13.3 Calibration Drift. The calibration drift at the end of any run or series of runs within a 24-hour period must not differ by more than 3.0 percent from the original ACE at the test concentration level or |ACEi−ACE
13.4 Interference Check. For the analyzer, the total interference response (i.e., the sum of the interference responses of all tested gaseous components) must not be greater than 2.5 percent of the calibration span. Any interference is also acceptable if the sum of the responses does not exceed 0.5 ppmv for a calibration span of 5 to 10 ppmv, or 0.2 ppmv for a calibration span This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 2, Method 3, Method 5.
1.1 Analyte. Particulate matter (PM). No CAS number assigned.
Particulate matter is not an absolute quantity. It is a function of temperature and pressure. Therefore, to prevent variability in PM emission regulations and/or associated test methods, the temperature and pressure at which PM is to be measured must be carefully defined. Of the two variables (i.e., temperature and pressure), temperature has the greater effect upon the amount of PM in an effluent gas stream; in most stationary source categories, the effect of pressure appears to be negligible. In Method 5, 120 °C (248 °F) is established as a nominal reference temperature. Thus, where Method 5 is specified in an applicable subpart of the standard, PM is defined with respect to temperature. In order to maintain a collection temperature of 120 °C (248 °F), Method 5 employs a heated glass sample probe and a heated filter holder. This equipment is somewhat cumbersome and requires care in its operation. Therefore, where PM concentrations (over the normal range of temperature associated with a specified source category) are known to be independent of temperature, it is desirable to eliminate the glass probe and the heating systems, and to sample at stack temperature.
1.2 Applicability. This method is applicable for the determination of PM emissions, where PM concentrations are known to be independent of temperature over the normal range of temperatures characteristic of emissions from a specified source category. It is intended to be used only when specified by an applicable subpart of the standards, and only within the applicable temperature limits (if specified), or when otherwise approved by the Administrator. This method is not applicable to stacks that contain liquid droplets or are saturated with water vapor. In addition, this method shall not be used as written if the projected cross-sectional area of the probe extension-filter holder assembly covers more than 5 percent of the stack cross-sectional area (see section 8.1.2).
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 Particulate matter is withdrawn isokinetically from the source and collected on a glass fiber filter maintained at stack temperature. The PM mass is determined gravimetrically after the removal of uncombined water.
Same as Method 5, section 3.0.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method.
6.1 Sampling Train. A schematic of the sampling train used in this method is shown in Figure 17-1. The sampling train components and operation and maintenance are very similar to Method 5, which should be consulted for details.
6.1.1 Probe Nozzle, Differential Pressure Gauge, Metering System, Barometer, Gas Density Determination Equipment. Same as in Method 5, sections 6.1.1, 6.1.4, 6.1.8, 6.1.9, and 6.1.10, respectively.
6.1.2 Filter Holder. The in-stack filter holder shall be constructed of borosilicate or quartz glass, or stainless steel. If a gasket is used, it shall be made of silicone rubber, Teflon, or stainless steel. Other holder and gasket materials may be used, subject to the approval of the Administrator. The filter holder shall be designed to provide a positive seal against leakage from the outside or around the filter.
6.1.3 Probe Extension. Any suitable rigid probe extension may be used after the filter holder.
6.1.4 Pitot Tube. Same as in Method 5, section 6.1.3.
6.1.4.1 It is recommended (1) that the pitot tube have a known baseline coefficient, determined as outlined in section 10 of Method 2; and (2) that this known coefficient be preserved by placing the pitot tube in an interference-free arrangement with respect to the sampling nozzle, filter holder, and temperature sensor (see Figure 17-1). Note that the 1.9 cm (
6.1.4.2 Source-sampling assemblies that do not meet the minimum spacing requirements of Figure 17-1 (or the equivalent of these requirements, e.g., Figure 2-4 of Method 2) may be used; however, the pitot tube coefficients of such assemblies shall be determined by calibration, using methods subject to the approval of the Administrator.
6.1.5 Condenser. It is recommended that the impinger system or alternatives described in Method 5 be used to determine the moisture content of the stack gas. Flexible tubing may be used between the probe extension and condenser. Long tubing lengths may affect the moisture determination.
6.2 Sample Recovery. Probe-liner and probe-nozzle brushes, wash bottles, glass sample storage containers, petri dishes, graduated cylinder and/or balance, plastic storage containers, funnel and rubber policeman, funnel. Same as in Method 5, sections 6.2.1 through 6.2.8, respectively.
6.3 Sample Analysis. Glass weighing dishes, desiccator, analytical balance, balance, beakers, hygrometer, temperature sensor. Same as in Method 5, sections 6.3.1 through 6.3.7, respectively.
7.1 Sampling. Filters, silica gel, water, crushed ice, stopcock grease. Same as in Method 5, sections 7.1.1, 7.1.2, 7.1.3, 7.1.4, and 7.1.5, respectively. Thimble glass fiber filters may also be used.
7.2 Sample Recovery. Acetone (reagent grade). Same as in Method 5, section 7.2.
7.3 Sample Analysis. Acetone and Desiccant. Same as in Method 5, sections 7.3.1 and 7.3.2, respectively.
8.1 Sampling.
8.1.1 Pretest Preparation. Same as in Method 5, section 8.1.1.
8.1.2 Preliminary Determinations. Same as in Method 5, section 8.1.2, except as follows: Make a projected-area model of the probe extension-filter holder assembly, with the pitot tube face openings positioned along the centerline of the stack, as shown in Figure 17-2. Calculate the estimated cross-section blockage, as shown in Figure 17-2. If the blockage exceeds 5 percent of the duct cross sectional area, the tester has the following options exist: (1) a suitable out-of-stack filtration method may be used instead of in-stack filtration; or (2) a special in-stack arrangement, in which the sampling and velocity measurement sites are separate, may be used; for details concerning this approach, consult with the Administrator (see also Reference 1 in section 17.0). Select a probe extension length such that all traverse points can be sampled. For large stacks, consider sampling from opposite sides of the stack to reduce the length of probes.
8.1.3 Preparation of Sampling Train. Same as in Method 5, section 8.1.3, except the following: Using a tweezer or clean disposable surgical gloves, place a labeled (identified) and weighed filter in the filter holder. Be sure that the filter is properly centered and the gasket properly placed so as not to allow the sample gas stream to circumvent the filter. Check filter for tears after assembly is completed. Mark the probe extension with heat resistant tape or by some other method to denote the proper distance into the stack or duct for each sampling point. Assemble the train as in Figure 17-1, using a very light coat of silicone grease on all ground glass joints and greasing only the outer portion (see APTD-0576) to avoid possibility of contamination by the silicone grease. Place crushed ice around the impingers.
8.1.4 Leak-Check Procedures. Same as in Method 5, section 8.1.4, except that the filter holder is inserted into the stack during the sampling train leak-check. To do this, plug the inlet to the probe nozzle with a material that will be able to withstand the stack temperature. Insert the filter holder into the stack and wait approximately 5 minutes (or longer, if necessary) to allow the system to come to equilibrium with the temperature of the stack gas stream.
8.1.5 Sampling Train Operation. The operation is the same as in Method 5. Use a data sheet such as the one shown in Figure 5-3 of Method 5, except that the filter holder temperature is not recorded.
8.1.6 Calculation of Percent Isokinetic. Same as in Method 5, section 12.11.
8.2 Sample Recovery.
8.2.1 Proper cleanup procedure begins as soon as the probe extension assembly is removed from the stack at the end of the sampling period. Allow the assembly to cool.
8.2.2 When the assembly can be safely handled, wipe off all external particulate matter near the tip of the probe nozzle and place a cap over it to prevent losing or gaining particulate matter. Do not cap off the probe tip tightly while the sampling train is cooling down as this would create a vacuum in the filter holder, forcing condenser water backward.
8.2.3 Before moving the sample train to the cleanup site, disconnect the filter holder-probe nozzle assembly from the probe extension; cap the open inlet of the probe extension. Be careful not to lose any condensate, if present. Remove the umbilical cord from the condenser outlet and cap the outlet. If a flexible line is used between the first impinger (or condenser) and the probe extension, disconnect the line at the probe extension and let any condensed water or liquid drain into the impingers or condenser. Disconnect the probe extension from the condenser; cap the probe extension outlet. After wiping off the silicone grease, cap off the condenser inlet. Ground glass stoppers, plastic caps, or serum caps (whichever are appropriate) may be used to close these openings.
8.2.4 Transfer both the filter holder-probe nozzle assembly and the condenser to the cleanup area. This area should be clean and protected from the wind so that the chances of contaminating or losing the sample will be minimized.
8.2.5 Save a portion of the acetone used for cleanup as a blank. Take 200 ml of this acetone from the wash bottle being used and place it in a glass sample container labeled “acetone blank.” Inspect the train prior to and during disassembly and not any abnormal conditions. Treat the sample as discussed in Method 5, section 8.2.
The calibrations of the probe nozzle, pitot tube, metering system, temperature sensors, and barometer are the same as in Method 5, sections 10.1 through 10.3, 10.5, and 10.6, respectively.
Same as in Method 5, section 11.0. Analytical data should be recorded on a form similar to that shown in Figure 5-6 of Method 5.
Same as in Method 5, section 12.0.
Same as in Method 5, section 16.0.
Same as in Method 5, section 17.0, with the addition of the following:
1. Vollaro, R.F. Recommended Procedure for Sample Traverses in Ducts Smaller than 12 Inches in Diameter. U.S. Environmental Protection Agency, Emission Measurement Branch. Research Triangle Park, NC. November 1976.
This method is not inclusive with respect to specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 2, Method 3.
This method should not be attempted by persons unfamiliar with the performance characteristics of gas chromatography, nor by those persons who are unfamiliar with source sampling. Particular care should be exercised in the area of safety concerning choice of equipment and operation in potentially explosive atmospheres.
1.1 Analyte. Total gaseous organic compounds.
1.2 Applicability.
1.2.1 This method is designed to measure gaseous organics emitted from an industrial source. While designed for ppm level sources, some detectors are quite capable of detecting compounds at ambient levels, e.g., ECD, ELCD, and helium ionization detectors. Some other types of detectors are evolving such that the sensitivity and applicability may well be in the ppb range in only a few years.
1.2.2 This method will not determine compounds that (1) are polymeric (high molecular weight), (2) can polymerize before analysis, or (3) have very low vapor pressures at stack or instrument conditions.
1.3 Range. The lower range of this method is determined by the sampling system; adsorbents may be used to concentrate the sample, thus lowering the limit of detection below the 1 part per million (ppm) typically achievable with direct interface or bag sampling. The upper limit is governed by GC detector saturation or column overloading; the upper range can be extended by dilution of sample with an inert gas or by using smaller volume gas sampling loops. The upper limit can also be governed by condensation of higher boiling compounds.
1.4 Sensitivity. The sensitivity limit for a compound is defined as the minimum detectable concentration of that compound, or the concentration that produces a signal-to-noise ratio of three to one. The minimum detectable concentration is determined during the presurvey calibration for each compound.
The major organic components of a gas mixture are separated by gas chromatography (GC) and individually quantified by flame ionization, photoionization, electron capture, or other appropriate detection principles. The retention times of each separated component are compared with those of known compounds under identical conditions. Therefore, the analyst confirms the identity and approximate concentrations of the organic emission components beforehand. With this information, the analyst then prepares or purchases commercially available standard mixtures to calibrate the GC under conditions identical to those of the samples. The analyst also determines the need for sample dilution to avoid detector saturation, gas stream filtration to eliminate particulate matter, and prevention of moisture condensation.
4.1 Resolution interferences that may occur can be eliminated by appropriate GC column and detector choice or by shifting the retention times through changes in the column flow rate and the use of temperature programming.
4.2 The analytical system is demonstrated to be essentially free from contaminants by periodically analyzing blanks that consist of hydrocarbon-free air or nitrogen.
4.3 Sample cross-contamination that occurs when high-level and low-level samples or standards are analyzed alternately is best dealt with by thorough purging of the GC sample loop between samples.
4.4 To assure consistent detector response, calibration gases are contained in dry air. To adjust gaseous organic concentrations when water vapor is present in the sample, water vapor concentrations are determined for those samples, and a correction factor is applied.
4.5 The gas chromatograph run time must be sufficient to clear all eluting peaks from the column before proceeding to the next run (in order to prevent sample carryover).
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method. The analyzer users manual should be consulted for specific precautions to be taken with regard to the analytical procedure.
6.1 Equipment needed for the presurvey sampling procedure can be found in section 16.1.1.
6.2 Equipment needed for the integrated bag sampling and analysis procedure can be found in section 8.2.1.1.1.
6.3 Equipment needed for direct interface sampling and analysis can be found in section 8.2.2.1.
6.4 Equipment needed for the dilution interface sampling and analysis can be found in section 8.2.3.1.
6.5 Equipment needed for adsorbent tube sampling and analysis can be found in section 8.2.4.1.
7.1 Reagents needed for the presurvey sampling procedure can be found in section 16.1.2.
8.2 Final Sampling and Analysis Procedure. Considering safety (flame hazards) and the source conditions, select an appropriate sampling and analysis procedure (Section 8.2.1, 8.2.2, 8.2.3 or 8.2.4). In situations where a hydrogen flame is a hazard and no intrinsically safe GC is suitable, use the flexible bag collection technique or an adsorption technique.
8.2.1 Integrated Bag Sampling and Analysis.
8.2.1.1 Evacuated Container Sampling Procedure. In this procedure, the bags are filled by evacuating the rigid air-tight container holding the bags. Use a field sample data sheet as shown in Figure 18-10. Collect triplicate samples from each sample location.
8.2.1.1.1 Apparatus.
8.2.1.1.1.1 Probe. Stainless steel, Pyrex glass, or Teflon tubing probe, according to the duct temperature, with Teflon tubing of sufficient length to connect to the sample bag. Use stainless steel or Teflon unions to connect probe and sample line.
8.2.1.1.1.2 Quick Connects. Male (2) and female (2) of stainless steel construction.
8.2.1.1.1.3 Needle Valve. To control gas flow.
8.2.1.1.1.4 Pump. Leakless Teflon-coated diaphragm-type pump or equivalent. To deliver at least 1 liter/min.
8.2.1.1.1.5 Charcoal Adsorption Tube. Tube filled with activated charcoal, with glass wool plugs at each end, to adsorb organic vapors.
8.2.1.1.1.6 Flowmeter. 0 to 500-ml flow range; with manufacturer’s calibration curve.
8.2.1.1.2 Sampling Procedure. To obtain a sample, assemble the sample train as shown in Figure 18-9. Leak-check both the bag and the container. Connect the vacuum line from the needle valve to the Teflon sample line from the probe. Place the end of the probe at the centroid of the stack or at a point no closer to the walls than 1 in., and start the pump. Set the flow rate so that the final volume of the sample is approximately 80 percent of the bag capacity. After allowing sufficient time to purge the line several times, connect the vacuum line to the bag, and evacuate until the rotameter indicates no flow. Then position the sample and vacuum lines for sampling, and begin the actual sampling, keeping the rate proportional to the stack velocity. As a precaution, direct the gas exiting the rotameter away from sampling personnel. At the end of the sample period, shut off the pump, disconnect the sample line from the bag, and disconnect the vacuum line from the bag container. Record the source temperature, barometric pressure, ambient temperature, sampling flow rate, and initial and final sampling time on the data sheet shown in Figure 18-10. Protect the bag and its container from sunlight. Record the time lapsed between sample collection and analysis, and then conduct the recovery procedure in Section 8.4.2.
8.2.1.2 Direct Pump Sampling Procedure. Follow 8.2.1.1, except place the pump and needle valve between the probe and the bag. Use a pump and needle valve constructed of inert material not affected by the stack gas. Leak-check the system, and then purge with stack gas before connecting to the previously evacuated bag.
8.2.1.3 Explosion Risk Area Bag Sampling Procedure. Follow 8.2.1.1 except replace the pump with another evacuated can (see Figure 18-9a). Use this method whenever there is a possibility of an explosion due to pumps, heated probes, or other flame producing equipment.
8.2.1.4 Other Modified Bag Sampling Procedures. In the event that condensation is observed in the bag while collecting the sample and a direct interface system cannot be used, heat the bag during collection and maintain it at a suitably elevated temperature during all subsequent operations. (Note: Take care to leak-check the system prior to the dilutions so as not to create a potentially explosive atmosphere.) As an alternative, collect the sample gas, and simultaneously dilute it in the bag.
8.2.1.4.1 First Alternative Procedure. Heat the box containing the sample bag to 120 °C (±5 °C). Then transport the bag as rapidly as possible to the analytical area while maintaining the heating, or cover the box with an insulating blanket. In the analytical area, keep the box heated to 120 °C (±5 °C) until analysis. Be sure that the method of heating the box and the control for the heating circuit are compatible with the safety restrictions required in each area.
8.2.1.4.2 Second Alternative Procedure. Prefill the bag with a known quantity of inert gas. Meter the inert gas into the bag according to the procedure for the preparation of gas concentration standards of volatile liquid materials (Section 10.1.2.2), but eliminate the midget impinger section. Take the partly filled bag to the source, and meter the source gas into the bag through heated sampling lines and a heated flowmeter, or Teflon positive displacement pump. Verify the dilution factors before sampling each bag through dilution and analysis of gases of known concentration.
8.2.1.5 Analysis of Bag Samples.
8.2.1.5.1 Apparatus. Same as section 8.1. A minimum of three gas standards are required.
8.2.1.5.2 Procedure.
8.2.1.5.2.1 Establish proper GC operating conditions as described in section 10.2, and record all data listed in Figure 18-7. Prepare the GC so that gas can be drawn through the sample valve. Flush the sample loop with calibration gas mixture, and activate the valve (sample pressure at the inlet to the GC introduction valve should be similar during calibration as during actual sample analysis). Obtain at least three chromatograms for the mixture. The results are acceptable when the peak areas for the three injections agree to within 5 percent of their average. If they do not agree, run additional samples or correct the analytical techniques until this requirement is met. Then analyze the other two calibration mixtures in the same manner. Prepare a calibration curve as described in section 10.2.
8.2.1.5.2.2 Analyze the three source gas samples by connecting each bag to the sampling valve with a piece of Teflon tubing identified with that bag. Analyze each bag sample three times. Record the data in Figure 18-11. If certain items do not apply, use the notation “N.A.” If the bag has been maintained at an elevated temperature as described in section 8.2.1.4, determine the stack gas water content by Method 4. After all samples have been analyzed, repeat the analysis of the mid-level calibration gas for each compound. Compare the average response factor of the pre- and post-test analysis for each compound. If they differ by >5percent, analyze the other calibration gas levels for that compound, and prepare a calibration curve using all the pre- and post-test calibration gas mixture values. If the two response factor averages (pre-and post-test) differ by less than 5 percent from their mean value, the tester has the option of using only the pre-test calibration curve to generate the concentration values.
8.2.1.6 Determination of Bag Water Vapor Content. Measure the ambient temperature and barometric pressure near the bag. From a water saturation vapor pressure table, determine and record the water vapor content of the bag as a decimal figure. (Assume the relative humidity to be 100 percent unless a lesser value is known.) If the bag has been maintained at an elevated temperature as described in section 8.2.1.4, determine the stack gas water content by Method 4.
8.2.1.8 Emission Calculations. From the calibration curve described in section 8.2.1.5, select the value of C
8.2.2 Direct Interface Sampling and Analysis Procedure. The direct interface procedure can be used provided that the moisture content of the gas does not interfere with the analysis procedure, the physical requirements of the equipment can be met at the site, and the source gas concentration falls within the linear range of the detector. Adhere to all safety requirements with this method.
8.2.2.1 Apparatus.
8.2.2.1.1 Probe. Constructed of stainless steel, Pyrex glass, or Teflon tubing as dictated by duct temperature and reactivity of target compounds. A filter or glass wool plug may be needed if particulate is present in the stack gas. If necessary, heat the probe with heating tape or a special heating unit capable of maintaining a temperature greater than 110 °C.
8.2.2.1.2 Sample Lines. 6.4-mm OD (or other diameter as needed) Teflon lines, heat-traced to prevent condensation of material (greater than 110 °C).
8.2.2.1.3 Quick Connects. To connect sample line to gas sampling valve on GC instrument and to pump unit used to withdraw source gas. Use a quick connect or equivalent on the cylinder or bag containing calibration gas to allow connection of the calibration gas to the gas sampling valve.
8.2.2.1.4 Thermocouple Readout Device. Potentiometer or digital thermometer, to measure source temperature and probe temperature.
8.2.2.1.5 Heated Gas Sampling Valve. Of two-position, six-port design, to allow sample loop to be purged with source gas or to direct source gas into the GC instrument.
8.2.2.1.6 Needle Valve. To control gas sampling rate from the source.
8.2.2.1.7 Pump. Leakless Teflon-coated diaphragm-type pump or equivalent, capable of at least 1 liter/minute sampling rate.
8.2.2.1.8 Flowmeter. Of suitable range to measure sampling rate.
8.2.2.1.9 Charcoal Adsorber. To adsorb organic vapor vented from the source to prevent exposure of personnel to source gas.
8.2.2.1.10 Gas Cylinders. Carrier gas, oxygen and fuel as needed to run GC and detector.
8.2.2.1.11 Gas Chromatograph. Capable of being moved into the field, with detector, heated gas sampling valve, column required to complete separation of desired components, and option for temperature programming.
8.2.2.1.12 Recorder/Integrator. To record results.
8.2.2.2 Procedure. Calibrate the GC using the procedures in section 8.2.1.5.2.1. To obtain a stack gas sample, assemble the sampling system as shown in Figure 18-12. Make sure all connections are tight. Turn on the probe and sample line heaters. As the temperature of the probe and heated line approaches the target temperature as indicated on the thermocouple readout device, control the heating to maintain a temperature greater than 110 °C. Conduct a 3-point calibration of the GC by analyzing each gas mixture in triplicate. Generate a calibration curve. Place the inlet of the probe at the centroid of the duct, or at a point no closer to the walls than 1 m, and draw source gas into the probe, heated line, and sample loop. After thorough flushing, analyze the stack gas sample using the same conditions as for the calibration gas mixture. For each run, sample, analyze, and record five consecutive samples. A test consists of three runs (five samples per run times three runs, for a total of fifteen samples). After all samples have been analyzed, repeat the analysis of the mid-level calibration gas for each compound. For each calibration standard, compare the pre- and post-test average response factors (RF) for each compound. If the two calibration RF values (pre- and post-analysis) differ by more than 5 percent from their mean value, then analyze the other calibration gas levels for that compound and determine the stack gas sample concentrations by comparison to both calibration curves (this is done by preparing a calibration curve using all the pre- and post-test calibration gas mixture values.) If the two calibration RF values differ by less than 5 percent from their mean value, the tester has the option of using only the pre-test calibration curve to generate the concentration values. Record this calibration data and the other required data on the data sheet shown in Figure 18-11, deleting the dilution gas information.
Take care to draw all samples and calibration mixtures through the sample loop at the same pressure.
8.2.2.3 Determination of Stack Gas Moisture Content. Use Method 4 to measure the stack gas moisture content.
8.2.2.5 Emission Calculations. Same as section 8.2.1.8.
8.2.3 Dilution Interface Sampling and Analysis Procedure. Source samples that contain a high concentration of organic materials may require dilution prior to analysis to prevent saturating the GC detector. The apparatus required for this direct interface procedure is basically the same as that described in the section 8.2.2, except a dilution system is added between the heated sample line and the gas sampling valve. The apparatus is arranged so that either a 10:1 or 100:1 dilution of the source gas can be directed to the chromatograph. A pump of larger capacity is also required, and this pump must be heated and placed in the system between the sample line and the dilution apparatus.
8.2.3.1 Apparatus. The equipment required in addition to that specified for the direct interface system is as follows:
8.2.3.1.1 Sample Pump. Leakless Teflon-coated diaphragm-type that can withstand being heated to 120 °C and deliver 1.5 liters/minute.
8.2.3.1.2 Dilution Pumps. Two Model A-150 Komhyr Teflon positive displacement type delivering 150 cc/minute, or equivalent. As an option, calibrated flowmeters can be used in conjunction with Teflon-coated diaphragm pumps.
8.2.3.1.3 Valves. Two Teflon three-way valves, suitable for connecting to Teflon tubing.
8.2.3.1.4 Flowmeters. Two, for measurement of diluent gas.
8.2.3.1.5 Diluent Gas with Cylinders and Regulators. Gas can be nitrogen or clean dry air, depending on the nature of the source gases.
8.2.3.1.6 Heated Box. Suitable for being heated to 120 °C, to contain the three pumps, three-way valves, and associated connections. The box should be equipped with quick connect fittings to facilitate connection of: (1) the heated sample line from the probe, (2) the gas sampling valve, (3) the calibration gas mixtures, and (4) diluent gas lines. A schematic diagram of the components and connections is shown in Figure 18-13. The heated box shown in Figure 18-13 is designed to receive a heated line from the probe. An optional design is to build a probe unit that attaches directly to the heated box. In this way, the heated box contains the controls for the probe heaters, or, if the box is placed against the duct being sampled, it may be possible to eliminate the probe heaters. In either case, a heated Teflon line is used to connect the heated box to the gas sampling valve on the chromatograph.
Care must be taken to leak-check the system prior to the dilutions so as not to create a potentially explosive atmosphere.
8.2.3.2 Procedure.
8.2.3.2.1 Assemble the apparatus by connecting the heated box, shown in Figure 18-13, between the heated sample line from the probe and the gas sampling valve on the chromatograph. Vent the source gas from the gas sampling valve directly to the charcoal filter, eliminating the pump and rotameter. Heat the sample probe, sample line, and heated box. Insert the probe and source thermocouple at the centroid of the duct, or to a point no closer to the walls than 1 m. Measure the source temperature, and adjust all heating units to a temperature 0 to 3 °C above this temperature. If this temperature is above the safe operating temperature of the Teflon components, adjust the heating to maintain a temperature high enough to prevent condensation of water and organic compounds (greater than 110 °C). Calibrate the GC through the dilution system by following the procedures in section 8.2.1.5.2.1. Determine the concentration of the diluted calibration gas using the dilution factor and the certified concentration of the calibration gas. Record the pertinent data on the data sheet shown in Figure 18-11.
8.2.3.2.2 Once the dilution system and GC operations are satisfactory, proceed with the analysis of source gas, maintaining the same dilution settings as used for the standards.
8.2.3.2.3 Analyze the audit samples using either the dilution system, or directly connect to the gas sampling valve as required. Record all data and report the results to the audit supervisor.
8.2.3.3 Determination of Stack Gas Moisture Content. Same as section 8.2.2.3.
8.2.3.4 Quality Assurance. Same as section 8.2.2.4.
8.2.3.5 Emission Calculations. Same as section 8.2.2.5, with the dilution factor applied.
8.2.4 Adsorption Tube Procedure. Any commercially available adsorbent is allowed for the purposes of this method, as long as the recovery study criteria in section 8.4.3 are met. Help in choosing the adsorbent may be found by calling the distributor, or the tester may refer to National Institute for Occupational Safety and Health (NIOSH) methods for the particular organics to be sampled. For some adsorbents, the principal interferent will be water vapor. If water vapor is thought to be a problem, the tester may place a midget impinger in an ice bath before the adsorbent tubes. If this option is chosen, the water catch in the midget impinger shall be analyzed for the target compounds. Also, the spike for the recovery study (in section 8.4.3) shall be conducted in both the midget impinger and the adsorbent tubes. The combined recovery (add the recovered amount in the impinger and the adsorbent tubes to calculate R) shall then meet the criteria in section 8.4.3.
Post-test leak-checks are not allowed for this technique since this can result in sample contamination.
8.2.4.1 Additional Apparatus. The following items (or equivalent) are suggested.
8.2.4.1.1 Probe. Borosilicate glass or stainless steel, approximately 6-mm ID, with a heating system if water condensation is a problem, and a filter (either in-stack or out-of-stack, heated to stack temperature) to remove particulate matter. In most instances, a plug of glass wool is a satisfactory filter.
8.2.4.1.2 Flexible Tubing. To connect probe to adsorption tubes. Use a material that exhibits minimal sample adsorption.
8.2.4.1.3 Leakless Sample Pump. Flow controlled, constant rate pump, with a set of limiting (sonic) orifices.
8.2.4.1.4 Bubble-Tube Flowmeter. Volume accuracy within 1 percent, to calibrate pump.
8.2.4.1.5 Stopwatch. To time sampling and pump rate calibration.
8.2.4.1.6 Adsorption Tubes. Precleaned adsorbent, with mass of adsorbent to be determined by calculating breakthrough volume and expected concentration in the stack.
8.2.4.1.7 Barometer. Accurate to 5 mm Hg, to measure atmospheric pressure during sampling and pump calibration.
8.2.4.1.8 Rotameter. O to 100 cc/min, to detect changes in flow rate during sampling.
8.2.4.2 Sampling and Analysis.
8.2.4.2.1 Calibrate the pump and limiting orifice flow rate through adsorption tubes with the bubble tube flowmeter before sampling. The sample system can be operated as a “recirculating loop” for this operation. Record the ambient temperature and barometric pressure. Then, during sampling, use the rotameter to verify that the pump and orifice sampling rate remains constant.
8.2.4.2.2 Use a sample probe, if required, to obtain the sample at the centroid of the duct or at a point no closer to the walls than 1 m. Minimize the length of flexible tubing between the probe and adsorption tubes. Several adsorption tubes can be connected in series, if the extra adsorptive capacity is needed. Adsorption tubes should be maintained vertically during the test in order to prevent channeling. Provide the gas sample to the sample system at a pressure sufficient for the limiting orifice to function as a sonic orifice. Record the total time and sample flow rate (or the number of pump strokes), the barometric pressure, and ambient temperature. Obtain a total sample volume commensurate with the expected concentration(s) of the volatile organic(s) present and recommended sample loading factors (weight sample per weight adsorption media). Laboratory tests prior to actual sampling may be necessary to predetermine this volume. If water vapor is present in the sample at concentrations above 2 to 3 percent, the adsorptive capacity may be severely reduced. Operate the gas chromatograph according to the manufacturer’s instructions. After establishing optimum conditions, verify and document these conditions during all operations. Calibrate the instrument and then analyze the emission samples.
8.2.4.3 Standards and Calibration. If using thermal desorption, obtain calibration gases using the procedures in section 10.1. If using solvent extraction, prepare liquid standards in the desorption solvent. Use a minimum of three different standards; select the concentrations to bracket the expected average sample concentration. Perform the calibration before and after each day’s sample analyses using the procedures in section 8.2.1.5.2.1.
8.2.4.4 Quality Assurance.
8.2.4.4.1 Determine the recovery efficiency of the pollutants of interest according to section 8.4.3.
8.2.4.4.2 Determination of Sample Collection Efficiency (Optional). If sample breakthrough is thought to be a problem, a routine procedure for determining breakthrough is to analyze the primary and backup portions of the adsorption tubes separately. If the backup portion exceeds 10 percent of the total amount (primary and back-up), it is usually a sign of sample breakthrough. For the purposes of this method, only the recovery efficiency value (Section 8.4.3) is used to determine the appropriateness of the sampling and analytical procedure.
8.2.4.4.3 Volume Flow Rate Checks. Perform this check immediately after sampling with all sampling train components in place. Use the bubble-tube flowmeter to measure the pump volume flow rate with the orifice used in the test sampling, and record the result. If it has changed by more than 5 but less than 20 percent, calculate an average flow rate for the test. If the flow rate has changed by more than 20 percent, recalibrate the pump and repeat the sampling.
8.2.4.4.4 Calculations. Correct all sample volumes to standard conditions. If a sample dilution system has been used, multiply the results by the appropriate dilution ratio. Correct all results according to the applicable procedure in section 8.4.3. Report results as ppm by volume, dry basis.
8.3 Reporting of Results. At the completion of the field analysis portion of the study, ensure that the data sheets shown in Figure 18-11 have been completed. Summarize this data on the data sheets shown in Figure 18-15.
8.4 Recovery Study. After conducting the presurvey and identifying all of the pollutants of interest, conduct the appropriate recovery study during the test based on the sampling system chosen for the compounds of interest.
8.4.1 Recovery Study for Direct Interface or Dilution Interface Sampling. If the procedures in section 8.2.2 or 8.2.3 are to be used to analyze the stack gas, conduct the calibration procedure as stated in section 8.2.2.2 or 8.2.3.2, as appropriate. Upon successful completion of the appropriate calibration procedure, attach the mid-level calibration gas for at least one target compound to the inlet of the probe or as close as possible to the inlet of the probe, but before the filter. Repeat the calibration procedure by sampling and analyzing the mid-level calibration gas through the entire sampling and analytical system in triplicate. The mean of the calibration gas response sampled through the probe shall be within 10 percent of the analyzer response. If the difference in the two means is greater than 10 percent, check for leaks throughout the sampling system and repeat the analysis of the standard through the sampling system until this criterion is met.
8.4.2 Recovery Study for Bag Sampling.
8.4.2.1 Follow the procedures for the bag sampling and analysis in section 8.2.1. After analyzing all three bag samples, choose one of the bag samples and tag this bag as the spiked bag. Spike the chosen bag sample with a known mixture (gaseous or liquid) of all of the target pollutants. The theoretical concentration, in ppm, of each spiked compound in the bag shall be 40 to 60 percent of the average concentration measured in the three bag samples. If a target compound was not detected in the bag samples, the concentration of that compound to be spiked shall be 5 times the limit of detection for that compound. Store the spiked bag for the same period of time as the bag samples collected in the field. After the appropriate storage time has passed, analyze the spiked bag three times. Calculate the average fraction recovered (R) of each spiked target compound with the equation in section 12.7.
8.4.2.2 For the bag sampling technique to be considered valid for a compound, 0.70 ≤R ≤1.30. If the R value does not meet this criterion for a target compound, the sampling technique is not acceptable for that compound, and therefore another sampling technique shall be evaluated for acceptance (by repeating the recovery study with another sampling technique). Report the R value in the test report and correct all field measurements with the calculated R value for that compound by using the equation in section 12.8.
8.4.3 Recovery Study for Adsorption Tube Sampling. If following the adsorption tube procedure in section 8.2.4, conduct a recovery study of the compounds of interest during the actual field test. Set up two identical sampling trains. Collocate the two sampling probes in the stack. The probes shall be placed in the same horizontal plane, where the first probe tip is 2.5 cm from the outside edge of the other. One of the sampling trains shall be designated the spiked train and the other the unspiked train. Spike all of the compounds of interest (in gaseous or liquid form) onto the adsorbent tube(s) in the spiked train before sampling. The mass of each spiked compound shall be 40 to 60 percent of the mass expected to be collected with the unspiked train. Sample the stack gas into the two trains simultaneously. Analyze the adsorbents from the two trains utilizing identical analytical procedures and instrumentation. Determine the fraction of spiked compound recovered (R) using the equations in section 12.9.
8.4.3.1 Repeat the procedure in section 8.4.3 twice more, for a total of three runs. In order for the adsorbent tube sampling and analytical procedure to be acceptable for a compound, 0.70≤R≤1.30 (R in this case is the average of three runs). If the average R value does not meet this criterion for a target compound, the sampling technique is not acceptable for that compound, and therefore another sampling technique shall be evaluated for acceptance (by repeating the recovery study with another sampling technique). Report the R value in the test report and correct all field measurements with the calculated R value for that compound by using the equation in section 12.8.
9.1 Miscellaneous Quality Control Measures
| Section | Quality control measure | Effect |
|---|---|---|
| 8.4.1 | Recovery study for direct interface or dilution interface sampling | Ensure that there are no significant leaks in the sampling system. |
| 8.4.2 | Recovery study for bag sampling | Demonstrate that proper sampling/analysis procedures were selected. |
| 8.4.3 | Recovery study for adsorption tube sampling | Demonstrate that proper sampling/analysis procedures were selected. |
10.1 Calibration Standards. Obtain calibration gas standards for each target compound to be analyzed. Commercial cylinder gases certified by the manufacturer to be accurate to within 1 percent of the certified label value are preferable, although cylinder gases certified by the manufacturer to 2 percent accuracy are allowed. Another option allowed by this method is for the tester to obtain high concentration certified cylinder gases and then use a dilution system meeting the requirements of Test Method 205, 40 CFR Part 51, Appendix M to make multi-level calibration gas standards. Prepare or obtain enough calibration standards so that there are three different concentrations of each organic compound expected to be measured in the source sample. For each organic compound, select those concentrations that bracket the concentrations expected in the source samples. A calibration standard may contain more than one organic compound. If samples are collected in adsorbent tubes and extracted using solvent extraction, prepare or obtain standards in the same solvent used for the sample extraction procedure. Verify the stability of all standards for the time periods they are used.
10.2 Preparation of Calibration Curves.
10.2.1 Establish proper GC conditions, then flush the sampling loop for 30 seconds. Allow the sample loop pressure to equilibrate to atmospheric pressure, and activate the injection valve. Record the standard concentration, attenuator factor, injection time, chart speed, retention time, peak area, sample loop temperature, column temperature, and carrier gas flow rate. Analyze each standard in triplicate.
10.2.2 Repeat this procedure for each standard. Prepare a graphical plot of concentration (C
11.1 Analysis Development
11.1.1 Selection of GC Parameters
11.1.1.1 Column Choice. Based on the initial contact with plant personnel concerning the plant process and the anticipated emissions, choose a column that provides good resolution and rapid analysis time. The choice of an appropriate column can be aided by a literature search, contact with manufacturers of GC columns, and discussion with personnel at the emission source.
Most column manufacturers keep excellent records on their products. Their technical service departments may be able to recommend appropriate columns and detector type for separating the anticipated compounds, and they may be able to provide information on interferences, optimum operating conditions, and column limitations. Plants with analytical laboratories may be able to provide information on their analytical procedures.
11.1.1.2 Preliminary GC Adjustment. Using the standards and column obtained in section 11.1.1.1, perform initial tests to determine appropriate GC conditions that provide good resolution and minimum analysis time for the compounds of interest.
11.1.1.3 Preparation of Presurvey Samples. If the samples were collected on an adsorbent, extract the sample as recommended by the manufacturer for removal of the compounds with a solvent suitable to the type of GC analysis. Prepare other samples in an appropriate manner.
11.1.1.4 Presurvey Sample Analysis.
11.1.1.4.1 Before analysis, heat the presurvey sample to the duct temperature to vaporize any condensed material. Analyze the samples by the GC procedure, and compare the retention times against those of the calibration samples that contain the components expected to be in the stream. If any compounds cannot be identified with certainty by this procedure, identify them by other means such as GC/mass spectroscopy (GC/MS) or GC/infrared techniques. A GC/MS system is recommended.
11.1.1.4.2 Use the GC conditions determined by the procedure of section 11.1.1.2 for the first injection. Vary the GC parameters during subsequent injections to determine the optimum settings. Once the optimum settings have been determined, perform repeat injections of the sample to determine the retention time of each compound. To inject a sample, draw sample through the loop at a constant rate (100 ml/min for 30 seconds). Be careful not to pressurize the gas in the loop. Turn off the pump and allow the gas in the sample loop to come to ambient pressure. Activate the sample valve, and record injection time, loop temperature, column temperature, carrier flow rate, chart speed, and attenuator setting. Calculate the retention time of each peak using the distance from injection to the peak maximum divided by the chart speed. Retention times should be repeatable within 0.5 seconds.
11.1.1.4.3 If the concentrations are too high for appropriate detector response, a smaller sample loop or dilutions may be used for gas samples, and, for liquid samples, dilution with solvent is appropriate. Use the standard curves (Section 10.2) to obtain an estimate of the concentrations.
11.1.1.4.4 Identify all peaks by comparing the known retention times of compounds expected to be in the retention times of peaks in the sample. Identify any remaining unidentified peaks which have areas larger than 5 percent of the total using a GC/MS, or estimation of possible compounds by their retention times compared to known compounds, with confirmation by further GC analysis.
12.1 Nomenclature.
12.2 Calculate the concentration, C
12.3 Calculate the concentration, C
12.4 Calculate each organic standard concentration, C
12.5 Calculate each organic standard concentration, C
12.6 Calculate the concentration, C
12.7 Calculate the average fraction recovered (R) of each spiked target compound using the following equation:
12.8 Correct all field measurements with the calculated R value for that compound using the following equation:
12.9 Determine the mass per volume of spiked compound measured using the following equation:
12.10 Calculate the fraction of spiked compound recovered, R, using the following equation:
13.1 Since a potential sample may contain a variety of compounds from various sources, a specific precision limit for the analysis of field samples is impractical. Precision in the range of 5 to 10 percent relative standard deviation (RSD) is typical for gas chromatographic techniques, but an experienced GC operator with a reliable instrument can readily achieve 5 percent RSD. For this method, the following combined GC/operator values are required.
(a) Precision. Triplicate analyses of calibration standards fall within 5 percent of their mean value.
(b) Recovery. After developing an appropriate sampling and analytical system for the pollutants of interest, conduct the procedure in section 8.4. Conduct the appropriate recovery study in section 8.4 at each sampling point where the method is being applied. Submit the data and results of the recovery procedure with the reporting of results under section 8.3.
16.1 Optional Presurvey and Presurvey Sampling.
Presurvey screening is optional. Presurvey sampling should be conducted for sources where the target pollutants are not known from previous tests and/or process knowledge.
Perform a presurvey for each source to be tested. Refer to Figure 18-1. Some of the information can be collected from literature surveys and source personnel. Collect gas samples that can be analyzed to confirm the identities and approximate concentrations of the organic emissions.
16.1.1 Apparatus. This apparatus list also applies to sections 8.2 and 11.
16.1.1.1 Teflon Tubing. (Mention of trade names or specific products does not constitute endorsement by the U.S. Environmental Protection Agency.) Diameter and length determined by connection requirements of cylinder regulators and the GC. Additional tubing is necessary to connect the GC sample loop to the sample.
16.1.1.2 Gas Chromatograph. GC with suitable detector, columns, temperature-controlled sample loop and valve assembly, and temperature programmable oven, if necessary. The GC shall achieve sensitivity requirements for the compounds under study.
16.1.1.3 Pump. Capable of pumping 100 ml/min. For flushing sample loop.
16.1.1.4 Flow Meter. To measure flow rates.
16.1.1.5 Regulators. Used on gas cylinders for GC and for cylinder standards.
16.1.1.6 Recorder. Recorder with linear strip chart is minimum acceptable. Integrator (optional) is recommended.
16.1.1.7 Syringes. 0.5-ml, 1.0- and 10-microliter size, calibrated, maximum accuracy (gas tight) for preparing calibration standards. Other appropriate sizes can be used.
16.1.1.8 Tubing Fittings. To plumb GC and gas cylinders.
16.1.1.9 Septa. For syringe injections.
16.1.1.10 Glass Jars. If necessary, clean, colored glass jars with Teflon-lined lids for condensate sample collection. Size depends on volume of condensate.
16.1.1.11 Soap Film Flowmeter. To determine flow rates.
16.1.1.12 Flexible Bags. Tedlar or equivalent, 10- and 50-liter capacity, for preparation of standards. (Verify through the manufacturer that the Tedlar alternative is suitable for the compound of interest and make this verifying information available for inspection.)
16.1.1.13 Dry Gas Meter with Temperature and Pressure Gauges. Accurate to ±2 percent, for preparation of gas standards.
16.1.1.14 Midget Impinger/Hot Plate Assembly. For preparation of gas standards.
16.1.1.15 Sample Flasks. For presurvey samples, must have gas-tight seals.
16.1.1.16 Adsorption Tubes. If necessary, blank tubes filled with necessary adsorbent (charcoal, Tenax, XAD-2, etc.) for presurvey samples.
16.1.1.17 Personnel Sampling Pump. Calibrated, for collecting adsorbent tube presurvey samples.
16.1.1.18 Dilution System. Calibrated, the dilution system is to be constructed following the specifications of an acceptable method.
16.1.1.19 Sample Probes. Pyrex or stainless steel, of sufficient length to reach centroid of stack, or a point no closer to the walls than 1 m.
16.1.1.20 Barometer. To measure barometric pressure.
16.1.2 Reagents.
16.1.2.1 Water. Deionized distilled.
16.1.2.2 Methylene chloride.
16.1.2.3 Calibration Gases. A series of standards prepared for every compound of interest.
16.1.2.4 Organic Compound Solutions. Pure (99.9 percent), or as pure as can reasonably be obtained, liquid samples of all the organic compounds needed to prepare calibration standards.
16.1.2.5 Extraction Solvents. For extraction of adsorbent tube samples in preparation for analysis.
16.1.2.6 Fuel. As recommended by the manufacturer for operation of the GC.
16.1.2.7 Carrier Gas. Hydrocarbon free, as recommended by the manufacturer for operation of the detector and compatibility with the column.
16.1.2.8 Zero Gas. Hydrocarbon free air or nitrogen, to be used for dilutions, blank preparation, and standard preparation.
16.1.3 Sampling.
16.1.3.1 Collection of Samples with Glass Sampling Flasks. Presurvey samples may be collected in precleaned 250-ml double-ended glass sampling flasks. Teflon stopcocks, without grease, are preferred. Flasks should be cleaned as follows: Remove the stopcocks from both ends of the flasks, and wipe the parts to remove any grease. Clean the stopcocks, barrels, and receivers with methylene chloride (or other non-target pollutant solvent, or heat and humidified air). Clean all glass ports with a soap solution, then rinse with tap and deionized distilled water. Place the flask in a cool glass annealing furnace, and apply heat up to 500 °C. Maintain at this temperature for 1 hour. After this time period, shut off and open the furnace to allow the flask to cool. Return the stopcocks to the flask receivers. Purge the assembly with high-purity nitrogen for 2 to 5 minutes. Close off the stopcocks after purging to maintain a slight positive nitrogen pressure. Secure the stopcocks with tape. Presurvey samples can be obtained either by drawing the gases into the previously evacuated flask or by drawing the gases into and purging the flask with a rubber suction bulb.
16.1.3.1.1 Evacuated Flask Procedure. Use a high-vacuum pump to evacuate the flask to the capacity of the pump; then close off the stopcock leading to the pump. Attach a 6-mm outside diameter (OD) glass tee to the flask inlet with a short piece of Teflon tubing. Select a 6-mm OD borosilicate sampling probe, enlarged at one end to a 12-mm OD and of sufficient length to reach the centroid of the duct to be sampled. Insert a glass wool plug in the enlarged end of the probe to remove particulate matter. Attach the other end of the probe to the tee with a short piece of Teflon tubing. Connect a rubber suction bulb to the third leg of the tee. Place the filter end of the probe at the centroid of the duct, and purge the probe with the rubber suction bulb. After the probe is completely purged and filled with duct gases, open the stopcock to the grab flask until the pressure in the flask reaches duct pressure. Close off the stopcock, and remove the probe from the duct. Remove the tee from the flask and tape the stopcocks to prevent leaks during shipment. Measure and record the duct temperature and pressure.
16.1.3.1.2 Purged Flask Procedure. Attach one end of the sampling flask to a rubber suction bulb. Attach the other end to a 6-mm OD glass probe as described in section 8.3.3.1.1. Place the filter end of the probe at the centroid of the duct, or at a point no closer to the walls than 1 m, and apply suction with the bulb to completely purge the probe and flask. After the flask has been purged, close off the stopcock near the suction bulb, and then close off the stopcock near the probe. Remove the probe from the duct, and disconnect both the probe and suction bulb. Tape the stopcocks to prevent leakage during shipment. Measure and record the duct temperature and pressure.
16.1.3.2 Flexible Bag Procedure. Any leak-free plastic (e.g., Tedlar, Mylar, Teflon) or plastic-coated aluminum (e.g., aluminized Mylar) bag, or equivalent, can be used to obtain the pre-survey sample. Use new bags, and leak-check them before field use. In addition, check the bag before use for contamination by filling it with nitrogen or air and analyzing the gas by GC at high sensitivity. Experience indicates that it is desirable to allow the inert gas to remain in the bag about 24 hours or longer to check for desorption of organics from the bag. Follow the leak-check and sample collection procedures given in Section 8.2.1.
16.1.3.3 Determination of Moisture Content. For combustion or water-controlled processes, obtain the moisture content from plant personnel or by measurement during the presurvey. If the source is below 59 °C, measure the wet bulb and dry bulb temperatures, and calculate the moisture content using a psychrometric chart. At higher temperatures, use Method 4 to determine the moisture content.
16.1.4 Determination of Static Pressure. Obtain the static pressure from the plant personnel or measurement. If a type S pitot tube and an inclined manometer are used, take care to align the pitot tube 90° from the direction of the flow. Disconnect one of the tubes to the manometer, and read the static pressure; note whether the reading is positive or negative.
16.1.5 Collection of Presurvey Samples with Adsorption Tube. Follow section 8.2.4 for presurvey sampling.
1. American Society for Testing and Materials. C1 Through C5 Hydrocarbons in the Atmosphere by Gas Chromatography. ASTM D 2820-72, Part 23. Philadelphia, Pa. 23:950-958. 1973.
2. Corazon, V.V. Methodology for Collecting and Analyzing Organic Air Pollutants. U.S. Environmental Protection Agency. Research Triangle Park, N.C. Publication No. EPA-600/2-79-042. February 1979.
3. Dravnieks, A., B.K. Krotoszynski, J. Whitfield, A. O’Donnell, and T. Burgwald. Environmental Science and Technology. 5(12):1200-1222. 1971.
4. Eggertsen, F.T., and F.M. Nelsen. Gas Chromatographic Analysis of Engine Exhaust and Atmosphere. Analytical Chemistry. 30(6): 1040-1043. 1958.
5. Feairheller, W.R., P.J. Marn, D.H. Harris, and D.L. Harris. Technical Manual for Process Sampling Strategies for Organic Materials. U.S. Environmental Protection Agency. Research Triangle Park, N.C. Publication No. EPA 600/2-76-122. April 1976. 172 p.
6.
7.
8.
9.
10.
11. Fishbein, L. Chromatography of Environmental Hazards, Volume II. Elesevier Scientific Publishing Company. New York, N.Y. 1973.
12. Hamersma, J.W., S.L. Reynolds, and R.F. Maddalone. EPA/IERL-RTP Procedures Manual: Level 1 Environmental Assessment. U.S. Environmental Protection Agency. Research Triangle Park, N.C. Publication No. EPA 600/276-160a. June 1976. 130 p.
13. Harris, J.C., M.J. Hayes, P.L. Levins, and D.B. Lindsay. EPA/IERL-RTP Procedures for Level 2 Sampling and Analysis of Organic Materials. U.S. Environmental Protection Agency. Research Triangle Park, N.C. Publication No. EPA 600/7-79-033. February 1979. 154 p.
14. Harris, W.E., H.W. Habgood. Programmed Temperature Gas Chromatography. John Wiley and Sons, Inc. New York. 1966.
15. Intersociety Committee. Methods of Air Sampling and Analysis. American Health Association. Washington, D.C. 1972.
16. Jones, P.W., R.D. Grammer, P.E. Strup, and T.B. Stanford. Environmental Science and Technology. 10:806-810. 1976.
17. McNair Han Bunelli, E.J. Basic Gas Chromatography. Consolidated Printers. Berkeley. 1969.
18. Nelson, G.O. Controlled Test Atmospheres, Principles and Techniques. Ann Arbor. Ann Arbor Science Publishers. 1971. 247 p.
19. NIOSH Manual of Analytical Methods, Volumes 1, 2, 3, 4, 5, 6, 7. U.S. Department of Health and Human Services, National Institute for Occupational Safety and Health. Center for Disease Control. 4676 Columbia Parkway, Cincinnati, Ohio 45226. April 1977 – August 1981. May be available from the Superintendent of Documents, Government Printing Office, Washington, D.C. 20402. Stock Number/Price:
20. Schuetzle, D., T.J. Prater, and S.R. Ruddell. Sampling and Analysis of Emissions from Stationary Sources; I. Odor and Total Hydrocarbons. Journal of the Air Pollution Control Association. 25(9): 925-932. 1975.
21. Snyder, A.D., F.N. Hodgson, M.A. Kemmer and J.R. McKendree. Utility of Solid Sorbents for Sampling Organic Emissions from Stationary Sources. U.S. Environmental Protection Agency. Research Triangle Park, N.C. Publication No. EPA 600/2-76-201. July 1976. 71 p.
22. Tentative Method for Continuous Analysis of Total Hydrocarbons in the Atmosphere. Intersociety Committee, American Public Health Association. Washington, D.C. 1972. p. 184-186.
23. Zwerg, G. CRC Handbook of Chromatography, Volumes I and II. Sherma, Joseph (ed.). CRC Press. Cleveland. 1972.
Figure 18-3. Preparation of Standards in Tedlar or Tedlar-Equlivalent Bags and Calibration Curve
| Standards | |||
|---|---|---|---|
| Mixture #1 | Mixture #2 | Mixture #3 | |
| Standards Preparation Data: | |||
| Organic: | |||
| Bag number or identification | |||
| Dry gas meter calibration factor | |||
| Final meter reading (liters) | |||
| Initial meter reading (liters) | |||
| Metered volume (liters) | |||
| Average meter temperature (°K) | |||
| Average meter pressure, gauge (mm Hg) | |||
| Average atmospheric perssure (mm Hg) | |||
| Average meter pressure, absolute (mm Hg) | |||
| Syringe temperature (°K) (see section 10.1.2.1) | |||
| Syringe pressure, absolute (mm Hg) (see section 10.1.2.1) | |||
| Volume of gas in syringe (ml) (Section 10.1.2.1) | |||
| Density of liquid organic (g/ml) (Section 10.1.2.1) | |||
| Volume of liquid in syringe (ml) (Section 10.1.2.1) | |||
| GC Operating Conditions: | |||
| Sample loop volume (ml) | |||
| Sample loop temperature ( °C) | |||
| Carrier gas flow rate (ml/min) | |||
| Column temperature: | |||
| Initial ( °C) | |||
| Rate change ( °C/min) | |||
| Final ( °C) | |||
| Organic Peak Identification and Calculated Concentrations: | |||
| Injection time (24 hour clock) | |||
| Distance to peak (cm) | |||
| Chart speed (cm/min) | |||
| Organic retention time (min) | |||
| Attenuation factor | |||
| Peak height (mm) | |||
| Peak area (mm | |||
| Peak area * attenuation factor (mm | |||
| Calculated concentration (ppm) (Equation 18-3 or 18-4) | |||
Plot peak area * attenuation factor against calculated concentration to obtain calibration curve.
Flowmeter
| Reading (as marked) | Temp. (°K) | Pressure (absolute) |
|---|---|---|
Calibration Device
| Time (min) | Gas volume a | Flow rate b |
|---|---|---|
a Vol. of gas may be measured in milliliters, liters or cubic feet.
b Convert to standard conditions (20 °C and 760 mm Hg). Plot flowmeter reading against flow rate (standard conditions), and draw a smooth curve. If the flowmeter being calibrated is a rotameter or other flow device that is viscosity dependent, it may be necessary to generate a “family” of calibration curves that cover the operating pressure and temperature ranges of the flowmeter. While the following technique should be verified before application, it may be possible to calculate flow rate reading for rotameters at standard conditions Q
| Flow rate (laboratory conditions) | Flow rate (STD conditions) |
|---|---|
Preparation of Standards by Dilution of Cylinder Standard
[Cylinder Standard: Organic ________ Certified Concentration ________ ppm]
| Standards preparation data: | Date: | ||
|---|---|---|---|
| Mixture 1 | Mixture 2 | Mixture 3 | |
| Stage 1: | |||
| Standard gas flowmeter reading | |||
| Diluent gas flowmeter reading | |||
| Laboratory temperature (°K) | |||
| Barometric pressure (mm Hg) | |||
| Flowmeter gage pressure (mm Hg) | |||
| Flow rate cylinder gas at standard conditions (ml/min) | |||
| Flow rate diluent gas at standard conditions (ml/min) | |||
| Calculated concentration (ppm) | |||
| Stage 2 (if used): | |||
| Standard gas flowmeter reading | |||
| Diluent gas flowmeter reading | |||
| Flow rate Stage 1 gas at standard conditions (ml/min) | |||
| Flow rate diluent gas at standard conditions | |||
| Calculated concentration (ppm) | |||
| GC Operating Conditions: | |||
| Sample loop volume (ml) | |||
| Sample loop temperature ( °C) | |||
| Carrier gas flow rate (ml/min) | |||
| Column temperature: | |||
| Initial ( °C) | |||
| Program rate ( °C/min) | |||
| Final ( °C) | |||
| Organic Peak Identification and Calculated Concentrations: | |||
| Injection time (24-hour clock) | |||
| Distance to peak (cm) | |||
| Chart speed (cm/min) | |||
| Retention time (min) | |||
| Attenuation factor | |||
| Peak area (mm 2) | |||
| Peak area *attenuation factor | |||
Plot peak area *attenuation factor against calculated concentration to obtain calibration curve.
Plant________ Date________ Site________
| Sample 1 | Sample 2 | Sample 3 | |
|---|---|---|---|
| Source temperature ( °C) | |||
| Barometric pressure (mm Hg) | |||
| Ambient temperature ( °C) | |||
| Sample flow rate (appr.) | |||
| Bag number | |||
| Start time | |||
| Finish time |
Plant __________________ Date ________________ Location ________________________
| 1. General information: | |
| Source temperature ( °C) | |
| Probe temperature ( °C) | |
| Ambient temperature ( °C) | |
| Atmospheric pressure (mm) | |
| Source pressure (′Hg) | |
| Absolute source pressure (mm) | |
| Sampling rate (liter/min) | |
| Sample loop volume (ml) | |
| Sample loop temperature ( °C) | |
| Columnar temperature: | |
| Initial ( °C) time (min) | |
| Program rate ( °C/min) | |
| Final ( °C)/time (min) | |
| Carrier gas flow rate (ml/min) | |
| Detector temperature ( °C) | |
| Injection time (24-hour basis) | |
| Chart Speed (mm/min) | |
| Dilution gas flow rate (ml/min) | |
| Dilution gas used (symbol) | |
| Dilution ratio |
2. Field Analysis Data – Calibration Gas
2. [Run No. ________ Time ____________]
| Components | Area | Attenuation | A × A Factor | Conc.__ (ppm) |
|---|---|---|---|---|
Gaseous Organic Sampling and Analysis Check List
[Respond with initials or number as appropriate]
| Date | ||
|---|---|---|
| 1. Presurvey data: | ||
| A. Grab sample collected | □ | ______ |
| B. Grab sample analyzed for composition | □ | ______ |
| Method GC | □ | ______ |
| GC/MS | □ | ______ |
| Other | □ | ______ |
| C. GC-FID analysis performed | □ | ______ |
| 2. Laboratory calibration data: | ||
| A. Calibration curves prepared | □ | ______ |
| Number of components | □ | ______ |
| Number of concentrations/component (3 required) | □ | ______ |
| B. Audit samples (optional): | ||
| Analysis completed | □ | ______ |
| Verified for concentration | □ | ______ |
| OK obtained for field work | □ | ______ |
| 3. Sampling procedures: | ||
| A. Method: | ||
| Bag sample | □ | ______ |
| Direct interface | □ | ______ |
| Dilution interface | □ | ______ |
| B. Number of samples collected | □ | ______ |
| 4. Field Analysis: | ||
| A. Total hydrocarbon analysis performed | □ | ______ |
| B. Calibration curve prepared | □ | ______ |
| Number of components | □ | ______ |
| Number of concentrations per component (3 required) | □ | ______ |
Gaseous Organic Sampling and Analysis Check List (Respond With Initials or Number as Appropriate)
| 1. Pre-survey data | Date |
| A. Grab sample collected | ________ |
| B. Grab sample analyzed for composition | ________ |
| Method GC | ________ |
| GC/MS | ________ |
| Other________________________ | ________ |
| C. GC-FID analysis performed | ________ |
| 2. Laboratory calibration curves prepared | ________ |
| A. Number of components | ________ |
| B. Number of concentrations per component (3 required) | ________ |
| C. OK obtained for field work | ________ |
| 3. Sampling procedures | |
| A. Method | |
| Bag sample | ________ |
| Direct interface | ________ |
| Dilution interface | ________ |
| B. Number of samples collected | ________ |
| 4. Field Analysis | |
| A. Total hydrocarbon analysis performed | ________ |
| B. Calibration curve prepared | ________ |
| Number of components | ________ |
| Number of concentrations per component (3 required) | ________ |
Appendix A-7 to Part 60 – Test Methods 19 through 25E
The test methods in this appendix are referred to in § 60.8 (Performance Tests) and § 60.11 (Compliance With Standards and Maintenance Requirements) of 40 CFR part 60, subpart A (General Provisions). Specific uses of these test methods are described in the standards of performance contained in the subparts, beginning with Subpart D.
Within each standard of performance, a section title “Test Methods and Procedures” is provided to: (1) Identify the test methods to be used as reference methods to the facility subject to the respective standard and (2) identify any special instructions or conditions to be followed when applying a method to the respective facility. Such instructions (for example, establish sampling rates, volumes, or temperatures) are to be used either in addition to, or as a substitute for procedures in a test method. Similarly, for sources subject to emission monitoring requirements, specific instructions pertaining to any use of a test method as a reference method are provided in the subpart or in Appendix B.
Inclusion of methods in this appendix is not intended as an endorsement or denial of their applicability to sources that are not subject to standards of performance. The methods are potentially applicable to other sources; however, applicability should be confirmed by careful and appropriate evaluation of the conditions prevalent at such sources.
The approach followed in the formulation of the test methods involves specifications for equipment, procedures, and performance. In concept, a performance specification approach would be preferable in all methods because this allows the greatest flexibility to the user. In practice, however, this approach is impractical in most cases because performance specifications cannot be established. Most of the methods described herein, therefore, involve specific equipment specifications and procedures, and only a few methods in this appendix rely on performance criteria.
Minor changes in the test methods should not necessarily affect the validity of the results and it is recognized that alternative and equivalent methods exist. section 60.8 provides authority for the Administrator to specify or approve (1) equivalent methods, (2) alternative methods, and (3) minor changes in the methodology of the test methods. It should be clearly understood that unless otherwise identified all such methods and changes must have prior approval of the Administrator. An owner employing such methods or deviations from the test methods without obtaining prior approval does so at the risk of subsequent disapproval and retesting with approved methods.
Within the test methods, certain specific equipment or procedures are recognized as being acceptable or potentially acceptable and are specifically identified in the methods. The items identified as acceptable options may be used without approval but must be identified in the test report. The potentially approvable options are cited as “subject to the approval of the Administrator” or as “or equivalent.” Such potentially approvable techniques or alternatives may be used at the discretion of the owner without prior approval. However, detailed descriptions for applying these potentially approvable techniques or alternatives are not provided in the test methods. Also, the potentially approvable options are not necessarily acceptable in all applications. Therefore, an owner electing to use such potentially approvable techniques or alternatives is responsible for: (1) assuring that the techniques or alternatives are in fact applicable and are properly executed; (2) including a written description of the alternative method in the test report (the written method must be clear and must be capable of being performed without additional instruction, and the degree of detail should be similar to the detail contained in the test methods); and (3) providing any rationale or supporting data necessary to show the validity of the alternative in the particular application. Failure to meet these requirements can result in the Administrator’s disapproval of the alternative.
1.1 Analytes. This method provides data reduction procedures relating to the following pollutants, but does not include any sample collection or analysis procedures.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Nitrogen oxides (NO | ||
| Nitric oxide (NO) | 10102-43-9 | N/A |
| Nitrogen dioxide (NO | 10102-44-0 | |
| Particulate matter (PM) | None assigned | N/A |
| Sulfur dioxide (SO | 7499-09-05 | N/A |
1.2 Applicability. Where specified by an applicable subpart of the regulations, this method is applicable for the determination of (a) PM, SO
2.1 Emission Rates. Oxygen (O
2.2 Sulfur Reduction Efficiency and SO
2.2.1 The sulfur removal efficiency of a fuel pretreatment system is determined by fuel sampling and analysis of the sulfur and heat contents of the fuel before and after the pretreatment system.
2.2.2 The SO
2.2.2.1 The inlet rates to SO
12.1 Nomenclature
12.2 Emission Rates of PM, SO
Since F
12.2.1 Oxygen-Based F Factor, Dry Basis. When measurements are on a dry basis for both O (%O
12.2.2 Oxygen-Based F Factor, Wet Basis. When measurements are on a wet basis for both O
12.2.2.1 If the moisture fraction of ambient air (B
Instead of actual measurement, B
The estimates are selected to ensure that negative errors will not be larger than −1.5 percent. However, positive errors, or over-estimation of emissions by as much as 5 percent may be introduced depending upon the geographic location of the facility and the associated range of ambient moisture.
12.2.2.1.1 B
12.2.2.1.2 B
12.2.2.1.3 B
12.2.2.2 If the moisture fraction (B
12.2.3 Oxygen-Based F Factor, Dry/Wet Basis.
12.2.3.1 When the pollutant concentration is measured on a wet basis (C
12.2.3.2 When the pollutant concentration is measured on a dry basis (C
12.2.4 Carbon Dioxide-Based F Factor, Dry Basis. When measurements are on a dry basis for both CO
12.2.5 Carbon Dioxide-Based F Factor, Wet Basis. When measurements are on a wet basis for both CO
12.2.6 Carbon Dioxide-Based F Factor, Dry/Wet Basis.
12.2.6.1 When the pollutant concentration is measured on a wet basis (C
12.2.6.2 When the pollutant concentration is measured on a dry basis (C
12.2.7 Direct-Fired Reheat Fuel Burning. The effect of direct-fired reheat fuel burning (for the purpose of raising the temperature of the exhaust effluent from wet scrubbers to above the moisture dew-point) on emission rates will be less than 1.0 percent and, therefore, may be ignored.
12.2.8 Combined Cycle-Gas Turbine Systems. For gas turbine-steam generator combined cycle systems, determine the emissions from the steam generating unit or the percent reduction in potential SO
12.2.8.1 Compute the emission rate from the steam generating unit using the following equation:
12.2.8.1.1 Use the test methods and procedures section of 40 CFR Part 60, Subpart GG to obtain E
12.2.8.1.2 Suitable methods shall be used to determine the heat input rates to the steam generating units (H
12.2.8.2 If a control device is used, compute the percent of potential SO
Use the test methods and procedures section of Subpart GG to obtain E
12.3 F Factors. Use an average F factor according to section 12.3.1 or determine an applicable F factor according to section 12.3.2. If combined fuels are fired, prorate the applicable F factors using the procedure in section 12.3.3.
12.3.1 Average F Factors. Average F factors (F
12.3.2 Determined F Factors. If the fuel burned is not listed in Table 19-2 or if the owner or operator chooses to determine an F factor rather than use the values in Table 19-2, use the procedure below:
12.3.2.1 Equations. Use the equations below, as appropriate, to compute the F factors:
Omit the %H
12.3.2.2 Use applicable sampling procedures in section 12.5.2.1 or 12.5.2.2 to obtain samples for analyses.
12.3.2.3 Use ASTM D 3176-74 or 89 (all cited ASTM standards are incorporated by reference – see § 60.17) for ultimate analysis of the fuel.
12.3.2.4 Use applicable methods in section 12.5.2.1 or 12.5.2.2 to determine the heat content of solid or liquid fuels. For gaseous fuels, use ASTM D 1826-77 or 94 (incorporated by reference – see § 60.17) to determine the heat content.
12.3.3 F Factors for Combination of Fuels. If combinations of fuels are burned, use the following equations, as applicable unless otherwise specified in an applicable subpart:
12.4 Determination of Average Pollutant Rates.
12.4.1 Average Pollutant Rates from Hourly Values. When hourly average pollutant rates (E
12.4.2 Average Pollutant Rates from Other than Hourly Averages. When pollutant rates are determined from measured values representing longer than 1-hour periods (e.g., daily fuel sampling and analyses or Method 6B values), or when pollutant rates are determined from combinations of 1-hour and longer than 1-hour periods (e.g., CEMS and Method 6B values), compute the average pollutant rate (E
12.4.3 Daily Geometric Average Pollutant Rates from Hourly Values. The geometric average pollutant rate (E
12.5 Determination of Overall Reduction in Potential Sulfur Dioxide Emission.
12.5.1 Overall Percent Reduction. Compute the overall percent SO
12.5.2 Pretreatment Removal Efficiency (Optional). Compute the SO
In calculating %R
12.5.2.1 Solid Fossil (Including Waste) Fuel/Sampling and Analysis.
For the purposes of this method, raw fuel (coal or oil) is the fuel delivered to the desulfurization (pretreatment) facility. For oil, the input oil to the oil desulfurization process (e.g., hydrotreatment) is considered to be the raw fuel.
12.5.2.1.1 Sample Increment Collection. Use ASTM D 2234-76, 96, 97a, or 98 (incorporated by reference – see § 60.17), Type I, Conditions A, B, or C, and systematic spacing. As used in this method, systematic spacing is intended to include evenly spaced increments in time or increments based on equal weights of coal passing the collection area. As a minimum, determine the number and weight of increments required per gross sample representing each coal lot according to Table 2 or Paragraph 7.1.5.2 of ASTM D 2234. Collect one gross sample for each lot of raw coal and one gross sample for each lot of product coal.
12.5.2.1.2 ASTM Lot Size. For the purpose of section 12.5.2 (fuel pretreatment), the lot size of product coal is the weight of product coal from one type of raw coal. The lot size of raw coal is the weight of raw coal used to produce one lot of product coal. Typically, the lot size is the weight of coal processed in a 1-day (24-hour) period. If more than one type of coal is treated and produced in 1 day, then gross samples must be collected and analyzed for each type of coal. A coal lot size equaling the 90-day quarterly fuel quantity for a steam generating unit may be used if representative sampling can be conducted for each raw coal and product coal.
Alternative definitions of lot sizes may be used, subject to prior approval of the Administrator.
12.5.2.1.3 Gross Sample Analysis. Use ASTM D 2013-72 or 86 to prepare the sample, ASTM D 3177-75 or 89 or ASTM D 4239-85, 94, or 97 to determine sulfur content (%S), ASTM D 3173-73 or 87 to determine moisture content, and ASTM D 2015-77 (Reapproved 1978) or 96, D 3286-85 or 96, or D 5865-98 or 10 to determine gross calorific value (GCV) (all standards cited are incorporated by reference – see § 60.17 for acceptable versions of the standards) on a dry basis for each gross sample.
12.5.2.2 Liquid Fossil Fuel-Sampling and Analysis. See Note under section 12.5.2.1.
12.5.2.2.1 Sample Collection. Follow the procedures for continuous sampling in ASTM D 270 or D 4177-95 (incorporated by reference – see § 60.17) for each gross sample from each fuel lot.
12.5.2.2.2 Lot Size. For the purpose of section 12.5.2 (fuel pretreatment), the lot size of a product oil is the weight of product oil from one pretreatment facility and intended as one shipment (ship load, barge load, etc.). The lot size of raw oil is the weight of each crude liquid fuel type used to produce a lot of product oil.
Alternative definitions of lot sizes may be used, subject to prior approval of the Administrator.
12.5.2.2.3 Sample Analysis. Use ASTM D 129-64, 78, or 95, ASTM D 1552-83 or 95, or ASTM D 4057-81 or 95 to determine the sulfur content (%S) and ASTM D 240-76 or 92 (all standards cited are incorporated by reference – see § 60.17) to determine the GCV of each gross sample. These values may be assumed to be on a dry basis. The owner or operator of an affected facility may elect to determine the GCV by sampling the oil combusted on the first steam generating unit operating day of each calendar month and then using the lowest GCV value of the three GCV values per quarter for the GCV of all oil combusted in that calendar quarter.
12.5.2.3 Use appropriate procedures, subject to the approval of the Administrator, to determine the fraction of total mass input derived from each type of fuel.
12.5.3 Control Device Removal Efficiency. Compute the percent removal efficiency (%R
12.5.3.1 Use continuous emission monitoring systems or test methods, as appropriate, to determine the outlet SO
12.5.3.2 As an alternative, as-fired fuel sampling and analysis may be used to determine inlet SO
12.5.3.2.1 Compute the average inlet SO
12.5.3.2.2 Collect the fuel samples from a location in the fuel handling system that provides a sample representative of the fuel bunkered or consumed during a steam generating unit operating day. For the purpose of as-fired fuel sampling under section 12.5.3.2 or section 12.6, the lot size for coal is the weight of coal bunkered or consumed during each steam generating unit operating day. The lot size for oil is the weight of oil supplied to the “day” tank or consumed during each steam generating unit operating day. For reporting and calculation purposes, the gross sample shall be identified with the calendar day on which sampling began. For steam generating unit operating days when a coal-fired steam generating unit is operated without coal being added to the bunkers, the coal analysis from the previous “as bunkered” coal sample shall be used until coal is bunkered again. For steam generating unit operating days when an oil-fired steam generating unit is operated without oil being added to the oil “day” tank, the oil analysis from the previous day shall be used until the “day” tank is filled again. Alternative definitions of fuel lot size may be used, subject to prior approval of the Administrator.
12.5.3.2.3 Use ASTM procedures specified in section 12.5.2.1 or 12.5.2.2 to determine %S and GCV.
12.5.4 Daily Geometric Average Percent Reduction from Hourly Values. The geometric average percent reduction (%R
The calculation includes only paired data sets (hourly average) for the inlet and outlet pollutant measurements.
12.6 Sulfur Retention Credit for Compliance Fuel. If fuel sampling and analysis procedures in section 12.5.2.1 are being used to determine average SO
After calculating E
12.7 Determination of Compliance When Minimum Data Requirement Is Not Met.
12.7.1 Adjusted Emission Rates and Control Device Removal Efficiency. When the minimum data requirement is not met, the Administrator may use the following adjusted emission rates or control device removal efficiencies to determine compliance with the applicable standards.
12.7.1.1 Emission Rate. Compliance with the emission rate standard may be determined by using the lower confidence limit of the emission rate (E
12.7.1.2 Control Device Removal Efficiency. Compliance with the overall emission reduction (%R
12.7.2 Standard Deviation of Hourly Average Pollutant Rates. Compute the standard deviation (S
Equation 19-19 through 19-31 may be used to compute the standard deviation for both the outlet (S
Table 19-1 – Conversion Factors for Concentration
| From | To | Multiply by |
|---|---|---|
| g/scm | ng/scm | 10 9 |
| mg/scm | ng/scm | 10 6 |
| lb/scf | ng/scm | 1.602 × 10 13 |
| ppm SO | ng/scm | 2.66 × 10 6 |
| ppm NO | ng/scm | 1.912 × 10 6 |
| ppm SO | lb/scf | 1.660 × 10 |
| ppm NO | lb/scf | 1.194 × 10 |
Table 19-2 – F Factors for Various Fuels
1
| Fuel Type | F | F | F | |||
|---|---|---|---|---|---|---|
| dscm/J | dscf/10 6 Btu | wscm/J | wscf/10 6 Btu | scm/J | scf/10 6 Btu | |
| Coal: | ||||||
| Anthracite 2 | 2.71 × 10 | 10,100 | 2.83 × 10 | 10,540 | 0.530 × 10 | 1,970 |
| Bituminus 2 | 2.63 × 10 | 9,780 | 2.86 × 10 | 10,640 | 0.484 × 10 | 1,800 |
| Lignite | 2.65 × 10 | 9,860 | 3.21 × 10 | 11,950 | 0.513 × 10 | 1,910 |
| Oil 3 | 2.47 × 10 | 9,190 | 2.77 × 10 | 10,320 | 0.383 × 10 | 1,420 |
| Gas: | ||||||
| Natural | 2.34 × 10 | 8,710 | 2.85 × 10 | 10,610 | 0.287 × 10 | 1,040 |
| Propane | 2.34 × 10 | 8,710 | 2.74 × 10 | 10,200 | 0.321 × 10 | 1,190 |
| Butane | 2.34 × 10 | 8,710 | 2.79 × 10 | 10,390 | 0.337 × 10 | 1,250 |
| Wood | 2.48 × 10 | 9,240 | 0.492 × 10 | 1,830 | ||
| Wood Bark | 2.58 × 10 | 9,600 | 0.516 × 10 | 1,920 | ||
| Municipal | 2.57 × 10 | 9,570 | 0.488 × 10 | 1,820 | ||
| Solid Waste | ||||||
1 Determined at standard conditions: 20 °C (68 °F) and 760 mm Hg (29.92 in Hg)
2 As classified according to ASTM D 388.
3 Crude, residual, or distillate.
Table 19-3 – Values for T
| n 1 | t | n 1 | t | n 1 | t |
|---|---|---|---|---|---|
| 2 | 6.31 | 8 | 1.89 | 22-26 | 1.71 |
| 3 | 2.42 | 9 | 1.86 | 27-31 | 1.70 |
| 4 | 2.35 | 10 | 1.83 | 32-51 | 1.68 |
| 5 | 2.13 | 11 | 1.81 | 52-91 | 1.67 |
| 6 | 2.02 | 12-16 | 1.77 | 92-151 | 1.66 |
| 7 | 1.94 | 17-21 | 1.73 | 152 or more | 1.65 |
1The values of this table are corrected for n-1 degrees of freedom. Use n equal to the number (H) of hourly average data points.
Method 20 contains the details you must follow when using an instrumental analyzer to determine concentrations of nitrogen oxides, oxygen, carbon dioxide, and sulfur dioxide in the emissions from stationary gas turbines. This method follows the specific instructions for equipment and performance requirements, supplies, sample collection and analysis, calculations, and data analysis in the methods listed in section 2.0.
1.1 Analytes. What does this method determine?
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Nitrogen oxides (NO | 10102-43-9 | Typically |
| Nitric oxide (NO) | 10102-44-0 | |
| Nitrogen dioxide NO | ||
| Diluent oxygen (O | Typically | |
| Sulfur dioxide (SO | 7446-09-5 | Typically |
1.2 Applicability. When is this method required? The use of Method 20 may be required by specific New Source Performance Standards, Clean Air Marketing rules, and State Implementation Plans and permits where measuring SO
1.3 Data Quality Objectives. How good must my collected data be? Refer to section 1.3 of Method 7E.
In this method, NO
(a) Method 1 – Sample and Velocity Traverses for Stationary Sources.
(b) Method 3A – Determination of Oxygen and Carbon Dioxide Emissions From Stationary Sources (Instrumental Analyzer Procedure).
(c) Method 6C – Determination of Sulfur Dioxide Emissions From Stationary Sources (Instrumental Analyzer Procedure).
(d) Method 7E – Determination of Nitrogen Oxides Emissions From Stationary Sources (Instrumental Analyzer Procedure).
(e) Method 19 – Determination of Sulfur Dioxide Removal Efficiency and Particulate Matter, Sulfur Dioxide, and Nitrogen Oxide Emission Rates.
Refer to section 3.0 of Method 7E for the applicable definitions.
Refer to section 4.0 of Methods 3A, 6C, and 7E as applicable.
Refer to section 5.0 of Method 7E.
The measurement system design is shown in Figure 7E-1 of Method 7E. Refer to the appropriate methods listed in section 2.0 for equipment and supplies.
Refer to the appropriate methods listed in section 2.0 for reagents and standards.
8.1 Sampling Site and Sampling Points. Follow the procedures of section 8.1 of Method 7E. For the stratification test in section 8.1.2, determine the diluent-corrected pollutant concentration at each traverse point.
8.2 Initial Measurement System Performance Tests. You must refer to the appropriate methods listed in section 2.0 for the measurement system performance tests as applicable.
8.3 Interference Check. You must follow the procedures in section 8.3 of Method 3A or 6C, or section 8.2.7 of Method 7E (as appropriate).
8.4 Sample Collection. You must follow the procedures of section 8.4 of the appropriate methods listed in section 2.0. A test run must have a duration of at least 21 minutes.
8.5 Post-Run System Bias Check, Drift Assessment, and Alternative Dynamic Spike Procedure. You must follow the procedures of sections 8.5 and 8.6 of the appropriate methods listed in section 2.0. A test run must have a duration of at least 21 minutes.
Follow quality control procedures in section 9.0 of Method 7E.
Follow the procedures for calibration and standardization in section 10.0 of Method 7E.
Because sample collection and analysis are performed together (see section 8), additional discussion of the analytical procedure is not necessary.
You must follow the procedures for calculations and data analysis in section 12.0 of the appropriate method listed in section 2.0. Follow the procedures in section 12.0 of Method 19 for calculating fuel-specific F factors, diluent-corrected pollutant concentrations, and emission rates.
The specifications for the applicable performance checks are the same as in section 13.0 of Method 7E.
Refer to section 16.0 of the appropriate method listed in section 2.0 for alternative procedures.
Refer to section 17.0 of the appropriate method listed in section 2.0 for references.
Refer to section 18.0 of the appropriate method listed in section 2.0 for tables, diagrams, flowcharts, and validation data.
1.1 Analytes.
| Analyte | CAS No. |
|---|---|
| Volatile Organic Compounds (VOC) | No CAS number assigned. |
1.2 Scope. This method is applicable for the determination of VOC leaks from process equipment. These sources include, but are not limited to, valves, flanges and other connections, pumps and compressors, pressure relief devices, process drains, open-ended valves, pump and compressor seal system degassing vents, accumulator vessel vents, agitator seals, and access door seals.
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 A portable instrument is used to detect VOC leaks from individual sources. The instrument detector type is not specified, but it must meet the specifications and performance criteria contained in section 6.0. A leak definition concentration based on a reference compound is specified in each applicable regulation. This method is intended to locate and classify leaks only, and is not to be used as a direct measure of mass emission rate from individual sources.
3.1 Calibration gas means the VOC compound used to adjust the instrument meter reading to a known value. The calibration gas is usually the reference compound at a known concentration approximately equal to the leak definition concentration.
3.2 Calibration precision means the degree of agreement between measurements of the same known value, expressed as the relative percentage of the average difference between the meter readings and the known concentration to the known concentration.
3.3 Leak definition concentration means the local VOC concentration at the surface of a leak source that indicates that a VOC emission (leak) is present. The leak definition is an instrument meter reading based on a reference compound.
3.4 No detectable emission means a local VOC concentration at the surface of a leak source, adjusted for local VOC ambient concentration, that is less than 2.5 percent of the specified leak definition concentration. that indicates that a VOC emission (leak) is not present.
3.5 Reference compound means the VOC species selected as the instrument calibration basis for specification of the leak definition concentration. (For example, if a leak definition concentration is 10,000 ppm as methane, then any source emission that results in a local concentration that yields a meter reading of 10,000 on an instrument meter calibrated with methane would be classified as a leak. In this example, the leak definition concentration is 10,000 ppm and the reference compound is methane.)
3.6 Response factor means the ratio of the known concentration of a VOC compound to the observed meter reading when measured using an instrument calibrated with the reference compound specified in the applicable regulation.
3.7 Response time means the time interval from a step change in VOC concentration at the input of the sampling system to the time at which 90 percent of the corresponding final value is reached as displayed on the instrument readout meter.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method.
5.2 Hazardous Pollutants. Several of the compounds, leaks of which may be determined by this method, may be irritating or corrosive to tissues (e.g., heptane) or may be toxic (e.g., benzene, methyl alcohol). Nearly all are fire hazards. Compounds in emissions should be determined through familiarity with the source. Appropriate precautions can be found in reference documents, such as reference No. 4 in section 16.0.
A VOC monitoring instrument meeting the following specifications is required:
6.1 The VOC instrument detector shall respond to the compounds being processed. Detector types that may meet this requirement include, but are not limited to, catalytic oxidation, flame ionization, infrared absorption, and photoionization.
6.2 The instrument shall be capable of measuring the leak definition concentration specified in the regulation.
6.3 The scale of the instrument meter shall be readable to ±2.5 percent of the specified leak definition concentration.
6.4 The instrument shall be equipped with an electrically driven pump to ensure that a sample is provided to the detector at a constant flow rate. The nominal sample flow rate, as measured at the sample probe tip, shall be 0.10 to 3.0 l/min (0.004 to 0.1 ft
6.5 The instrument shall be equipped with a probe or probe extension or sampling not to exceed 6.4 mm (
6.6 The instrument shall be intrinsically safe for operation in explosive atmospheres as defined by the National Electrical Code by the National Fire Prevention Association or other applicable regulatory code for operation in any explosive atmospheres that may be encountered in its use. The instrument shall, at a minimum, be intrinsically safe for Class 1, Division 1 conditions, and/or Class 2, Division 1 conditions, as appropriate, as defined by the example code. The instrument shall not be operated with any safety device, such as an exhaust flame arrestor, removed.
7.1 Two gas mixtures are required for instrument calibration and performance evaluation:
7.1.1 Zero Gas. Air, less than 10 parts per million by volume (ppmv) VOC.
7.1.2 Calibration Gas. For each organic species that is to be measured during individual source surveys, obtain or prepare a known standard in air at a concentration approximately equal to the applicable leak definition specified in the regulation.
7.2 Cylinder Gases. If cylinder calibration gas mixtures are used, they must be analyzed and certified by the manufacturer to be within 2 percent accuracy, and a shelf life must be specified. Cylinder standards must be either reanalyzed or replaced at the end of the specified shelf life.
7.3 Prepared Gases. Calibration gases may be prepared by the user according to any accepted gaseous preparation procedure that will yield a mixture accurate to within 2 percent. Prepared standards must be replaced each day of use unless it is demonstrated that degradation does not occur during storage.
7.4 Mixtures with non-Reference Compound Gases. Calibrations may be performed using a compound other than the reference compound. In this case, a conversion factor must be determined for the alternative compound such that the resulting meter readings during source surveys can be converted to reference compound results.
8.1 Instrument Performance Evaluation. Assemble and start up the instrument according to the manufacturer’s instructions for recommended warmup period and preliminary adjustments.
8.1.1 Response Factor. A response factor must be determined for each compound that is to be measured, either by testing or from reference sources. The response factor tests are required before placing the analyzer into service, but do not have to be repeated at subsequent intervals.
8.1.1.1 Calibrate the instrument with the reference compound as specified in the applicable regulation. Introduce the calibration gas mixture to the analyzer and record the observed meter reading. Introduce zero gas until a stable reading is obtained. Make a total of three measurements by alternating between the calibration gas and zero gas. Calculate the response factor for each repetition and the average response factor.
8.1.1.2 The instrument response factors for each of the individual VOC to be measured shall be less than 10 unless otherwise specified in the applicable regulation. When no instrument is available that meets this specification when calibrated with the reference VOC specified in the applicable regulation, the available instrument may be calibrated with one of the VOC to be measured, or any other VOC, so long as the instrument then has a response factor of less than 10 for each of the individual VOC to be measured.
8.1.1.3 Alternatively, if response factors have been published for the compounds of interest for the instrument or detector type, the response factor determination is not required, and existing results may be referenced. Examples of published response factors for flame ionization and catalytic oxidation detectors are included in References 1-3 of section 17.0.
8.1.2 Calibration Precision. The calibration precision test must be completed prior to placing the analyzer into service and at subsequent 3-month intervals or at the next use, whichever is later.
8.1.2.1 Make a total of three measurements by alternately using zero gas and the specified calibration gas. Record the meter readings. Calculate the average algebraic difference between the meter readings and the known value. Divide this average difference by the known calibration value and multiply by 100 to express the resulting calibration precision as a percentage.
8.1.2.2 The calibration precision shall be equal to or less than 10 percent of the calibration gas value.
8.1.3 Response Time. The response time test is required before placing the instrument into service. If a modification to the sample pumping system or flow configuration is made that would change the response time, a new test is required before further use.
8.1.3.1 Introduce zero gas into the instrument sample probe. When the meter reading has stabilized, switch quickly to the specified calibration gas. After switching, measure the time required to attain 90 percent of the final stable reading. Perform this test sequence three times and record the results. Calculate the average response time.
8.1.3.2 The instrument response time shall be equal to or less than 30 seconds. The instrument pump, dilution probe (if any), sample probe, and probe filter that will be used during testing shall all be in place during the response time determination.
8.2 Instrument Calibration. Calibrate the VOC monitoring instrument according to section 10.0.
8.3 Individual Source Surveys.
8.3.1 Type I – Leak Definition Based on Concentration. Place the probe inlet at the surface of the component interface where leakage could occur. Move the probe along the interface periphery while observing the instrument readout. If an increased meter reading is observed, slowly sample the interface where leakage is indicated until the maximum meter reading is obtained. Leave the probe inlet at this maximum reading location for approximately two times the instrument response time. If the maximum observed meter reading is greater than the leak definition in the applicable regulation, record and report the results as specified in the regulation reporting requirements. Examples of the application of this general technique to specific equipment types are:
8.3.1.1 Valves. The most common source of leaks from valves is the seal between the stem and housing. Place the probe at the interface where the stem exits the packing gland and sample the stem circumference. Also, place the probe at the interface of the packing gland take-up flange seat and sample the periphery. In addition, survey valve housings of multipart assembly at the surface of all interfaces where a leak could occur.
8.3.1.2 Flanges and Other Connections. For welded flanges, place the probe at the outer edge of the flange-gasket interface and sample the circumference of the flange. Sample other types of nonpermanent joints (such as threaded connections) with a similar traverse.
8.3.1.3 Pumps and Compressors. Conduct a circumferential traverse at the outer surface of the pump or compressor shaft and seal interface. If the source is a rotating shaft, position the probe inlet within 1 cm of the shaft-seal interface for the survey. If the housing configuration prevents a complete traverse of the shaft periphery, sample all accessible portions. Sample all other joints on the pump or compressor housing where leakage could occur.
8.3.1.4 Pressure Relief Devices. The configuration of most pressure relief devices prevents sampling at the sealing seat interface. For those devices equipped with an enclosed extension, or horn, place the probe inlet at approximately the center of the exhaust area to the atmosphere.
8.3.1.5 Process Drains. For open drains, place the probe inlet at approximately the center of the area open to the atmosphere. For covered drains, place the probe at the surface of the cover interface and conduct a peripheral traverse.
8.3.1.6 Open-ended Lines or Valves. Place the probe inlet at approximately the center of the opening to the atmosphere.
8.3.1.7 Seal System Degassing Vents and Accumulator Vents. Place the probe inlet at approximately the center of the opening to the atmosphere.
8.3.1.8 Access door seals. Place the probe inlet at the surface of the door seal interface and conduct a peripheral traverse.
8.3.2 Type II – “No Detectable Emission”. Determine the local ambient VOC concentration around the source by moving the probe randomly upwind and downwind at a distance of one to two meters from the source. If an interference exists with this determination due to a nearby emission or leak, the local ambient concentration may be determined at distances closer to the source, but in no case shall the distance be less than 25 centimeters. Then move the probe inlet to the surface of the source and determine the concentration as outlined in section 8.3.1. The difference between these concentrations determines whether there are no detectable emissions. Record and report the results as specified by the regulation. For those cases where the regulation requires a specific device installation, or that specified vents be ducted or piped to a control device, the existence of these conditions shall be visually confirmed. When the regulation also requires that no detectable emissions exist, visual observations and sampling surveys are required. Examples of this technique are:
8.3.2.1 Pump or Compressor Seals. If applicable, determine the type of shaft seal. Perform a survey of the local area ambient VOC concentration and determine if detectable emissions exist as described in section 8.3.2.
8.3.2.2 Seal System Degassing Vents, Accumulator Vessel Vents, Pressure Relief Devices. If applicable, observe whether or not the applicable ducting or piping exists. Also, determine if any sources exist in the ducting or piping where emissions could occur upstream of the control device. If the required ducting or piping exists and there are no sources where the emissions could be vented to the atmosphere upstream of the control device, then it is presumed that no detectable emissions are present. If there are sources in the ducting or piping where emissions could be vented or sources where leaks could occur, the sampling surveys described in section 8.3.2 shall be used to determine if detectable emissions exist.
8.3.3 Alternative Screening Procedure.
8.3.3.1 A screening procedure based on the formation of bubbles in a soap solution that is sprayed on a potential leak source may be used for those sources that do not have continuously moving parts, that do not have surface temperatures greater than the boiling point or less than the freezing point of the soap solution, that do not have open areas to the atmosphere that the soap solution cannot bridge, or that do not exhibit evidence of liquid leakage. Sources that have these conditions present must be surveyed using the instrument technique of section 8.3.1 or 8.3.2.
8.3.3.2 Spray a soap solution over all potential leak sources. The soap solution may be a commercially available leak detection solution or may be prepared using concentrated detergent and water. A pressure sprayer or squeeze bottle may be used to dispense the solution. Observe the potential leak sites to determine if any bubbles are formed. If no bubbles are observed, the source is presumed to have no detectable emissions or leaks as applicable. If any bubbles are observed, the instrument techniques of section 8.3.1 or 8.3.2 shall be used to determine if a leak exists, or if the source has detectable emissions, as applicable.
| Section | Quality control measure | Effect |
|---|---|---|
| 8.1.2 | Instrument calibration precision check | Ensure precision and accuracy, respectively, of instrument response to standard. |
| 10.0 | Instrument calibration |
10.1 Calibrate the VOC monitoring instrument as follows. After the appropriate warmup period and zero internal calibration procedure, introduce the calibration gas into the instrument sample probe. Adjust the instrument meter readout to correspond to the calibration gas value.
If the meter readout cannot be adjusted to the proper value, a malfunction of the analyzer is indicated and corrective actions are necessary before use.
1. Dubose, D.A., and G.E. Harris. Response Factors of VOC Analyzers at a Meter Reading of 10,000 ppmv for Selected Organic Compounds. U.S. Environmental Protection Agency, Research Triangle Park, NC. Publication No. EPA 600/2-81051. September 1981.
2. Brown, G.E., et al. Response Factors of VOC Analyzers Calibrated with Methane for Selected Organic Compounds. U.S. Environmental Protection Agency, Research Triangle Park, NC. Publication No. EPA 600/2-81-022. May 1981.
3. DuBose, D.A. et al. Response of Portable VOC Analyzers to Chemical Mixtures. U.S. Environmental Protection Agency, Research Triangle Park, NC. Publication No. EPA 600/2-81-110. September 1981.
4. Handbook of Hazardous Materials: Fire, Safety, Health. Alliance of American Insurers. Schaumberg, IL. 1983.
This method is not inclusive with respect to observer certification. Some material is incorporated by reference from Method 9.
This method is applicable for the determination of the frequency of fugitive emissions from stationary sources, only as specified in an applicable subpart of the regulations. This method also is applicable for the determination of the frequency of visible smoke emissions from flares.
2.1 Fugitive emissions produced during material processing, handling, and transfer operations or smoke emissions from flares are visually determined by an observer without the aid of instruments.
2.2 This method is used also to determine visible smoke emissions from flares used for combustion of waste process materials.
2.3 This method determines the amount of time that visible emissions occur during the observation period (i.e., the accumulated emission time). This method does not require that the opacity of emissions be determined. Since this procedure requires only the determination of whether visible emissions occur and does not require the determination of opacity levels, observer certification according to the procedures of Method 9 is not required. However, it is necessary that the observer is knowledgeable with respect to the general procedures for determining the presence of visible emissions. At a minimum, the observer must be trained and knowledgeable regarding the effects of background contrast, ambient lighting, observer position relative to lighting, wind, and the presence of uncombined water (condensing water vapor) on the visibility of emissions. This training is to be obtained from written materials found in References 1 and 2 or from the lecture portion of the Method 9 certification course.
3.1 Emission frequency means the percentage of time that emissions are visible during the observation period.
3.2 Emission time means the accumulated amount of time that emissions are visible during the observation period.
3.3 Fugitive emissions means emissions generated by an affected facility which is not collected by a capture system and is released to the atmosphere. This includes emissions that (1) escape capture by process equipment exhaust hoods; (2) are emitted during material transfer; (3) are emitted from buildings housing material processing or handling equipment; or (4) are emitted directly from process equipment.
3.4 Observation period means the accumulated time period during which observations are conducted, not to be less than the period specified in the applicable regulation.
3.5 Smoke emissions means a pollutant generated by combustion in a flare and occurring immediately downstream of the flame. Smoke occurring within the flame, but not downstream of the flame, is not considered a smoke emission.
4.1 Occasionally, fugitive emissions from sources other than the affected facility (e.g., road dust) may prevent a clear view of the affected facility. This may particularly be a problem during periods of high wind. If the view of the potential emission points is obscured to such a degree that the observer questions the validity of continuing observations, then the observations shall be terminated, and the observer shall clearly note this fact on the data form.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method.
6.1 Stopwatches (two). Accumulative type with unit divisions of at least 0.5 seconds.
6.2 Light Meter. Light meter capable of measuring illuminance in the 50 to 200 lux range, required for indoor observations only.
11.1 Selection of Observation Location. Survey the affected facility, or the building or structure housing the process to be observed, and determine the locations of potential emissions. If the affected facility is located inside a building, determine an observation location that is consistent with the requirements of the applicable regulation (i.e., outside observation of emissions escaping the building/structure or inside observation of emissions directly emitted from the affected facility process unit). Then select a position that enables a clear view of the potential emission point(s) of the affected facility or of the building or structure housing the affected facility, as appropriate for the applicable subpart. A position at least 4.6 m (15 feet), but not more than 400 m (0.25 miles), from the emission source is recommended. For outdoor locations, select a position where the sunlight is not shining directly in the observer’s eyes.
11.2 Field Records.
11.2.1 Outdoor Location. Record the following information on the field data sheet (Figure 22-1): Company name, industry, process unit, observer’s name, observer’s affiliation, and date. Record also the estimated wind speed, wind direction, and sky condition. Sketch the process unit being observed, and note the observer location relative to the source and the sun. Indicate the potential and actual emission points on the sketch. Alternatively, digital photography as described in section 11.2.3 may be used for a subset of the recordkeeping requirements of this section.
11.2.2 Indoor Location. Record the following information on the field data sheet (Figure 22-2): Company name, industry, process unit, observer’s name, observer’s affiliation, and date. Record as appropriate the type, location, and intensity of lighting on the data sheet. Sketch the process unit being observed, and note the observer location relative to the source. Indicate the potential and actual fugitive emission points on the sketch. Alternatively, digital photography as described in section 11.2.3 may be used for a subset of the recordkeeping requirements of this section.
11.2.3 Digital Photographic Records. Digital photographs, annotated or unaltered, may be used to record and report sky conditions, observer’s location relative to the source, observer’s location relative to the sun, process unit being observed, potential emission points and actual emission points for the requirements in sections 11.2.1 and 11.2.2. The image must have the proper lighting, field of view and depth of field to properly distinguish the sky condition (if applicable), process unit, potential emission point and actual emission point. At least one digital photograph must be from the point of the view of the observer. The photograph(s) representing the environmental conditions including the sky conditions and the position of the sun relative to the observer and the emission point must be taken within a reasonable time of the observation (i.e., 15 minutes). When observations are taken from exactly the same observation point on a routine basis (i.e., daily) and as long as there are no modifications to the units depicted, only a single photograph each is necessary to document the observer’s location relative to the emissions source, the process unit being observed, and the location of potential and actual emission points. Any photographs altered or annotated must be retained in an unaltered format for recordkeeping purposes.
11.3 Indoor Lighting Requirements. For indoor locations, use a light meter to measure the level of illumination at a location as close to the emission source(s) as is feasible. An illumination of greater than 100 lux (10 foot candles) is considered necessary for proper application of this method.
11.4 Observations.
11.4.1 Procedure. Record the clock time when observations begin. Use one stopwatch to monitor the duration of the observation period. Start this stopwatch when the observation period begins. If the observation period is divided into two or more segments by process shutdowns or observer rest breaks (see section 11.4.3), stop the stopwatch when a break begins and restart the stopwatch without resetting it when the break ends. Stop the stopwatch at the end of the observation period. The accumulated time indicated by this stopwatch is the duration of observation period. When the observation period is completed, record the clock time. During the observation period, continuously watch the emission source. Upon observing an emission (condensed water vapor is not considered an emission), start the second accumulative stopwatch; stop the watch when the emission stops. Continue this procedure for the entire observation period. The accumulated elapsed time on this stopwatch is the total time emissions were visible during the observation period (i.e., the emission time.)
11.4.2 Observation Period. Choose an observation period of sufficient length to meet the requirements for determining compliance with the emission standard in the applicable subpart of the regulations. When the length of the observation period is specifically stated in the applicable subpart, it may not be necessary to observe the source for this entire period if the emission time required to indicate noncompliance (based on the specified observation period) is observed in a shorter time period. In other words, if the regulation prohibits emissions for more than 6 minutes in any hour, then observations may (optional) be stopped after an emission time of 6 minutes is exceeded. Similarly, when the regulation is expressed as an emission frequency and the regulation prohibits emissions for greater than 10 percent of the time in any hour, then observations may (optional) be terminated after 6 minutes of emission are observed since 6 minutes is 10 percent of an hour. In any case, the observation period shall not be less than 6 minutes in duration. In some cases, the process operation may be intermittent or cyclic. In such cases, it may be convenient for the observation period to coincide with the length of the process cycle.
11.4.3 Observer Rest Breaks. Do not observe emissions continuously for a period of more than 15 to 20 minutes without taking a rest break. For sources requiring observation periods of greater than 20 minutes, the observer shall take a break of not less than 5 minutes and not more than 10 minutes after every 15 to 20 minutes of observation. If continuous observations are desired for extended time periods, two observers can alternate between making observations and taking breaks.
11.5 Recording Observations. Record the accumulated time of the observation period on the data sheet as the observation period duration. Record the accumulated time emissions were observed on the data sheet as the emission time. Record the clock time the observation period began and ended, as well as the clock time any observer breaks began and ended.
If the applicable subpart requires that the emission rate be expressed as an emission frequency (in percent), determine this value as follows: Divide the accumulated emission time (in seconds) by the duration of the observation period (in seconds) or by any minimum observation period required in the applicable subpart, if the actual observation period is less than the required period, and multiply this quotient by 100.
1. Missan, R., and A. Stein. Guidelines for Evaluation of Visible Emissions Certification, Field Procedures, Legal Aspects, and Background Material. EPA Publication No. EPA-340/1-75-007. April 1975.
2. Wohlschlegel, P., and D.E. Wagoner. Guideline for Development of a Quality Assurance Program: Volume IX – Visual Determination of Opacity Emissions from Stationary Sources. EPA Publication No. EPA-650/4-74-005i. November 1975.
1.1 Applicability. This method applies to the measurement of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/PCDF), polychlorinated biphenyls (PCB), and/or polycyclic aromatic hydrocarbons (PAH) in emissions from stationary sources. Using this method, you can measure these analyte groups individually or in any combination using a single sample acquisition unless otherwise specified in a rule, regulation, or permit. Tables 23-1 through 23-3 of this method list the applicable target analytes for Method 23. If all 209 PCB are analyzed, the 17 toxic PCB congeners should be resolved and reported while the other PCB can be reported as totals by homolog, for example, total trichlorobiphenyl (TrCB).
1.2 Scope. This method describes the sampling and analytical procedures used to measure selected PCDD and PCDF in stationary sources when required in an applicable subpart. This method also describes how the same sampling and analysis technology can be used to measure selected PCB and PAH from stationary source in combination or as each individual compound class when required in an applicable subpart. However, Method 23 incorporates by reference some of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) from other methods in this part that are essential to conducting Method 23. To obtain reliable samples, source sampling teams should be trained and experienced with the following additional EPA test methods: Method 1, Method 2, Method 3, Method 4, and Method 5 of Appendices A-1, A-2, and A-3 to 40 CFR part 60. Laboratory analysis teams should be trained and experienced with Method 1668C (found at: https://www.epa.gov/sites/production/files/2015-09/documents/method_1668c_2010.pdf) and Method 1613B of 40 CFR part 136 Appendix A and have a working knowledge of isotope dilution and the use of high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS).
1.3 The HRGC/HRMS portions of this method are for use by laboratory analysts experienced with HRGC/HRMS analysis of PCDD, PCDF, PCB, and PAH or under the close supervision of such qualified persons. Each source testing team, including the sampling and laboratory organization(s) that use this method, must demonstrate the ability to generate acceptable results that meet the performance criteria in Section 13 of this method.
1.4 This method is “performance-based” and includes acceptability criteria for assessing sampling and analytical procedures. Users may modify the method to overcome interferences or to substitute superior materials and equipment, provided that they meet all performance criteria in this method. Section 13 of this method presents requirements for method performance.
This method identifies and determines the concentration of specific PCDD, PCDF, PCB, and PAH compounds. Gaseous and particulate bound target pollutants are withdrawn from the gas stream isokinetically and collected in the sample probe, on a glass fiber or quartz filter, and on a packed column of adsorbent material. This method is not intended to differentiate between target compounds in particulate or vapor fractions. The target compounds are extracted from the combined sample collection media. Portions of the extract are chromatographically fractionated to remove interferences, separated into individual compounds or simple mixtures by HRGC, and measured with HRMS. This method uses isotopically labeled standards to improve method accuracy and precision through isotope dilution quantitation.
3.1 Alternate Recovery Standards. A group of isotopically labeled compounds that is not otherwise designated in this method for quality control (QC) purposes. Alternate recovery standards can be used to assess the recovery of a compound class relative to any step in the sampling and analysis procedure that is not already assessed as a mandatory part of this method, such as the cleanup step.
3.2 Benzo[a]pyrene Toxic Equivalency Quotient (B[a]P-TEQ). One of several schemes that express the toxicity for PAH compounds in terms of the most toxic form of PAH, benzo[a]pyrene, as specified in applicable regulations, permits, or other requirements.
3.3 Continuing Calibration Verification (CCV) Standard. A standard prepared at the mid-point concentration of the calibration used to verify the initial calibration. Prepare the CCV standard at the same time as the batch of field samples using the same labeled standards.
3.4 Congener. An individual compound with a common structure (dioxin, furan, or biphenyl), only differing by the number of chlorine or other substituent attached to the structure.
3.5 Estimated Detection Limit (EDL). The minimum qualitatively recognizable signal above background for a target compound. The EDL is a detection limit specific to each sample analysis based on the noise signal measured near the retention time of a target compound or target isomer group. Being sample specific, the EDL is affected by sample size, dilution, recoveries of pre-extraction standard, chemical noise from sample extract, electronic noise from instrument, extract aliquot, relative response of instrument, etc.
3.6 Estimated Maximum Possible Concentration (EMPC). An EMPC is a worst-case estimate of the target compound concentration. Report the results as EMPC when the ion abundance ratio for a target analyte is outside the performance criteria. Calculate the EMPC using both quantitation ions.
3.7 Field Train Proof Blank. A field train proof blank train is a QC sample to evaluate equipment preparation and potential contamination during sample recovery and consists of a fully assembled train at the sampling site, without actual sampling. The field train proof blank train uses glassware from the same preparation batch as the field samples.
3.8 Homolog. A compound belonging to a series of compounds with the same general molecular formula, differing from each other by the number of repeating units of chlorine.
3.9 Isomer. An individual compound with a common structure (dioxin, furan, or biphenyl), only differing by the position of chlorine atoms attached to the structure.
3.10 Isotope Dilution. A means of determining a naturally occurring (native) compound by reference to the same compound in which one or more atoms has been isotopically enriched.
3.11 Laboratory Method Blank (LMB). A quality control sample to assess background contamination or interference from media, reagents, equipment, etc. An LMB is prepared in the laboratory, composed of clean sampling media (filter and XAD-2), using same labeled standards, media, reagents, and materials (sodium sulfate, glass wool, etc.) and processed (extraction, fractionations, cleanup) and analyzed using the same procedures as a field sample.
3.12 Polychlorinated Biphenyl (PCB) congeners. Any or all 209 chlorinated biphenyl congeners. Table 23-3 of this method lists the primary target compounds and Appendix A to this method provides the full list of 209 PCB congeners and isomers.
3.12.1 Monochlorobiphenyl (MoCB). Any or all three monochlorinated biphenyl isomers.
3.12.2 Dichlorobiphenyl (DiCB). Any or all 12 dichlorinated biphenyl isomers.
3.12.3 Trichlorobiphenyl (TrCB). Any or all 24 trichlorinated biphenyl isomers.
3.12.4 Tetrachlorobiphenyl (TeCB). Any or all 42 tetrachlorinated biphenyl isomers.
3.12.5 Pentachlorobiphenyl (PeCB). Any or all 46 pentachlorinated biphenyl isomers.
3.12.6 Hexachlorobiphenyl (HxCB). Any or all 42 hexachlorinated biphenyl isomers.
3.12.7 Heptachlorobiphenyl (HpCB). Any or all 24 heptachlorinated biphenyl isomers.
3.12.8 Octachlorobiphenyl (OcCB). Any or all 12 octachlorinated biphenyl isomers.
3.12.9 Nonachlorobiphenyl (NoCB). Any or all three nonachlorinated biphenyl isomers.
3.12.10 Decachlorobiphenyl (DeCB). Biphenyl fully chlorinated with 10 chlorine atom substituents replacing hydrogen in the parent compound.
3.13 Polychlorinated dibenzo-p-dioxin (PCDD) congeners. Any or all 75 chlorinated dibenzo-p-dioxin congeners. There are seven 2,3,7,8 substituted PCDD congeners and four PCDD homolog groups listed in Table 23-1 of this method. This method does not measure mono- through tri-PCDD and includes non-2,3,7,8 substituted congeners in the total homolog categories.
3.13.1 Tetrachlorodibenzo-p-dioxin (TeCDD). Any or all 22 tetrachlorinated dibenzo-p-dioxin isomers.
3.13.2 Pentachlorodibenzo-p-dioxin (PeCDD). Any or all 14 pentachlorinated dibenzo-p-dioxin isomers.
3.13.3 Hexachlorodibenzo-p-dioxin (HxCDD). Any or all 10 hexachlorinated dibenzo-p-dioxin isomers.
3.13.4 Heptachlorodibenzo-p-dioxin (HpCDD). Any or all two heptachlorinated dibenzo-p-dioxin isomers.
3.13.5 Octachlorodibenzo-p-dioxin (OCDD). Dibenzodioxin fully chlorinated with eight chlorine atom substituents replacing hydrogen in the parent compound.
3.14 Polychlorinated dibenzofuran (PCDF) congeners. Any or all chlorinated dibenzofuran congeners. There are ten 2,3,7,8 substituted PCDF congeners and four PCDF homolog groups listed in Table 23-1 of this method. This method does not measure mono- through tri-PCDF and includes non-2,3,7,8 substituted congeners in the total homolog categories.
3.14.1 Tetrachlorodibenzofuran (TeCDF). Any or all 38 tetrachlorinated dibenzofuran isomers.
3.14.2 Pentachlorodibenzofuran (PeCDF). Any or all 28 pentachlorinated dibenzofuran isomers.
3.14.3 Hexachlorodibenzofuran (HxCDF). Any or all 16 hexachlorinated dibenzofuran isomers.
3.14.4 Heptachlordibenzofuran (HpCDF). Any or all four heptachlorinated dibenzofuran isomers.
3.14.5 Octachlorodibenzofuran (OCDF). Dibenzofuran fully chlorinated with eight chlorine atom substituents replacing hydrogen in the parent compound.
3.15 Polychlorinated diphenyl ethers (PCDPE). Any or all chlorinated substituted diphenyl ethers.
3.15.1 Hexachlorodiphenyl ether (HxCDPE). Any or all 42 hexachlorinated diphenyl ether isomers.
3.15.2 Heptachlorodiphenyl ether (HpCDPE). Any or all 24 heptachlorinated diphenyl ether isomers.
3.15.3 Octachlorodiphenyl ether (OCDPE). Any or all 12 octachlorinated diphenyl ether isomers.
3.15.4 Nonachlorodiphenyl ether (NCDPE). Any or all three nonachlorinated diphenyl ether isomers.
3.15.5 Decachlorodiphenyl ether (DCDPE).
3.16 Polycyclic Aromatic Hydrocarbons (PAH). Any or all aromatic compounds with two or more fused six-member rings. Table 23-2 of this method lists the target PAH compounds for this method. You may add and analyze additional PAH compounds by adding the appropriate
3.17 Pre-analysis Standard. A group of isotopically labeled compounds added at a known amount immediately prior to analysis and used to monitor instrument response, injection errors, instrument drift and to determine the recovery of the pre-extraction standard compounds. Add pre-analysis standard to every sample (including blank, QC samples, and calibration solutions) at a known amount.
3.18 Pre-extraction Filter Recovery Standard. A group of isotopically labeled compounds added at a known amount to the filter used to indicate the extraction efficiency of the filter media. Add pre-extraction filter recovery standard to the filter samples just prior extraction. The pre-extraction filter recovery standard is not used for quantitating or recovery correction.
3.19 Pre-extraction Standard. A group of isotopically labeled compounds added in a known amount to the XAD-2 adsorbent resin of each sample immediately before extraction and used for quantitation of target and other labeled compounds to correct for extraction, cleanup, and concentration recovery. These isotopically labeled compounds constitute a matrix spike of the resin. Add pre-extraction standard to every sample at the same level (including blank, QC samples, and calibration solutions).
3.20 Pre-sampling Adsorbent Standard. A group of isotopically labeled compounds added in a known amount to the XAD-2 adsorbent prior to sampling used to monitor sampling aspects of the method.
3.21 Pre-transport Standard. Spiking compound from the list of alternative recovery standards that can be added by the laboratory to the sample shipping containers used to transport field equipment rinse and recovery samples prior to sampling. The measured concentration of the pre-transport recovery standard provides a quality check on potential probe rinse sample spillage or mishandling after sample collection and during shipping.
3.22 Quality Control Sample (QCS). A mid-level standard prepared from a second source standard or prepared from a source of standards different from the source of calibration standards. The purpose of the QCS is to verify the integrity of the primary calibration standards. A QCS is analyzed during the initial demonstration of capability (IDC) and following each initial calibration (at a minimum quarterly) thereafter.
3.23 Relative Response Factor (RRF). The response of the mass spectrometer (MS) to a known amount of an analyte relative to a known amount of an isotopically labeled standard.
3.24 2,3,7,8-Tetrachlorodibenzo-p-dioxin Toxic Equivalency Quotient (2,3,7,8-TeCDD TEQ). A procedure that expresses the toxicity of PCDD, PCDF, and PCB in terms of the most toxic dioxin, as specified in applicable regulations, permits, or other requirements.
Despite interferences, confidence of the data is based on the enhanced selectivity of fractionation, gas chromatograph (GC) separation and detector resolving power, the QC check ions, and monitoring PCDPE.
4.1 PCB and PCDPE have similar molecular weight and chromatographic properties to PCDD and PCDF. PCB may produce fragment ions at interfering mass-to-charge ratios (m/z) when losing chlorine (Cl
4.2 Very high amounts of other organic compounds in the matrix may interfere with the analysis. This method provides examples of column-chromatographic cleanup as procedures to reduce, but not necessarily eliminate, matrix effects due to high concentrations of organic compounds (International Agency for Research on Cancer 1991).
4.3 Target compound contaminants or related organics in solvents, reagents, glassware, isotopically labeled spiking standards, and other sample processing hardware are potential method interferences. Routinely evaluate all these materials to demonstrate that they are either free from interferences under the conditions of the analysis, or that the interference does not compromise the quality of the analysis results. Evaluate chemical interference through the preparation and analysis of an LMB. Use high purity reagents, solvents, and standards to minimize interferences in sample analysis.
4.4 PAH are subject to degradation when exposed to ultraviolet light. Take precautions to shield samples from sunlight or fluorescent light sources during sample collection, recovery, extraction, cleanup, and concentration.
5.1 Compounds in the PCDD and PCDF classes such as 2,3,7,8-TeCDD are aneugenic, carcinogenic, and teratogenic in laboratory animal studies. Other PCDD and PCDF containing chlorine atoms in positions 2,3,7,8 have toxicities comparable to that of 2,3,7,8-TeCDD.
5.2 PCB and benzo[a]pyrene are classified as known or suspected human or mammalian carcinogens. Be aware of the potential for inhalation and ingestion exposure to laboratory analysts.
5.3 This method recommends that the laboratory purchase dilute standard solutions of the analytes required for this method. However, if preparing primary solutions, use a hood or glove box. Laboratory personnel handling primary solutions should wear personal protective equipment including a toxic gas respirator mask fitted with charcoal filters approved by the National Institute for Occupational Safety and Health (NIOSH)/Mine Safety Health Administration (MSHA) to prevent the inhalation of airborne particulates if not working in an approved hood or glove box.
5.4 The toxicity or carcinogenicity of other reagents or chemicals used in this method is not precisely defined. However, treat each chemical as a potential health hazard and minimize exposure to these chemicals. The laboratory is responsible for maintaining a current awareness file of Occupational Safety and Health Administration (OSHA) regulations regarding the safe handling of the chemicals specified in this method. Ensure that a reference file or list of internet sites that contain safety data sheets (SDS) is available to all personnel involved in the sampling and chemical analysis of samples known or suspected to contain PCDD, PCDF, PCB, and PAH.
6.1 Sampling Apparatus. Figure 23-1 of this method shows a schematic of the Method 23 sampling train. Do not use sealing greases or brominated flame retardant-coated tape in assembling the train. Do not use silicon tubing in direct contact with flue gases. The train is identical to that described in Section 6.1.1 of Method 5 of Appendix A-3 to 40 CFR part 60 with the following additions:
6.1.1 Nozzle. The nozzle must be made of quartz, borosilicate glass, or titanium. Stainless steel nozzles should not be used.
6.1.2 Probe Liner. Use either polytetrafluoroethylene (PTFE), borosilicate, or quartz glass probe liners with a heating system capable of maintaining a probe gas temperature of 120 ± 14 °C (248 ± 25 °F) during sampling, or such other temperature as specified by an applicable subpart of the standards or as approved by the Administrator. Use a PTFE ferrule or single-use PTFE coated O-ring to achieve the seal at the nozzle end of the probe for stack temperatures up to about 300 °C (572 °F). Use a quartz glass liner and integrated quartz nozzle for stack temperatures between 300 and 1,200 °C (572 and 2,192 °F).
6.1.3 Filter Holder. Use a filter holder of borosilicate glass with a PTFE frit or PTFE-coated wire filter support. The holder design should provide a positive seal against leakage from the outside or around the filter. The holder should be durable, easy to load, leak-free in normal applications, and positioned immediately following the probe and cyclone bypass (or cyclone, if used) with the active side of the filter perpendicular to the source of the flow.
6.1.4 Filter Heating System. Use any heating system capable of monitoring and maintaining the temperature around the filter to ensure that the sample gas temperature exiting the filter is 120 ± 14 °C (248 ± 25 °F) during sampling or such other temperature as specified by an applicable subpart of the standards or approved by the Administrator for a particular application.
6.1.5 Filter Temperature Sensor. Install a temperature sensor capable of measuring temperature to within ±3 °C (5.4 °F) so that the sensing tip protrudes at least 1.3 centimeters (cm) (1-2 in.) into the sample gas exiting the filter. Encase the sensing tip of the sensor in glass or PTFE, if needed.
6.1.6 Sample Transfer Line. The sample transfer line transports gaseous emissions from the heated filter holder to the condenser and must be heat traced and constructed of glass or PTFE with connecting fittings that form leak-free, vacuum-tight connections without using sealing greases or tapes. Keep the sample transfer lines as short as possible and maintain the lines at a temperature of 120 °C ± 14 °C (248 °F ± 25 °F) using active heating when necessary. Orient the sample transfer lines with the downstream end lower than the upstream end so that any condensate will flow away from the filter and into the condenser.
6.1.7 Condenser. Glass, water-jacketed, coil-type with compatible fittings. Orient the condenser to cause moisture to flow down to the adsorbent module to facilitate condensate drainage. Figure 23-2 of this method shows a schematic diagram of the condenser.
6.1.8 Water Circulating Bath. Use a bath pump circulating system capable of providing chilled water flow to the condenser and adsorbent module water jackets. Typically, a submersible pump is placed in the impinger ice water bath to circulate the ice water contained in the bath. Verify the function of this system by measuring the gas temperature at the entrance to the adsorbent module. Maintain this temperature at
6.1.9 Adsorbent Module. Use a water-jacketed glass container to hold up to 40 grams (g) of the solid adsorbent. Figure 23-2 of this method shows a schematic diagram of the adsorbent module. Other physical configurations of the adsorbent resin module/condenser assembly are acceptable if the configuration contains the requisite amount of solid adsorbent and maintains the minimum length-to-width adsorbent bed ratio of two-to-one. Orient the adsorbent module vertically to facilitate condensate drainage. The connecting fittings must form leak-free, vacuum-tight seals. Include a coarse glass frit in the adsorbent module to retain the adsorbent.
6.1.10 Impingers. Use five impingers connected in series with leak-free ground glass fittings or any similar leak-free noncontaminating fittings. The first impinger must be a short-stem (water-dropout) design or equivalent. The second, fourth, and fifth impingers must be of the Greenburg-Smith design, modified by replacing the tip with a 1.3 cm (
6.2 Sample Recovery Equipment.
6.2.1 Fitting Caps. Use leak-free ground glass fittings or any similar leak-free non-contaminating fitting to cap the sections of the sampling train exposed to the sample gas. Alternatively, use PTFE tape or contaminant-free aluminum foil for this purpose (see Section 6.2.6 of this method).
6.2.2 Wash Bottles. Use PTFE bottles.
6.2.3 Probe-Liner, Probe-Nozzle, and Filter-Holder Brushes. Use inert bristle brushes with precleaned stainless steel or PTFE handles. Extensions of the probe brush must be made of stainless steel or PTFE and be at least as long as the probe. Use brushes that are properly sized and shaped to remove accumulated material from the nozzle and probe liner if used.
6.2.4 Filter Storage Container. Use a sealed filter holder, wide-mouth amber glass jar with PTFE-lined cap, or glass petri dish sealed with PTFE tape. Purchase precleaned amber glass jars and petri dishes, or clean according to the glassware cleaning procedures listed in Section 8.1.1.1 of this method.
6.2.5 Field Balance. Use a weighing device capable of measurements to an accuracy of 0.5 g.
6.2.6 Aluminum Foil. Use heavy duty aluminum foil cleaned by rinsing three times with hexane or toluene and stored in a pre-cleaned glass petri dish or glass jar. Do not use aluminum foil to wrap or contact filter samples due to the possibility of reaction between the sample and the aluminum.
6.2.7 Silica Adsorbent Storage Container. Use an air-tight container to store silica gel.
6.2.8 Glass Sample Storage Container. Recover samples in amber glass bottles, 500- or 1000-milliliters (mL) with leak-free PTFE-lined caps. Either purchase precleaned bottles or clean containers according to glassware cleaning procedures listed in Section 8.1.1.1 of this method.
6.3 Sample Extraction Equipment.
6.3.1 Sample Container. Use 125- and 250-mL amber glass bottles with PTFE-lined caps.
6.3.2 Test Tubes. Use glass test tubes or small (e.g., 5 to 10 mL) amber vials.
6.3.3 Soxhlet/Dean-Stark Extraction Apparatus.
6.3.3.1 Soxhlet Apparatus. Use 200-mL capacity thimble holder capable of holding 43 × 123-millimeter (mm) extraction thimbles, with receiving flask (typically round-bottom).
6.3.3.2 Moisture Trap. Use Dean-Stark or Barret with fluoropolymer stopcock trap to fit between the Soxhlet extractor body and the condenser as shown in Figure 23-3 of this method.
6.3.3.3 Extraction Thimble. Use quartz, glass, or glass fiber thimble, typically 43 × 123 mm to fit Soxhlet apparatus. The use of cellulose thimbles for sample extraction in this method is prohibited.
6.3.3.4 Heating Mantle. Use a hemispherical shaped heating mantle to fit round-bottom flask.
6.3.4 Kuderna-Danish (KD) Concentrator. Use an apparatus consisting of a three-ball Snyder column, a flask with leak-free joint to accept the three-ball Snyder column at the top, a leak-free joint to receive a graduated concentration tube at the bottom and a heating mantle.
6.3.5 Nitrogen Evaporative Concentrator. Use a nitrogen evaporative concentrator equipped with a water bath with the temperature controlled in the range of 30 to 60 °C (86 to 140 °F) (N-Evap Organomation Associates, Inc., South Berlin, MA, or equivalent).
6.3.6 Separatory Funnels. Use glass or PTFE 2-liter separatory funnels.
6.4 Glass Liquid Chromatography Columns.
6.4.1 Pasteur Pipettes. Use disposable pipettes, or glass serological pipettes typically 150 mm long × 6 mm ID.
6.4.2 Liquid Chromatography Columns. 200 to 300 mm long × 20 mm ID with 250-mL reservoir.
6.5 Analytical Equipment.
6.5.1 Gas Chromatograph. Use a gas chromatograph consisting of the following components:
6.5.1.1 GC Oven. Use an oven capable of maintaining the separation column at the proper operating temperature ± 1.0 °C (1.8 °F) and performing programmed increases in temperature at rates of at least 40 °C/min with isothermal hold.
6.5.1.2 GC Temperature Monitor. Use a temperature monitor to measure column oven temperature to ± 1.0 °C (1.8 °F).
6.5.1.3 GC Flow System. Use an electronic pressure control or equivalent gas metering system to control carrier gas flow or pressure.
6.5.1.4 GC Injection Port. Use a split/splitless injection port in the splitless mode or on-column injection port for the capillary column.
6.5.2 Capillary GC Column. Use different columns for the analysis of the different target compound classes in this method, if needed. Perform the resolution checks in Sections 10.2.3.5 and 10.2.3.6 of this method to document the required resolution. Compound separation must meet the resolution specifications in Section 10.2.3.5 of this method and the identification specifications found in Section 11.4.3.4 of this method.
6.5.2.1 PCDD/PCDF Column. Gas chromatographic columns used to measure PCDD/PCDF should be capable of achieving separation of the 17 PCDD/PCDF target compounds from the nearest eluting target compound(s). The valley height resolution between 2,3,7,8-substituted TeCDD and TeCDF and the nearest eluting isomers must not exceed 25% of the taller of the two peaks. The valley height resolution between all other target PCDD/PCDF compounds and the nearest eluting targets (or interference) must not exceed 40% of the taller of the two peaks.
6.5.2.2 PAH Column. Use column systems for measuring PAH that can achieve separation of anthracene and phenanthrene at m/z 178 such that the valley between the peaks does not exceed 50% of the taller of the two peaks, and benzo[b]fluoranthene and benzo[k]fluoranthene such that the valley between the peaks is less than 60% of the height of the taller peak. These requirements are achievable using a 30-m narrow bore (0.25 mm ID) 5% phenyl polysilphenylene-siloxane (BPX5 or equivalent) bonded-phase, fused-silica capillary column.
6.5.2.3 PCB Column. Use column systems for measuring PCB that can achieve unique resolution and identification of the toxics for determination of a TEQ
6.5.3 Mass Spectrometer. Instrument employing 28 to 70 electron volt ionization. The instrument and data system must be capable of repetitive monitoring of at least 12 exact m/z values with a mass resolution defined in Section 10.2.1 within the measurement mass range. The recommended lock-mass ions to be used for mass drift correction are presented in Tables 23-4, 23-5, and 23-6 of this method for PCDD/PCDF, PAH, and PCB, respectively, as applicable to target analytes. Mass drifts of 5 parts per million (ppm) or more can have serious effects on instrument performance.
6.5.4 Mass Spectrometer Data System. Use a data system compatible with the mass spectrometer and capable of sequencing and monitoring multiple groups of selected ions.
6.5.5 Analytical Balance. Use an analytical balance to measure within 0.1 milligram (mg).
7.1 Filter. Glass fiber filters, without organic binder, exhibiting at least 99.95% efficiency (
7.1.1 Conduct a QC check on the filter lot prior to the field test to demonstrate that filters are free from contamination or interference by extracting and analyzing a minimum of three filters from each lot as follows. Spike with pre-extraction and pre-extraction filter recovery standards for target compounds to be measured and extract each filter separately with toluene as described in Section 11 of this method. After extraction, remove the filters and the solvent from the filters under clean conditions (e.g., a clean nitrogen stream). Analyze the extracts according to the procedures in Section 11 of this method, including adding pre-analysis standard. This filter check analysis must meet the performance requirements in Section 13.1 of this method. Ongoing analysis of LMB can be used to fulfill this check. If criteria are not met for target compounds, repeat with additional filters from the lot or evaluate another lot.
7.2 Adsorbent Resin. Amberlite® XAD-2 resin. All adsorbent resin must meet the cleanliness criteria described for LMB in Section 13.1 of this method following the same extraction, concentration, cleanup, and analysis steps as field samples. This method recommends using the procedures provided in Appendix B to this method to clean the resin before use, if needed. However, this method allows alternative cleanup procedures that use automated extraction equipment if the adsorbent meets the required performance criteria described for LMB in Section 13.1 of this method.
7.2.1 Conduct a QC check on the cleaned adsorbent lot or batch following the extraction and analyses procedures in Section 11 of this method, including adding applicable labeled standards. The cleaned adsorbent must meet the criteria described for LMB in Section 13.1 of this method. An LMB conducted with an adsorbent lot or batch can serve this purpose.
7.2.2 Storage. Store adsorbent in a solvent-rinsed nonporous clean container and secure lid.
7.3 Glass Wool. Clean the glass wool to meet the specifications in Section 13.1 of this method. Glass wool is dried of the solvent and stored in a clean glass container with a PTFE-lined screw cap.
7.4 Water. Use deionized or distilled water meeting requirements in Section 13.1 of this method and store in its original container or in a clean glass container with a PTFE-lined screw cap.
7.5 Silica Gel. Indicating type for sampling, 6-16 mesh. If previously used, dry at 175 °C (347 °F) for two hours. Use new silica gel as received. As an alternative, use other types of desiccants (equivalent or better), subject to the approval of the Administrator.
7.6 Methylene Chloride. Pesticide grade or better.
7.7 Sample Recovery Reagents.
7.7.1 Acetone. Pesticide grade or better.
7.7.2 Toluene. Pesticide grade or better.
7.8 Sample Extraction and Cleanup.
7.8.1 Potassium Hydroxide. American Chemical Society (ACS) grade, 2% (weight/volume) in water.
7.8.2 Sodium Sulfate. Granulated or powdered, reagent grade. Evaluate for cleanliness prior to use with an LMB. The LMB must meet the requirements in Section 13.1 of this method for target compounds. Store in a clean glass container with a PTFE-lined screw cap.
7.8.3 Sulfuric Acid. Reagent grade.
7.8.4 Sodium Hydroxide. 1.0 N. Weigh 40 g of sodium hydroxide into a 1-liter volumetric flask. Dilute to 1 liter with water.
7.8.5 Hexane. Pesticide grade or better.
7.8.6 Methanol. Pesticide grade or better.
7.8.7 Toluene. Pesticide grade or better.
7.8.8 High-Boiling Alkanes Used as Keeper Solvents (e.g., tetradecane, nonane, decane). Pesticide grade.
7.8.9 Liquid Column Chromatography Packing Materials. Use the following column chromatography packing materials, as needed, to prepare sample extracts by fractionation and removal of interferences. Commercially prepacked cleaning columns may be available for this purpose. The liquid column chromatography packing materials must be adequate to clean the samples to be fit for purpose and meet the performance criteria of this method. All procedures for preparing column chromatography packing materials are recommendations shown to meet the performance specifications required for the recovery of labeled compounds described in Section 13 of this method.
7.8.9.1 Alumina. Use either acidic or basic alumina in the cleanup of sample extracts. Use the same type of alumina for all samples in an analytical sequence, including those used to demonstrate LMB performance.
7.8.9.1.1 Acidic Alumina (Sigma-Aldrich® 199966 or equivalent). Brockmann activity grade 1, 100-200 mesh. Prior to use, activate the alumina by heating for 12 hours at 130 °C (266 °F). Store in a desiccator. You may use pre-activated alumina purchased from a supplier as received.
7.8.9.1.2 Basic Alumina (Sigma-Aldrich® 19943 or equivalent). Brockmann activity grade 1. Activate by heating to 600 °C (1,112 °F) for a minimum of 24 hours. Do not heat to over 700 °C (1,292 °F) because this can lead to reduced capacity for retaining the target compounds. Store at 130 °C (266 °F) in a covered flask. Recommended storage time for acidic alumina is up to five days from baking. Use prepacked alumina columns immediately after opening the vacuum-sealed pouch or container.
7.8.9.2 Florisil®. Activated, 60-100 mesh recommended. Heat previously activated Florisil® in a glass container loosely covered with aluminum foil in an oven at 130 to 150 °C (266 to 302 °F) for a minimum of 24 hours. Allow to cool and store activated Florisil® silica in a desiccator.
7.8.9.3 Silica Gel. Use either activated, acid- or base-coated silica gel in the cleanup of sample extracts. Use the same type of silica gel for all samples in an analytical sequence, including those used to demonstrate LMB performance.
7.8.9.3.1 Activated Silica Gel. Supelco® 1-3651, Bio-Sil® A, 100-200 mesh (or equivalent). Prior to use, silica gel should be activated by solvent rinsing and heat activation. It is recommended to rinse with methylene chloride and activate the silica gel by heating for at least 1 hour at 180 °C (356 °F). After allowing to cool, rinse the silica gel sequentially with methanol and toluene. Heat the rinsed silica gel at 50 °C (122 °F) for 10 minutes, then increase the temperature gradually to 180 °C (356 °F) over 25 minutes and maintain the gel at this temperature for 90 minutes. Allow to cool in a desiccator to room temperature and store in a glass container with a PTFE-lined screw cap. Alternative conditioning procedure may be used if the performance criteria in Section 13.1 are met for target compounds.
7.8.9.3.2 Acidic Silica Gel (30% weight/weight). Combine 100 g of activated silica gel with 44 g of concentrated sulfuric acid in a clean screw-capped glass container and agitate thoroughly. Disperse the solids with a stirring rod until obtaining a uniform mixture of acid-coated silica gel. Store the mixture in a glass container with a PTFE-lined screw cap.
7.8.9.3.3 Basic Silica Gel. Combine 30 g of 1 N sodium hydroxide with 100 g of activated silica gel in a clean screw-capped glass container and agitate thoroughly. Disperse solids with a stirring rod until obtaining a uniform mixture of base-coated silica gel. Store the mixture in glass container with a PTFE-lined screw cap.
7.8.9.4 Carbon/Celite® 545 (or equivalent solid support). Use of a carbon-based column cleanup material (e.g., one of the many including for example Carbopack® B or C) to further remove non-planar impurities from the samples prior to analysis may be necessary. You must evaluate alternative carbon-based sorbents for this purpose prior to their use. An 18% weight/weight mixture of Carbopack® C and Celite® 545 has been used for this purpose and should be activated at 130 °C (266 °F) for a minimum of 6 hours. Allow to cool and store this mixture in a desiccator.
7.8.10 Nitrogen. 99.999% (ultra-high) purity.
7.9 Sample Analysis.
7.9.1 Helium. 99.999% (ultra-high) purity.
7.9.2 Spiking Standards. Prepare spiking standards quantitatively at a convenient concentration (e.g., 10 nanograms (ng)/mL) or use commercial standards if available, to enable accurate spiking of a labeled standard at various stages of the sample and extract preparation. You may adjust the sample fortification concentrations from those recommended in Tables 23-7, 23-8, and 23-9 of this method to accommodate the concentration of target compounds anticipated in samples if the performance criteria in Section 13 of this method are met.
7.9.3 Pre-Sampling Adsorbent Standard. Prepare stock standard solutions in nonane to enable spiking so that the isotopically labeled compounds in the final sample extract are at the concentration shown under the heading “Pre-sampling Adsorbent Standard” in Tables 23-7, 23-8, and 23-9 of this method, for applicable target compound classes.
7.9.4 Pre-extraction Filter Recovery Standard. Prepare stock standard solutions in nonane to enable spiking so that the isotopically labeled compounds in the final sample extract are at the concentration shown under the heading “Pre-extraction Filter Recovery Standard” in Tables 23-7, 23-8, and 23-9 of this method, for applicable target compound classes.
7.9.5 Pre-extraction Standard. Prepare stock standard solutions in nonane to enable spiking so that the isotopically labeled compounds in the final sample extract are at the concentration shown under the heading “Pre-extraction Standard” in Tables 23-7, 23-8, and 23-9 of this method, for applicable target compound classes.
7.9.6 Pre-analysis Standard. Prepare stock standard solutions in nonane to enable spiking so that the isotopically labeled compounds in the final sample extract are at the concentration shown under the heading “Pre-analysis Standard” in Tables 23-7, 23-8, and 23-9 of this method, for applicable target compound classes.
8.1 Sampling. This method involves collection and recovery of trace concentrations of target semivolatile organic compounds. Therefore, field sampling and recovery staff should be trained and experienced in the best practices for handling and using organic solvents in field environments to recover and protect samples from contamination.
8.1.1 Pretest Preparation.
8.1.1.1 Cleaning Glassware. Clean glassware thoroughly before using. This section provides a recommended procedure, but any protocol that consistently results in contamination-free glassware meeting the LMB criteria in Section 13.1 of this method is acceptable.
8.1.1.1.1 Soak all glassware in hot soapy water (Alconox® or equivalent).
8.1.1.1.2 Rinse with hot tap water.
8.1.1.1.3 Rinse with deionized/distilled water.
8.1.1.1.4 Rinse with methanol.
8.1.1.1.5 Rinse with toluene.
8.1.1.1.6 Baking glassware up to 400 °C (752 °F) for a minimum of 2 hours may be necessary to remove contaminants or interferents from particularly dirty samples. Allow glassware to cool after baking.
8.1.1.1.7 Cover glassware openings with clean glass fitting caps or cleaned aluminum foil (see Section 6.2.6 of this method).
8.1.1.1.8 Rinse glassware immediately before use with acetone and toluene.
8.1.1.2 Adsorbent Module. Load the modules in a clean area to avoid contamination. Fill a module with 20 to 40 g of XAD-2. Spike modules before the sampling event, but do not spike the modules in the field. Add the pre-sampling adsorbent standard to the top quarter of the adsorbent bed rather than onto the top or bottom of the adsorbent bed. Add sufficient spike (picograms (pg)/module) to result in the final sample theoretical concentrations specified in Tables 23-7, 23-8, and 23-9 of this method for PCDD/PCDF, PAH, and PCB, respectively, and to be above the lowest calibration concentration to ensure the standard recovery is quantitative. For samples with known or anticipated target compound concentration significantly higher or lower than the specified concentration in these tables, adjust the pre-sampling adsorbent standard concentration to the expected native compound concentration, but no less than 10 times the method detection limit (MDL). Follow the XAD-2 with cleaned glass wool and tightly cap both ends of the module. For analysis that includes PAH, use spiked modules within 14 days of preparation. See Table 23-10 of this method for storage conditions.
8.1.1.3 Sampling Train. Figure 23-1 of this method shows the complete sampling train. Follow the best practices by maintaining all sampling train components according to the procedure described in APTD-0576 Maintenance, Calibration, and Operation of Isokinetic Source-sampling Equipment (U.S. EPA 1972).
8.1.1.4 Silica Gel. Weigh several 200 to 300 g portions of silica gel in an air-tight container to the nearest 0.5 g. Record the total weight of the silica gel plus container, on the outside of each container. As an alternative, directly weigh the silica gel in its impinger or sampling holder just prior to sampling.
8.1.1.5 Filter. Check each filter against light for irregularities and flaws or pinhole leaks. Pack the filters flat in a clean glass container. Do not mark filters with ink or any other contaminating substance.
8.1.2 Preliminary Determinations. Use the procedures specified in Section 8.2 of Method 5 of Appendix A-3 to 40 CFR part 60.
8.1.2.1 Sample Volume. Unless otherwise specified in an applicable rule, regulation, or permit, sample for a minimum of 2 minutes at each traverse point. This method recommends sampling a minimum of 2.5 dry standard cubic meters (dscm).
8.1.2.2 For continuously operating processes, use the same sampling time at each traverse point. To avoid timekeeping errors, use an integer, or an integer plus one-half minute, for each traverse point.
8.1.2.3 For batch processes, determine the minimum operating cycle duration, dividing the sampling time evenly between the required numbers of traverse points. After sampling all traverse points once, sample each point again for the same duration of time per sampling point in reverse order until the operating cycle is completed. Sample all traverse points at least once during each test run.
8.1.3 Preparation of Sampling Train.
8.1.3.1 During field preparation and assembly of the sampling train, keep all train openings where contamination can enter sealed until just prior to assembly or until sampling is about to begin. To protect the adsorbent module from radiant heat and sunlight, you must wrap the module with aluminum foil or other suitable material capable of shielding the module from light. The XAD-2 adsorbent resin temperature must never exceed 50 °C (122 °F) because thermal decomposition will occur. Clean and prepare a complete set of sampling train components that will contact the sample for each sampling run, including one complete set to be used as a field train proof blank as a tool to evaluate equipment preparation and potential contamination during sample recovery as described in Section 9.6 of this method.
8.1.3.2 Place approximately 100 mL of water in the second and third impingers but leave the first and fourth impingers empty. Transfer approximately 200 g or more of silica gel from its container to the fifth impinger. Weigh each impinger and the adsorbent module, including the fitting caps, to the nearest 0.5 g using the field balance and record the weight for moisture determination. Remove the aluminum foil from the adsorbent module before weighing. Keep the module out of direct sunlight and rewrap the module with foil immediately after recording the module weight.
8.1.3.3 Using tweezers or clean disposable surgical gloves, place a filter in the filter holder. Be sure that the filter is properly centered, and the gasket properly placed, to prevent the sample gas stream from circumventing the filter. Check the filter for tears after completing the assembly.
8.1.3.4 Prepare the inside of the sampling probe and nozzle by brushing each component while rinsing three times each with acetone and toluene. Install the selected nozzle, using the connecting systems described in Section 6.1.2 of this method. Mark the probe with heat resistant tape or by some other method to denote the proper distance into the stack or duct for each sampling point. Assemble the train as shown in Figure 23-1 of this method. Orient the adsorbent module vertically so condensed moisture drains into the first impinger. See APTD-0576 Maintenance, Calibration, and Operation of Isokinetic Source-sampling Equipment (U.S. EPA 1972) for details.
8.1.3.5 Turn on the recirculation pump to the adsorbent module and condenser coil and begin monitoring the temperature of the gas entering the adsorbent module. Ensure proper temperature of the gas entering the adsorbent module before proceeding.
8.1.4 Leak-Check Procedure. Same as Section 8.4 of Method 5 of Appendix A-3 to 40 CFR part 60.
8.1.5 Sampling Train Operation. Same as Sections 8.5.1 through 8.5.9 of Method 5 of Appendix A-3 to 40 CFR part 60.
8.1.5.1 Monitor the filter temperature with a sensor and record the filter temperature during sampling to ensure a sample gas temperature exiting the filter of 120 °C ± 14 °C (248 °F ± 25 °F), or such other temperature as specified by an applicable subpart of the standards or approved by the Administrator for an application of this method.
8.1.5.2 During testing, you must record the temperature of the gas entering the XAD-2 adsorbent module. The temperature of the gas must not exceed 20 °C (68 °F) for efficient capture of the target compounds.
8.2 Sample Recovery. Begin the cleanup procedure as soon as the probe is removed from the stack at the end of the sampling period. Seal the nozzle end of the sampling probe with PTFE tape or clean (e.g., toluene rinsed) aluminum foil.
8.2.1 When the probe can be safely handled, wipe off all external particulate matter near the tip of the probe. Conduct a post-test leak check. Remove the probe from the train and close off both ends with PTFE tape or clean aluminum foil. Seal off the inlet to the train with PTFE tape, a ground glass cap, or clean aluminum foil.
8.2.2 Transfer the probe and impinger assembly to the cleanup area. This method recommends cleaning and enclosing this area to minimize the chances of losing or contaminating the sample. To avoid sample contamination and unnecessary exposure to toxic chemicals, smoking or eating in the sample recovery area shall not be allowed.
8.2.3 Inspect the train prior to and during disassembly. Note and record any abnormal conditions (e.g., broken filters, colored impinger liquid). Recover and prepare samples for shipping as follows in Sections 8.2.4 through 8.2.12 of this method.
8.2.4 Container No. 1. Either seal the filter holder or carefully remove the filter from the filter holder and place it in its identified container. If it is necessary to remove the filter, use a pair of cleaned tweezers to handle the filter. If necessary, fold the filter such that the particulate cake is inside the fold. Carefully transfer to the container any particulate matter and filter fibers that adhere to the filter holder gasket by using a dry inert bristle brush and a sharp-edged blade. Seal the container and store cool (≤20 °C, 68 °F) for transport to the laboratory.
8.2.5 Adsorbent Module Sample. Remove the module from the train, tightly cover both ends with fitting caps and PTFE tape, remove the foil, drain the recirculating water from the module, weigh and record the module weight, and label the adsorbent module. Moisture measurement in the field using the Method 23 train requires weighing the adsorbent module before sampling and after sampling as part of the sample recovery.
8.2.6 Container No. 2. Quantitatively recover material deposited in the nozzle, the front half of the filter holder, and the cyclone, if used, by brushing while rinsing three times with acetone followed by three rinses with toluene. Collect all the rinses in Container No. 2.
8.2.7 Rinse the back half of the filter holder three times with acetone followed by three rinses with toluene. Rinse the sample transfer line between the filter and the condenser three times with acetone followed by three rinses with toluene. If using a separate condenser and adsorbent module, rinse the condenser three times with acetone followed by three rinses with toluene. Collect all the rinses in Container No. 2 and mark the level of the liquid on the container.
8.2.8 Moisture Weight. Weigh the adsorbent module, impingers, and silica gel impinger to within ±0.5 g using the field balance and record the weights. This information is required to calculate the moisture content of the effluent gas. For PCDD/PCDF-only measurements, discard the liquid after measuring and recording the weight.
8.2.9 Container No. 3. You must save and analyze impinger water samples if PAH and/or PCB are the target compounds. Quantitatively recover impinger water samples for analysis if PAH and/or PCB are the target compounds by rinsing three times with acetone followed by three rinses with toluene. Collect impinger water and rinses in Container No. 3 and mark the level of the liquid on the container.
8.2.10 Silica Gel. Note the color of the indicating silica gel to determine if it has been completely spent and report its condition on the field data sheet.
8.2.11 Field Sample Handling, Preservation, Storage, and Transport. Store all field samples temporarily in cool (≤20 °C, 68 °F) and dark conditions prior to transport to the laboratory. Ship samples cool (≤20 °C, 68 °F), shielded from ultraviolet light. In addition, follow the procedures in American Society for Testing and Materials (ASTM) D6911-15 (Guide for Packaging and Shipping Environmental Samples for Laboratory Analysis) for all samples, where appropriate. To avoid contamination of the samples, pay special attention to cleanliness during transport, field handling, sampling, recovery, and laboratory analysis, as well as during preparation of the adsorbent cartridges.
8.2.12 Sample Custody. Proper procedures and documentation for sample chain of custody are critical to ensuring data integrity. Follow the chain of custody procedures in ASTM D4840-99(2018)e1 (Standard Guide for Sample Chain-of-Custody Procedures) for all samples (including field samples and blanks).
8.3 Sample Storage Conditions and Laboratory Hold Times.
8.3.1 Table 23-10 of this method summarizes the sample storage conditions and laboratory hold times.
8.3.2 Store sampling train rinses and filter samples in the dark at the storage conditions in Table 23-10 from the time the laboratory receives the samples until analysis.
8.3.3 You may store adsorbent samples for PCDD/PCDF or PCB analysis prior to extraction in the dark at 6 °C (43 °F) or less for up to one year from the time the laboratory receives the samples.
8.3.4 Protect adsorbent samples destined for PAH analysis from ultraviolet light. You may store adsorbent samples for PAH analysis in the dark at 6 °C (43 °F) or less for up to 30 days from the time the laboratory receives the samples.
8.3.5 Analyze PAH extracts within 40 days of extraction.
8.3.6 You may store sample aliquots including archived extracts of PCDD/PCDF, PAH and/or PCB samples in the dark at −10 °C (14 °F) or less for up to one year. Sample extracts must not be stored with pierced septa.
9.1 Record and report data and information that will allow an independent reviewer to validate the determination of each target compound concentration. Record and report the data as described in Sections 9.1.1 through 9.1.7 of this method and performance criteria results required in Section 13 of this method.
9.1.1 Sample numbers and other sample identifiers. Each sample must have a unique identifier.
9.1.2 Field sample volume.
9.1.3 Field sampling date.
9.1.4 Extraction dates.
9.1.5 Analysis dates and times.
9.1.6 Analysis sequence/run chronology.
9.1.7 Quantitation Reports.
9.1.7.1 This method does not consider EMPC-flagged data to be zero concentrations. Calculate and report the EMPC concentrations.
9.1.7.2 In determining compliance with any PCDD and PCDF standard developed using zero for values that are below the EDL of the method, including federal emission standards using Method 23 promulgated under 40 CFR parts 60 and 63 prior to March 20, 2023, use zero for the determination of total and weighted concentrations when the target compound is not detected. For all other circumstances, unless otherwise specified in applicable regulations, permits, or other requirements, when a target compound is measured at or below EDL, use EDL as the concentration for calculating compliance.
9.1.7.3 For each sample you must report EDLs, MDLs, LMBs and Field Train Proof Blank results and target compound analysis results.
9.2 Isotopically Labeled Standard Recovery.
9.2.1 Pre-sampling Adsorbent Standard and Pre-extraction Filter Recovery Standard Recoveries. Pre-sampling adsorbent standard and pre-extraction filter recovery standard recoveries must demonstrate on a per sample basis that recovery of the labeled standard achieved the requirements in Section 13 of this method. Recoveries below the acceptable range for the pre-sampling adsorbent standard may be an indication of breakthrough in the sampling train.
9.2.1.1 If the pre-sampling adsorbent standard average percent recovery is below 70%, the sampling run is not valid, and the stack test must be repeated. As an alternative, you do not have to repeat the stack test for invalid analyses if the pre-sampling adsorbent standard average percent recovery is 25% or more and you divide the final results by the fraction of the pre-sampling adsorbent standard average percent recovery.
9.2.1.2 If the percent recovery of all the pre-extraction filter recovery standard compounds is below 70%, you may reanalyze the sample. If the recovery is still below the limit, the filter sampling extraction is not valid, and you must repeat the stack or vent sampling and subsequent analysis.
9.2.2 Pre-extraction Standard Recoveries. Pre-extraction standard recoveries must demonstrate on a per sample basis that recovery of the labeled standard achieved the requirements in Section 13.15 of this method. If the recovery criteria are not met, you may reanalyze the sample. If the recovery criteria are still not met, the sampling run is not valid, and the stack test must be repeated. Recoveries outside the acceptable range for pre-extraction standard are an indication that sample preparation procedures did not adequately address sample and or sample matrix processing to recover native target compounds.
9.2.3 Pre-analysis Standard Response. Pre-analysis standard recoveries must demonstrate on a per sample basis that adequate labeled standard signal meets the requirements in Section 13.16 of this method. Add pre-analysis standard to every sample (including blanks, QC samples, and calibration solutions) in a known concentration. If the prepared samples do not meet the pre-analysis standard response criteria, you may reanalyze and/or prepare and analyze archive samples to attempt meeting requirements for the compounds that do not meet the pre-analysis standard response criteria. Poor sensitivity compared to initial calibration response may indicate injection errors or instrument drift.
9.3 Initial Demonstration of Capability (IDC). The IDC must be successfully performed prior to analyzing field samples by meeting the QC requirements in Table 23-18. The IDC must be repeated if changes are made to analytical parameters not previously validated during the IDC. This may include, for example, changing the sample volume, selecting alternate quantitation ions, extending the calibration range, adding additional pre-analysis standard, or adding additional pre-extraction standard. The same calibration range used during the IDC must be used for the analysis of field samples.
9.3.1 Perform initial calibration following the procedures in Section 10. The lowest calibration standard used to establish the initial calibration must not be less than three times the MDL. The initial calibration must meet performance criteria in Section 13.9.
9.3.2 Lowest Calibration Concentration Confirmation. Establish a target concentration for the lowest calibration standard based on the intended use of the method. The lowest calibration concentration may be established by a laboratory or programmatic lowest quantitative reporting requirement. The laboratory calibration curve must be set at or below this level. Perform seven replicate analyses of a calibration sample prepared at proposed lowest calibration concentration. The replicate analyses of the lowest calibration concentrations standards must meet the criteria in Sections 13.9 and 13.17.1.
9.3.3 Calculate Lowest Calibration Statistics. Calculate the mean and standard deviation for each analyte in these replicates (those used in Section 9.3.2). Determine the Half Range for the Prediction Interval of Results (HRPIR) using Equation 23-13. Calculate the Upper and Lower Limits for the Prediction Interval of Results (PIR) with Equations 23-14 and 23-15.
9.3.4 Lowest Calibration Point Acceptance Criteria. The laboratory’s ability to measure analyte concentrations down to the lowest calibration point is confirmed if the criteria presented in Section 13.17.1 are met. If these criteria are not met, the lowest calibration point as been set too low and must be confirmed at a higher concentration.
9.3.5 Demonstration of Low System Background. Analyze an LMB after the highest standard in the calibration range. If an automated extraction system is used, an LMB must be extracted on each port. Performance criteria are presented in Section 13.1. Note: When using automated systems, the same systems must be used for samples and QC samples, such as blanks and resin checks.
9.3.6 Initial Calibration Verification. A QCS must be analyzed during the IDC, and then following each initial calibration thereafter (at a minimum quarterly). A QCS is a mid-level standard prepared from a second source standard or prepared from a source of standards different from the source of calibration standards. The purpose of the QCS is to verify the integrity of the primary calibration standards. The acceptance criterion is presented in Section 13.11.
9.3.7 MDL. Perform an MDL determination using a minimum of seven spiked combined filter/sorbent media samples, spiked within 2 to 10 times of the expected MDL, and seven LMBs (combined filter/sorbent media) through all the steps of the method following the requirements in 40 CFR part 136 Appendix B. Confirm target compounds meet the qualitative identification criteria in Sections 13.12 and 13.13. The criteria for the MDL determination are presented in Section 13.6.1 of this method.
9.3.8 MDL Confirmation. Confirm newly determined MDLs by preparing a low-level spiked combined filter/sorbent media sample by spiking the sorbent with native target compounds at 1 to 5 times the MDL and pre-extraction standard at the concentration used to analyze field samples and analyze. The criterion for the MDL confirmation is presented in Section 13.6.1 of this method.
9.3.9 Demonstration of Precision. Prepare, extract, and analyze seven replicate spiked samples in a valid Extraction Batch. Fortify the spiked samples near the midpoint of the initial calibration curve. The criterion is presented in Section 13.17.2 and Table 23-18. Demonstration is repeated for failed compounds only.
9.3.10 Demonstration of Accuracy. Using the same set of replicate data generated for Section 9.3.9 of this method, calculate the average % recovery. The criterion is presented in Section 13.17.3 and Table 23-18. Demonstration is repeated for failed compounds only.
9.4 LMBs. Evaluate background contamination from glassware, equipment, solvents, standards, and media used for sample batches using an LMB prepared and analyzed identically to the field samples, including the same labeled standards, media, sodium sulfate, glass wool, glassware, solvents, etc. An LMB must be extracted with every batch of samples. Analyze an LMB at least once during each analytical sequence or every 12 hours, whichever period is shorter. If multiple LMB are required for an analytical sequence, report the initial LMB associated with each 12 hour analysis period.
9.5 EDL. Calculate the EDL using Equation 23-11 of this method.
9.6 Field Train Proof Blank Assessment. Conduct at least one field train proof blank for each test series at a single facility. A field train proof blank is used to evaluate equipment preparation and potential contamination during sample recovery and consists of a fully assembled train at the sampling site. Prepare and assemble the field train proof blank train in a manner identical to that described in Sections 8.1.3 and 8.1.4 of this method using glassware from the same preparation batch as the field samples. The field train proof blank train must remain assembled for the same average amount of time samples are collected. Recover the field train proof blank train as described in Section 8.2 of this method. Follow all subsequent steps for field train proof blank train sample preparation and analysis used for field samples including data reporting. Section 13.1 of this method describes the criteria for the field train proof blank.
10.1 Sampling System. Same as Sections 6.1 and 10.1 through 10.7 of Method 5 of Appendix A-3 to 40 CFR part 60.
10.2 HRGC/HRMS System.
10.2.1 Mass Resolution. Tune the HRMS instrument to a resolving power of at least 10,000 at 10% percent of the peak height or 25,000 at 50% percent of the peak height. The resolving power for PAH and PCB analysis may be 8,000 at 10% of the peak height or 15,000 at 50% of the peak height. Assess the resolution at three exact m/z’s representing the low-, mid-, and high-m/z range of the masses used to measure the target compound class. You may use peak matching and the chosen perfluoro-kerosene (PFK) or perfluorotributylamine (FC43) reference peak to verify that the exact mass is within 5 ppm of the required value.
10.2.2 Initial Calibration. Calibrate the HRGC/HRMS system using a minimum of five concentrations over a range that brackets expected field sample concentrations and the concentration of isotopically labeled standards in spiked samples. Tables 23-11, 23-12, and/or 23-13 of this method show the calibration concentrations recommended by this method, as applicable to the target compound classes. Determine the initial relative response factors for the target compounds and isotopically labeled standards using the initial calibration. Criteria for the initial calibration is in Section 13.9 of this method.
10.2.2.1 Lock-Mass Ions. Tables 23-4, 23-5, and 23-6 of this method present the recommended mass spectrometer lock-mass ions for PCDD/PCDF, PAH, and PCB, respectively. The reference compounds PFK or FC43 have ions that may be selected as your lock-mass and QC check ions. Monitor the QC check ions specified in these tables to verify instrument stability during the analysis (see Section 13.8 for performance criteria). Additional cleanup of the sample extract (or archive extract) and reanalysis is necessary for failure to maintain the lock-mass during analysis.
10.2.2.2 The relative standard deviation (RSD) for the mean calibration relative response factor from each of the unlabeled analytes and isotopically labeled compounds used in an analysis must be less than or equal to the values in Table 23-14 of this method.
10.2.2.3 The signal-to-noise (S/N) ratio for the GC/MS signal present in every selected ion current profile must be greater than or equal to 10 in all concentrations of calibration standards for unlabeled targets and isotopically labeled standards. The ion abundance ratios must be within the control limits in Table 23-15 of this method.
10.2.3 Continuing Calibration Verification.
10.2.3.1 Prepare the CCV standard at the same time as the batch of field samples using the same labeled standards. Prepare CCV standards at mid-level of the calibration (C3 level from Tables 23-11, 23-12, or 23-13 of this method). Inject a CCV standard, for the target compound class, at least once every 12 hours during an analysis sequence. Calculate the RRF for each compound and compare each RRF to the corresponding mean RRF obtained during the initial calibration. The RRF for each native compound measured in a CCV must not deviate from the initial calibration RRF by more than the limits shown in Table 23-14.
10.2.3.2 The ion abundance ratios must be within the allowable control limits shown in Table 23-15 of this method.
10.2.3.3 The S/N ratio for the GC/MS signal present in every selected ion current profile must be greater than or equal to 10.
10.2.3.4 Repeat the initial calibration when there is a failure to meet the requirements for acceptable CCV standard analysis.
10.2.3.5 Column Separation Check. Use the results from a CCV to verify and document the resolution required in Section 13.2, 13.3, or 13.4 of this method for the target compound classes analyzed with this method. If target compounds are not sufficiently resolved to meet the requirement, an analysis on a confirmation column is recommended (see Section 13.5 of this method).
10.2.3.6 If you use a confirmation column, perform the resolution check in Section 10.2.3.5 of this method to document the required resolution on the confirmation column. See Section 13.5 of this method on confirmation columns, if needed.
11.1 Sample Extraction and Concentration. The sample extraction procedures in this method are the same for PCDD, PCDF, PCB and PAH targets. Figure 23-4 provides a flow chart showing sample container combination and extraction steps. Do not allow samples and extracts destined for PAH or PCB analysis to concentrate to dryness because the lower molecular weight PAH and the mono- through tri-chlorobiphenyls may be totally or partially lost. Note: Rotary evaporation is applicable when analyzing for PCDD/PCDF only. Snyder column apparatus is recommended when analyzing for PAH and PCB.
11.1.1 Optional Soxhlet Precleaning. Place an extraction thimble (see Section 6.3.3.3 of this method) and a plug of glass wool into the Soxhlet apparatus equipped with a Dean-Stark trap, charge the apparatus with toluene, and reflux for a minimum of 3 hours. Remove the toluene and discard it. Remove the extraction thimble from the extraction system and place it in a glass beaker to catch the solvent rinses from sample transfer to the extraction thimble. Retain the clean glass wool plug. Alternatively, confirm that the LMB for associated reagents, materials, and media meets the performance requirements in Section 13.1 of this method.
11.1.2 Container No. 1 (Filter) Preparation. Spike the filter with the appropriate pre-extraction filter recovery standard to result in the final sample extract concentrations shown in Tables 23-7, 23-8, and 23-9 of this method taking care that all spike liquid is distributed on the filter. Allow the filter to dry enough to prevent overspill, then transfer the filter and the contents of Container No. 1 directly to the glass extraction thimble in the glass solvent rinse catch beaker so that the filter will be completely immersed in the solvent during extraction.
11.1.3 Adsorbent Module. Spike the adsorbent with the appropriate pre-extraction standard to result in the final sample extract concentrations shown in Tables 23-7, 23-8, and 23-9 of this method, as applicable, spiked into the adsorbent, not on top of the adsorbent. Transfer the adsorbent material to the glass extraction thimble in the glass solvent rinse catch beaker. Rinse the module into the thimble in the beaker with the contents of Container No. 1. Alternatively, suspend the adsorbent module directly over the extraction thimble in a beaker, then, using a wash bottle containing methanol, flush the XAD-2 into the thimble onto the filter. Thoroughly rinse the interior of the glass module that contained the XAD-2 with toluene.
11.1.4 Container No. 2 (Acetone and Toluene Rinses). Concentrate the sample to a volume of no less than 5 mL. Concentrate samples containing toluene using a heating mantle and three-ball Snyder column or a rotary evaporator. Rinse sample Container No. 2 three times with small portions of toluene and add these to the concentrated solution and concentrate further to no less than 5 mL. This residue contains particulate matter removed in the rinse of the train probe and nozzle. Rinse the concentrated material from Container No. 2 into the glass extraction thimble containing the filter and the XAD-2 resin.
11.1.5 Transfer the solvent contained in the glass solvent rinse catch beaker to the extraction apparatus solvent reservoir. Rinse the beaker into the Soxhlet extraction apparatus solvent reservoir three times with small portions of toluene.
11.1.6 Container No. 3 (Impinger Water and Rinses). For PAH and PCB analysis, transfer the contents of Container No. 3 to a separatory funnel. Adjust to pH 2 with 6 N sulfuric acid, if necessary. Rinse the sample container with three successive 10-mL aliquots of the toluene and add these rinses to the separatory funnel. Extract the sample by vigorously shaking the separatory funnel for 5 minutes. After complete separation of the phases, remove the solvent and filter it through a bed of precleaned, dry sodium sulfate into the Soxhlet extraction apparatus solvent reservoir. Repeat the extraction step two additional times. Adjust the pH to 11 with 6 N sodium hydroxide, re-extract the impinger water and rinses, and filter it through a bed of precleaned, dry sodium sulfate into the Soxhlet extraction apparatus solvent reservoir. Rinse the sodium sulfate into the extraction apparatus solvent reservoir with fresh solvent and discard the sodium sulfate.
11.1.7 Add the appropriate pre-extraction standard for the target compound classes (to result in the final sample extract concentrations shown in Tables 23-7, 23-8, and 23-9 of this method) to the extraction thimble containing the combined filter and adsorbent sample fractions. Cover the contents of the extraction thimble with the cleaned glass wool plug to prevent the XAD-2 resin from splashing into the solvent reservoir of the extractor. Place the extraction thimble into the Soxhlet extraction apparatus.
11.1.8 Pour additional toluene to fill the solvent reservoir to approximately two-thirds capacity. Add PTFE boiling chips and assemble the apparatus.
11.1.9 Adjust the heat source to cause the extractor to cycle approximately three times per hour. Extract the sample for sufficient time to meet the pre-extraction standard recovery performance criteria in Section 13.15 of this method. The solvent should cycle completely through the system a minimum of 48 times.
11.2 Sample Aliquots for Cleanup and Analysis.
11.2.1 After extraction, allow the Soxhlet apparatus to cool.
11.2.2 Initial Extract Concentration. You may perform an initial concentration of the sample extract using the techniques (e.g., Kuderna Danish, rotary evaporation, nitrogen blowdown) found to recover the pre-extraction standard sufficient to meet the performance criteria in Section 13.15 of this method. Concentrate initial extracts in toluene using a heating mantle and three-ball Snyder column or a rotary evaporator. Concentrate the field train proof blank and LMB samples in the same manner as samples.
11.2.3 Allow the sample extract to cool. You should use a minimum of one half of the sample extract for PCDD/PCDF analysis. You may archive the remaining sample extract or further split the sample extract for PCB and/or PAH analysis and archive.
11.2.4 If necessary, further concentrate the sample extract for cleanup and analysis using concentration techniques (e.g., Kuderna Danish, rotary evaporation, nitrogen blowdown) found to recover the pre-extraction standard sufficient to meet the performance criteria in Section 13 of this method.
11.3 Sample Cleanup and Fractionation. You may process a separate aliquot/split of the sample extract for each of the compound classes analyzed by this method. Sample cleanup for each compound class may include techniques in addition to column chromatography such as acid/base back-extraction, Gel Permeation Chromatography, or high-performance liquid chromatography (HPLC) to isolate target compounds from interferences. This section includes a description of column chromatography shown to meet the performance criteria in Sections 9.2 and 13 of this method. The following sample cleanup and fractionation procedures are recommended but not required. You may modify cleanup column dimensions to meet manual or automated cleanup procedures as technology changes and improves. You must evaluate the cleanup and fractionation procedures used to confirm acceptable recovery of isotopically labeled standards. The alternative procedures must provide sufficient cleanup to meet method identification criteria (Section 11.4.3.4 of this method) and recovery criteria (Section 9.2 of this method). Section 13 of this method summarizes the method performance requirements.
11.3.1 PAH and PCDPE Fractionation and Cleanup. You may use a Florisil® column to remove PAH and PCDPE from the sample extract. You may also fractionate sample extracts using Florisil® as the first cleanup step to separate PAH for analysis.
11.3.1.1 Pack a 6-mm ID chromatographic column or equivalent diameter glass pipet with a glass wool plug followed by approximately 1.5 g (approximately 2 mL) of activated Florisil®. Add approximately 1 cm (approximately 1 mL) of anhydrous sodium sulfate followed by a glass wool plug to the head of the column. Pre-elute the column with 10 mL of methylene chloride followed by 10 mL of hexane and discard the eluate.
11.3.1.2 When the solvent is within 1 mm of the packing, transfer the concentrated extract (up to 5 mL) to the top of the Florisil® column, rinse the sample container twice with 1 to 2 mL of hexane, adding each rinse to the column, and elute the column with 35 mL of 5% dichloromethane in hexane. This fraction (Fraction 1) should contain target PCB, and selected hydrocarbons and chlorinated monoaromatic compounds.
11.3.1.3 Elute the column with 35 mL of 15% of dichloromethane in hexane and collect the eluate. This fraction (Fraction 2) should contain target PCDD/PCDF compounds.
11.3.1.4 Elute the column with 50 mL of 50% dichloromethane in hexane. The fraction (Fraction 3) should contain target PAH.
11.3.1.5 If necessary to remove any remaining polar organic compounds, elute the column with 70 mL of 15% acetone in hexane.
11.3.2 PCDD/PCDF and PCB Fractionation and Cleanup. You may remove PAH from the original aliquot of sample extract used for PCDD/PCDF analysis as described in Section 11.3.1 of this method. Design the column cleanup chromatography for PCDD/PCDF and PCB such that two consecutive fractions are collected (one with PCDD/PCDF and one with PCB) without impacting the detection limits. Depending on the source and sample matrix of the original sample, one or more of the following column cleanup approaches may be necessary to further remove polyhalogenated diphenyl ethers. You may use any number of permutations found in the referenced literature for this cleanup if the pre-extraction standard recoveries from field and LMB samples meet the associated performance criteria in Section 13 of this method. Alternatively, you may use an automated cleanup approach that meets the labeled spike recovery requirements in Section 13 of this method.
11.3.2.1 Silica Gel Column Chromatography. Pack one end of a glass column, approximately 20 mm ID × 230 mm long, with glass wool. Add in sequence to the glass column, 1 g of silica gel, 2 g of sodium hydroxide impregnated silica gel, 1 g of silica gel, 4 g of acid-modified silica gel, 1 g of silica gel, and 1 cm layer of anhydrous sodium sulfate. Pre-elute the column with 30 to 50 mL of hexane leaving a small quantity of hexane above the sodium sulfate layer. Discard the pre-elution hexane. Add the sample extract, dissolved in 5 mL of hexane to the head of the column. Allow the sample to flow into the column leaving a small quantity of hexane above the sodium sulfate layer. Rinse the extract container with two additional 5-mL rinses of hexane and apply each rinse to the column separately as the previous addition elutes. Elute the column with an additional 90 mL of hexane and retain the entire eluate. Concentrate this solution to a volume of about 1 mL using the nitrogen evaporative concentrator (see Section 6.3.5 of this method).
11.3.2.2 Silver Nitrate Silica Gel Column Chromatography. Pack a column (6 mm ID, 150 mm in length) sequentially with 1 g of silica gel and 1 g of 10% silver nitrate silica gel followed by a layer of about 10 mm of sodium sulfate (anhydrous). Wash the column sufficiently with hexane, elute until the liquid level reaches to the upper end of the column, and then transfer the concentrated sample (about 5 mL). Rinse the container several times with a small amount of hexane, elute with 200 mL of hexane at a flow rate about 2.5 mL/min (approximately one drop per second) to elute PCDD/PCDF.
11.3.2.3 Multi-layer Silica Gel Column Chromatography. You may use a multi-layer silica gel column in place of separate silica columns. Pack a column of 20 mm ID and 300 mm in length sequentially by the dry pack method with 0.9 g of silica gel, 3.0 g of 2% potassium hydroxide silica gel, 0.9 g of silica gel, 4.5 g of 44% sulfuric acid silica gel, 6.0 g of 22% sulfuric acid silica gel, 0.9 g of silica gel, 3.0 g of 10% silver nitrate silica gel, 2.0 g of silica gel and 6.0 g of sodium sulfate (anhydrous). Wash the column sufficiently with hexane, elute until the liquid level reaches to the upper end of the column, and then load the sample solution. Rinse the container several times with a small amount of hexane, elute with 150-200 mL of hexane at a flow rate about 2.5 mL/min (approximately one drop per second) to elute PCDD/PCDF.
11.3.2.4 Basic Alumina Column Chromatography. Pack a column (20 mm ID, 300 mm in length) with approximately 6 to 12 g of basic alumina. Pre-elute the column with 50 to 100 mL of hexane. Transfer the concentrated extract from the previous column cleanup to the top of the basic alumina column. Allow the sample to flow into the column leaving a small quantity of solvent above the top of the bed. Rinse the extract container with two additional 1-mL rinses of hexane and apply each rinse to the column separately as the previous addition elutes. Elute the column with 100 mL hexane to remove the interferences. Elute the PCDD/PCDF from the column with 20 to 40 mL of 50% methylene chloride in hexane. The ratio of methylene chloride to hexane may vary depending on the activity of the alumina used in the column preparation. Do not let the head of the column go without solvent. The first 100 mL hexane eluate is not used for subsequent PCDD/PCDF analysis. The eluate is concentrated to approximately 0.5 mL using the nitrogen evaporative concentrator.
11.3.2.5 Carbopack® C/Celite® 545 Column or Equivalent. Cut both ends from a 10 mL disposable Pasteur pipette (see Section 6.4.1 of this method) to produce a 10 cm column. Fire-polish both ends and flare both ends if desired. Insert a glass wool plug at one end and pack the column with 0.55 g of Carbopack®/Celite® (see Section 7.8.9.4 of this method) to form an adsorbent bed approximately 2 cm long. Insert a glass wool plug on top of the bed to hold the adsorbent in place. Pre-elute the column with 5 mL of toluene followed by 2 mL of methylene chloride:methanol:toluene (15:4:1 volume/volume (v/v)), 1 mL of methylene chloride:cyclohexane (1:1 v/v), and 5 mL of hexane. If the flow rate of eluate exceeds 0.5 mL/minute, discard the column. Do not let the head of the column go without solvent. Add the sample extract to the column. Rinse the sample container twice with 1 mL portions of hexane and apply separately to the column. Apply 2 mL of hexane to the head of the column to complete the transfer. Elute the interfering compounds with two 3 mL portions of hexane, 2 mL of methylene chloride:cyclohexane (1:1 v/v), and 2 mL of methylene chloride:methanol:toluene (15:4:1 v/v). Discard the eluate. Invert the column and elute the PCDD/PCDF with 20 mL of toluene. If carbon particles are present in the eluate, filter through glass-fiber filter paper. Concentrate the eluate to approximately 0.5 mL using the nitrogen evaporative concentrator for further cleanup or analysis by HRGC/HRMS.
11.4 PCDD, PCDF, PCB and PAH Analysis.
11.4.1 Analyze the sample extract with an HRGC/HRMS using the instrumental parameters in Sections 11.4.2 and 11.4.3 of this method.
11.4.1.1 Immediately prior to analysis, add an aliquot (typically 20 microliters (µl)) of the pre-analysis standard to result in the final sample extract concentrations in Tables 23-7, 23-8, and 23-9 of this method to each sample as appropriate for the compounds you are measuring by this method.
11.4.1.2 Inject an aliquot of the sample extract into the GC, typically 1 µl. You may perform separate analyses using different GC columns for each of the target compound classes. Perform calibration and sample analysis for each target compound class using the same instrument operating conditions including injection volume.
11.4.1.2.1 If target compounds are not resolved sufficiently from other target compounds or interferences in the sample to meet the requirements in Section 10.2.3.5 or 10.2.3.6 of this method, as applicable to the compound class being analyzed, or as otherwise specified in an applicable regulation, permit, or other requirement, analyze sample (or another aliquot of the sample) using an alternative column that provides elution order to uniquely quantify the target compounds subject to interference on the first GC column.
11.4.1.2.2 You may use column systems other than those recommended in this method provided the analyst is able to demonstrate, using calibration and CCVs, that the alternative column system is able to meet the applicable specifications of Section 10.2.3.5 or 10.2.3.6 of this method.
11.4.2 Example Gas Chromatograph Operating Conditions.
11.4.2.1 Injector. Configured for capillary column, splitless, 250 °C (482 °F).
11.4.2.2 Carrier Gas. Helium, 1 to 2 mL/min.
11.4.2.3 Oven. Optimize the GC temperature program to achieve the required separation and target compound recovery for the GC column in use. Table 23-16 of this method presents the typical conditions for a DB5-MS column.
11.4.3 High-Resolution Mass Spectrometer.
11.4.3.1 Ionization Mode. Electron ionization.
11.4.3.2 Source Temperature. Maintain the source temperature in the range of 250 to 300 °C (482 to 572 °F).
11.4.3.3 Ion Monitoring Mode. Tables 23-4, 23-5, and 23-6 of this method summarize the various ions to be monitored for PCDD/PCDF, PAH, and PCB, respectively.
11.4.3.4 Identification Criteria for Target Compounds. Use the following identification criteria for the characterization of target compounds in this method. The available native and isotopically labeled standards allow the unique identification of all PCDD/PCDF, PAH, and selected PCB congeners analyzed in this method. Also see Sections 13.12 and 13.13 of this method for identification criteria for PCDD/PCDF/PCB and PAH target compounds, respectively.
11.4.3.4.1 For PCDD/PCDF and PCB, Table 23-15 of this method provides acceptance limits for the integrated ion abundance ratio of primary and secondary target compound ions. When the ion abundance ratio for a target analyte is outside the performance criteria, you may reanalyze samples on an alternative GC column to resolve chemical interferences, tune the mass spectrometer to operate at a higher mass resolution to discriminate against the interference(s), and/or further cleanup an archived sample to remove the interference(s). Report analysis results as an EMPC when a response meets identification criteria except the ion abundance ratio criteria or when a peak representing a PCDPE has been detected at the retention time. This method does not consider EMPC-flagged data to be zero concentrations.
11.4.3.4.2 The retention time for the analytes must be within 3 seconds of the corresponding labeled pre-extraction standard.
11.4.3.4.3 The signals for the two exact masses in Tables 23-4 and 23-6 of this method for PCDD/PCDF and PCB, respectively, must be present and must reach their maximum response within two seconds of each other.
11.4.3.4.4 Identify and quantify specific target compounds or isomers that do not have corresponding pre-extraction standard compounds by comparing to the pre-extraction standard of the same compound class with the nearest retention time to target compound.
11.4.3.4.5 For the identification of specific PCB congeners, the retention time of the native congener must be within 0.006 relative retention time (RRT) units of the pre-extraction standard.
11.4.3.4.6 For qualitative identification, the S/N ratio for the GC signal present in every selected ion current profile for native compound response must be greater than or equal to 2.5.
11.4.3.4.7 The separation of target compounds, including 2,3,7,8-TeCDD and 2,3,7,8-TeCDF, must satisfy the separation criteria in Section 10.2.3.5 of this method and all the identification criteria specified in Sections 11.4.3.4.1 through 11.4.3.4.6 of this method. See Section 13.5 of this method on confirmation columns, if needed.
11.4.3.4.8 Chlorodiphenyl Ether Interference. If chromatographic peaks are detected at the retention time of any PCDF in any of the m/z channels used to monitor PCDPE, there is evidence of a positive interference and you may opt to flag data noting the interference and keep the value to calculate PCDF concentration as EMPC or reanalyze to remove or shift the interference. This method recommends alumina (see Section 11.3.2.4 of this method) and Florisil® (see Section 11.3.1 of this method) liquid column chromatography packing materials for removal of PCDPE during sample cleanup.
11.4.3.4.9 The recommended MS lock-mass ions are specified in Tables 23-4, 23-5, and 23-6 of this method for PCDD/PCDF, PAH, and PCB, respectively. Monitor the QC check ions to verify instrument stability during the analysis. If the QC check ion signal varies by more than 25% from the average response across the run, flag results for all isomers at corresponding retention time as the lock-mass ions or QC check ions. You have the option to reanalyze after additional cleanup on the sample (or an archived portion of the sample if the archive is available), or after dilution of the sample. Alternately, determine through additional quality review whether the target analyte and its corresponding isotopically labeled standard are equally affected by the change in lock-mass ions and/or QC check ions. When you reanalyze a sample, ensure all concentration calculations are reported from the reanalyzed sample.
11.4.3.4.10 For the identification of PAH, the RRT of each native to its labeled compound must be within 0.006 RRT units compared to the corresponding RRTs in the continuing calibration. The signals for the characteristic ion listed in Table 23-5 of this method must be present.
11.4.3.5 Quantitation. Measure the response of each native target compound and the corresponding pre-extraction standard. Using the CCV RRF, calculate the mass of each target compound, using equations in Section 12.7 of this method. Use the pre-extraction standard to correct the native target compounds result for variations in performance of the extraction, cleanup, and concentration steps of the analysis. Recovery of pre-extraction standard must meet the minimum specifications in Section 9.2. of this method to ensure that the method performance and reliability have not been compromised by unacceptable losses during sample processing. Table 23-17 of this method shows the assignments for pre-extraction standard compounds for use in calculating the response factor and the concentrations of PCB. Recoveries of all labeled standard compounds must meet the minimum recovery specifications in Section 13 of this method. Note: Unacceptably low recoveries can be an indication of a sample processing step that caused the low recoveries, such as spiking errors.
11.4.3.5.1 Use Equation 23-7 to calculate the amount of each target compound or group in the sample.
11.4.3.5.2 Use Equation 23-8 to calculate the concentration per dscm of each target compound or group in the gas.
11.4.3.5.3 Quantify native PCDD and PCDF in its homologous series using the corresponding native and pre-extraction standard response in its homologous series. For example, use
11.4.3.5.4 As an option or as required or specified in applicable regulations, permits, or other requirements, you may quantify any or all other PCB congeners as resolved or coeluting combinations using the RRF of the nearest eluting native target PCB in the same homolog group and the pre-extraction standard assigned in Appendix A to this method.
11.4.3.5.5 As an option or as required or specified in applicable regulations, permits, or other requirements, report the total concentration of congeners at a given level of chlorination (homolog; i.e., total TrCB, total PeCB, total HxCB, etc.) by summing the concentrations of all congeners identified in the retention time window for the homologs as assigned in Appendix A to this method.
11.4.3.5.6 As an option or if required in an applicable regulation, permit or other requirement, total PCB may be reported by summing all congeners identified at all window-defining congeners (WDCs) as assigned in Appendix A to this method.
12.1 Nomenclature.
12.2 Individual Compound RRF for Each Calibration Level i. Equation 23-1 for the response factor of each target native compound relative to its labeled pre-extraction standard analog includes the integrated ion current of both the primary and secondary m/z values for each compound in the calibration standard, excluding PAH, which use only primary m/z values. Use Equation 23-2 to calculate the RRF for pre-extraction standard.
12.3 Average RRF for Each Compound Over the Minimum of Five Calibration Levels.
12.4 Percent RSD of the RRFs for a Compound Over the Calibration Levels. The requirement for the initial calibration RSD is in Section 13.9 and Table 23-14 of this method.
12.5 Standard Deviation of the RRFs for a Compound Over the Calibration Levels.
12.6 Percent Difference of the RRF of the Continuing Calibration Verification Compared to the Average RRF from the Initial Calibration for Each Target Compound. Use Equation 23-1 to calculate the RRF for the continuing calibration verification for comparison to the average RRF from the initial calibration. The requirement for the continuing calibration verification % difference is in Section 13.10 and Table 23-14 of this method.
12.7 Amount of Individual Target Compound i in the Sample by Isotope Dilution (pg). This equation corrects for the target native compound recovery based on its labeled pre-extraction standard analog. This equation is also used to calculate the amount of pre-sampling adsorbent standard and pre-extraction filter recovery standard recovered.
12.8 Concentration of the Individual Target Compound or Group i in the Emission Gas (pg/dscm). The total concentration of a target compound group in the sample can be calculated by substituting C
12.9 Recovery of Labeled Compound Standards. Use Equation 23-9 to determine the recovery of pre-sampling adsorbent standard and the pre-extraction filter recovery standard. Use Equation 23-10 to determine the recovery of the pre-extraction standard. The recovery performance criteria for these standards are in Sections 13.14, 13.15, and 13.16 of this method.
12.10 Estimated Detection Limit (EDL).
12.11 Total Target Compound Mass.
12.12 Upper and Lower Limits for the Prediction Interval of Results (PIR)
Half Range (HR) for the Predication Interval of Results
Upper and Lower Limits for the Prediction Interval of Results
Data generated with this method must be fit for purpose. Applicable results of method performance criteria in this section must be reported. Consequences of failed quality criteria are provided with the criteria in this section.
13.1 Background Assessment – Field Train Proof Blank, LMB and Materials. Determine the contribution to target compound concentration from reagents, media and glassware used to make target compound measurements. Conduct at least one field train proof blank for each test series at a single facility. Analyze at least one LMB sample during an analytical sequence or every 12 hours, whichever is shorter. Native target compound concentrations in the field train proof blank, LMB and materials assessment must be less than or equal to three times the EDL of the method or 10 times lower than the quantitation limit required by the end use of the data (e.g., compliance limit or other limits set by consent decree or permit), whichever is higher. The field train proof blank, LMB and materials assessment must also meet the performance specifications in Tables 23-7, 23-8, and 23-9, as applicable to the compound target list.
13.2 GC column or column systems used to measure PCDD/PCDF must meet the column separation requirements in Section 6.5.2.1 of this method and the applicable requirements in Sections 10.2.3.5 and 11.4.3.4 of this method using the continuing calibration verification. Failure to meet this chromatographic resolution criterion requires data from this analysis to be flagged explaining the potential bias of the results.
13.3 GC column or column systems used to measure PAH must meet the column separation requirements in Section 6.5.2.2 of this method and the applicable requirements in Sections 10.2.3.5 and 11.4.3.4 of this method using the continuing calibration check. Failure to meet this chromatographic resolution criterion requires data from this analysis to be flagged explaining the potential bias of the results.
13.4 GC column or column systems used to measure PCB must meet the column separation requirements in Section 6.5.2.3 of this method and the applicable requirements in Sections 10.2.3.5 and 11.4.3.4 of this method using the continuing calibration check and be able to achieve unique resolution and identification of the toxics for determination of a TEQ
13.5 Confirmation Column. If target compounds are not sufficiently resolved from other target compounds or interferences in the sample to meet the requirements for target compounds in Sections 13.2, 13.3, and/or 13.4 of this method, analyze sample (or another aliquot of the sample) using an alternative column that provides elution order to uniquely quantify the target compounds subject to interference on the first GC column. When using a confirmation column, document the required resolution.
13.6 Detection Limits.
13.6.1 MDL. The MDLs are determined following the procedures in Section 9.3.7 of this method. MDLs are confirmed by preparing and analyzing a spiked sample (spiked at 1 to 5 times the determined MDL, see Section 9.3.8), then confirm that the target compounds meet the qualitative identification criteria in Section 11.4.3.4 of this method. If the MDL confirmation criteria are not met, the MDL determination is repeated with a higher spike concentration until criteria are met.
13.6.2 EDL. If the sample specific EDLs are less than 50% of the emission standard, the EDLs are acceptable.
13.7 Tune. The groups of monitored ions are listed in Tables 23-4, 23-5, and 23-6 of this method, as applicable for the target compound class. Tune the instrument to meet the required resolving power in Section 10.2.1 for the desired target compound class. Assess the resolution at three exact m/z’s representing the low-, mid-, and high-m/z range of the masses used to measure the target compound class. You may use peak matching and the chosen PFK (or FC43) reference peak to verify that the exact mass is within 5 ppm of the required value.
13.8 Lock-Mass Ions. The MS lock-mass and QC check ions in Tables 23-4, 23-5, and 23-6 of this method are recommended for PCDD/PCDF, PCB, or PAH, respectively. The reference compounds PFK or FC43 have ions that may be selected as your lock-mass and QC check ions. Monitor the QC check ions specified in these tables to verify instrument stability during the analysis; these must not vary >25% from the average response. Additional cleanup on sample extract (or archive extract) and reanalysis is necessary for failure to maintain lock-mass during analysis.
13.9 Initial Calibration.
13.9.1 The RSD for mean RRF from each of the target analytes and labeled standards in the calibration samples must not exceed the values in Table 23-14 of this method.
13.9.2 The S/N in every selected ion current profile must be ≥10 for all unlabeled targets and labeled standards in the calibration samples.
13.9.3 The ion abundance ratios must be within the control limits in Table 23-15 of this method.
13.10 Continuing Calibration Verification.
13.10.1 The RRF for each unlabeled and labeled compound measured in a CCV must not deviate from the initial calibration RRF by more than the limits shown in Table 23-14 of this method.
13.10.2 The ion abundance ratios must be within the control limits in Table 23-15 of this method.
13.10.3 The S/N ratio for the GC/MS signal present in every selected ion current profile must be greater than or equal to 10.
13.10.4 Repeat the initial calibration when there is a failure to meet the requirements for an acceptable CCV analysis.
13.10.5 Column Separation Check. Use the results from a CCV to verify and document the resolution required in Sections 13.2, 13.3, or 13.4 of this method for the target compound classes analyzed with this method. The separation criteria are applicable to all the compounds in a target class whether analyzed by a single or multiple GC columns. If a confirmation column is used, document required resolution (see Section 13.5).
13.11 QCS. A QCS must be analyzed during the IDC and after initial calibrations (at a minimum quarterly). The acceptance criterion for the QCS is 70-130% of the true value. If the accuracy for any analyte fails the recovery criterion, prepare a fresh standard dilution and repeat. If the freshly prepared QCS fails, determine the cause, recalibrate the instrument if necessary and reanalyze the QCS.
13.12 Compound Identification for PCDD/PCDF and PCB.
13.12.1 Target compounds must have ion abundance ratios within the control limits in Table 23-15 of this method. PAH target compounds have single ion identifiers with no ion abundance ratio requirement. Report analysis results as an EMPC when a response meets identification criteria but fails the ion abundance ratio criteria or when a peak representing a PCDPE has been detected at the target compound retention time.
13.12.2 The retention time for the analytes must be within 3 seconds of the corresponding pre-extraction standard.
13.12.3 The monitored ions, shown in Table 23-4 of this method for a given PCDD/PCDF, must reach their maximum response within 2 seconds of each other.
13.12.4 The monitored ions, shown in Table 23-6 of this method for a given PCB, must reach their maximum response within 2 seconds of each other.
13.12.5 For the identification of specific PCB, the RRT of the native congener must be within 0.006 RRT units of the pre-extraction standard RRT.
13.12.6 The S/N ratio for the monitored ions for native compounds must be greater than or equal to 2.5.
13.12.7 Identify and quantify isomers that do not have corresponding pre-extraction standard compounds by comparing to the pre-extraction standard of the same compound class with the nearest retention time to the target compound.
13.12.8 If chromatographic peaks are detected at the retention time of any PCDD/PCDF in any of the m/z channels used to monitor PCDPE, there is evidence of interference and positive bias. Data must be flagged to indicate an interference. You may report the total with bias for the affected target. To reduce the bias, you may use a confirmatory column or perform additional clean up on an archived sample followed by reanalysis.
13.13 Compound Identification for PAH.
13.13.1 The signals for the characteristic ion listed in Table 23-5 of this method must be present.
13.13.2 The RRT between each native and labeled compound must be within 0.006 RRT units.
13.14 Pre-sampling Adsorbent Standard and Pre-extraction Filter Recovery Standard Recovery. Recoveries of pre-sampling adsorbent standard added to the sample and pre-extraction filter recovery standard added to the filter must be between 70 and 130% (see Tables 23-7, 23-8, and 23-9 of this method).
13.14.1 If the recovery of all the pre-sampling adsorbent standard compounds is below 70%, the sampling runs are not valid, and you must repeat the stack or vent sampling. As an alternative, you do not have to repeat the test if the average pre-sampling adsorbent standard recovery is 25% or more and you divide the final results by the average fraction of pre-sampling adsorbent standard recovery.
13.14.2 If the recovery of all the pre-extraction filter recovery standard compounds is below 70%, you may reanalyze the sample. If the recovery criteria are still not met, the sampling recovery is not valid, and you must repeat the stack or vent sampling.
13.15 Pre-extraction Standard Recovery. Recoveries of all pre-extraction standard compounds added to the sample must be between 20 to 130% for PCDD/PCDF and PAH (see Tables 23-7 and 23-8 of this method) and between 20 to 145% for PCB (see Table 23-9 of this method). If the recovery criteria are not met, you may reanalyze the sample and/or prepare and analyze the archive sample. If the recovery criteria are still not met, the sampling run is not valid, and the stack test must be repeated.
13.16 Pre-analysis Standard Response. Response of all pre-analysis standard compounds must show a S/N for every selected ion current profile of ≥ 10. If the minimum response is not met, you must reanalyze the sample. Poor sensitivity compared to initial calibration response may indicate injection errors or instrument drift.
13.17 IDC – Lowest calibration concentration, Demonstration of precision, Demonstration of accuracy.
13.17.1 Lowest calibration concentration. The Upper PIR Limit must be less than, or equal, to 150%; and the Lower PIR Limit must be greater than, or equal to, 50%. If these criteria are not met, the lowest calibration point has been set too low and must be confirmed at a higher concentration.
13.17.2 Demonstration of precision. The percent relative standard deviation (%RSD) of the concentrations from the replicate analyses must be less than 20% for all target analytes. Demonstration would be repeated for failed compounds only.
13.17.3 Demonstration of accuracy. The average % recovery for each target analyte must be within 70 to 130%. Demonstration would be repeated for failed compounds only.
13.18 Requirements for Equivalency. The Administrator considers any modification of this method, beyond those expressly permitted in this method as options, to be a major modification subject to application and approval of alternative test procedures following EPA Guidance Document 22 currently found at: https://www.epa.gov/emc/emc-guideline-documents.
13.19 Records. As part of the laboratory’s quality system, the laboratory must maintain records of modifications to this method.
The target compounds used as standards in this method are prepared in extremely small amounts and pose little threat to the environment when managed properly. Prepare standards in volumes consistent with laboratory use to minimize the disposal of excess volumes of expired standards.
15.1 The laboratory is responsible for complying with all federal, state, and local regulations governing waste management, particularly the hazardous waste identification rules and land disposal restrictions, and for protecting the air, water, and land by minimizing and controlling all releases from fume hoods and bench operations. The laboratory must also comply with any sewage discharge permits and regulations. The EPA’s Environmental Management Guide for Small Laboratories (EPA 233-B-98-001) provides an overview of requirements.
15.2 Samples containing hydrogen chloride or sulfuric acid to pH
15.3 For further information on waste management, consult The Waste Management Manual for Laboratory Personnel and Less is Better-Laboratory Chemical Management for Waste Reduction, available from the American Chemical Society’s Department of Government Relations and Science Policy, 1155 16th Street NW, Washington, DC 20036.
Table 23-1 – Polychlorinated Dibenzo-
| Polychlorinated dibenzo- | CAS a Registry No. | Polychlorinated dibenzofurans | CAS a Registry No. |
|---|---|---|---|
| 2,3,7,8-TeCDD | 1746-01-6 | 2,3,7,8-TeCDF | 51207-31-9 |
| 1,2,3,7,8-PeCDD | 40321-76-4 | 1,2,3,7,8-PeCDF | 57117-41-6 |
| 1,2,3,4,7,8-HxCDD | 39227-28-6 | 2,3,4,7,8-PeCDF | 57117-31-4 |
| 1,2,3,6,7,8-HxCDD | 57653-85-7 | 1,2,3,4,7,8-HxCDF | 70648-26-9 |
| 1,2,3,7,8,9-HxCDD | 19408-74-3 | 1,2,3,6,7,8-HxCDF | 57117-44-9 |
| 1,2,3,4,6,7,8-HpCDD | 35822-46-9 | 1,2,3,7,8,9-HxCDF | 72918-21-9 |
| Total TeCDD | 41903-57-5 | 2,3,4,6,7,8-HxCDF | 60851-34-5 |
| Total PeCDD | 36088-22-9 | 1,2,3,4,6,7,8-HpCDF | 67562-39-4 |
| Total HxCDD | 34465-46-8 | 1,2,3,4,7,8,9-HpCDF | 55673-89-7 |
| Total HpCDD | 37871-00-4 | Total TeCDF | 55722-27-5 |
| OCDD | 3268-87-9 | Total PeCDF | 30402-15-4 |
| Total HxCDF | 55684-94-1 | ||
| Total HpCDF | 38998-75-3 | ||
| OCDF | 39001-02-0 |
a Chemical Abstract Service.
Table 23-2 – Polycyclic Aromatic Hydrocarbon Target Analytes
| Polycyclic aromatic hydrocarbons | CAS a Registry No. | Polycyclic aromatic hydrocarbons | CAS a Registry No. |
|---|---|---|---|
| Naphthalene | 91-20-3 | Chrysene | 218-01-9 |
| 2-Methylnaphthalene | 91-57-6 | Benzo[ | 205-99-2 |
| Acenaphthylene | 208-96-8 | Benzo[ | 207-08-9 |
| Acenaphthene | 83-32-9 | Perylene | 198-55-8 |
| Fluorene | 86-73-7 | Benzo[ | 50-32-8 |
| Anthracene | 120-12-7 | Benzo[ | 192-97-2 |
| Phenanthrene | 85-01-8 | Benzo[ | 191-24-2 |
| Fluoranthene | 206-44-0 | Indeno[ | 193-39-5 |
| Pyrene | 129-00-0 | Dibenz[ | 53-70-3 |
| Benz[ | 56-55-3 |
a Chemical Abstract Service.
Table 23-3 – Polychlorinated Biphenyl Target Analytes
| PCB congener | BZ No. a | CAS b Registry No. | PCB congener | BZ No. a | CAS b Registry No. |
|---|---|---|---|---|---|
| 2,4′-DiCB | 8 | 34883-43-7 | 2,2′,3,3′,4,4′-HxCB | 128 | 38380-07-3 |
| 2,2′,5-TrCB | 18 | 37680-65-2 | 2,2′,3,4,4′,5′-HxCB | 138 | 35065-28-2 |
| 2,4,4′-TrCB | 28 | 7012-37-5 | 2,2′,4,4′,5,5′-HxCB | 153 | 35065-27-1 |
| 2,2′,3,5′-TeCB | 44 | 41464-39-5 | 2,3,3′,4,4′,5-HxCB | 156 | 38380-08-4 |
| 2,2′,5,5′-TeCB | 52 | 35693-99-3 | 2,3,3′,4,4′,5′-HxCB | 157 | 69782-90-7 |
| 2,3′,4,4′-TeCB | 66 | 32598-10-0 | 2,3′,4,4′,5,5′-HxCB | 167 | 52663-72-6 |
| 3,3′,4,4′-TeCB | 77 | 32598-13-3 | 3,3′,4,4′,5,5′-HxCB | 169 | 32774-16-6 |
| 3,4,4′,5-TeCB | 81 | 70362-50-4 | 2,2′,3,3′,4,4′,5-HpCB | 170 | 35065-30-6 |
| 2,2′,4,5,5′-PeCB | 101 | 37680-73-2 | 2,2′,3,4,4′,5,5′-HpCB | 180 | 35065-29-3 |
| 2,3,3′,4,4′-PeCB | 105 | 32598-14-4 | 2,2′,3,4′,5,5′,6-HpCB | 187 | 52663-68-0 |
| 2,3,4,4′,5-PeCB | 114 | 74472-37-0 | 2,3,3′,4,4′,5,5′-HpCB | 189 | 39635-31-9 |
| 2,3′,4,4′,5-PeCB | 118 | 31508-00-6 | 2,2′,3,3′,4,4′,5,6-OcCB | 195 | 52663-78-2 |
| 2′,3,4,4′,5-PeCB | 123 | 65510-44-3 | 2,2′,3,3′,4,4′,5,5′,6-NoCB | 206 | 40186-72-9 |
| 3,3′,4,4′,5-PeCB | 126 | 57465-28-8 | 2,2′,3,3′,4,4′,5,5′,6,6′-DeCB | 209 | 2051-24-3 |
a BZ No.: Ballschmiter and Zell 1980, or International Union of Pure and Applied Chemistry (IUPAC) number.
b Chemical Abstract Service.
Table 23-4 – Elemental Compositions and Exact Masses of the Ions Monitored by High-Resolution Mass Spectrometry for PCDD and PCDF
| Mass a | Ion type b | Elemental composition | Target analyte b | Mass a | Ion type b | Elemental composition | Target analyte b |
|---|---|---|---|---|---|---|---|
| 263.9871 | LOCK | C | FC43 | 383.8639 | M | 13C 35Cl | HxCDF (S). |
| 292.9825 | LOCK | C | PFK | 385.8610 | M+2 | 13C 35Cl 37ClO | HxCDF (S). |
| 303.9016 | M | C 35Cl | TeCDF | 389.8157 | M+2 | C 35Cl 37ClO | HxCDD. |
| 305.8987 | M+2 | C 35Cl 37ClO | TeCDF | 391.8127 | M+4 | C 35Cl 37Cl | HxCDD. |
| 313.9839 | QC | C | FC43 | 392.9760 | LOCK | C | PFK. |
| 315.9419 | M | 13C 35Cl | TeCDF (S) | 401.8559 | M+2 | 13C 35Cl 37ClO | HxCDD (S). |
| 316.9745 | M+2 | 13C 35Cl 37ClO | TeCDF (S) | 403.8529 | M+4 | 13C 35Cl 37Cl | HxCDD (S). |
| 317.9389 | M+2 | 13C 35Cl 37ClO | TeCDF (S) | 425.9775 | QC | C | FC43. |
| 319.8965 | M | C 35Cl | TeCDD | 445.7555 | M+4 | C 35Cl 37Cl | OCDPE. |
| 321.8936 | M+2 | C 35Cl 37ClO | TeCDD | 407.7818 | M+2 | C 35Cl 37ClO | HpCDF. |
| 325.9839 | QC | C | FC43 | 409.7789 | M+4 | C 35Cl 37Cl | HpCDF. |
| 330.9792 | QC | C | PFK | 417.8253 | M | 13C 35Cl | HpCDF (S). |
| 331.9368 | M | 13C 35Cl | TeCDD (S) | 419.8220 | M+2 | 13C 35Cl 37ClO | HpCDF (S). |
| 333.9339 | M+2 | 13C 35Cl 37ClO | TeCDD (S) | 423.7766 | M+2 | C 35Cl 37ClO | HpCDD. |
| 339.8597 | M+2 | C 35Cl 37ClO | PeCDF | 425.7737 | M+4 | C 35Cl 37Cl | HpCDD. |
| 341.8567 | M+4 | C 35Cl 37Cl | PeCDF | 430.9729 | QC | C | PFK. |
| 354.9792 | LOCK | C | PFK | 435.8169 | M+2 | 13C 35Cl 37ClO | HpCDD (S). |
| 351.9000 | M+2 | 13C 35Cl 37ClO | PeCDF (S) | 437.8140 | M+4 | 13C 35Cl 37Cl | HpCDD (S). |
| 353.8970 | M+4 | 13C 35Cl 37Cl | PeCDF (S) | 442.9728 | LOCK | C | PFK. |
| 355.8546 | M+2 | C 35Cl 37ClO | PeCDD | 479.7165 | M+4 | C 35Cl 37Cl | NCPDE. |
| 357.8516 | M+4 | C 35Cl 37Cl | PeCDD | 430.9729 | LOCK | C | PFK. |
| 367.8949 | M+2 | 13C 35Cl 37ClO | PeCDD (S) | 441.7428 | M+2 | C 35Cl 37ClO | OCDF. |
| 369.8919 | M+4 | 13C 35Cl 37Cl | PeCDD (S) | 443.7399 | M+4 | C 35Cl 37Cl | OCDF. |
| 375.9807 | QC | C | FC43 | 457.7377 | M+2 | C 35Cl 37ClO | OCDD. |
| 375.8364 | M+2 | C 35Cl 37ClO | HxCDPE | 459.7348 | M+4 | C 35Cl 37Cl | OCDD. |
| 409.7974 | M+2 | C 35Cl 37ClO | HpCPDE | 463.9743 | QC | C | FC43. |
| 373.8208 | M+2 | C 37ClO | HxCDF | 469.7779 | M+2 | 13C 35Cl 37ClO | OCDD (S). |
| 375.8178 | M+4 | C 35Cl 37Cl | HxCDF | 471.7750 | M+4 | 13C 35Cl 37Cl | OCDD (S). |
| 375.9807 | QC | C | FC43 | 513.6775 | M+4 | C 35Cl 37Cl | DCDPE. |
| 442.9728 | QC | C | PFK. |
a The following nuclidic masses were used to calculate exact masses: H = 1.007825, C = 12.000000,
13C = 13.003355, F = 18.9984, O = 15.994915,
35C l= 34.968853,
37Cl = 36.965903.
b (S) = Labeled Standard. LOCK = Lock-Mass Ion PFK or FC43. QC = Quality Control Check Ion. Note: Consider monitoring 328 m/z if a high level of PCB is expected.
Table 23-5 – Elemental Compositions and Exact Masses of the Ions Monitored by High-Resolution Mass Spectrometry for PAH
| Aromatic ring No. | Mass a | Ion type b | Elemental composition | Target analyte |
|---|---|---|---|---|
| 2 | 128.0624 | M | C | Naphthalene. |
| 130.9920 | LOCK | PFK/FC43. | ||
| 2 | 134.0828 | M | 13C 12C | 13C |
| 2 | 142.078 | M | C | 2-Methylnaphthalene. |
| 2 | 148.0984 | M | 13C 12C | 13C |
| 2 | 152.0624 | M | C | Acenaphthylene. |
| 2 | 158.0828 | M | 13C 12C | 13C |
| 2 | 154.078 | M | C | Acenaphthene. |
| 2 | 160.078 | M | 13C 12C | 13C |
| 2 | 166.078 | M | C | Fluorene. |
| 169.988 | QC | PFK/FC43. | ||
| 2 | 172.0984 | M | 13C 12C | 13C |
| 3 | 178.078 | M | C | Phenanthrene. |
| 3 | 184.0984 | M | 13C 12C | 13C |
| 3 | 178.078 | M | C | Anthracene. |
| 3 | 184.078 | M | 13C 12C | 13C |
| 3 | 202.078 | M | C | Fluoranthene. |
| 204.9888 | QC | PFK. | ||
| 3 | 208.0984 | M | 13C 12C | 13C |
| 4 | 202.078 | M | C | Pyrene. |
| 4 | 205.078 | M | 13C 12C | 13C |
| 213.9898 | QC | FC43. | ||
| 218.9856 | LOCK | FC43. | ||
| 4 | 228.0936 | M | C | Benz[ |
| 230.9856 | LOCK | PFK. | ||
| 4 | 234.114 | M | 13C | 13C |
| 4 | 228.0936 | M | C | Chrysene. |
| 4 | 234.114 | M | 13C 12C | 13C |
| 4 | 252.0936 | M | C | Benzo[ |
| 4 | 258.114 | M | 13C 12C | 13C |
| 4 | 252.32 | M | C | Benzo[ |
| 4 | 258.114 | M | 13C 12C | 13C |
| 5 | 252.0936 | M | C | Benzo[ |
| 5 | 256.1072 | M | 13C 12C | 13C |
| 5 | 256.1072 | M | 13C 12C | 13C |
| 5 | 252.0936 | M | C | Benzo[ |
| 5 | 252.0936 | M | C | Perylene. |
| 5 | 264.1692 | M | C | d |
| 268.9824 | QC | PFK. | ||
| 263.9871 | LOCK | FC43. | ||
| 6 | 276.0936 | M | C | Indeno[ |
| 6 | 282.114 | M | 13C 12C | 13C |
| 5 | 278.1092 | M | C | Dibenz[ |
| 280.9824 | LOCK | PFK. | ||
| 5 | 284.1296 | M | 13C 12C | 13C |
| 6 | 276.0936 | M | C | Benzo[ |
| 6 | 288.1344 | M | 13C 12C | 13C |
| 313.9839 | QC | FC43. |
a Isotopic masses used for accurate mass calculation:
1H = 1.0078,
12C = 12.0000,
13C = 13.0034,
2H = 2.0141.
b LOCK = Lock-Mass Ion PFK or FC43. QC = Quality Control Check Ion.
Table 23-6 – Elemental Compositions and Exact Masses of the Ions Monitored by High-Resolution Mass Spectrometry for PCB
| Chlorine substitution | Mass a | Ion type b | Elemental composition | Target analyte | Chlorine substitution | Mass a | Ion type b | Elemental composition | Target analyte |
|---|---|---|---|---|---|---|---|---|---|
| Fn-1; Cl-1 | 188.0393 | M | 12C 35Cl | Cl-1 PCB | Fn-5; Cl-5,6,7 | 323.8834 | M | 12C 35Cl | Cl-5 PCB. |
| 190.0363 | M+2 | 12C 37Cl | Cl-1 PCB | 325.8804 | M+2 | 12C 35Cl 37Cl | Cl-5 PCB. | ||
| 200.0795 | M | 13C 35Cl | 13C | 327.8775 | M+4 | 12C 35Cl 37Cl | Cl-5 PCB. | ||
| 202.0766 | M+2 | 12C 37Cl | 13C | 337.9207 | M+2 | 13C 35Cl 37Cl | 13C | ||
| 218.9856 | LOCK | C | PFK | 339.9178 | M+4 | 13C 35Cl 37Cl | 13C | ||
| Fn-2;
Cl-2,3 | 222.0003 | M | 12C 35Cl | Cl-2 PCB | 354.9792 | LOCK | C | PFK. | |
| 223.9974 | M+2 | 12C 35Cl 37Cl | Cl-2 PCB | 359.8415 | M+2 | 12C 35Cl 37Cl | Cl-6 PCB. | ||
| 225.9944 | M+4 | 12C 37Cl | Cl-2 PCB | 361.8385 | M+4 | 12C 35Cl 37Cl | Cl-6 PCB. | ||
| 234.0406 | M | 13C 35Cl | 13C | 363.8356 | M+6 | 12C 35Cl 37Cl | Cl-6 PCB. | ||
| 236.0376 | M+2 | 13C 35Cl 37Cl | 13C | 371.8817 | M+2 | 13C 35Cl 37Cl | 13C | ||
| 242.9856 | LOCK | C | PFK | 373.8788 | M+4 | 13C 35Cl 37Cl | 13C | ||
| 255.9613 | M | 12C 35Cl | Cl-3 PCB | 393.8025 | M+2 | 12C 35Cl 37Cl | Cl-7 PCB. | ||
| 257.9584 | M+2 | 12C 35Cl 37Cl | Cl-3 PCB | 395.7995 | M+4 | 12C 35Cl 37Cl | Cl-7 PCB. | ||
| 268.0016 | M | 13C 35Cl | 13C | 397.7966 | M+6 | 12C 35Cl 37Cl | 37Cl | ||
| 269.9986 | M+2 | 13C 35Cl 37Cl | 13C | 405.8428 | M+2 | 13C 35Cl 37Cl | 13C | ||
| Fn-3;
Cl-3,4,5 | 255.9613 | M | 12C 35Cl | Cl-3 PCB | 407.8398 | M+4 | 13C 35Cl 37Cl | 13C | |
| 257.9584 | M+2 | 12C 35Cl 37Cl | Cl-3 PCB | 454.9728 | QC | C | PFK. | ||
| 259.9554 | M+4 | 12C 35Cl 37Cl | Cl-3 PCB | Fn-6;
Cl-7,8,9,10 | 393.8025 | M+2 | 12C 35Cl 37Cl | Cl-7 PCB. | |
| 268.0016 | M | 13C 35Cl | 13C | 395.7995 | M+4 | 12C 35Cl 37Cl | Cl-7 PCB. | ||
| 269.9986 | M+2 | 13C 35Cl 37Cl | 13C | 397.7966 | M+6 | 12C 35Cl 37Cl | Cl-7 PCB. | ||
| 280.9825 | LOCK | C | PFK | 405.8428 | M+2 | 13C 35Cl 37Cl | 13C | ||
| 289.9224 | M | 12C 35Cl | Cl-4 PCB | 407.8398 | M+4 | 13C 35Cl 37Cl | 13C | ||
| 291.9194 | M+2 | 12C 35Cl 37Cl | Cl-4 PCB | 427.7635 | M+2 | 12C 35Cl 37Cl | Cl-8 PCB. | ||
| 293.9165 | M+4 | 12C 35Cl 37Cl | Cl-4 PCB | 429.7606 | M+4 | 12C 35Cl 37Cl | Cl-8 PCB. | ||
| 301.9626 | M | 13C 35Cl | 13C | 431.7576 | M+6 | 12C 35Cl 37Cl | Cl-8 PCB. | ||
| 303.9597 | M+2 | 13C 35Cl 37Cl | 13C | 439.8038 | M+2 | 13C 35Cl 37Cl | 13C | ||
| 323.8834 | M | 12C 35Cl | Cl-5 PCB | 441.8008 | M+4 | 13C 35Cl 37Cl | 13C | ||
| 325.8804 | M+2 | 12C 35Cl 37Cl | Cl-5 PCB | 454.9728 | QC | C | PFK. | ||
| 327.8775 | M+4 | 12C 35Cl 37Cl | Cl-5 PCB | 427.7635 | M+2 | 12C 35Cl 37Cl | Cl-8 PCB. | ||
| 337.9207 | M+2 | 13C 35Cl 37Cl | 13C | 429.7606 | M+4 | 12C 35Cl 37Cl | Cl-8 PCB. | ||
| 339.9178 | M+4 | 13C 35Cl 37Cl | 13C | 431.7576 | M+6 | 12C 35Cl 37Cl | Cl-8 PCB. | ||
| Fn-4;
Cl-4,5,6 | 289.9224 | M | 12C 35Cl | Cl-4 PCB | 439.8038 | M+2 | 13C 35Cl 37Cl | 13C | |
| 291.9194 | M+2 | 12C 35Cl 37Cl | Cl-4 PCB | 441.8008 | M+4 | 13C 35Cl 37Cl | 13C | ||
| 293.9165 | M+4 | 12C 35Cl 37Cl | Cl-4 PCB | 442.9728 | QC | C | PFK. | ||
| 301.9626 | M+2 | 13C 35Cl 37Cl | 13C | 454.9728 | LOCK | C | PFK. | ||
| 303.9597 | M+4 | 13C 35Cl 37Cl | 13C | 461.7246 | M+2 | 12C 35Cl 37Cl | Cl-9 PCB. | ||
| 323.8834 | M | 12C 35Cl | Cl-5 PCB | 463.7216 | M+4 | 12C 35Cl 37Cl | Cl-9 PCB. | ||
| 325.8804 | M+2 | 12C 35Cl 37Cl | Cl-5 PCB | 465.7187 | M+6 | 12C 35Cl 37Cl | Cl-9 PCB. | ||
| 327.8775 | M+4 | 12C 35Cl 37Cl | Cl-5 PCB | 473.7648 | M+2 | 13C 35Cl 37Cl | 13C | ||
| 330.9792 | LOCK | C | PFK | 475.7619 | M+4 | 13C 35Cl 37Cl | 13C | ||
| 337.9207 | M+2 | 13C 35Cl 37Cl | 13C | 495.6856 | M+2 | 13C 5Cl 37Cl | Cl-10 PCB. | ||
| 339.9178 | M+4 | 13C 35Cl 37Cl | 13C | 499.6797 | M+6 | 12C 35Cl 37Cl | Cl-10 PCB. | ||
| 359.8415 | M+2 | 13C 35Cl 37Cl | Cl-6 PCB | 501.6767 | M+8 | 12C 35Cl 37Cl | Cl-10 PCB. | ||
| 361.8385 | M+4 | 13C 35Cl 37Cl | Cl-6 PCB | 507.7258 | M+2 | 13C 35Cl 37Cl | 13C | ||
| 363.8356 | M+6 | 12C 35Cl 37Cl | Cl-6 PCB | 509.7229 | M+4 | 13C 35Cl 37Cl | 13C | ||
| 371.8817 | M+2 | 13C 35Cl 37Cl | 13C | 511.7199 | M+6 | 13C 35Cl 37Cl | 13C | ||
| 373.8788 | M+4 | 13C 35Cl 37Cl | 13C |
a Isotopic masses used for accurate mass calculation:
1H = 1.0078,
12C = 12.0000,
13C = 13.0034,
35Cl = 34.9689,
37Cl = 36.9659,
19F = 18.9984. An interference with PFK m/z 223.9872 may preclude meeting 10:1 S/N for the DiCB congeners at optional Cal 1 level (Table 23-11). If this interference occurs, 10:1 S/N must be met at the Cal 2 level.
b LOCK = Lock-Mass Ion PFK or FC43. QC = Quality Control Check Ion.
Table 23-7 – Concentration of the Sample Fortification for PCDD and PCDF
a
| Compound | pg/µL in final extract b | Spike recovery |
|---|---|---|
13C | 50 | 70-130% |
13C | 50 | 70-130% |
13C | 50 | 70-130% |
13C | 50 | 70-130% |
13C | 50 | 70-130% |
13C | 50 | 70-130% |
13C | 50 | 70-130% |
13C | 50 | 20-130% |
13C | 50 | 20-130% |
13C | 50 | 20-130% |
13C | 50 | 20-130% |
13C | 50 | 20-130% |
13C | 50 | 20-130% |
13C | 50 | 20-130% |
13C | 50 | 20-130% |
13C | 50 | 20-130% |
13C | 50 | 20-130% |
13C | 50 | 20-130% |
13C | 50 | 20-130% |
13C | 50 | 20-130% |
13C | 50 | 20-130% |
13C | 50 | 20-130% |
13C | 100 | 20-130% |
13C | 100 | 20-130% |
13C | 50 | S/N≥10 |
13C | 50 | S/N≥10 |
13C | 50 | S/N≥10 |
13C | 50 | S/N≥10 |
13C | 50 | 20-130% |
13C | 50 | 20-130% |
a Changes in the amounts of labeled standards added to the sample or its representative extract will necessitate an adjustment of the calibration solutions to prevent the introduction of inconsistencies. Spike concentration assumes 1 µL sample injection volume for analysis or the injection volume for calibration standards and samples is the same.
b Labeled standard concentrations are recommendations (equivalent mass per sample of 25 pg pre-extraction standard, as an example, based on a 200 µL extract volume split in half before cleanup with a 20 µL aliquot of a 500 pg/µL spiking solution). Recommendations are based on assumption that half of the extract will be archived before cleanup. Spike levels may be adjusted for different split levels.
Table 23-8 – Concentration of the Sample Fortification for PAH
a
| Compound | pg/µL in final extract b | Spike recovery |
|---|---|---|
13C | 100 | 70-130% |
13C | 100 | 70-130% |
| d | 100 | 70-130% |
13C | 100 | 20-130% |
13C | 100 | 20-130% |
13C | 100 | 20-130% |
13C | 100 | 20-130% |
13C | 100 | 20-130% |
13C | 100 | 20-130% |
13C | 100 | 20-130% |
13C | 100 | 20-130% |
13C | 100 | 20-130% |
13C | 100 | 20-130% |
13C | 100 | 20-130% |
13C | 100 | 20-130% |
13C | 100 | 20-130% |
13C | 100 | 20-130% |
13C | 100 | 20-130% |
| d | 100 | 20-130% |
13C | 100 | 20-130% |
13C | 100 | 20-130% |
13C | 100 | 20-130% |
| d | 100 | S/N≥10 |
| d | 100 | S/N≥10 |
| d | 100 | S/N≥10 |
a Changes in the amounts of labeled standards added to the sample or its representative extract will necessitate an adjustment of the calibration solutions to prevent the introduction of inconsistencies.
b Labeled standard concentrations are recommendations (equivalent mass per sample of 25 pg pre-extraction standard, as an example, based on a 200 µL extract volume split in half before cleanup with a 20 µL aliquot of a 1000 pg/µL spiking solution). Recommendations are based on assumption that half of the extract will be archived before cleanup. Spike levels may be adjusted for different split levels.
Table 23-9 – Concentration of the Sample Fortification for PCB
a
| Compound | BZ No. b | pg/µL in final extract c | Spike recovery |
|---|---|---|---|
13C | 11L | 100 | 70-130% |
13C | 31L | 100 | 70-130% |
13C | 95L | 100 | 70-130% |
13C | 153L | 100 | 70-130% |
13C | 159L | 100 | 70-130% |
13C | 1L | 100 | 20-145% |
13C | 3L | 100 | 20-145% |
13C | 4L | 100 | 20-145% |
13C | 15L | 100 | 20-145% |
13C | 19L | 100 | 20-145% |
13C | 37L | 100 | 20-145% |
13C | 54L | 100 | 20-145% |
13C | 77L | 100 | 20-145% |
13C | 81L | 100 | 20-145% |
13C | 104L | 100 | 20-145% |
13C | 105L | 100 | 20-145% |
13C | 114L | 100 | 20-145% |
13C | 118L | 100 | 20-145% |
13C | 123L | 100 | 20-145% |
13C | 126L | 100 | 20-145% |
13C | 155L | 100 | 20-145% |
13C | 156L | 100 | 20-145% |
13C | 157L | 100 | 20-145% |
13C | 167L | 100 | 20-145% |
13C | 169L | 100 | 20-145% |
13C | 170L | 100 | 20-145% |
13C | 180L | 100 | 20-145% |
13C | 188L | 100 | 20-145% |
13C | 189L | 100 | 20-145% |
13C | 202L | 100 | 20-145% |
13C | 205L | 100 | 20-145% |
13C | 206L | 100 | 20-145% |
13C | 208L | 100 | 20-145% |
13C | 209L | 100 | 20-145% |
13C | 9L | 100 | S/N≥10 |
13C | 52L | 100 | S/N≥10 |
13C | 101L | 100 | S/N≥10 |
13C | 138L | 100 | S/N≥10 |
13C | 194L | 100 | S/N≥10 |
13C | 28L | 100 | 20-130% |
13C | 111L | 100 | 20-130% |
13C | 178L | 100 | 20-130% |
13C | 70L | 100 | 20-130% |
13C | 60L | 100 | 20-130% |
13C | 127L | 100 | 20-130% |
a Changes in the amounts of spike standards added to the sample or its representative extract will necessitate an adjustment of the calibration solutions to prevent the introduction of inconsistencies.
b BZ No.: Ballschmiter and Zell 1980, or IUPAC number.
c Labeled standard concentrations are recommendations (equivalent mass per sample of 25 pg pre-extraction standard, as an example, based on a 200 µL extract volume split in half before cleanup with a 20 µL aliquot of a 1000 pg/µL spiking solution). Recommendations are based on assumption that half of the extract will be archived before cleanup. Spike levels may be adjusted for different split levels.
NOAAT = PCB considered toxic by the National Oceanic and Atmospheric Administration.
WHOT = PCB considered toxic by the World Health Organization.
Table 23-10 – Sample Storage Conditions
a
b
| Sample type | PCDD/PCDF | PAH | PCB |
|---|---|---|---|
| All Field Samples | ≤20 °C, (68 °F) | ≤20 °C, (68 °F) | ≤20 °C, (68 °F). |
| Sampling Train Rinses and Filters | ≤6 °C (43 °F) | ≤6 °C (43 °F) | ≤6 °C (43 °F). |
| Adsorbent | ≤6 °C (43 °F) | ≤6 °C (43 °F) | ≤6 °C (43 °F). |
| Extract and Archive | c | ||
| Extract and Archive | One year | 45 Days | One year. |
a Samples and extracts must be stored in the dark.
b Hold times begin from the time the laboratory receives the sample.
c Room temperature is acceptable if PCDD/PCDF are the only target compounds.
Table 23-11 – Concentration of the Initial Calibration Standard Solutions for PCDD and PCDF
a
[pg/µL]
| Standard compound | Cal 1 (optional) | Cal 2 | Cal 3 | Cal 4 | Cal 5 | Cal 6 | Cal 7 (optional) |
|---|---|---|---|---|---|---|---|
| Target (Unlabeled) Analytes | 0.50 | 1.0 | 5.0 | 10.0 | 25 | 50 | 100 |
| Pre-sampling Adsorbent Standard | 50 | 50 | 50 | 50 | 50 | 50 | 50 |
| Pre-extraction Filter Recovery Standard | 50 | 50 | 50 | 50 | 50 | 50 | 50 |
| Pre-extraction Standard ( 13C 13C | 50 | 50 | 50 | 50 | 50 | 50 | 50 |
| Pre-analysis Standard | 50 | 50 | 50 | 50 | 50 | 50 | 50 |
| Alternate Recovery Standard | 50 | 50 | 50 | 50 | 50 | 50 | 50 |
a Assumes 1 µL injection volume or the injection volume for standards and samples is the same.
Table 23-12 – Concentration of the Initial Calibration Standard Solutions for PAH
a
[pg/µL]
| Standard compound | Cal 1 (optional) | Cal 2 | Cal 3 | Cal 4 | Cal 5 | Cal 6 | Cal 7 (optional) |
|---|---|---|---|---|---|---|---|
| Target (Unlabeled) Analytes | 1 | 2 | 4 | 20 | 80 | 400 | 1,000 |
| Pre-sampling Adsorbent Standard | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
| Pre-extraction Filter Recovery Standard | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
| Pre-extraction Standard | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
| Pre-analysis Standard | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
a Assumes 1 µL injection volume.
Table 23-13 – Concentration of the Initial Calibration Standard Solutions for PCB
a
[pg/µL]
| Standard compound | Cal 1 (optional) | Cal 2 | Cal 3 | Cal 4 | Cal 5 | Cal 6 | Cal 7 (optional) |
|---|---|---|---|---|---|---|---|
| Target (Unlabeled) Analytes | 0.50 | 1 | 5 | 10 | 50 | 400 | 2,000 |
| Pre-sampling Adsorbent Standard | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
| Pre-extraction Filter Recovery Standard | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
| Pre-extraction Standard | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
| Pre-analysis Standard | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
| Alternate Standard | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
a Assumes 1 µL injection volume.
Table 23-14 – Minimum Requirements for Initial and Continuing Calibration Response Factors for Isotopically Labeled and Native Compounds
| Analyte group | Initial calibration RRF RSD | Continuing calibration RRF compared to ICAL RRF (PD) |
|---|---|---|
| Native (Unlabeled) Analytes | 10 | 25 |
| Pre-sampling Adsorbent Standard | 20 | 25 |
| Pre-extraction Filter Recovery Standard | 20 | 25 |
| Pre-extraction Standard | 20 | 30 |
| Alternative Recovery Standard | 20 | 30 |
Table 23-15 – Recommended Ion Type and Acceptable Ion Abundance Ratios
| Number of chlorine atoms | Ion type | Theoretical ratio | Lower control limit | Upper control limit |
|---|---|---|---|---|
| 1 | M/M+2 | 3.13 | 2.66 | 3.60 |
| 2 | M/M+2 | 1.56 | 1.33 | 1.79 |
| 3 | M/M+2 | 1.04 | 0.88 | 1.20 |
| 4 | M/M+2 | 0.77 | 0.65 | 0.89 |
| 5 | M+2/M+4 | 1.55 | 1.32 | 1.78 |
| 6 | M+2/M+4 | 1.24 | 1.05 | 1.43 |
| 6 a | M/M+2 | 0.51 | 0.43 | 0.59 |
| 7 | M+2/M+4 | 1.05 | 0.89 | 1.21 |
| 7 b | M/M+2 | 0.44 | 0.37 | 0.51 |
| 8 | M+2/M+4 | 0.89 | 0.76 | 1.02 |
| 9 | M+2/M+4 | 0.77 | 0.65 | 0.89 |
| 10 | M+4/M+6 | 1.16 | 0.99 | 1.33 |
a Used only for
13C-HxCDF.
b Used only for
13C-HpCDF.
Table 23-16 – Typical DB5-MS Column Conditions
| Column parameter | PCDD/PCDF | PAH | PCB |
|---|---|---|---|
| Injector temperature | 250 °C | 320 °C | 270 °C. |
| Initial oven temperature | 100 °C | 100 °C | 100 °C. |
| Initial hold time (minutes) | 2 | 2 | 2. |
| Temperature program | 100 to 190 °C at 40 °C/min, then 190 to 300 °C at 3 °C/min | 100 to 300 °C at 8 °C/min | 100 to 150 °C at 15 °C/min, then 150 to 290 °C at 2.5 °C/min. |
Table 23-17 – Assignment of Pre-Extraction Standards for Quantitation of Target PCB
b
| PCB Congener | BZ No. a | Labeled analog | BZ No. |
|---|---|---|---|
| 2,4′-DiCB (NOAAT) | 8 | 13C | 4L |
| 2,2′,5-TrCB (NOAAT) | 18 | 13C | 19L |
| 2,4,4′-TrCB (NOAAT) | 28 | 13C | 19L |
| 2,2′,3,5′-TeCB (NOAAT) | 52 | 13C | 54L |
| 2,2′,5,5′-TeCB (NOAAT) | 52 | 13C | 54L |
| 2,3′,4,4′-TeCB (NOAAT) | 66 | 13C | 54L |
| 3,3′,4,4′-TeCB (NOAAT) (WHOT) | 77 | 13C | 77L |
| 3,4,4′,5-TeCB (WHOT) | 81 | 13C | 81L |
| 2,2′,4,5,5′-PeCB (NOAAT) | 101 | 13C | 104L |
| 2,3,3′,4,4′-PeCB (NOAAT) (WHOT) | 105 | 13C | 105L |
| 2,3,4,4′,5-PeCB (WHOT) | 114 | 13C | 114L |
| 2,3′,4,4′,5-PeCB (WHOT) | 118 | 13C | 118L |
| 2′,3,4,4′,5-PeCB (WHOT) | 123 | 13C | 123L |
| 3,3′,4,4′,5-PeCB (NOAAT) (WHOT) | 126 | 13C | 126L |
| 2,2′,3,3′,4,4′-HxCB (NOAAT) | 128 | 13C | 155L |
| 2,2′,3,4,4′,5′-HxCB (NOAAT) | 138 | 13C | 155L |
| 2,2′,4,4′,5,5′-HxCB (NOAAT) | 153 | 13C | 155L |
| 2,3,3′,4,4′,5-HxCB (WHOT) | 156 | 13C | 156L |
| 2,3,3′,4,4′,5′-HxCB (WHOT) | 157 | 13C | 157L |
| 2,3′,4,4′,5,5′-HxCB (WHOT) | 167 | 13C | 167L |
| 3,3′,4,4′,5,5′-HxCB (NOAAT) (WHOT) | 169 | 13C | 169L |
| 2,2′,3,3′,4,4′,5-HpCB (NOAAT) | 170 | 13C | 170L |
| 2,2′,3,4,4′,5,5′-HpCB (NOAAT) | 180 | 13C | 180L |
| 2,2′,3,4′,5,5′,6-HpCB (NOAAT) | 187 | 13C | 188L |
| 2,3,3′,4,4′,5,5′-HpCB (WHOT) | 189 | 13C | 189L |
| 2,2′,3,3′,4,4′,5,6-OcCB (NOAAT) | 195 | 13C | 202L |
| 2,2′,3,3′,4,4′,5,5′,6-NoCB (NOAAT) | 206 | 13C | 206L |
| 2,2′,3,3′,4,4′,5,5′,6,6′-DeCB (NOAAT) | 209 | 13C | 209L |
a BZ No.: Ballschmiter and Zell 1980, or IUPAC number.
b Assignments assume the use of the SPB-Octyl column. In the event you choose another column, you may select the labeled standard having the same number of chlorine substituents and the closest retention time to the target analyte in question as the labeled standard to use for quantitation.
NOAAT = PCB considered toxic by the National Oceanic and Atmospheric Administration.
WHOT = PCB considered toxic by the World Health Organization.
Table 23-18 – Initial Demonstration of Capability QC Requirements
| Section | Requirement | Specification and frequency | Acceptance criteria |
|---|---|---|---|
| 9.3.5 | Demonstration of low system background | Analyze an LMB after the highest calibration standard Note: If an automated extraction system is used, an LMB must be extracted on each port | Confirm that the LMB is free from contamination as defined in Section 13.1. |
| 9.3.7 | Determination of MDL | Prepare, extract, and analyze 7 replicate spiked samples (spiked within 2 to 10 times of the expected MDL) and 7 LMBs See 40 CFR Part 136 Appendix B | See MDL confirmation. |
| 9.3.8 | MDL confirmation | Prepare, extract, and analyze a spiked sample (spiked at the MDL) | Confirm that the target compounds meet the qualitative identification criteria in Section 11.4.3.4 of this method. |
| 9.3.9 | Demonstration of precision | Prepare, extract, and analyze 7 replicate spiked samples (spiked near mid-range) | Percent relative standard deviation must be ≤20%. |
| 9.3.10 | Demonstration of accuracy | Calculate mean recovery for replicate spiked samples in Section 9.3.9 | Mean recovery within 70-130% of true value. |
| 9.3.2 | Lowest Calibration Concentration Confirmation | Establish a target concentration for the lowest calibration based on the intended use of the method | Upper PIR ≤150%. Lower PIR ≥50%. |
| 9.3.6 | Calibration Verification | Analyze a mid-level QCS | Within limits in Section 13.11. |
Complete List of 209 PCB Congeners and Their Isomers With Corresponding Isotope Dilution Quantitation Standards
a
| Pre-extraction standard | BZ b No. | Unlabeled target analyte | BZ b No. | Pre-extraction standard | BZ b No. | Unlabeled target analyte | BZ b No. |
|---|---|---|---|---|---|---|---|
13C | 1L | 2-MoCB | 1 | 13C | 4L | 2,2′-DiCB | 4 |
13C | 1L | 3-MoCB | 2 | 13C | 4L | 2,3-DiCB | 5 |
13C | 3L | 4-MoCB | 3 | 13C | 4L | 2,3′-DiCB | 6 |
13C | 4L | 2,4-DiCB | 7 | ||||
13C | 4L | 2,4′-DiCB | 8 | ||||
13C | 4L | 2,5-DiCB | 9 | ||||
13C | 4L | 2,6-DiCB | 10 | ||||
13C | 4L | 3,3′-DiCB | 11 | ||||
13C | 4L | 3,4-DiCB | 12 | ||||
13C | 4L | 3,4′-DiCB | 13 | ||||
13C | 4L | 3,5-DiCB | 14 | ||||
13C | 15L | 4,4′-DiCB | 15 | ||||
13C | 19L | 2,2′,3-TrCB | 16 | 13C | 19L | 2,4,4′-TrCB | 28 |
13C | 19L | 2,2′,4-TrCB | 17 | 13C | 19L | 2,4,5-TrCB | 29 |
13C | 19L | 2,2′,5-TrCB | 18 | 13C | 19L | 2,4,6-TrCB | 30 |
13C | 19L | 2,2′,6-TrCB | 19 | 13C | 19L | 2,4′,5-TrCB | 31 |
13C | 19L | 2,3,3′-TrCB | 20 | 13C | 19L | 2,4′,6-TrCB | 32 |
13C | 19L | 2,3,4-TrCB | 21 | 13C | 19L | 2′,3,4-TrCB | 33 |
13C | 19L | 2,3,4′-TrCB | 22 | 13C | 19L | 2′,3,5-TrCB | 34 |
13C | 19L | 2,3,5- TrCB | 23 | 13C | 19L | 3,3′,4-TrCB | 35 |
13C | 19L | 2,3,6- TrCB | 23 | 13C | 19L | 3,3′,5-TrCB | 36 |
13C | 19L | 2,3′,4-TrCB | 25 | 13C | 37L | 3,4,4′-TrCB | 37 |
13C | 19L | 2,3′,5-TrCB | 26 | 13C | 37L | 3,4,5-TrCB | 38 |
13C | 19L | 2,3′,6-TrCB | 27 | 13C | 37L | 3,4′,5-TrCB | 39 |
13C | 54L | 2,2′,3,3′-TeCB | 40 | 13C | 54L | 2,3,4,5-TeCB | 61 |
13C | 54L | 2,2′,3,4-TeCB | 41 | 13C | 54L | 2,3,4,6-TeCB | 62 |
13C | 54L | 2,2′,3,4′-TeCB | 42 | 13C | 54L | 2,3,4′,5-TeCB | 63 |
13C | 54L | 2,2′,3,5-TeCB | 43 | 13C | 54L | 2,3,4′,6-TeCB | 64 |
13C | 54L | 2,2′,3,5′-TeCB | 44 | 13C | 54L | 2,3,5,6-TeCB | 65 |
13C | 54L | 2,2′,3,6-TeCB | 45 | 13C | 54L | 2,3′,4,4′-TeCB | 66 |
13C | 54L | 2,2′,3,6′-TeCB | 46 | 13C | 54L | 2,3′,4,5-TeCB | 67 |
13C | 54L | 2,2′,4,4′-TeCB | 47 | 13C | 54L | 2,3′,4,5′-TeCB | 68 |
13C | 54L | 2,2′,4,5-TeCB | 48 | 13C | 54L | 2,3′,4,6-TeCB | 69 |
13C | 54L | 2,2′,4,5′-TeCB | 49 | 13C | 54L | 2,3′,4′,5-TeCB | 70 |
13C | 54L | 2,2′,4,6-TeCB | 50 | 13C | 54L | 2,3′,4′,6-TeCB | 71 |
13C | 54L | 2,2′,4,6′-TeCB | 51 | 13C | 54L | 2,3′,5,5′-TeCB | 72 |
13C | 54L | 2,2′,5,5′-TeCB | 52 | 13C | 54L | 2,3′,5′,6-TeCB | 73 |
13C | 54L | 2,2′,5,6′-TeCB | 53 | 13C | 54L | 2,4,4′,5-TeCB | 74 |
13C | 54L | 2,2′,6,6′-TeCB | 54 | 13C | 54L | 2,4,4′,6-TeCB | 75 |
13C | 54L | 2,3,3′,4′-TeCB | 55 | 13C | 54L | 2′,3,4,5-TeCB | 76 |
13C | 54L | 2,3,3′,4′-TeCB | 56 | 13C | 77L | 3,3′,4,4′-TeCB | 77 |
13C | 54L | 2,3,3′,5-TeCB | 57 | 13C | 77L | 3,3′,4,5-TeCB | 78 |
13C | 54L | 2,3,3′,5′-TeCB | 58 | 13C | 77L | 3,3′,4,5′-TeCB | 79 |
13C | 54L | 2,3,3′,6-TeCB | 59 | 13C | 77L | 3,3′,5,5′-TeCB | 80 |
13C | 54L | 2,3,4,4′-TeCB | 60 | 13C | 81L | 3,4,4′,5-TeCB | 81 |
13C | 104L | 2,2′,3,3′,4-PeCB | 82 | 13C | 105L | 2,3,3′,4,4′-PeCB | 105 |
13C | 104L | 2,2′,3,3′,5-PeCB | 83 | 13C | 105L | 2,3,3′,4,5-PeCB | 106 |
13C | 104L | 2,2′,3,3′,6-PeCB | 84 | 13C | 105L | 2,3,3′,4′,5-PeCB | 107 |
13C | 104L | 2,2′,3,4,4′-PeCB | 85 | 13C | 105L | 2,3,3′,4,5′-PeCB | 108 |
13C | 104L | 2,2′,3,4,5-PeCB | 86 | 13C | 105L | 2,3,3′,4,6-PeCB | 109 |
13C | 104L | 2,2′,3,4,5′-PeCB | 87 | 13C | 105L | 2,3,3′,4′,6-PeCB | 110 |
13C | 104L | 2,2′,3,4,6-PeCB | 88 | 13C | 105L | 2,3,3′,5,5′-PeCB | 111 |
13C | 104L | 2,2′,3,4,6′-PeCB | 89 | 13C | 105L | 2,3,3′,5,6-PeCB | 112 |
13C | 104L | 2,2′,3,4′,5-PeCB | 90 | 13C | 105L | 2,3,3′,5′,6-PeCB | 113 |
13C | 104L | 2,2′,3,4′,6-PeCB | 91 | 13C | 114L | 2,3,4,4′,5-PeCB | 114 |
13C | 104L | 2,2′,3,5,5′-PeCB | 92 | 13C | 114L | 2,3,4,4′,6-PeCB | 115 |
13C | 104L | 2,2′,3,5,6-PeCB | 93 | 13C | 114L | 2,3,4,5,6-PeCB | 116 |
13C | 104L | 2,2′,3,5,6′-PeCB | 94 | 13C | 114L | 2,3,4′,5,6-PeCB | 117 |
13C | 104L | 2,2′,3,5′,6-PeCB | 95 | 13C | 118L | 2,3′,4,4′,5-PeCB | 118 |
13C | 104L | 2,2′,3,6,6′-PeCB | 96 | 13C | 118L | 2,3′,4,4′,6-PeCB | 119 |
13C | 104L | 2,2′,3′,4,5-PeCB | 97 | 13C | 118L | 2,3′,4,5,5′-PeCB | 120 |
13C | 104L | 2,2′,3′,4,6-PeCB | 98 | 13C | 118L | 2,3′,4,5,′6-PeCB | 121 |
13C | 104L | 2,2′,4,4′,5-PeCB | 99 | 13C | 118L | 2′,3,3′,4,5-PeCB | 122 |
13C | 104L | 2,2′,4,4′,6-PeCB | 100 | 13C | 123L | 2′,3,4,4′,5-PeCB | 123 |
13C | 104L | 2,2′,4,5,5′-PeCB | 101 | 13C | 123L | 2′,3,4,5,5′-PeCB | 124 |
13C | 104L | 2,2′,4,5,6′-PeCB | 102 | 13C | 123L | 2′,3,4,5,6′-PeCB | 125 |
13C | 104L | 2,2′,4,5,′6-PeCB | 103 | 13C | 126L | 3,3′,4,4′,5-PeCB | 126 |
13C | 104L | 2,2′,4,6,6′-PeCB | 104 | 13C | 126L | 3,3′,4,5,5′-PeCB | 127 |
13C | 155L | 2,2′,3,3′,4,4′-HxCB | 128 | 13C | 155L | 2,2′,3,4′,5′,6-HxCB | 149 |
13C | 155L | 2,2′,3,3′,4,5-HxCB | 129 | 13C | 155L | 2,2′,3,4′,6,6′-HxCB | 150 |
13C | 155L | 2,2′,3,3′,4,5′-HxCB | 130 | 13C | 155L | 2,2′,3,5,5′,6-HxCB | 151 |
13C | 155L | 2,2′,3,3′,4,6-HxCB | 131 | 13C | 155L | 2,2′,3,5,6,6′-HxCB | 152 |
13C | 155L | 2,2′,3,3′,4,6′-HxCB | 132 | 13C | 155L | 2,2′,4,4′,5,5′-HxCB | 153 |
13C | 155L | 2,2′,3,3′,5,5′-HxCB | 133 | 13C | 155L | 2,2′,4,4′,5′,6-HxCB | 154 |
13C | 155L | 2,2′,3,3′,5,6-HxCB | 134 | 13C | 155L | 2,2′,4,4′,6,6′-HxCB | 155 |
13C | 155L | 2,2′,3,3′,5,6′-HxCB | 135 | 13C | 156L | 2,3,3′,4,4′,5-HxCB | 156 |
13C | 155L | 2,2′,3,3′,6,6′-HxCB | 136 | 13C | 157L | 2,3,3′,4,4′,5′-HxCB | 157 |
13C | 155L | 2,2′,3,4,4′,5-HxCB | 137 | 13C | 157L | 2,3,3′,4,4′,6-HxCB | 158 |
13C | 155L | 2,2′,3,4,4′,5′-HxCB | 138 | 13C | 157L | 2,3,3′,4,5,5′-HxCB | 158 |
13C | 155L | 2,2′,3,4,4′,6-HxCB | 139 | 13C | 157L | 2,3,3′,4,5,6-HxCB | 160 |
13C | 155L | 2,2′,3,4,4′,6′-HxCB | 140 | 13C | 157L | 2,3,3′,4,5′,6-HxCB | 161 |
13C | 155L | 2,2′,3,4,5,5′-HxCB | 141 | 13C | 157L | 2,3,3′,4′,5,5′-HxCB | 162 |
13C | 155L | 2,2′,3,4,5,6-HxCB | 142 | 13C | 157L | 2,3,3′,4′,5,6-HxCB | 163 |
13C | 155L | 2,2′,3,4,5,6′-HxCB | 143 | 13C | 157L | 2,3,3′,4′,5′,6-HxCB | 164 |
13C | 155L | 2,2′,3,4,5′,6-HxCB | 144 | 13C | 157L | 2,3,3′,5,5′,6-HxCB | 165 |
13C | 155L | 2,2′,3,4,6,6′-HxCB | 145 | 13C | 157L | 2,3,4,4′,5,6-HxCB | 166 |
13C | 155L | 2,2′,3,4′,5,5′-HxCB | 146 | 13C | 167L | 2,3′,4,4′,5,5′-HxCB | 167 |
13C | 155L | 2,2′,3,4′,5,6-HxCB | 147 | 13C | 167L | 2,3′,4,4′,5′,6-HxCB | 168 |
13C | 155L | 2,2′,3,4′,5,6′-HxCB | 148 | 13C | 169L | 3,3′,4,4′,5,5′-HxCB | 169 |
13C | 188L | 2,2′,3,3′,4,4′,5-HpCB | 170 | 13C | 188L | 2,2′,3,4,4′,5,6′-HpCB | 182 |
13C | 188L | 2,2′,3,3′,4,4′,6-HpCB | 171 | 13C | 188L | 2,2′,3,4,4′,5′,6-HpCB | 183 |
13C | 188L | 2,2′,3,3′,4,5,5′-HpCB | 172 | 13C | 188L | 2,2′,3,4,4′,5′,6-HpCB | 184 |
13C | 188L | 2,2′,3,3′,4,5,6-HpCB | 173 | 13C | 188L | 2,2′,3,4,4′,6,6′-HpCB | 185 |
13C | 188L | 2,2′,3,3′,4,5,6′-HpCB | 174 | 13C | 188L | 2,2′,3,4,5,5′,6-HpCB | 186 |
13C | 188L | 2,2′,3,3′,4,5′,6-HpCB | 175 | 13C | 188L | 2,2′,3,4′,5,5′,6-HpCB | 187 |
13C | 188L | 2,2′,3,3′,4,6,6′-HpCB | 176 | 13C | 188L | 2,2′,3,4′,5,6,6′-HpCB | 188 |
13C | 188L | 2,2′,3,3′,4′,5,6-HpCB | 177 | 13C | 189L | 2,3,3′,4,4′,5,5′-HpCB | 189 |
13C | 188L | 2,2′,3,3′,5,5′,6-HpCB | 178 | 13C | 189L | 2,3,3′,4,4′,5,6-HpCB | 190 |
13C | 188L | 2,2′,3,3′,5,6,6′-HpCB | 179 | 13C | 189L | 2,3,3′,4,4′,5′,6-HpCB | 191 |
13C | 188L | 2,2′,3,4,4′,5,5′-HpCB | 180 | 13C | 189L | 2,3,3′,4,5,5′,6-HpCB | 192 |
13C | 188L | 2,2′,3,4,4′,5,6-HpCB | 181 | 13C | 189L | 2,3,3′,4′,5,5′,6-HpCB | 193 |
13C | 202L | 2,2′,3,3′,4,4′,5,5′-OcCB | 194 | 13C | 206L | 2,2′,3,3′,4,4′,5,5′,6-NoCB | 206 |
13C | 202L | 2,2′,3,3′,4,4′,5,6-OcCB | 195 | 13C | 206L | 2,2′,3,3′,4,4′,5,6,6′-NoCB | 207 |
13C | 202L | 2,2′,3,3′,4,4′,5,6′-OcCB | 196 | 13C | 208L | 2,2′,3,3′,4,5,5′,6,6′- NoCB | 208 |
13C | 202L | 2,2′,3,3′,4,4′,6,6′-OcCB | 197 | ||||
13C | 202L | 2,2′,3,3′,4,5,5′,6-OcCB | 198 | 13C | 209L | 2,2′,3,3′,4,4′,5,5′,6,6′-DeCB | 209 |
13C | 202L | 2,2′,3,3′,4,5,5′,6′-OcCB | 199 | ||||
13C | 202L | 2,2′,3,3′,4,5,6,6′-OcCB | 200 | ||||
13C | 202L | 2,2′,3,3′,4,5′,6,6′-OcCB | 201 | ||||
13C | 202L | 2,2′,3,3′,5,5′,6,6′-OcCB | 202 | ||||
13C | 205L | 2,2′,3,4,4′,5,5′,6-OcCB | 203 | ||||
13C | 205L | 2,2′,3,4,4′,5,6,6′-OcCB | 204 | ||||
13C | 205L | 2,3,3′,4,4′,5,5′,6-OcCB | 205 | ||||
a Assignments assume the use of the SPB-Octyl column. In the event you choose another column, you may select the labeled standard having the same number of chlorine substituents and the closest retention time to the target analyte in question as the labeled standard to use for quantitation.
b BZ No.: Ballschmiter and Zell 1980, also referred to as IUPAC number.
XAD-2® resin, as supplied by the original manufacturer, is impregnated with a bicarbonate solution to inhibit microbial growth during storage. Remove both the salt solution and any residual extractable chemicals used in the polymerization process before use. Prepare the resin by a series of water and organic extractions, followed by careful drying.
2.1 You may perform the extraction using a Soxhlet extractor or other apparatus that generates resin meeting the requirements in Section 13.1 of Method 23. Use an all-glass thimble containing an extra-coarse frit for extraction of the resin. The frit is recessed 10-15 mm above a crenellated ring at the bottom of the thimble to facilitate drainage. Because the resin floats on methylene chloride, carefully retain the resin in the extractor cup with a glass wool plug and stainless-steel screen. This process involves sequential extraction with the following recommended solvents in the listed order.
• Water initial rinse: Place resin in a suitable container, soak for approximately 5 min with Type II water, remove fine floating resin particles and discard the water. Fill with Type II water a second time, let stand overnight, remove fine floating resin particles, and discard the water.
• Hot water: Extract with water for 8 hr.
• Methyl alcohol: Extract for 22 hr.
• Methylene chloride: Extract for 22 hr.
• Toluene: Extract for 22 hr.
• Methylene chloride: Extract for 22 hr.
2.2 You may use alternative extraction procedures to clean large batches of resin. Any size extractor may be constructed; the choice depends on the needs of the sampling programs. The resin is held in a glass or stainless-steel cylinder between a pair of coarse and fine screens. Spacers placed under the bottom screen allow for even distribution of clean solvent. Clean solvent is circulated through the resin for extraction. A flow rate is maintained upward through the resin to allow maximum solvent contact and prevent channeling.
2.2.1 Experience has shown that 1 mL/g of resin extracted is the minimum necessary to extract and clean the resin. The aqueous rinse is critical to the subsequent organic rinses and may be accomplished by simply flushing the canister with about 1 liter of distilled water for every 25 g of resin. A small pump may be useful for pumping the water through the canister. You should perform the water extraction at the rate of about 20 to 40 mL/min.
2.2.2 All materials of construction are glass, PTFE, or stainless steel. Pumps, if used, should not contain extractable materials.
3.1 Dry the adsorbent of extraction solvent before use. This section provides a recommended procedure to dry adsorbent that is wet with solvent. However, you may use other procedures if the cleanliness requirements in Section 13.1 of Method 23 are met.
3.2 Drying Column. A simple column with suitable retainers will hold all the XAD-2 from the extractor or the Soxhlet extractor, as shown in Figure B-1, with sufficient space for drying the bed while generating a minimum backpressure in the column.
3.3 Drying Procedure: Dry the adsorbent using clean inert gas. Liquid nitrogen from a standard commercial liquid nitrogen cylinder has proven to be a reliable source of large volumes of gas free from organic contaminants. You may use high-purity tank nitrogen to dry the resin. However, you should pass the high-purity nitrogen through a bed of activated charcoal approximately 150 mL in volume prior to entering the drying apparatus.
3.3.1 Connect the gas vent of a liquid nitrogen cylinder or the exit of the activated carbon scrubber to the column by a length of precleaned copper tubing (e.g., 0.95 cm ID) coiled to pass through a heat source. A convenient heat source is a water bath heated from a steam line. The final nitrogen temperature should only be warm to the touch and not over 40 °C.
3.3.2 Allow the methylene chloride to drain from the resin prior to placing the resin in the drying apparatus.
3.3.3 Flow nitrogen through the drying apparatus at a rate that does not fluidize or agitate the resin. Continue the nitrogen flow until the residual solvent is removed.
1.1 Analytes.
| Analyte | CAS No. |
|---|---|
| Volatile organic compounds Water | No CAS Number assigned 7732-18-5 |
1.2 Applicability. This method is applicable for the determination of volatile matter content, water content, density, volume solids, and weight solids of paint, varnish, lacquer, or other related surface coatings.
1.3 Precision and Bias. Intra-and inter-laboratory analytical precision statements are presented in section 13.1. No bias has been identified.
2.1 Standard methods are used to determine the volatile matter content, water content, density, volume solids, and weight solids of paint, varnish, lacquer, or other related surface coatings.
3.1 Waterborne coating means any coating which contains more than 5 percent water by weight in its volatile fraction.
3.2 Multicomponent coatings are coatings that are packaged in two or more parts, which are combined before application. Upon combination a coreactant from one part of the coating chemically reacts, at ambient conditions, with a coreactant from another part of the coating.
3.3 Ultraviolet (UV) radiation-cured coatings are coatings which contain unreacted monomers that are polymerized by exposure to ultraviolet light.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to performing this test method.
5.2 Hazardous Components. Several of the compounds that may be contained in the coatings analyzed by this method may be irritating or corrosive to tissues (e.g., heptane) or may be toxic (e.g., benzene, methyl alcohol). Nearly all are fire hazards. Appropriate precautions can be found in reference documents, such as Reference 3 of section 16.0.
The equipment and supplies specified in the ASTM methods listed in sections 6.1 through 6.6 (incorporated by reference – see § 60.17 for acceptable versions of the methods) are required:
6.1 ASTM D 1475-60, 80, or 90, Standard Test Method for Density of Paint, Varnish, Lacquer, and Related Products.
6.2 ASTM D 2369-81, 87, 90, 92, 93, 95, or 10. Standard Test Method for Volatile Content of Coatings.
6.3 ASTM D 3792-79 or 91, Standard Test Method for Water Content of Water Reducible Paints by Direct Injection into a Gas Chromatograph.
6.4 ASTM D 4017-81, 90, or 96a, Standard Test Method for Water in Paints and Paint Materials by the Karl Fischer Titration Method.
6.5 ASTM 4457-85 91, Standard Test Method for Determination of Dichloromethane and 1,1,1-Trichloroethane in Paints and Coatings by Direct Injection into a Gas Chromatograph.
6.6 ASTM D 5403-93, Standard Test Methods for Volatile Content of Radiation Curable Materials.
6.7 ASTM D 6419-00, Test Method for Volatile Content of Sheet-Fed and Coldset Web Offset Printing Inks.
7.1 The reagents and standards specified in the ASTM methods listed in sections 6.1 through 6.6 are required.
8.1 Follow the sample collection, preservation, storage, and transport procedures described in Reference 1 of section 16.0.
9.1 Reproducibility
Not applicable to UV radiation-cured coatings). The variety of coatings that may be subject to analysis makes it necessary to verify the ability of the analyst and the analytical procedures to obtain reproducible results for the coatings tested. Verification is accomplished by running duplicate analyses on each sample tested (Sections 11.2 through 11.4) and comparing the results with the intra-laboratory precision statements (Section 13.1) for each parameter.
9.2 Confidence Limits for Waterborne Coatings. Because of the inherent increased imprecision in the determination of the VOC content of waterborne coatings as the weight percent of water increases, measured parameters for waterborne coatings are replaced with appropriate confidence limits (Section 12.6). These confidence limits are based on measured parameters and inter-laboratory precision statements.
10.1 Perform the calibration and standardization procedures specified in the ASTM methods listed in sections 6.1 through 6.6.
Additional guidance can be found in Reference 2 of section 16.0.
11.1 Non Thin-film Ultraviolet Radiation-cured (UV radiation-cured) Coatings.
11.1.1 Volatile Content. Use the procedure in ASTM D 5403 to determine the volatile matter content of the coating except the curing test described in NOTE 2 of ASTM D 5403 is required.
11.1.2 Water Content. To determine water content, follow section 11.3.2.
11.1.3 Coating Density. To determine coating density, follow section 11.3.3.
11.1.4 Solids Content. To determine solids content, follow section 11.3.4.
11.1.5 To determine if a coating or ink can be classified as a thin-film UV cured coating or ink, use the equation in section 12.2. If C is less than 0.2 g and A is greater than or equal to 225 cm
As noted in section 1.4 of ASTM D 5403, this method may not be applicable to radiation curable materials wherein the volatile material is water.
11.2 Multi-component Coatings.
11.2.1 Sample Preparation.
11.2.1.1 Prepare about 100 ml of sample by mixing the components in a storage container, such as a glass jar with a screw top or a metal can with a cap. The storage container should be just large enough to hold the mixture. Combine the components (by weight or volume) in the ratio recommended by the manufacturer. Tightly close the container between additions and during mixing to prevent loss of volatile materials. However, most manufacturers mixing instructions are by volume. Because of possible error caused by expansion of the liquid when measuring the volume, it is recommended that the components be combined by weight. When weight is used to combine the components and the manufacturer’s recommended ratio is by volume, the density must be determined by section 11.3.3.
11.2.1.2 Immediately after mixing, take aliquots from this 100 ml sample for determination of the total volatile content, water content, and density.
11.2.2 Volatile Content. To determine total volatile content, use the apparatus and reagents described in ASTM D2369 (incorporated by reference; see § 60.17 for the approved versions of the standard), respectively, and use the following procedures:
11.2.2.1 Weigh and record the weight of an aluminum foil weighing dish. Add 3 ±1 ml of suitable solvent as specified in ASTM D2369 to the weighing dish. Using a syringe as specified in ASTM D2369, weigh to 1 mg, by difference, a sample of coating into the weighing dish. For coatings believed to have a volatile content less than 40 weight percent, a suitable size is 0.3 + 0.10 g, but for coatings believed to have a volatile content greater than 40 weight percent, a suitable size is 0.5 ±0.1 g.
If the volatile content determined pursuant to section 12.4 is not in the range corresponding to the sample size chosen repeat the test with the appropriate sample size. Add the specimen dropwise, shaking (swirling) the dish to disperse the specimen completely in the solvent. If the material forms a lump that cannot be dispersed, discard the specimen and prepare a new one. Similarly, prepare a duplicate. The sample shall stand for a minimum of 1 hour, but no more than 24 hours prior to being oven cured at 110 ±5 °C (230 ±9 °F) for 1 hour.
11.2.2.2 Heat the aluminum foil dishes containing the dispersed specimens in the forced draft oven for 60 min at 110 ±5 °C (230 ±9 °F). Caution – provide adequate ventilation, consistent with accepted laboratory practice, to prevent solvent vapors from accumulating to a dangerous level.
11.2.2.3 Remove the dishes from the oven, place immediately in a desiccator, cool to ambient temperature, and weigh to within 1 mg.
11.2.2.4 Run analyses in pairs (duplicate sets) for each coating mixture until the criterion in section 11.4 is met. Calculate W
11.2.3 Water Content. To determine water content, follow section 11.3.2.
11.2.4 Coating Density. To determine coating density, follow section 11.3.3.
11.2.5 Solids Content. To determine solids content, follow section 11.3.4.
11.2.6 Exempt Solvent Content. To determine the exempt solvent content, follow section 11.3.5.
For all other coatings (i.e., water-or solvent-borne coatings) not covered by multicomponent or UV radiation-cured coatings, analyze as shown below:
11.3 Water-or Solvent-borne coatings.
11.3.1 Volatile Content. Use the procedure in ASTM D 2369 to determine the volatile matter content (may include water) of the coating.
11.3.1.1 Record the following information:
11.3.1.2 Calculate the weight fraction of the volatile matter (W
11.3.1.3 Run duplicate analyses until the difference between the two values in a set is less than or equal to the intra-laboratory precision statement in section 13.1.
11.3.1.4 Record the arithmetic average (W
11.3.2 Water Content. For waterborne coatings only, determine the weight fraction of water (W
11.3.2.1 Run duplicate analyses until the difference between the two values in a set is less than or equal to the intra-laboratory precision statement in section 13.1.
11.3.2.2 Record the arithmetic average (w
11.3.3 Coating Density. Determine the density (Dc, kg/l) of the surface coating using the procedure in ASTM D 1475.
11.3.3.1 Run duplicate analyses until each value in a set deviates from the mean of the set by no more than the intra-laboratory precision statement in section 13.1.
11.3.3.2 Record the arithmetic average (D
11.3.4 Solids Content. Determine the volume fraction (V
11.3.5 Exempt Solvent Content. Determine the weight fraction of exempt solvents (W
11.4 Sample Analysis Criteria. For W
12.1 Nomenclature.
12.2 To determine if a coating or ink can be classified as a thin-film UV cured coating or ink, use the following equation:
12.3 Calculate W
12.4 Nonaqueous Volatile Matter.
12.4.1 Solvent-borne Coatings.
12.4.2 Waterborne Coatings.
12.4.3 Coatings Containing Exempt Solvents.
12.5 Weight Fraction Solids.
12.6 Confidence Limit Calculations for Waterborne Coatings. To calculate the lower confidence limit, subtract the appropriate inter-laboratory precision value from the measured mean value for that parameter. To calculate the upper confidence limit, add the appropriate inter-laboratory precision value to the measured mean value for that parameter. For W
13.1 Analytical Precision Statements. The intra-and inter-laboratory precision statements are given in Table 24-1 in section 17.0.
Same as specified in section 6.0, with the addition of the following:
1. Standard Procedure for Collection of Coating and Ink Samples for Analysis by Reference Methods 24 and 24A. EPA-340/1-91-010. U.S. Environmental Protection Agency, Stationary Source Compliance Division, Washington, D.C. September 1991.
2. Standard Operating Procedure for Analysis of Coating and Ink Samples by Reference Methods 24 and 24A.
EPA-340/1-91-011. U.S. Environmental Protection Agency, Stationary Source Compliance Division, Washington, D.C. September 1991.
3. Handbook of Hazardous Materials: Fire, Safety, Health. Alliance of American Insurers. Schaumberg, IL. 1983.
Table 24-1 – Analytical Precision Statements
| Intra-laboratory | Inter-laboratory | |
|---|---|---|
| Volatile matter content, W | ±0.015 | ±0.047 |
| Water content, W | ±0.029 | ±0.075 |
| Density, D | ±0.001 kg/l | ±0.002 kg/l |
1.1 Analytes.
| Analyte | CAS No. |
|---|---|
| Volatile organic compounds (VOC) | No CAS number assigned. |
1.2 Applicability. This method is applicable for the determination of the VOC content and density of solvent-borne (solvent-reducible) publication rotogravure inks and related publication rotogravure coatings.
2.1 Separate procedures are used to determine the VOC weight fraction and density of the ink or related coating and the density of the solvent in the ink or related coating. The VOC weight fraction is determined by measuring the weight loss of a known sample quantity which has been heated for a specified length of time at a specified temperature. The density of both the ink or related coating and solvent are measured by a standard procedure. From this information, the VOC volume fraction is calculated.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to performing this test method.
5.2 Hazardous Components. Some of the compounds that may be contained in the inks or related coatings analyzed by this method may be irritating or corrosive to tissues or may be toxic. Nearly all are fire hazards. Appropriate precautions can be found in reference documents, such as Reference 6 of section 16.0.
The following equipment and supplies are required for sample analysis:
6.1 Weighing Dishes. Aluminum foil, 58 mm (2.3 in.) in diameter by 18 mm (0.7 in.) high, with a flat bottom. There must be at least three weighing dishes per sample.
6.2 Disposable Syringe. 5 ml.
6.3 Analytical Balance. To measure to within 0.1 mg.
6.4 Oven. Vacuum oven capable of maintaining a temperature of 120 ±2 °C (248 ±4 °F) and an absolute pressure of 510 ±51 mm Hg (20 ±2 in. Hg) for 4 hours. Alternatively, a forced draft oven capable of maintaining a temperature of 120 ±2 °C (248 ±4 °F) for 24 hours.
6.5 The equipment and supplies specified in ASTM D 1475-60, 80, or 90 (incorporated by reference – see § 60.17).
7.1 The reagents and standards specified in ASTM D 1475-60, 80, or 90 are required.
8.1 Follow the sample collection, preservation, storage, and transport procedures described in Reference 4 of section 16.0.
Additional guidance can be found in Reference 5 of section 16.0.
11.1 VOC Weight Fraction. Shake or mix the ink or related coating sample thoroughly to assure that all the solids are completely suspended. Label and weigh to the nearest 0.1 mg a weighing dish and record this weight (M
11.2 Ink or Related Coating Density. Determine the density of the ink or related coating (D
11.3 Solvent Density. Determine the density of the solvent (D
12.1 VOC Weight Fraction. For each determination, calculate the volatile organic content weight fraction (W
12.2 VOC Volume Fraction. Calculate the volume fraction volatile organic content (V
1. Standard Test Method for Density of Paint, Varnish, Lacquer, and Related Products. ASTM Designation D 1475.
2. Teleconversation. Wright, Chuck, Inmont Corporation with Reich, R., A., Radian Corporation. September 25, 1979, Gravure Ink Analysis.
3. Teleconversation. Oppenheimer, Robert, Gravure Research Institute with Burt, Rick, Radian Corporation, November 5, 1979, Gravure Ink Analysis.
4. Standard Procedure for Collection of Coating and Ink Samples for Analysis by Reference Methods 24 and 24A. EPA-340/1-91-010. U.S. Environmental Protection Agency, Stationary Source Compliance Division, Washington, D.C. September 1991.
5. Standard Operating Procedure for Analysis of Coating and Ink Samples by Reference Methods 24 and 24A. EPA-340/1-91-011. U.S. Environmental Protection Agency, Stationary Source Compliance Division, Washington, D.C. September 1991.
6. Handbook of Hazardous Materials: Fire, Safety, Health. Alliance of American Insurers. Schaumberg, IL. 1983.
1.1 Analytes.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Total gaseous nonmethane organic compounds (TGNMO) | N/A | Dependent upon analytical equipment. |
1.2 Applicability.
1.2.1 This method is applicable for the determination of volatile organic compounds (VOC) (measured as total gaseous nonmethane organics (TGNMO) and reported as carbon) in stationary source emissions. This method is not applicable for the determination of organic particulate matter.
1.2.2 This method is not the only method that applies to the measurement of VOC. Costs, logistics, and other practicalities of source testing may make other test methods more desirable for measuring VOC contents of certain effluent streams. Proper judgment is required in determining the most applicable VOC test method. For example, depending upon the molecular composition of the organics in the effluent stream, a totally automated semicontinuous nonmethane organics (NMO) analyzer interfaced directly to the source may yield accurate results. This approach has the advantage of providing emission data semicontinuously over an extended time period.
1.2.3 Direct measurement of an effluent with a flame ionization detector (FID) analyzer may be appropriate with prior characterization of the gas stream and knowledge that the detector responds predictably to the organic compounds in the stream. If present, methane (CH
1.2.4 Another example of the use of a direct FID is as a screening method. If there is enough information available to provide a rough estimate of the analyzer accuracy, the FID analyzer can be used to determine the VOC content of an uncharacterized gas stream. With a sufficient buffer to account for possible inaccuracies, the direct FID can be a useful tool to obtain the desired results without costly exact determination.
1.2.5 In situations where a qualitative/quantitative analysis of an effluent stream is desired or required, a gas chromatographic FID system may apply. However, for sources emitting numerous organics, the time and expense of this approach will be formidable.
2.1 An emission sample is withdrawn from the stack at a constant rate through a heated filter and a chilled condensate trap by means of an evacuated sample tank. After sampling is completed, the TGNMO are determined by independently analyzing the condensate trap and sample tank fractions and combining the analytical results. The organic content of the condensate trap fraction is determined by oxidizing the NMO to carbon dioxide (CO
4.1 Carbon Dioxide and Water Vapor. When carbon dioxide (CO
4.2. Particulate Matter. Collection of organic particulate matter in the condensate trap would produce a positive bias. A filter is included in the sampling equipment to minimize this bias.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method.
6.1 Sample Collection. The sampling system consists of a heated probe, heated filter, condensate trap, flow control system, and sample tank (see Figure 25-1). The TGNMO sampling equipment can be constructed from commercially available components and components fabricated in a machine shop. The following equipment is required:
6.1.1 Heated Probe. 6.4-mm (
If it is not possible to use a heating system for safety reasons, an unheated system with an in-stack filter is a suitable alternative.
6.1.2 Filter Holder. 25-mm (
6.1.3 Filter Heating System.
6.1.3.1 A metal box consisting of an inner and an outer shell separated by insulating material with a heating element in the inner shell capable of maintaining a gas temperature at the filter of 121 ±3 °C (250 ±5 °F). The heating box shall include temperature sensors to monitor the gas temperature immediately upstream and immediately downstream of the filter.
6.1.3.2 A suitable heating box is shown in Figure 25-2. The outer shell is a metal box that measures 102 mm × 280 mm × 292 mm (4 in. × 11 in. × 11
If it is not possible to use a heating system for safety reasons, an unheated system with an in-stack filter is a suitable alternative.
6.1.4 Condensate Trap. 9.5-mm (
6.1.5 Valve. Stainless steel control valve for starting and stopping sample flow.
6.1.6 Metering Valve. Stainless steel valve for regulating the sample flow rate through the sample train.
6.1.7 Rate Meter. Rotameter, or equivalent, capable of measuring sample flow in the range of 60 to 100 cm
6.1.8 Sample Tank. Stainless steel or aluminum tank with a minimum volume of 4 liters (0.14 ft
Sample volumes greater than 4 liters may be required for sources with low organic concentrations.
6.1.9 Mercury Manometer. U-tube manometer or absolute pressure gauge capable of measuring pressure to within 1 mm Hg in the range of 0 to 900 mm.
6.1.10 Vacuum Pump. Capable of evacuating to an absolute pressure of 10 mm Hg.
6.2 Condensate Recovery. The system for the recovery of the organics captured in the condensate trap consists of a heat source, an oxidation catalyst, a nondispersive infrared (NDIR) analyzer, and an intermediate collection vessel (ICV). Figure 25-4 is a schematic of a typical system. The system shall be capable of proper oxidation and recovery, as specified in section 10.1.1. The following major components are required:
6.2.1 Heat Source. Sufficient to heat the condensate trap (including probe) to a temperature of 200 °C (390 °F). A system using both a heat gun and an electric tube furnace is recommended.
6.2.2 Heat Tape. Sufficient to heat the connecting tubing between the water trap and the oxidation catalyst to 100 °C (212 °F).
6.2.3 Oxidation Catalyst. A suitable length of 9.5 mm (
6.2.4 Water Trap. Leak-proof, capable of removing moisture from the gas stream.
6.2.5 Syringe Port. A 6.4-mm (
6.2.6 NDIR Detector. Capable of indicating CO
6.2.7 Flow-Control Valve. Stainless steel, to maintain the trap conditioning system near atmospheric pressure.
6.2.8 Intermediate Collection Vessel. Stainless steel or aluminum, equipped with a female quick connect. Tanks with nominal volumes of at least 6 liters (0.2 ft
6.2.9 Mercury Manometer. Same as described in section 6.1.9.
6.2.10 Syringe. 10-ml gas-tight glass syringe equipped with an appropriate needle.
6.2.11 Syringes. 10-µl and 50-µl liquid injection syringes.
6.2.12 Liquid Sample Injection Unit. 316 Stainless steel U-tube fitted with an injection septum (see Figure 25-7).
6.3 Analysis.
6.3.1 NMO Analyzer. The NMO analyzer is a gas chromatograph (GC) with backflush capability for NMO analysis and is equipped with an oxidation catalyst, reduction catalyst, and FID. Figures 25-5 and 25-6 are schematics of a typical NMO analyzer. This semicontinuous GC/FID analyzer shall be capable of: (1) Separating CO, CO
6.3.1.1 Oxidation Catalyst. A suitable length of 9.5-mm (
6.3.1.2 Reduction Catalyst. A 7.6-cm (3-in.) length of 6.4-mm (
6.3.1.3 Separation Column(s). A 30-cm (1-ft) length of 3.2-mm (
6.3.1.4 Sample Injection System. A single 10-port GC sample injection valve or a group of valves with sufficient ports fitted with a sample loop properly sized to interface with the NMO analyzer (1-cc loop recommended).
6.3.1.5 FID. An FID meeting the following specifications is required:
6.3.1.5.1 Linearity. A linear response (±5 percent) over the operating range as demonstrated by the procedures established in section 10.1.2.3.
6.3.1.5.2 Range. A full scale range of 10 to 50,000 ppm CH
6.3.1.6 Data Recording System. Analog strip chart recorder or digital integration system compatible with the FID for permanently recording the analytical results.
6.3.2 Barometer. Mercury, aneroid, or other barometer capable of measuring atmospheric pressure to within 1 mm Hg.
6.3.3 Temperature Sensor. Capable of measuring the laboratory temperature within 1 °C (2 °F).
6.3.4 Vacuum Pump. Capable of evacuating to an absolute pressure of 10 mm Hg.
7.1 Sample Collection. The following reagents are required for sample collection:
7.1.1 Dry Ice. Solid CO2, crushed.
7.1.2 Coarse Quartz Wool. 8 to 15 um.
7.1.3 Filters. Glass fiber filters, without organic binder, exhibiting at least 99.95 percent efficiency (
7.2 NMO Analysis. The following gases are required for NMO analysis:
7.2.1 Carrier Gases. Helium (He) and oxygen (O
7.2.2 Fuel Gas. Hydrogen (H
7.2.3 Combustion Gas. Either air (less than 0.1 ppm total hydrocarbon content) or O
7.3 Condensate Analysis. The following are required for condensate analysis:
7.3.1 Gases. Containing less than 1 ppm carbon.
7.3.1.1 Air.
7.3.1.2 Oxygen.
7.3.2 Liquids. To conform to the specifications established by the Committee on Analytical Reagents of the American Chemical Society.
7.3.2.1 Hexane.
7.3.2.2 Decane.
7.4 Calibration. For all calibration gases, the manufacturer must recommend a maximum shelf life for each cylinder (i.e., the length of time the gas concentration is not expected to change more than ±5 percent from its certified value). The date of gas cylinder preparation, certified organic concentration, and recommended maximum shelf life must be affixed to each cylinder before shipment from the gas manufacturer to the buyer. The following calibration gases are required:
7.4.1 Oxidation Catalyst Efficiency Check Calibration Gas. Gas mixture standard with nominal concentration of 1 percent methane in air.
7.4.2 FID Linearity and NMO Calibration Gases. Three gas mixture standards with nominal propane concentrations of 20 ppm, 200 ppm, and 3000 ppm, in air.
7.4.3 CO
Total NMO less than 1 ppm required for 1 percent mixture.
7.4.4 NMO Analyzer System Check Calibration Gases. Four calibration gases are needed as follows:
7.4.4.1 Propane Mixture. Gas mixture standard containing (nominal) 50 ppm CO, 50 ppm CH
7.4.4.2 Hexane. Gas mixture standard containing (nominal) 50 ppm hexane in air.
7.4.4.3 Toluene. Gas mixture standard containing (nominal) 20 ppm toluene in air.
7.4.4.4 Methanol. Gas mixture standard containing (nominal) 100 ppm methanol in air.
8.1 Sampling Equipment Preparation.
8.1.1 Condensate Trap Cleaning. Before its initial use and after each use, a condensate trap should be thoroughly cleaned and checked to ensure that it is not contaminated. Both cleaning and checking can be accomplished by installing the trap in the condensate recovery system and treating it as if it were a sample. The trap should be heated as described in section 11.1.3. A trap may be considered clean when the CO
8.1.2 Sample Tank Evacuation and Leak-Check. Evacuate the sample tank to 10 mm Hg absolute pressure or less. Then close the sample tank valve, and allow the tank to sit for 60 minutes. The tank is acceptable if a change in tank vacuum of less than 1 mm Hg is noted. The evacuation and leak-check may be conducted either in the laboratory or the field.
8.1.3 Sampling Train Assembly. Just before assembly, measure the tank vacuum using a mercury manometer. Record this vacuum, the ambient temperature, and the barometric pressure at this time. Close the sample tank valve and assemble the sampling system as shown in Figure 25-1. Immerse the condensate trap body in dry ice at least 30 minutes before commencing sampling to improve collection efficiency. The point where the inlet tube joins the trap body should be 2.5 to 5 cm (1 to 2 in.) above the top of the dry ice.
8.1.4 Pretest Leak-Check. A pretest leak-check is required. Calculate or measure the approximate volume of the sampling train from the probe tip to the sample tank valve. After assembling the sampling train, plug the probe tip, and make certain that the sample tank valve is closed. Turn on the vacuum pump, and evacuate the sampling system from the probe tip to the sample tank valve to an absolute pressure of 10 mm Hg or less. Close the purge valve, turn off the pump, wait a minimum period of 10 minutes, and recheck the indicated vacuum. Calculate the maximum allowable pressure change based on a leak rate of 1 percent of the sampling rate using Equation 25-1, section 12.2. If the measured pressure change exceeds the allowable, correct the problem and repeat the leak-check before beginning sampling.
8.2 Sample Collection.
8.2.1 Unplug the probe tip, and place the probe into the stack such that the probe is perpendicular to the duct or stack axis; locate the probe tip at a single preselected point of average velocity facing away from the direction of gas flow. For stacks having a negative static pressure, seal the sample port sufficiently to prevent air in-leakage around the probe. Set the probe temperature controller to 129 °C (265 °F) and the filter temperature controller to 121 °C (250 °F). Allow the probe and filter to heat for about 30 minutes before purging the sample train.
8.2.2 Close the sample valve, open the purge valve, and start the vacuum pump. Set the flow rate between 60 and 100 cm
8.2.3 When the temperatures at the exit ends of the probe and filter are within the corresponding specified ranges, check the dry ice level around the condensate trap, and add dry ice if necessary. Record the clock time. To begin sampling, close the purge valve and stop the pump. Open the sample valve and the sample tank valve. Using the flow control valve, set the flow through the sample train to the proper rate. Adjust the flow rate as necessary to maintain a constant rate (±10 percent) throughout the duration of the sampling period. Record the sample tank vacuum and flowmeter setting at 5-minute intervals. (See Figure 25-8.) Select a total sample time greater than or equal to the minimum sampling time specified in the applicable subpart of the regulations; end the sampling when this time period is reached or when a constant flow rate can no longer be maintained because of reduced sample tank vacuum.
If sampling had to be stopped before obtaining the minimum sampling time (specified in the applicable subpart) because a constant flow rate could not be maintained, proceed as follows: After closing the sample tank valve, remove the used sample tank from the sampling train (without disconnecting other portions of the sampling train). Take another evacuated and leak-checked sample tank, measure and record the tank vacuum, and attach the new tank to the sampling train. After the new tank is attached to the sample train, proceed with the sampling until the required minimum sampling time has been exceeded.
8.3 Sample Recovery. After sampling is completed, close the flow control valve, and record the final tank vacuum; then record the tank temperature and barometric pressure. Close the sample tank valve, and disconnect the sample tank from the sample system. Disconnect the condensate trap at the inlet to the rate meter, and tightly seal both ends of the condensate trap. Do not include the probe from the stack to the filter as part of the condensate sample.
8.4 Sample Storage and Transport. Keep the trap packed in dry ice until the samples are returned to the laboratory for analysis. Ensure that run numbers are identified on the condensate trap and the sample tank(s).
| Section | Quality control measure | Effect |
|---|---|---|
| 10.1.1 | Initial performance check of condensate recovery apparatus | Ensure acceptable condensate recovery efficiency. |
| 10.1.2, 10.2 | NMO analyzer initial and daily performance checks | Ensure precision of analytical results. |
Maintain a record of performance of each item.
10.1 Initial Performance Checks.
10.1.1 Condensate Recovery Apparatus. Perform these tests before the system is first placed in operation, after any shutdown of 6 months or more, and after any major modification of the system, or at the frequency recommended by the manufacturer.
10.1.1.1 Carrier Gas and Auxiliary O
10.1.1.2 Oxidation Catalyst Efficiency Check.
10.1.1.2.1 With a clean condensate trap installed in the recovery system or a
10.1.1.2.2 After the NDIR response has stabilized, switch the sample recovery valve from vent to collect. When the manometer or pressure gauge begins to register a slight positive pressure, open the flow-control valve. Keep the flow adjusted such that the pressure in the system is maintained within 10 percent of atmospheric pressure. Continue collecting the sample in a normal manner until the ICV is filled to a nominal gauge pressure of 300 mm Hg. Close the ICV valve, and remove the ICV from the system. Place the sample recovery valve in the vent position, and return the recovery system to its normal carrier gas and normal operating conditions. Analyze the ICV for CO
10.1.1.3 System Performance Check. Construct a liquid sample injection unit similar in design to the unit shown in Figure 25-7. Insert this unit into the condensate recovery and conditioning system in place of a condensate trap, and set the carrier gas and auxiliary O
10.1.1.3.1 50 µl hexane.
10.1.1.3.2 10 µl hexane.
10.1.1.3.3 50 µl decane.
10.1.1.3.4 10 µl decane.
10.1.2 NMO Analyzer. Perform these tests before the system is first placed in operation, after any shutdown longer than 6 months, and after any major modification of the system.
10.1.2.1 Oxidation Catalyst Efficiency Check. Turn off or bypass the NMO analyzer reduction catalyst. Make triplicate injections of the high level methane standard (Section 7.4.1). The oxidation catalyst operation is acceptable if the FID response is less than 1 percent of the injected methane concentration.
10.1.2.2 Reduction Catalyst Efficiency Check. With the oxidation catalyst unheated or bypassed and the heated reduction catalyst bypassed, make triplicate injections of the high level methane standard (Section 7.4.1). Repeat this procedure with both catalysts operative. The reduction catalyst operation is acceptable if the responses under both conditions agree within 5 percent of their average.
10.1.2.3 NMO Analyzer Linearity Check Calibration. While operating both the oxidation and reduction catalysts, conduct a linearity check of the analyzer using the propane standards specified in section 7.4.2. Make triplicate injections of each calibration gas. For each gas (i.e., each set of triplicate injections), calculate the average response factor (area/ppm C) for each gas, as well as and the relative standard deviation (according to section 12.8). Then calculate the overall mean of the response factor values. The instrument linearity is acceptable if the average response factor of each calibration gas is within 2.5 percent of the overall mean value and if the relative standard deviation gas is less than 2 percent of the overall mean value. Record the overall mean of the propane response factor values as the NMO calibration response factor (RF
10.1.2.4 System Performance Check. Check the column separation and overall performance of the analyzer by making triplicate injections of the calibration gases listed in section 7.4.4. The analyzer performance is acceptable if the measured NMO value for each gas (average of triplicate injections) is within 5 percent of the expected value.
10.2 NMO Analyzer Daily Calibration. The following calibration procedures shall be performed before and immediately after the analysis of each set of samples, or on a daily basis, whichever is more stringent:
10.2.1 CO
10.2.2 NMO Response Factors. Inject triplicate samples of the mixed propane calibration cylinder gas (Section 7.4.4.1), and calculate the average NMO response factor. The system operation is adequate if the calculated response factor is within 10 percent of the RF
10.3 Sample Tank and ICV Volume. The volume of the gas sampling tanks used must be determined. Determine the tank and ICV volumes by weighing them empty and then filled with deionized distilled water; weigh to the nearest 5 g, and record the results. Alternatively, measure the volume of water used to fill them to the nearest 5 ml.
11.1 Condensate Recovery. See Figure 25-9. Set the carrier gas flow rate, and heat the catalyst to its operating temperature to condition the apparatus.
11.1.1 Daily Performance Checks. Each day before analyzing any samples, perform the following tests:
11.1.1.1 Leak-Check. With the carrier gas inlets and the sample recovery valve closed, install a clean condensate trap in the system, and evacuate the system to 10 mm Hg absolute pressure or less. Monitor the system pressure for 10 minutes. The system is acceptable if the pressure change is less than 2 mm Hg.
11.1.1.2 System Background Test. Adjust the carrier gas and auxiliary oxygen flow rate to their normal values of 100 cc/min and 150 cc/min, respectively, with the sample recovery valve in vent position. Using a 10-ml syringe, withdraw a sample from the system effluent through the syringe port. Inject this sample into the NMO analyzer, and measure the CO
11.1.1.3 Oxidation Catalyst Efficiency Check. Conduct a catalyst efficiency test as specified in section 10.1.1.2. If the criterion of this test cannot be met, make the necessary repairs to the system before proceeding.
11.1.2 Condensate Trap CO
11.1.2.1 After sampling is completed, the condensate trap will contain condensed water and organics and a small volume of sampled gas. This gas from the stack may contain a significant amount of CO
11.1.2.2 Begin with the sample tank and condensate trap from the test run to be analyzed. Set the four-port valve of the condensate recovery system in the CO
11.1.2.3 Attach the dry ice-cooled condensate trap to the recovery system, and initiate the purge by switching the sample recovery valve from vent to collect position. Adjust the flow control valve to maintain atmospheric pressure in the recovery system. Continue the purge until the CO
11.1.2.4 After the completion of the CO
11.1.3 Recovery of the Condensate Trap Sample (See Figure 25-10).
11.1.3.1 Attach the ICV to the sample recovery system. With the sample recovery valve in a closed position, between vent and collect, and the flow control and ICV valves fully open, evacuate the manometer or gauge, the connecting tubing, and the ICV to 10 mm Hg absolute pressure. Close the flow-control and vacuum pump valves.
11.1.3.2 Begin auxiliary oxygen flow to the oxidation catalyst at a rate of 150 cc/min, then switch the four-way valve to the trap recovery position and the sample recovery valve to collect position. The system should now be set up to operate as indicated in Figure 25-10. After the manometer or pressure gauge begins to register a slight positive pressure, open the flow control valve. Adjust the flow-control valve to maintain atmospheric pressure in the system within 10 percent.
11.1.3.3 Remove the condensate trap from the dry ice, and allow it to warm to ambient temperature while monitoring the NDIR response. If, after 5 minutes, the CO
11.1.3.4 After the sample recovery is completed, use the carrier gas bypass valve to pressurize the ICV to approximately 1060 mm Hg absolute pressure with zero air.
11.2 Analysis. Once the initial performance test of the NMO analyzer has been successfully completed (see section 10.1.2) and the daily CO
11.2.1 Operating Conditions. The carrier gas flow rate is 29.5 cc/min He and 2.2 cc/min O
11.2.2 Analysis of Recovered Condensate Sample. Purge the sample loop with sample, and then inject the sample. Under the specified operating conditions, the CO
11.2.3 Analysis of Sample Tank. Perform the analysis as described in section 11.2.2, but record only the value measured for NMO (C
Carry out the calculations, retaining at least one extra significant figure beyond that of the acquired data. Round off figures after final calculations. All equations are written using absolute pressure; absolute pressures are determined by adding the measured barometric pressure to the measured gauge or manometer pressure.
12.1 Nomenclature.
12.2 Allowable Pressure Change. For the pretest leak-check, calculate the allowable pressure change using Equation 25-1:
12.3 Sample Volume. For each test run, calculate the gas volume sampled using Equation 25-2:
12.4 Noncondensible Organics. For each sample tank, determine the concentration of nonmethane organics (ppm C) using Equation 25-3:
12.5 Condensible Organics. For each condensate trap determine the concentration of organics (ppm C) using Equation 25-4:
12.6 TGNMO Mass Concentration. Determine the TGNMO mass concentration as carbon for each test run, using Equation 25-5:
12.7 Percent Recovery. Calculate the percent recovery for the liquid injections to the condensate recovery and conditioning system using Equation 25-6:
12.8 Relative Standard Deviation. Use Equation 25-7 to calculate the relative standard deviation (RSD) of percent recovery and analyzer linearity.
13.1 Range. The minimum detectable limit of the method has been determined to be 50 parts per million by volume (ppm). No upper limit has been established.
1. Salo, A.E., S. Witz, and R.D. MacPhee. Determination of Solvent Vapor Concentrations by Total Combustion Analysis: A Comparison of Infrared with Flame Ionization Detectors. Paper No. 75-33.2. (Presented at the 68th Annual Meeting of the Air Pollution Control Association. Boston, MA. June 15-20, 1975.) 14 p.
2. Salo, A.E., W.L. Oaks, and R.D. MacPhee. Measuring the Organic Carbon Content of Source Emissions for Air Pollution Control. Paper No. 74-190. (Presented at the 67th Annual Meeting of the Air Pollution Control Association. Denver, CO. June 9-13, 1974.) 25 p.
1.1 Analytes.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Total Organic Compounds | N/A |
1.2 Applicability. This method is applicable for the determination of total gaseous organic concentration of vapors consisting primarily of alkanes, alkenes, and/or arenes (aromatic hydrocarbons). The concentration is expressed in terms of propane (or other appropriate organic calibration gas) or in terms of carbon.
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 A gas sample is extracted from the source through a heated sample line and glass fiber filter to a flame ionization analyzer (FIA). Results are reported as volume concentration equivalents of the calibration gas or as carbon equivalents.
3.1 Calibration drift means the difference in the measurement system response to a mid-level calibration gas before and after a stated period of operation during which no unscheduled maintenance, repair, or adjustment took place.
3.2 Calibration error means the difference between the gas concentration indicated by the measurement system and the know concentration of the calibration gas.
3.3 Calibration gas means a known concentration of a gas in an appropriate diluent gas.
3.4 Measurement system means the total equipment required for the determination of the gas concentration. The system consists of the following major subsystems:
3.4.1 Sample interface means that portion of a system used for one or more of the following: sample acquisition, sample transportation, sample conditioning, or protection of the analyzer(s) from the effects of the stack effluent.
3.4.2 Organic analyzer means that portion of the measurement system that senses the gas to be measured and generates an output proportional to its concentration.
3.5 Response time means the time interval from a step change in pollutant concentration at the inlet to the emission measurement system to the time at which 95 percent of the corresponding final value is reached as displayed on the recorder.
3.6 Span Value means the upper limit of a gas concentration measurement range that is specified for affected source categories in the applicable part of the regulations. The span value is established in the applicable regulation and is usually 1.5 to 2.5 times the applicable emission limit. If no span value is provided, use a span value equivalent to 1.5 to 2.5 times the expected concentration. For convenience, the span value should correspond to 100 percent of the recorder scale.
3.7 Zero drift means the difference in the measurement system response to a zero level calibration gas before or after a stated period of operation during which no unscheduled maintenance, repair, or adjustment took place.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method. The analyzer users manual should be consulted for specific precautions to be taken with regard to the analytical procedure.
5.2 Explosive Atmosphere. This method is often applied in highly explosive areas. Caution and care should be exercised in choice of equipment and installation.
6.1 Measurement System. Any measurement system for total organic concentration that meets the specifications of this method. A schematic of an acceptable measurement system is shown in Figure 25A-1. All sampling components leading to the analyzer shall be heated ≥110 °C (220 °F) throughout the sampling period, unless safety reasons are cited (Section 5.2) The essential components of the measurement system are described below:
6.1.1 Organic Concentration Analyzer. A flame ionization analyzer (FIA) capable of meeting or exceeding the specifications of this method. The flame ionization detector block shall be heated >120 °C (250 °F).
6.1.2 Sample Probe. Stainless steel, or equivalent, three-hole rake type. Sample holes shall be 4 mm (0.16-in.) in diameter or smaller and located at 16.7, 50, and 83.3 percent of the equivalent stack diameter. Alternatively, a single opening probe may be used so that a gas sample is collected from the centrally located 10 percent area of the stack cross-section.
6.1.3 Heated Sample Line. Stainless steel or Teflon” tubing to transport the sample gas to the analyzer. The sample line should be heated (≥110 °C) to prevent any condensation.
6.1.4 Calibration Valve Assembly. A three-way valve assembly to direct the zero and calibration gases to the analyzers is recommended. Other methods, such as quick-connect lines, to route calibration gas to the analyzers are applicable.
6.1.5 Particulate Filter. An in-stack or an out-of-stack glass fiber filter is recommended if exhaust gas particulate loading is significant. An out-of-stack filter should be heated to prevent any condensation.
6.1.6 Recorder. A strip-chart recorder, analog computer, or digital recorder for recording measurement data. The minimum data recording requirement is one measurement value per minute.
7.1 Calibration Gases. The calibration gases for the gas analyzer shall be propane in air or propane in nitrogen. Alternatively, organic compounds other than propane can be used; the appropriate corrections for response factor must be made. Calibration gases shall be prepared in accordance with the procedure listed in Citation 2 of section 16. Additionally, the manufacturer of the cylinder should provide a recommended shelf life for each calibration gas cylinder over which the concentration does not change more than ±2 percent from the certified value. For calibration gas values not generally available (i.e., organics between 1 and 10 percent by volume), alternative methods for preparing calibration gas mixtures, such as dilution systems (Test Method 205, 40 CFR Part 51, Appendix M), may be used with prior approval of the Administrator.
7.1.1 Fuel. A 40 percent H
7.1.2 Zero Gas. High purity air with less than 0.1 part per million by volume (ppmv) of organic material (propane or carbon equivalent) or less than 0.1 percent of the span value, whichever is greater.
7.1.3 Low-level Calibration Gas. An organic calibration gas with a concentration equivalent to 25 to 35 percent of the applicable span value.
7.1.4 Mid-level Calibration Gas. An organic calibration gas with a concentration equivalent to 45 to 55 percent of the applicable span value.
7.1.5 High-level Calibration Gas. An organic calibration gas with a concentration equivalent to 80 to 90 percent of the applicable span value.
8.1 Selection of Sampling Site. The location of the sampling site is generally specified by the applicable regulation or purpose of the test (i.e., exhaust stack, inlet line, etc.). The sample port shall be located to meet the testing requirements of Method 1.
8.2 Location of Sample Probe. Install the sample probe so that the probe is centrally located in the stack, pipe, or duct and is sealed tightly at the stack port connection.
8.3 Measurement System Preparation. Prior to the emission test, assemble the measurement system by following the manufacturer’s written instructions for preparing sample interface and the organic analyzer. Make the system operable (Section 10.1).
8.4 Calibration Error Test. Immediately prior to the test series (within 2 hours of the start of the test), introduce zero gas and high-level calibration gas at the calibration valve assembly. Adjust the analyzer output to the appropriate levels, if necessary. Calculate the predicted response for the low-level and mid-level gases based on a linear response line between the zero and high-level response. Then introduce low-level and mid-level calibration gases successively to the measurement system. Record the analyzer responses for low-level and mid-level calibration gases and determine the differences between the measurement system responses and the predicted responses. These differences must be less than 5 percent of the respective calibration gas value. If not, the measurement system is not acceptable and must be replaced or repaired prior to testing. No adjustments to the measurement system shall be conducted after the calibration and before the drift check (Section 8.6.2). If adjustments are necessary before the completion of the test series, perform the drift checks prior to the required adjustments and repeat the calibration following the adjustments. If multiple electronic ranges are to be used, each additional range must be checked with a mid-level calibration gas to verify the multiplication factor.
8.5 Response Time Test. Introduce zero gas into the measurement system at the calibration valve assembly. When the system output has stabilized, switch quickly to the high-level calibration gas. Record the time from the concentration change to the measurement system response equivalent to 95 percent of the step change. Repeat the test three times and average the results.
8.6 Emission Measurement Test Procedure.
8.6.1 Organic Measurement. Begin sampling at the start of the test period, recording time and any required process information as appropriate. In particulate, note on the recording chart, periods of process interruption or cyclic operation.
8.6.2 Drift Determination. Immediately following the completion of the test period and hourly during the test period, reintroduce the zero and mid-level calibration gases, one at a time, to the measurement system at the calibration valve assembly. (Make no adjustments to the measurement system until both the zero and calibration drift checks are made.) Record the analyzer response. If the drift values exceed the specified limits, invalidate the test results preceding the check and repeat the test following corrections to the measurement system. Alternatively, recalibrate the test measurement system as in section 8.4 and report the results using both sets of calibration data (i.e., data determined prior to the test period and data determined following the test period).
Note on the recording chart periods of process interruption or cyclic operation.
| Method section | Quality control measure | Effect |
|---|---|---|
| 8.4 | Zero and calibration drift tests | Ensures that bias introduced by drift in the measurement system output during the run is no greater than 3 percent of span. |
10.1 FIA equipment can be calibrated for almost any range of total organic concentrations. For high concentrations of organics (>1.0 percent by volume as propane), modifications to most commonly available analyzers are necessary. One accepted method of equipment modification is to decrease the size of the sample to the analyzer through the use of a smaller diameter sample capillary. Direct and continuous measurement of organic concentration is a necessary consideration when determining any modification design.
The sample collection and analysis are concurrent for this method (see section 8.0).
12.1 Determine the average organic concentration in terms of ppmv as propane or other calibration gas. The average shall be determined by integration of the output recording over the period specified in the applicable regulation. If results are required in terms of ppmv as carbon, adjust measured concentrations using Equation 25A-1.
13.1 Measurement System Performance Specifications.
13.1.1 Zero Drift. Less than ±3 percent of the span value.
13.1.2 Calibration Drift. Less than ±3 percent of span value.
13.1.3 Calibration Error. Less than ±5 percent of the calibration gas value.
1. Measurement of Volatile Organic Compounds – Guideline Series. U.S. Environmental Protection Agency. Research Triangle Park, NC. Publication No. EPA-450/2-78-041. June 1978. p. 46-54.
2. EPA Traceability Protocol for Assay and Certification of Gaseous Calibration Standards. U.S. Environmental Protection Agency, Quality Assurance and Technical Support Division. Research Triangle Park, N.C. September 1993.
3. Gasoline Vapor Emission Laboratory Evaluation – Part 2. U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards. Research Triangle Park, NC. EMB Report No. 75-GAS-6. August 1975.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 6C, and Method 25A.
1.1 Analytes.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Total Organic Compounds | N/A |
1.2 Applicability. This method is applicable for the determination of total gaseous organic concentration of vapors consisting primarily of alkanes. Other organic materials may be measured using the general procedure in this method, the appropriate calibration gas, and an analyzer set to the appropriate absorption band.
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
A gas sample is extracted from the source through a heated sample line, if necessary, and glass fiber filter to a nondispersive infrared analyzer (NDIR). Results are reported as volume concentration equivalents of the calibration gas or as carbon equivalents.
Same as Method 25A, section 3.0.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method. The analyzer users manual should be consulted for specific precautions to be taken with regard to the analytical procedure.
5.2 Explosive Atmosphere. This method is often applied in highly explosive areas. Caution and care should be exercised in choice of equipment and installation.
Same as Method 25A, section 6.0, with the exception of the following:
6.1 Organic Concentration Analyzer. A nondispersive infrared analyzer designed to measure alkane organics and capable of meeting or exceeding the specifications in this method.
Same as Method 25A, section 7.1. No fuel gas is required for an NDIR.
Same as Method 25A, section 8.0.
Same as Method 25A, section 9.0.
Same as Method 25A, section 10.0.
The sample collection and analysis are concurrent for this method (see section 8.0).
Same as Method 25A, section 12.0.
Same as Method 25A, section 16.0.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should also have a thorough knowledge of EPA Method 25.
1.1 Analytes.
| Analyte | CAS No. |
|---|---|
| Nonmethane organic compounds (NMOC) | No CAS number assigned. |
1.2 Applicability. This method is applicable to the sampling and measurement of NMOC as carbon in landfill gases (LFG).
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 A sample probe that has been perforated at one end is driven or augured to a depth of 0.9 m (3 ft) below the bottom of the landfill cover. A sample of the landfill gas is extracted with an evacuated cylinder. The NMOC content of the gas is determined by injecting a portion of the gas into a gas chromatographic column to separate the NMOC from carbon monoxide (CO), carbon dioxide (CO
5.1 Since this method is complex, only experienced personnel should perform this test. LFG contains methane, therefore explosive mixtures may exist on or near the landfill. It is advisable to take appropriate safety precautions when testing landfills, such as refraining from smoking and installing explosion-proof equipment.
6.1 Sample Probe. Stainless steel, with the bottom third perforated. Teflon probe liners and sampling lines are also allowed. Non-perforated probes are allowed as long as they are withdrawn to create a gap equivalent to having the bottom third perforated. The sample probe must be capped at the bottom and must have a threaded cap with a sampling attachment at the top. The sample probe must be long enough to go through and extend no less than 0.9 m (3 ft) below the landfill cover. If the sample probe is to be driven into the landfill, the bottom cap should be designed to facilitate driving the probe into the landfill.
6.2 Sampling Train.
6.2.1 Rotameter with Flow Control Valve. Capable of measuring a sample flow rate of 100 ±10 ml/min. The control valve must be made of stainless steel.
6.2.2 Sampling Valve. Stainless steel.
6.2.3 Pressure Gauge. U-tube mercury manometer, or equivalent, capable of measuring pressure to within 1 mm Hg (0.5 in H
6.2.4 Sample Tank. Stainless steel or aluminum cylinder, equipped with a stainless steel sample tank valve.
6.3 Vacuum Pump. Capable of evacuating to an absolute pressure of 10 mm Hg (5.4 in H
6.4 Purging Pump. Portable, explosion proof, and suitable for sampling NMOC.
6.5 Pilot Probe Procedure. The following are needed only if the tester chooses to use the procedure described in section 8.2.1.
6.5.1 Pilot Probe. Tubing of sufficient strength to withstand being driven into the landfill by a post driver and an outside diameter of at least 6 mm (0.25 in.) smaller than the sample probe. The pilot probe shall be capped on both ends and long enough to go through the landfill cover and extend no less than 0.9 m (3 ft) into the landfill.
6.5.2 Post Driver and Compressor. Capable of driving the pilot probe and the sampling probe into the landfill. The Kitty Hawk portable post driver has been found to be acceptable.
6.6 Auger Procedure. The following are needed only if the tester chooses to use the procedure described in section 8.2.2.
6.6.1 Auger. Capable of drilling through the landfill cover and to a depth of no less than 0.9 m (3 ft) into the landfill.
6.6.2 Pea Gravel.
6.6.3 Bentonite.
6.7 NMOC Analyzer, Barometer, Thermometer, and Syringes. Same as in sections 6.3.1, 6.3.2, 6.33, and 6.2.10, respectively, of Method 25.
7.1 NMOC Analysis. Same as in Method 25, section 7.2.
7.2 Calibration. Same as in Method 25, section 7.4, except omit section 7.4.3.
8.1 Sample Tank Evacuation and Leak-Check. Conduct the sample tank evacuation and leak-check either in the laboratory or the field. Connect the pressure gauge and sampling valve to the sample tank. Evacuate the sample tank to 10 mm Hg (5.4 in H
8.2 Sample Probe Installation. The tester may use the procedure in section 8.2.1 or 8.2.2.
8.2.1 Pilot Probe Procedure. Use the post driver to drive the pilot probe at least 0.9 m (3 ft) below the landfill cover. Alternative procedures to drive the probe into the landfill may be used subject to the approval of the Administrator’s designated representative.
8.2.1.1 Remove the pilot probe and drive the sample probe into the hole left by the pilot probe. The sample probe shall extend at least 0.9 m (3 ft) below the landfill cover and shall protrude about 0.3 m (1 ft) above the landfill cover. Seal around the sampling probe with bentonite and cap the sampling probe with the sampling probe cap.
8.2.2 Auger Procedure. Use an auger to drill a hole to at least 0.9 m (3 ft) below the landfill cover. Place the sample probe in the hole and backfill with pea gravel to a level 0.6 m (2 ft) from the surface. The sample probe shall protrude at least 0.3 m (1 ft) above the landfill cover. Seal the remaining area around the probe with bentonite. Allow 24 hours for the landfill gases to equilibrate inside the augured probe before sampling.
8.2.3 Driven Probes. Closed-point probes may be driven directly into the landfill in a single step. This method may not require backfilling if the probe is adequately sealed by its insertion. Unperforated probes that are inserted in this manner and withdrawn at a distance from a detachable tip to create an open space are also acceptable.
8.3 Sample Train Assembly. Just before assembling the sample train, measure the sample tank vacuum using the pressure gauge. Record the vacuum, the ambient temperature, and the barometric pressure at this time. Assemble the sampling probe purging system as shown in Figure 25C-1.
8.4 Sampling Procedure. Open the sampling valve and use the purge pump and the flow control valve to evacuate at least two sample probe volumes from the system at a flow rate of 500 ml/min or less. Close the sampling valve and replace the purge pump with the sample tank apparatus as shown in Figure 25C-2. Open the sampling valve and the sample tank valve and, using the flow control valve, sample at a flow rate of 500 ml/min or less until either a constant flow rate can no longer be maintained because of reduced sample tank vacuum or the appropriate composite volume is attained. Disconnect the sampling tank apparatus and pressurize the sample cylinder to approximately 1,060 mm Hg (567 in. H
8.4.1 The following restrictions apply to compositing samples from different probe sites into a single cylinder: (1) Individual composite samples per cylinder must be of equal volume; this must be verified by recording the flow rate, sampling time, vacuum readings, or other appropriate volume measuring data, (2) individual composite samples must have a minimum volume of 1 liter unless data is provided showing smaller volumes can be accurately measured, and (3) composite samples must not be collected using the final cylinder vacuum as it diminishes to ambient pressure.
8.4.2 Use Method 3C to determine the percent N
9.1 Miscellaneous Quality Control Measures.
| Section | Quality control measure | Effect |
|---|---|---|
| 8.4.2 | If the 3-year average annual rainfall is greater than 20 inches, verify that landfill gas sample contains less than 20 percent N | Ensures that ambient air was not drawn into the landfill gas sample and gas was sampled from an appropriate location. If outside of range, invalidate sample and repeat sample collection. |
| 10.1, 10.2 | NMOC analyzer initial and daily performance checks | Ensures precision of analytical results. |
Maintain a record of performance of each item.
10.1 Initial NMOC Analyzer Performance Test. Same as in Method 25, section 10.1, except omit the linearity checks for CO
10.2 NMOC Analyzer Daily Calibration.
10.2.1 NMOC Response Factors. Same as in Method 25, section 10.2.2.
10.3 Sample Tank Volume. The volume of the gas sampling tanks must be determined. Determine the tank volumes by weighing them empty and then filled with deionized water; weigh to the nearest 5 g, and record the results. Alternatively, measure the volume of water used to fill them to the nearest 5 ml.
11.1 The oxidation, reduction, and measurement of NMOC’s is similar to Method 25. Before putting the NMOC analyzer into routine operation, conduct an initial performance test. Start the analyzer, and perform all the necessary functions in order to put the analyzer into proper working order. Conduct the performance test according to the procedures established in section 10.1. Once the performance test has been successfully completed and the NMOC calibration response factor has been determined, proceed with sample analysis as follows:
11.1.1 Daily Operations and Calibration Checks. Before and immediately after the analysis of each set of samples or on a daily basis (whichever occurs first), conduct a calibration test according to the procedures established in section 10.2. If the criteria of the daily calibration test cannot be met, repeat the NMOC analyzer performance test (Section 10.1) before proceeding.
11.1.2 Operating Conditions. Same as in Method 25, section 11.2.1.
11.1.3 Analysis of Sample Tank. Purge the sample loop with sample, and then inject the sample. Under the specified operating conditions, the CO
All equations are written using absolute pressure; absolute pressures are determined by adding the measured barometric pressure to the measured gauge or manometer pressure.
12.1 Nomenclature
12.2 Water Correction. Use Table 25C-1 (Section 17.0), the LFG temperature, and barometric pressure at the sampling site to calculate B
12.3 Nitrogen Concentration in the landfill gas. Use equation 25C-2 to calculate the measured concentration of nitrogen in the original landfill gas.
12.4 Oxygen Concentration in the landfill gas. Use equation 25C-3 to calculate the measured concentration of oxygen in the original landfill gas.
12.5 You must correct the NMOC Concentration for the concentration of nitrogen or oxygen based on which gas or gases passes the requirements in section 9.1 or based on the 3-year average annual rainfall based on the closest NOAA land-based station.
12.5.1 NMOC Concentration with nitrogen correction. Use Equation 25C-4 to calculate the concentration of NMOC for each sample tank when the nitrogen concentration is less than 20 percent.
12.5.2 NMOC Concentration with oxygen correction. Use Equation 25C-5 to calculate the concentration of NMOC for each sample tank if the landfill gas oxygen is less than 5 percent and the landfill gas nitrogen concentration is greater than 20 percent, or 3-year average annual rainfall based annual rainfall of less than 20 inches.
1. Salo, Albert E., Samuel Witz, and Robert D. MacPhee. Determination of Solvent Vapor Concentrations by Total Combustion Analysis: A Comparison of Infrared with Flame Ionization Detectors. Paper No. 75-33.2. (Presented at the 68th Annual Meeting of the Air Pollution Control Association. Boston, Massachusetts. June 15-20, 1975.) 14 p.
2. Salo, Albert E., William L. Oaks, and Robert D. MacPhee. Measuring the Organic Carbon Content of Source Emissions for Air Pollution Control. Paper No. 74-190. (Presented at the 67th Annual Meeting of the Air Pollution Control Association. Denver, Colorado. June 9-13, 1974.) 25 p.
Table 25C-1 – Moisture Correction
| Temperature, °C | Vapor Pressure of H | Temperature, °C | Vapor Pressure of H |
|---|---|---|---|
| 4 | 6.1 | 18 | 15.5 |
| 6 | 7.0 | 20 | 17.5 |
| 8 | 8.0 | 22 | 19.8 |
| 10 | 9.2 | 24 | 22.4 |
| 12 | 10.5 | 26 | 25.2 |
| 14 | 12.0 | 28 | 28.3 |
| 16 | 13.6 | 30 | 31.8 |
Performance of this method should not be attempted by persons unfamiliar with the operation of a flame ionization detector (FID) or an electrolytic conductivity detector (ELCD) because knowledge beyond the scope of this presentation is required.
1.1 Analyte. Volatile Organic Compounds. No CAS No. assigned.
1.2 Applicability. This method is applicable for determining the volatile organic (VO) concentration of a waste sample.
2.1 Principle. A sample of waste is obtained at a point which is most representative of the unexposed waste (where the waste has had minimum opportunity to volatilize to the atmosphere). The sample is suspended in an organic/aqueous matrix, then heated and purged with nitrogen for 30 min. in order to separate certain organic compounds. Part of the sample is analyzed for carbon concentration, as methane, with an FID, and part of the sample is analyzed for chlorine concentration, as chloride, with an ELCD. The VO concentration is the sum of the carbon and chlorine content of the sample.
3.1 Well-mixed in the context of this method refers to turbulent flow which results in multiple-phase waste in effect behaving as single-phase waste due to good mixing.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to performing this test method.
Mention of trade names or specific products does not constitute endorsement by the Environmental Protection Agency.
6.1 Sampling. The following equipment is required:
6.1.1 Sampling Tube. Flexible Teflon, 0.25 in. ID (6.35 mm).
6.1.2 Sample Container. Borosilicate glass, 40-mL, and a Teflon-lined screw cap capable of forming an air tight seal.
6.1.3 Cooling Coil. Fabricated from 0.25 in (6.35 mm). ID 304 stainless steel tubing with a thermocouple at the coil outlet.
6.2 Analysis. The following equipment is required.
6.2.1 Purging Apparatus. For separating the VO from the waste sample. A schematic of the system is shown in Figure 25D-1. The purging apparatus consists of the following major components.
6.2.1.1 Purging Flask. A glass container to hold the sample while it is heated and purged with dry nitrogen. The cap of the purging flask is equipped with three fittings: one for a purging lance (fitting with the #7 Ace-thread), one for the Teflon exit tubing (side fitting, also a #7 Ace-thread), and a third (a 50-mm Ace-thread) to attach the base of the purging flask as shown in Figure 25D-2. The base of the purging flask is a 50-mm ID (2 in) cylindrical glass tube. One end of the tube is open while the other end is sealed. Exact dimensions are shown in Figure 25D-2.
6.2.1.2 Purging Lance. Glass tube, 6-mm OD (0.2 in) by 30 cm (12 in) long. The purging end of the tube is fitted with a four-arm bubbler with each tip drawn to an opening 1 mm (0.04 in) in diameter. Details and exact dimensions are shown in Figure 25D-2.
6.2.1.3 Coalescing Filter. Porous fritted disc incorporated into a container with the same dimensions as the purging flask. The details of the design are shown in Figure 25D-3.
6.2.1.4 Constant Temperature Chamber. A forced draft oven capable of maintaining a uniform temperature around the purging flask and coalescing filter of 75 ±2 °C (167 ±3.6 °F).
6.2.1.5 Three-way Valve. Manually operated, stainless steel. To introduce calibration gas into system.
6.2.1.6 Flow Controllers. Two, adjustable. One capable of maintaining a purge gas flow rate of 6 ±0.06 L/min (0.2 ±0.002 ft
6.2.1.7 Rotameter. For monitoring the air flow through the purging system (0-10 L/min)(0-0.4 ft
6.2.1.8 Sample Splitters. Two heated flow restrictors (placed inside oven or heated to 120 ±10 °C (248 ±18 °F) ). At a purge rate of 6 L/min (0.2 ft
6.2.1.9 Flow Restrictor. Stainless steel tubing, 1/8′ OD (3.175 mm), connecting the second sample splitter to the ice bath. Length is determined by the resulting pressure in the purging flask (as measured by the pressure gauge). The resulting pressure from the use of the flow restrictor shall be 6-7 psig.
6.2.1.10 Filter Flask. With one-hole stopper. Used to hold ice bath. Excess purge gas is vented through the flask to prevent condensation in the flowmeter and to trap volatile organic compounds.
6.2.1.11 Four-way Valve. Manually operated, stainless steel. Placed inside oven, used to bypass purging flask.
6.2.1.12 On/Off Valves. Two, stainless steel. One heat resistant up to 130 °C (266 °F) and placed between oven and ELCD. The other a toggle valve used to control purge gas flow.
6.2.1.13 Pressure Gauge. Range 0-40 psi. To monitor pressure in purging flask and coalescing filter.
6.2.1.14 Sample Lines. Teflon, 1/4′ OD (6.35 mm), used inside the oven to carry purge gas to and from purging chamber and to and from coalescing filter to four-way valve. Also used to carry sample from four-way valve to first sample splitter.
6.2.1.15 Detector Tubing. Stainless steel, 1/8′ OD (3.175 mm), heated to 120 ±10 °C (248 ±18 °F) . Used to carry sample gas from each sample splitter to a detector. Each piece of tubing must be wrapped with heat tape and insulating tape in order to insure that no cold spots exist. The tubing leading to the ELCD will also contain a heat-resistant on-off valve (Section 6.2.1.12) which shall also be wrapped with heat-tape and insulation.
6.2.2 Volatile Organic Measurement System. Consisting of an FID to measure the carbon concentration of the sample and an ELCD to measure the chlorine concentration.
6.2.2.1 FID. A heated FID meeting the following specifications is required.
6.2.2.1.1 Linearity. A linear response (±5 percent) over the operating range as demonstrated by the procedures established in section 10.1.1.
6.2.2.1.2 Range. A full scale range of 50 pg carbon/sec to 50 µg carbon/sec. Signal attenuators shall be available to produce a minimum signal response of 10 percent of full scale.
6.2.2.1.3 Data Recording System. A digital integration system compatible with the FID for permanently recording the output of the detector. The recorder shall have the capability to start and stop integration at points selected by the operator or it shall be capable of the “integration by slices” technique (this technique involves breaking down the chromatogram into smaller increments, integrating the area under the curve for each portion, subtracting the background for each portion, and then adding all of the areas together for the final area count).
6.2.2.2 ELCD. An ELCD meeting the following specifications is required. 1-propanol must be used as the electrolyte. The electrolyte flow through the conductivity cell shall be 1 to 2 mL/min (0.00004 to 0.00007 ft
A
6.2.2.2.1 Linearity. A linear response (±10 percent) over the response range as demonstrated by the procedures in section 10.1.2.
6.2.2.2.2 Range. A full scale range of 5.0 pg/sec to 500 ng/sec chloride. Signal attenuators shall be available to produce a minimum signal response of 10 percent of full scale.
6.2.2.2.3 Data Recording System. A digital integration system compatible with the output voltage range of the ELCD. The recorder must have the capability to start and stop integration at points selected by the operator or it shall be capable of performing the “integration by slices” technique.
7.1 Sampling.
7.1.1 Polyethylene Glycol (PEG). Ninety-eight percent pure with an average molecular weight of 400. Before using the PEG, remove any organic compounds that might be detected as volatile organics by heating it to 120 °C (248 °F) and purging it with nitrogen at a flow rate of 1 to 2 L/min (0.04 to 0.07 ft
7.2 Analysis.
7.2.1 Sample Separation. The following are required for the sample purging step.
7.2.1.1 PEG. Same as section 7.1.1.
7.2.1.2 Purge Gas. Zero grade nitrogen (N
7.2.2 Volatile Organics Measurement. The following are required for measuring the VO concentration.
7.2.2.1 Hydrogen (H
7.2.2.2 Combustion Gas. Zero grade air or oxygen as required by the FID.
7.2.2.3 Calibration Gas. Pressurized gas cylinder containing 10 percent propane and 1 percent 1,1-dichloroethylene by volume in nitrogen.
7.2.2.4 Water. Deionized distilled water that conforms to American Society for Testing and Materials Specification D 1193-74, Type 3, is required for analysis. At the option of the analyst, the KMnO
7.2.2.5 1-Propanol. ACS grade or better. Electrolyte Solution. For use in the ELCD.
8.1 Sampling.
8.1.1 Sampling Plan Design and Development. Use the procedures in chapter nine of Reference 1 in section 16 as guidance in developing a sampling plan.
8.1.2 Single Phase or Well-mixed Waste.
8.1.2.1 Install a sampling tap to obtain the sample at a point which is most representative of the unexposed waste (where the waste has had minimum opportunity to volatilize to the atmosphere). Assemble the sampling apparatus as shown in Figure 25D-5.
8.1.2.2 Prepare the sampling containers as follows: Pour 30 mL of clean PEG into the container. PEG will reduce but not eliminate the loss of organics during sample collection. Weigh the sample container with the screw cap, the PEG, and any labels to the nearest 0.01 g and record the weight (m
8.1.2.3 Begin sampling by purging the sample lines and cooling coil with at least four volumes of waste. Collect the purged material in a separate container and dispose of it properly.
8.1.2.4 After purging, stop the sample flow and direct the sampling tube to a preweighed sample container, prepared as described in section 8.1.2.2. Keep the tip of the tube below the surface of the PEG during sampling to minimize contact with the atmosphere. Sample at a flow rate such that the temperature of the waste is less than 10 °C (50 °F). Fill the sample container and immediately cap it (within 5 seconds) so that a minimum headspace exists in the container. Store immediately in a cooler and cover with ice.
8.1.3 Multiple-phase Waste. Collect a 10 g sample of each phase of waste generated using the procedures described in section 8.1.2 or 8.1.5. Each phase of the waste shall be analyzed as a separate sample. Calculate the weighted average VO concentration of the waste using Equation 25D-13 (Section 12.14).
8.1.4 Solid waste. Add approximately 10 g of the solid waste to a container prepared in the manner described in section 8.1.2.2, minimizing headspace. Cap and chill immediately.
8.1.5 Alternative to Tap Installation. If tap installation is impractical or impossible, fill a large, clean, empty container by submerging the container into the waste below the surface of the waste. Immediately fill a container prepared in the manner described in section 8.1.2.2 with approximately 10 g of the waste collected in the large container. Minimize headspace, cap and chill immediately.
8.1.6 Alternative sampling techniques may be used upon the approval of the Administrator.
8.2 Sample Recovery.
8.2.1 Assemble the purging apparatus as shown in Figures 25D-1 and 25D-2. The oven shall be heated to 75 ±2 °C (167 ±3.6 °F). The sampling lines leading from the oven to the detectors shall be heated to 120 ±10 °C (248 ±18 °F) with no cold spots. The flame ionization detector shall be operated with a heated block. Adjust the purging lance so that it reaches the bottom of the chamber.
8.2.2 Remove the sample container from the cooler, and wipe the exterior of the container to remove any extraneous ice, water, or other debris. Reweigh the sample container to the nearest 0.01 g, and record the weight (m
9.1 Quality Control Samples. If audit samples are not available, prepare and analyze the two types of quality control samples (QCS) listed in Sections 9.1.1 and 9.1.2. Before placing the system in operation, after a shutdown of greater than six months, and after any major modifications, analyze each QCS in triplicate. For each detector, calculate the percent recovery by dividing measured concentration by theoretical concentration and multiplying by 100. Determine the mean percent recovery for each detector for each QCS triplicate analysis. The RSD for any triplicate analysis shall be ≤10 percent. For QCS 1 (methylene chloride), the percent recovery shall be ≥90 percent for carbon as methane, and ≥55 percent for chlorine as chloride. For QCS 2 (1,3-dichloro-2-propanol), the percent recovery shall be ≤15 percent for carbon as methane, and ≤6 percent for chlorine as chloride. If the analytical system does not meet the above-mentioned criteria for both detectors, check the system parameters (temperature, system pressure, purge rate, etc.), correct the problem, and repeat the triplicate analysis of each QCS.
9.1.1 QCS 1, Methylene Chloride. Prepare a stock solution by weighing, to the nearest 0.1 mg, 55 µL of HPLC grade methylene chloride in a tared 5 mL volumetric flask. Record the weight in milligrams, dilute to 5 mL with cleaned PEG, and inject 100 µL of the stock solution into a sample prepared as a water blank (50 mL of cleaned PEG and 60 mL of water in the purging flask). Analyze the QCS according to the procedures described in sections 10.2 and 10.3, excluding section 10.2.2. To calculate the theoretical carbon concentration (in mg) in QCS 1, multiply mg of methylene chloride in the stock solution by 3.777 × 10
9.1.2 QCS 2, 1,3-dichloro-2-propanol. Prepare a stock solution by weighing, to the nearest 0.1 mg, 60 µL of high purity grade 1,3-dichloro-2-propanol in a tared 5 mL volumetric flask. Record the weight in milligrams, dilute to 5 mL with cleaned PEG, and inject 100 µL of the stock solution into a sample prepared as a water blank (50 mL of cleaned PEG and 60 mL of water in the purging flask). Analyze the QCS according to the procedures described in sections 10.2 and 10.3, excluding section 10.2.2. To calculate the theoretical carbon concentration (in mg) in QCS 2, multiply mg of 1,3-dichloro-2-propanol in the stock solution by 7.461 × 10
9.1.3 Routine QCS Analysis. For each set of compliance samples (in this context, set is per facility, per compliance test), analyze one QCS 1 and one QCS 2 sample. The percent recovery for each sample for each detector shall be ±13 percent of the mean recovery established for the most recent set of QCS triplicate analysis (Section 9.4). If the sample does not meet this criteria, check the system components and analyze another QCS 1 and 2 until a single set of QCS meet the ±13 percent criteria.
10.1 Initial Performance Check of Purging System. Before placing the system in operation, after a shutdown of greater than six months, after any major modifications, and at least once per month during continuous operation, conduct the linearity checks described in sections 10.1.1 and 10.1.2. Install calibration gas at the three-way calibration gas valve. See Figure 25D-1.
10.1.1 Linearity Check Procedure. Using the calibration standard described in section 7.2.2.3 and by varying the injection time, it is possible to calibrate at multiple concentration levels. Use Equation 25D-3 to calculate three sets of calibration gas flow rates and run times needed to introduce a total mass of carbon, as methane, (m
10.1.2 Linearity Criteria. Calculate the average response factor (Equations 25D-5 and 25D-6) and the relative standard deviation (RSD) (Equation 25D-10) at each level of the calibration curve for both detectors. Calculate the overall mean of the three response factor averages for each detector. The FID linearity is acceptable if each response factor is within 5 percent of the overall mean and if the RSD for each set of triplicate injections is less than 5 percent. The ELCD linearity is acceptable if each response factor is within 10 percent of the overall mean and if the RSD for each set of triplicate injections is less than 10 percent. Record the overall mean value of the response factors for the FID and the ELCD. If the calibration for either the FID or the ELCD does not meet the criteria, correct the detector/system problem and repeat sections 10.1.1 and 10.1.2.
10.2 Daily Calibrations.
10.2.1 Daily Linearity Check. Follow the procedures outlined in section 10.1.1 to analyze the medium level calibration for both the FID and the ELCD in duplicate at the start of the day. Calculate the response factors and the RSDs for each detector. For the FID, the calibration is acceptable if the average response factor is within 5 percent of the overall mean response factor (Section 10.1.2) and if the RSD for the duplicate injection is less than 5 percent. For the ELCD, the calibration is acceptable if the average response factor is within 10 percent of the overall mean response factor (Section 10.1.2) and if the RSD for the duplicate injection is less than 10 percent. If the calibration for either the FID or the ELCD does not meet the criteria, correct the detector/system problem and repeat sections 10.1.1 and 10.1.2.
10.2.2 Calibration Range Check.
10.2.2.1 If the waste concentration for either detector falls below the range of calibration for that detector, use the procedure outlined in section 10.1.1 to choose two calibration points that bracket the new target concentration. Analyze each of these points in triplicate (as outlined in section 10.1.1) and use the criteria in section 10.1.2 to determine the linearity of the detector in this “mini-calibration” range.
10.2.2.2 After the initial linearity check of the mini-calibration curve, it is only necessary to test one of the points in duplicate for the daily calibration check (in addition to the points specified in section 10.2.1). The average daily mini-calibration point should fit the linearity criteria specified in section 10.2.1. If the calibration for either the FID or the ELCD does not meet the criteria, correct the detector/system problem and repeat the calibration procedure mentioned in the first paragraph of section 10.2.2. A mini-calibration curve for waste concentrations above the calibration curve for either detector is optional.
10.3 Analytical Balance. Calibrate against standard weights.
11.1 Sample Analysis.
11.1.1 Turn on the constant temperature chamber and allow the temperature to equilibrate at 75 ±2 °C (167 ±3.6 °F). Turn the four-way valve so that the purge gas bypasses the purging flask, the purge gas flowing through the coalescing filter and to the detectors (standby mode). Turn on the purge gas. Allow both the FID and the ELCD to warm up until a stable baseline is achieved on each detector. Pack the filter flask with ice. Replace ice after each run and dispose of the waste water properly. When the temperature of the oven reaches 75 ±2 °C (167 ±3.6 °F), start both integrators and record baseline. After 1 min, turn the four-way valve so that the purge gas flows through the purging flask, to the coalescing filter and to the sample splitters (purge mode). Continue recording the response of the FID and the ELCD. Monitor the readings of the pressure gauge and the rotameter. If the readings fall below established setpoints, stop the purging, determine the source of the leak, and resolve the problem before resuming. Leaks detected during a sampling period invalidate that sample.
11.1.2 As the purging continues, monitor the output of the detectors to make certain that the analysis is proceeding correctly and that the results are being properly recorded. Every 10 minutes read and record the purge flow rate, the pressure and the chamber temperature. Continue the purging for 30 minutes.
11.1.3 For each detector output, integrate over the entire area of the peak starting at 1 minute and continuing until the end of the run. Subtract the established baseline area from the peak area. Record the corrected area of the peak. See Figure 25D-6 for an example integration.
11.2 Water Blank. A water blank shall be analyzed for each batch of cleaned PEG prepared. Transfer about 60 mL of water into the purging flask. Add 50 mL of the cleaned PEG to the purging flask. Treat the blank as described in sections 8.2 and 8.3, excluding section 8.2.2. Calculate the concentration of carbon and chlorine in the blank sample (assume 10 g of waste as the mass). A VO concentration equivalent to ≤10 percent of the applicable standard may be subtracted from the measured VO concentration of the waste samples. Include all blank results and documentation in the test report.
12.1 Nomenclature.
12.2 Concentration of Carbon, as Methane, in the Calibration Gas.
12.3 Concentration of Chloride in the Calibration Gas.
12.4 Mass of Carbon, as Methane, in a Calibration Run.
12.5 Mass of Chloride in a Calibration Run.
12.6 FID Response Factor, mg/counts.
12.7 ELCD Response Factor, mg/counts.
12.8 Mass of Carbon in the Sample.
12.9 Mass of Chloride in the Sample.
12.10 Mass of Volatile Organics in the Sample.
12.11 Relative Standard Deviation.
12.12 Mass of Sample.
12.13 Concentration of Volatile Organics in Waste.
12.14 Weighted Average VO Concentration of Multi-phase Waste.
1. “Test Methods for Evaluating Solid Waste, Physical/Chemistry Methods”, U.S. Environmental Protection Agency. Publication SW-846, 3rd Edition, November 1986 as amended by Update I, November 1990.
Performance of this method should not be attempted by persons unfamiliar with the operation of a flame ionization detector (FID) nor by those who are unfamiliar with source sampling because knowledge beyond the scope of this presentation is required. This method is not inclusive with respect to specifications (e.g., reagents and standards) and calibration procedures. Some material is incorporated by reference from other methods. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 106, part 61, Appendix B, and Method 18, part 60, Appendix A.
1.1 Applicability. This method is applicable for determining the vapor pressure of waste cited by an applicable regulation.
1.2 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 The headspace vapor of the sample is analyzed for carbon content by a headspace analyzer, which uses an FID.
4.1 The analyst shall select the operating parameters best suited to the requirements for a particular analysis. The analyst shall produce confirming data through an adequate supplemental analytical technique and have the data available for review by the Administrator.
6.1 Sampling. The following equipment is required:
6.1.1 Sample Containers. Vials, glass, with butyl rubber septa, Perkin-Elmer Corporation Numbers 0105-0129 (glass vials), B001-0728 (gray butyl rubber septum, plug style), 0105-0131 (butyl rubber septa), or equivalent. The seal must be made from butyl rubber. Silicone rubber seals are not acceptable.
6.1.2 Vial Sealer. Perkin-Elmer Number 105-0106, or equivalent.
6.1.3 Gas-Tight Syringe. Perkin-Elmer Number 00230117, or equivalent.
6.1.4 The following equipment is required for sampling.
6.1.4.1 Tap.
6.1.4.2 Tubing. Teflon, 0.25-in. ID.
Mention of trade names or specific products does not constitute endorsement by the Environmental Protection Agency.
6.1.4.3 Cooling Coil. Stainless steel (304), 0.25 in.-ID, equipped with a thermocouple at the coil outlet.
6.2 Analysis. The following equipment is required.
6.2.1 Balanced Pressure Headspace Sampler. Perkin-Elmer HS-6, HS-100, or equivalent, equipped with a glass bead column instead of a chromatographic column.
6.2.2 FID. An FID meeting the following specifications is required.
6.2.2.1 Linearity. A linear response (±5 percent) over the operating range as demonstrated by the procedures established in section 10.2.
6.2.2.2 Range. A full scale range of 1 to 10,000 parts per million (ppm) propane (C
6.2.3 Data Recording System. Analog strip chart recorder or digital integration system compatible with the FID for permanently recording the output of the detector.
6.2.4 Temperature Sensor. Capable of reading temperatures in the range of 30 to 60 °C (86 to 140 °F) with an accuracy of ±0.1 °C (±0.2 °F).
7.1 Analysis. The following items are required for analysis.
7.1.1 Hydrogen (H
7.1.2 Carrier Gas. Zero grade nitrogen, containing less than 1 ppm carbon (C) and less than 1 ppm carbon dioxide.
7.1.3 Combustion Gas. Zero grade air or oxygen as required by the FID.
7.2 Calibration and Linearity Check.
7.2.1 Stock Cylinder Gas Standard. 100 percent propane. The manufacturer shall: (a) Certify the gas composition to be accurate to ±3 percent or better (see section 7.2.1.1); (b) recommend a maximum shelf life over which the gas concentration does not change by greater than ±5 percent from the certified value; and (c) affix the date of gas cylinder preparation, certified propane concentration, and recommended maximum shelf life to the cylinder before shipment to the buyer.
7.2.1.1 Cylinder Standards Certification. The manufacturer shall certify the concentration of the calibration gas in the cylinder by (a) directly analyzing the cylinder and (b) calibrating his analytical procedure on the day of cylinder analysis. To calibrate his analytical procedure, the manufacturer shall use, as a minimum, a three-point calibration curve.
7.2.1.2 Verification of Manufacturer’s Calibration Standards. Before using, the manufacturer shall verify each calibration standard by (a) comparing it to gas mixtures prepared in accordance with the procedure described in section 7.1 of Method 106 of Part 61, Appendix B, or by (b) calibrating it against Standard Reference Materials (SRM’s) prepared by the National Bureau of Standards, if such SRM’s are available. The agreement between the initially determined concentration value and the verification concentration value must be within ±5 percent. The manufacturer must reverify all calibration standards on a time interval consistent with the shelf life of the cylinder standards sold.
8.1 Install a sampling tap to obtain a sample at a point which is most representative of the unexposed waste (where the waste has had minimum opportunity to volatilize to the atmosphere). Assemble the sampling apparatus as shown in Figure 25E-1.
8.2 Begin sampling by purging the sample lines and cooling coil with at least four volumes of waste. Collect the purged material in a separate container and dispose of it properly.
8.3 After purging, stop the sample flow and transfer the Teflon sampling tube to a sample container. Sample at a flow rate such that the temperature of the waste is
8.4 Alternative sampling techniques may be used upon the approval of the Administrator.
9.1 Miscellaneous Quality Control Measures.
| Section | Quality control measure | Effect |
|---|---|---|
| 10.2, 10.3 | FID calibration and response check | Ensure precision of analytical results. |
Maintain a record of performance of each item.
10.1 Use the procedures in sections 10.2 to calibrate the headspace analyzer and FID and check for linearity before the system is first placed in operation, after any shutdown longer than 6 months, and after any modification of the system.
10.2 Calibration and Linearity. Use the procedures in section 10 of Method 18 of Part 60, Appendix A, to prepare the standards and calibrate the flowmeters, using propane as the standard gas. Fill the calibration standard vials halfway (±5 percent) with deionized water. Purge and fill the airspace with calibration standard. Prepare a minimum of three concentrations of calibration standards in triplicate at concentrations that will bracket the applicable cutoff. For a cutoff of 5.2 kPa (0.75 psi), prepare nominal concentrations of 30,000, 50,000, and 70,000 ppm as propane. For a cutoff of 27.6 kPa (4.0 psi), prepare nominal concentrations of 200,000, 300,000, and 400,000 ppm as propane.
10.2.1 Use the procedures in section 11.3 to measure the FID response of each standard. Use a linear regression analysis to calculate the values for the slope (k) and the y-intercept (b). Use the procedures in sections 12.3 and 12.2 to test the calibration and the linearity.
10.3 Daily FID Calibration Check. Check the calibration at the beginning and at the end of the daily runs by using the following procedures. Prepare 2 calibration standards at the nominal cutoff concentration using the procedures in section 10.2. Place one at the beginning and one at the end of the daily run. Measure the FID response of the daily calibration standard and use the values for k and b from the most recent calibration to calculate the concentration of the daily standard. Use an equation similar to 25E-2 to calculate the percent difference between the daily standard and C
11.1 Allow one hour for the headspace vials to equilibrate at the temperature specified in the regulation. Allow the FID to warm up until a stable baseline is achieved on the detector.
11.2 Check the calibration of the FID daily using the procedures in section 10.3.
11.3 Follow the manufacturer’s recommended procedures for the normal operation of the headspace sampler and FID.
11.4 Use the procedures in sections 12.4 and 12.5 to calculate the vapor phase organic vapor pressure in the samples.
11.5 Monitor the output of the detector to make certain that the results are being properly recorded.
12.1 Nomenclature.
12.2 Linearity. Use the following equation to calculate the measured standard concentration for each standard vial.
12.2.1 Calculate the average measured standard concentration (C
12.3. Relative Standard Deviation (RSD). Use the following equation to calculate the RSD for each triplicate set of standards.
12.4 Concentration of organics in the headspace. Use the following equation to calculate the concentration of vapor phase organics in each sample.
12.5 Vapor Pressure of Organics in the Headspace Sample. Use the following equation to calculate the vapor pressure of organics in the sample.
1. Salo, Albert E., Samuel Witz, and Robert D. MacPhee. “Determination of Solvent Vapor Concentrations by Total Combustion Analysis: a Comparison of Infared with Flame Ionization Detectors. Paper No. 75-33.2. (Presented at the 68th Annual Meeting of the Air Pollution Control Association. Boston, Massachusetts.
2. Salo, Albert E., William L. Oaks, and Robert D. MacPhee. “Measuring the Organic Carbon Content of Source Emissions for Air Pollution Control. Paper No. 74-190. (Presented at the 67th Annual Meeting of the Air Pollution Control Association. Denver, Colorado. June 9-13, 1974.) p. 25.
Appendix A-8 to Part 60 – Test Methods 26 through 30B
The test methods in this appendix are referred to in § 60.8 (Performance Tests) and § 60.11 (Compliance With Standards and Maintenance Requirements) of 40 CFR part 60, subpart A (General Provisions). Specific uses of these test methods are described in the standards of performance contained in the subparts, beginning with Subpart D.
Within each standard of performance, a section title “Test Methods and Procedures” is provided to: (1) Identify the test methods to be used as reference methods to the facility subject to the respective standard and (2) identify any special instructions or conditions to be followed when applying a method to the respective facility. Such instructions (for example, establish sampling rates, volumes, or temperatures) are to be used either in addition to, or as a substitute for procedures in a test method. Similarly, for sources subject to emission monitoring requirements, specific instructions pertaining to any use of a test method as a reference method are provided in the subpart or in Appendix B.
Inclusion of methods in this appendix is not intended as an endorsement or denial of their applicability to sources that are not subject to standards of performance. The methods are potentially applicable to other sources; however, applicability should be confirmed by careful and appropriate evaluation of the conditions prevalent at such sources.
The approach followed in the formulation of the test methods involves specifications for equipment, procedures, and performance. In concept, a performance specification approach would be preferable in all methods because this allows the greatest flexibility to the user. In practice, however, this approach is impractical in most cases because performance specifications cannot be established. Most of the methods described herein, therefore, involve specific equipment specifications and procedures, and only a few methods in this appendix rely on performance criteria.
Minor changes in the test methods should not necessarily affect the validity of the results and it is recognized that alternative and equivalent methods exist. section 60.8 provides authority for the Administrator to specify or approve (1) equivalent methods, (2) alternative methods, and (3) minor changes in the methodology of the test methods. It should be clearly understood that unless otherwise identified all such methods and changes must have prior approval of the Administrator. An owner employing such methods or deviations from the test methods without obtaining prior approval does so at the risk of subsequent disapproval and retesting with approved methods.
Within the test methods, certain specific equipment or procedures are recognized as being acceptable or potentially acceptable and are specifically identified in the methods. The items identified as acceptable options may be used without approval but must be identified in the test report. The potentially approvable options are cited as “subject to the approval of the Administrator” or as “or equivalent.” Such potentially approvable techniques or alternatives may be used at the discretion of the owner without prior approval. However, detailed descriptions for applying these potentially approvable techniques or alternatives are not provided in the test methods. Also, the potentially approvable options are not necessarily acceptable in all applications. Therefore, an owner electing to use such potentially approvable techniques or alternatives is responsible for: (1) assuring that the techniques or alternatives are in fact applicable and are properly executed; (2) including a written description of the alternative method in the test report (the written method must be clear and must be capable of being performed without additional instruction, and the degree of detail should be similar to the detail contained in the test methods); and (3) providing any rationale or supporting data necessary to show the validity of the alternative in the particular application. Failure to meet these requirements can result in the Administrator’s disapproval of the alternative.
1.1 Analytes.
| Analytes | CAS No. |
|---|---|
| Hydrogen Chloride (HCl) | 7647-01-0 |
| Hydrogen Bromide (HBr) | 10035-10-6 |
| Hydrogen Fluoride (HF) | 7664-39-3 |
| Chlorine (Cl | 7882-50-5 |
| Bromine (Br | 7726-95-6 |
1.2 Applicability. This method is applicable for determining emissions of hydrogen halides (HX) (HCl, HBr, and HF) and halogens (X
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 An integrated sample is extracted from the source and passed through a prepurged heated probe and filter into dilute sulfuric acid and dilute sodium hydroxide solutions which collect the gaseous hydrogen halides and halogens, respectively. The filter collects particulate matter including halide salts but is not routinely recovered and analyzed. The hydrogen halides are solubilized in the acidic solution and form chloride (Cl
4.1 Volatile materials, such as chlorine dioxide (ClO
4.2 The simultaneous presence of HBr and CL
4.3 High concentrations of nitrogen oxides (NO
4.4 A glass wool plug should not be used to remove particulate matter since a negative bias in the data could result.
4.5 There is anecdotal evidence that HF may be outgassed from new teflon components. If HF is a target analyte, then preconditioning of new teflon components, by heating should be considered.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and determine the applicability of regulatory limitations before performing this test method.
5.2 Corrosive Reagents. The following reagents are hazardous. Personal protective equipment and safe procedures are useful in preventing chemical splashes. If contact occurs, immediately flush with copious amounts of water for at least 15 minutes. Remove clothing under shower and decontaminate. Treat residual chemical burns as thermal burns.
5.2.1 Sodium Hydroxide (NaOH). Causes severe damage to eyes and skin. Inhalation causes irritation to nose, throat, and lungs. Reacts exothermically with limited amounts of water.
5.2.2 Sulfuric Acid (H
Mention of trade names or specific products does not constitute endorsement by the Environmental Protection Agency.
6.1 Sampling. The sampling train is shown in Figure 26-1, and component parts are discussed below.
6.1.1 Probe. Borosilicate glass, approximately 3/8-in. (9-mm) I.D. with a heating system capable of maintaining a probe gas temperature during sampling between 120 and 134 °C (248 and 273 °F) to prevent moisture condensation; or Teflon where stack probes are below 210 °C. If HF is a target analyte, then preconditioning of new teflon components by heating should be considered to prevent potential HF outgassing. A Teflon-glass filter in a mat configuration should be installed to remove particulate matter from the gas stream.
6.1.2 Three-way Stopcock. A borosilicate-glass three-way stopcock with a heating system to prevent moisture condensation. The heated stopcock should connect to the outlet of the heated filter and the inlet of the first impinger. The heating system should be capable of preventing condensation up to the inlet of the first impinger. Silicone grease may be used, if necessary, to prevent leakage.
6.1.3 Impingers. Four 30-ml midget impingers with leak-free glass connectors. Silicone grease may be used, if necessary, to prevent leakage. For sampling at high moisture sources or for sampling times greater than one hour, a midget impinger with a shortened stem (such that the gas sample does not bubble through the collected condensate) should be used in front of the first impinger.
6.1.4 Drying Tube or Impinger. Tube or impinger, of Mae West design, filled with 6- to 16-mesh indicating type silica gel, or equivalent, to dry the gas sample and to protect the dry gas meter and pump. If the silica gel has been used previously, dry at 175 °C (350 °F) for 2 hours. New silica gel may be used as received. Alternatively, other types of desiccants (equivalent or better) may be used.
6.1.5 Heating System. Any heating system capable of maintaining a temperature around the probe and filter holder between 120 and 134 °C (248 and 273 °F) during sampling, or such other temperature as specified by an applicable subpart of the standards or approved by the Administrator for a particular application.
6.1.6 Filter Holder and Support. The filter holder shall be made of Teflon or quartz. The filter support shall be made of Teflon. All Teflon filter holders and supports are available from Savillex Corp., 5325 Hwy 101, Minnetonka, MN 55345.
6.1.7 Sample Line. Leak-free, with compatible fittings to connect the last impinger to the needle valve.
6.1.8 Rate Meter. Rotameter, or equivalent, capable of measuring flow rate to within 2 percent of the selected flow rate of 2 liters/min (0.07 ft
6.1.9 Purge Pump, Purge Line, Drying Tube, Needle Valve, and Rate Meter. Pump capable of purging the sampling probe at 2 liters/min, with drying tube, filled with silica gel or equivalent, to protect pump, and a rate meter capable of measuring 0 to 5 liters/min (0.2 ft
6.1.10 Stopcock Grease, Valve, Pump, Volume Meter, Barometer, and Vacuum Gauge. Same as in Method 6, sections 6.1.1.4, 6.1.1.7, 6.1.1.8, 6.1.1.10, 6.1.2, and 6.1.3.
6.1.11 Temperature Measuring Devices. Temperature sensors to monitor the temperature of the probe and to monitor the temperature of the sampling system from the outlet of the probe to the inlet of the first impinger.
6.1.12 Ice Water Bath. To minimize loss of absorbing solution.
6.2 Sample Recovery.
6.2.1 Wash Bottles. Polyethylene or glass, 500-ml or larger, two.
6.2.2 Storage Containers. 100- or 250-ml, high-density polyethylene or glass sample storage containers with Teflon screw cap liners to store impinger samples.
6.3 Sample Preparation and Analysis. The materials required for volumetric dilution and chromatographic analysis of samples are described below.
6.3.1 Volumetric Flasks. Class A, 100-ml size.
6.3.2 Volumetric Pipets. Class A, assortment. To dilute samples to the calibration range of the ion chromatograph.
6.3.3 Ion Chromatograph (IC). Suppressed or non-suppressed, with a conductivity detector and electronic integrator operating in the peak area mode. Other detectors, strip chart recorders, and peak height measurements may be used.
Unless otherwise indicated, all reagents must conform to the specifications established by the Committee on Analytical Reagents of the American Chemical Society (ACS reagent grade). When such specifications are not available, the best available grade shall be used.
7.1 Sampling.
7.1.1 Filter. A 25-mm (1 in) (or other size) Teflon glass mat, Pallflex TX40HI75 (Pallflex Inc., 125 Kennedy Drive, Putnam, CT 06260). This filter is in a mat configuration to prevent fine particulate matter from entering the sampling train. Its composition is 75% Teflon/25% borosilicate glass. Other filters may be used, but they must be in a mat (as opposed to a laminate) configuration and contain at least 75% Teflon. For practical rather than scientific reasons, when the stack gas temperature exceeds 210 °C (410 °F) and the HCl concentration is greater than 20 ppm, a quartz-fiber filter may be used since Teflon becomes unstable above this temperature.
7.1.2 Water. Deionized, distilled water that conforms to American Society of Testing and Materials (ASTM) Specification D 1193-77 or 91, Type 3 (incorporated by reference – see § 60.17).
7.1.3 Acidic Absorbing Solution, 0.1 N Sulfuric Acid (H
7.1.4 Silica Gel. Indicating type, 6 to 16 mesh. If previously used, dry at 180 °C (350 °F) for 2 hours. New silica gel may be used as received. Alternatively, other types of desiccants may be used, subject to the approval of the Administrator.
7.1.5 Alkaline Adsorbing Solution, 0.1 N Sodium Hydroxide (NaOH). To prepare 100 ml of the scrubber solution for the third and fourth impinger, dissolve 0.40 g of solid NaOH in about 90 ml of water, and adjust the final solution volume to 100 ml using additional water. Shake well to mix the solution.
7.1.6 Sodium Thiosulfate (Na
7.2 Sample Preparation and Analysis.
7.2.1 Water. Same as in section 7.1.2.
7.2.2 Absorbing Solution Blanks. A separate blank solution of each absorbing reagent should be prepared for analysis with the field samples. Dilute 30 ml of each absorbing solution to approximately the same final volume as the field samples using the blank sample of rinse water.
7.2.3 Halide Salt Stock Standard Solutions. Prepare concentrated stock solutions from reagent grade sodium chloride (NaCl), sodium bromide (NaBr), and sodium fluoride (NaF). Each must be dried at 110 °C (230 °F) for two or more hours and then cooled to room temperature in a desiccator immediately before weighing. Accurately weigh 1.6 to 1.7 g of the dried NaCl to within 0.1 mg, dissolve in water, and dilute to 1 liter. Calculate the exact Cl
7.2.4 Chromatographic Eluent. Effective eluents for nonsuppressed IC using a resin-or silica-based weak ion exchange column are a 4 mM potassium hydrogen phthalate solution, adjusted to pH 4.0 using a saturated sodium borate solution, and a 4 mM 4-hydroxy benzoate solution, adjusted to pH 8.6 using 1 N NaOH. An effective eluent for suppressed ion chromatography is a solution containing 3 mM sodium bicarbonate and 2.4 mM sodium carbonate. Other dilute solutions buffered to a similar pH and containing no interfering ions may be used. When using suppressed ion chromatography, if the “water dip” resulting from sample injection interferes with the chloride peak, use a 2 mM NaOH/2.4 mM sodium bicarbonate eluent.
Because of the complexity of this method, testers and analyst should be trained and experienced with the procedure to ensure reliable results.
8.1 Sampling.
8.1.1 Preparation of Collection Train. Prepare the sampling train as follows: Pour 15 ml of the acidic absorbing solution into each one of the first pair of impingers, and 15 ml of the alkaline absorbing solution into each one of the second pair of impingers. Connect the impingers in series with the knockout impinger first, if used, followed by the two impingers containing the acidic absorbing solution and the two impingers containing the alkaline absorbing solution. Place a fresh charge of silica gel, or equivalent, in the drying tube or impinger at the end of the impinger train.
8.1.2 Adjust the probe temperature and the temperature of the filter and the stopcock (i.e., the heated area in Figure 26-1) to a temperature sufficient to prevent water condensation. This temperature must be maintained between 120 and 134 °C (248 and 273 °F). The temperature should be monitored throughout a sampling run to ensure that the desired temperature is maintained. It is important to maintain a temperature around the probe and filter in this range since it is extremely difficult to purge acid gases off these components. (These components are not quantitatively recovered and, hence, any collection of acid gases on these components would result in potential under reporting of these emissions. The applicable subparts may specify alternative higher temperatures.)
8.1.3 Leak-Check Procedure.
8.1.3.1 Sampling Train. A leak-check prior to the sampling run is optional; however, a leak-check after the sampling run is mandatory. The leak-check procedure is as follows: Temporarily attach a suitable [e.g., 0-40 cc/min (0-2.4 in
Carefully release the probe inlet plug before turning off the pump.
8.1.3.2 Pump. It is suggested (not mandatory) that the pump be leak-checked separately, either prior to or after the sampling run. If done prior to the sampling run, the pump leak-check shall precede the leak-check of the sampling train described immediately above; if done after the sampling run, the pump leak-check shall follow the train leak-check. To leak-check the pump, proceed as follows: Disconnect the drying tube from the probe-impinger assembly. Place a vacuum gauge at the inlet to either the drying tube or pump, pull a vacuum of 250 mm (10 in) Hg, plug or pinch off the outlet of the flow meter, and then turn off the pump. The vacuum should remain stable for at least 30 sec. Other leak-check procedures may be used, subject to the approval of the Administrator, U.S. Environmental Protection Agency.
8.1.4 Purge Procedure. Immediately before sampling, connect the purge line to the stopcock, and turn the stopcock to permit the purge pump to purge the probe (see Figure 1A of Figure 26-1). Turn on the purge pump, and adjust the purge rate to 2 liters/min (0.07 ft
8.1.5 Sample Collection. Turn on the sampling pump, pull a slight vacuum of approximately 25 mm Hg (1 in Hg) on the impinger train, and turn the stopcock to permit stack gas to be pulled through the impinger train (see Figure 1C of Figure 26-1). Adjust the sampling rate to 2 liters/min, as indicated by the rate meter, and maintain this rate to within 10 percent during the entire sampling run. Take readings of the dry gas meter volume and temperature, rate meter, and vacuum gauge at least once every five minutes during the run. A sampling time of one hour is recommended. Shorter sampling times may introduce a significant negative bias in the HCl concentration. At the conclusion of the sampling run, remove the train from the stack, cool, and perform a leak-check as described in section 8.1.3.1.
8.2 Sample Recovery.
8.2.1 Disconnect the impingers after sampling. Quantitatively transfer the contents of the acid impingers and the knockout impinger, if used, to a leak-free storage bottle. Add the water rinses of each of these impingers and connecting glassware to the storage bottle.
8.2.2 Repeat this procedure for the alkaline impingers and connecting glassware using a separate storage bottle. Add 25 mg of sodium thiosulfate per the product of ppm of halogen anticipated to be in the stack gas times the volume (dscm) of stack gas sampled (0.7 mg per ppm-dscf).
This amount of sodium thiosulfate includes a safety factor of approximately 5 to assure complete reaction with the hypohalous acid to form a second Cl
8.2.3 Save portions of the absorbing reagents (0.1 N H
8.3 Sample Preparation for Analysis. Note the liquid levels in the storage bottles and confirm on the analysis sheet whether or not leakage occurred during transport. If a noticeable leakage has occurred, either void the sample or use methods, subject to the approval of the Administrator, to correct the final results. Quantitatively transfer the sample solutions to 100-ml volumetric flasks, and dilute to 100 ml with water.
Maintain a laboratory log of all calibrations.
10.1 Volume Metering System, Temperature Sensors, Rate Meter, and Barometer. Same as in Method 6, sections 10.1, 10.2, 10.3, and 10.4.
10.2 Ion Chromatograph.
10.2.1 To prepare the calibration standards, dilute given amounts (1.0 ml or greater) of the stock standard solutions to convenient volumes, using 0.1 N H
10.2.2 Using one of the standards in each series, ensure adequate baseline separation for the peaks of interest.
10.2.3 Inject the appropriate series of calibration standards, starting with the lowest concentration standard first both before and after injection of the quality control check sample, reagent blanks, and field samples. This allows compensation for any instrument drift occurring during sample analysis. The values from duplicate injections of these calibration samples should agree within 5 percent of their mean for the analysis to be valid.
10.2.4 Determine the peak areas, or heights, for the standards and plot individual values versus halide ion concentrations in µg/ml.
10.2.5 Draw a smooth curve through the points. Use linear regression to calculate a formula describing the resulting linear curve.
11.1 Sample Analysis.
11.1.1 The IC conditions will depend upon analytical column type and whether suppressed or non-suppressed IC is used. An example chromatogram from a non-suppressed system using a 150-mm Hamilton PRP-X100 anion column, a 2 ml/min flow rate of a 4 mM 4-hydroxy benzoate solution adjusted to a pH of 8.6 using 1 N NaOH, a 50 µl sample loop, and a conductivity detector set on 1.0 µS full scale is shown in Figure 26-2.
11.1.2 Before sample analysis, establish a stable baseline. Next, inject a sample of water, and determine if any Cl
11.1.3 Between injections of the appropriate series of calibration standards, inject in duplicate the reagent blanks, quality control sample, and the field samples. Measure the areas or heights of the Cl
Retain at least one extra decimal figure beyond those contained in the available data in intermediate calculations, and round off only the final answer appropriately.
12.1 Nomenclature.
12.2 Calculate the exact Cl
12.3 Sample Volume, Dry Basis, Corrected to Standard Conditions. Calculate the sample volume using Eq. 6-1 of Method 6.
12.4 Total µg HCl, HBr, or HF Per Sample.
12.5 Total µg Cl
12.6 Concentration of Hydrogen Halide or Halogen in Flue Gas.
13.1 Precision and Bias. The within-laboratory relative standard deviations are 6.2 and 3.2 percent at HCl concentrations of 3.9 and 15.3 ppm, respectively. The method does not exhibit a bias to Cl
13.2 Sample Stability. The collected Cl
13.3 Detection Limit. A typical IC instrumental detection limit for Cl
Method 26A. Method 26A, which uses isokinetic sampling equipment, is an acceptable alternative to Method 26.
1. Steinsberger, S. C. and J. H. Margeson, “Laboratory and Field Evaluation of a Methodology for Determination of Hydrogen Chloride Emissions from Municipal and Hazardous Waste Incinerators,” U.S. Environmental Protection Agency, Office of Research and Development, Report No. 600/3-89/064, April 1989. Available from the National Technical Information Service, Springfield, VA 22161 as PB89220586/AS.
2. State of California, Air Resources Board, Method 421, “Determination of Hydrochloric Acid Emissions from Stationary Sources,” March 18, 1987.
3. Cheney, J.L. and C.R. Fortune. Improvements in the Methodology for Measuring Hydrochloric Acid in Combustion Source Emissions. J. Environ. Sci. Health. A19(3): 337-350. 1984.
4. Stern, D. A., B. M. Myatt, J. F. Lachowski, and K. T. McGregor. Speciation of Halogen and Hydrogen Halide Compounds in Gaseous Emissions. In: Incineration and Treatment of Hazardous Waste: Proceedings of the 9th Annual Research Symposium, Cincinnati, Ohio, May 2-4, 1983. Publication No. 600/9-84-015. July 1984. Available from National Technical Information Service, Springfield, VA 22161 as PB84-234525.
5. Holm, R. D. and S. A. Barksdale. Analysis of Anions in Combustion Products. In: Ion Chromatographic Analysis of Environmental Pollutants. E. Sawicki, J. D. Mulik, and E. Wittgenstein (eds.). Ann Arbor, Michigan, Ann Arbor Science Publishers. 1978. pp. 99-110.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 2, Method 5, and Method 26.
1.1 Analytes.
| Analytes | CAS No. |
|---|---|
| Hydrogen Chloride (HCl) | 7647-01-0 |
| Hydrogen Bromide (HBr) | 10035-10-6 |
| Hydrogen Fluoride (HF) | 7664-39-3 |
| Chlorine (Cl | 7882-50-5 |
| Bromine (Br | 7726-95-6 |
1.2 This method is applicable for determining emissions of hydrogen halides (HX) [HCl, HBr, and HF] and halogens (X
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 Principle. Gaseous and particulate pollutants are withdrawn isokinetically from the source and collected in an optional cyclone, on a filter, and in absorbing solutions. The cyclone collects any liquid droplets and is not necessary if the source emissions do not contain them; however, it is preferable to include the cyclone in the sampling train to protect the filter from any liquid present. The filter collects particulate matter including halide salts but is not routinely recovered or analyzed. Acidic and alkaline absorbing solutions collect the gaseous hydrogen halides and halogens, respectively. Following sampling of emissions containing liquid droplets, any halides/halogens dissolved in the liquid in the cyclone and on the filter are vaporized to gas and collected in the impingers by pulling conditioned ambient air through the sampling train. The hydrogen halides are solubilized in the acidic solution and form chloride (Cl
If the tester intends to use this sampling arrangement to sample concurrently for particulate matter, the alternative Teflon probe liner, cyclone, and filter holder should not be used. The Teflon filter support must be used. The tester must also meet the probe and filter temperature requirements of both sampling trains.
4.1 Volatile materials, such as chlorine dioxide (ClO
4.2 The simultaneous presence of both HBr and Cl
4.3 High concentrations of nitrogen oxides (NO
4.4 There is anecdotal evidence that HF may be outgassed from new Teflon components. If HF is a target analyte then preconditioning of new Teflon components, by heating, should be considered.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and determine the applicability of regulatory limitations before performing this test method.
5.2 Corrosive Reagents. The following reagents are hazardous. Personal protective equipment and safe procedures are useful in preventing chemical splashes. If contact occurs, immediately flush with copious amounts of water for at least 15 minutes. Remove clothing under shower and decontaminate. Treat residual chemical burns as thermal burns.
5.2.1 Sodium Hydroxide (NaOH). Causes severe damage to eyes and skin. Inhalation causes irritation to nose, throat, and lungs. Reacts exothermically with limited amounts of water.
5.2.2 Sulfuric Acid (H
Mention of trade names or specific products does not constitute endorsement by the Environmental Protection Agency.
6.1 Sampling. The sampling train is shown in Figure 26A-1; the apparatus is similar to the Method 5 train where noted as follows:
6.1.1 Probe Nozzle. Borosilicate or quartz glass; constructed and calibrated according to Method 5, sections 6.1.1.1 and 10.1, and coupled to the probe liner using a Teflon union; a stainless steel nut is recommended for this union. When the stack temperature exceeds 210 °C (410 °F), a one-piece glass nozzle/liner assembly must be used.
6.1.2 Probe Liner. Same as Method 5, section 6.1.1.2, except metal liners shall not be used. Water-cooling of the stainless steel sheath is recommended at temperatures exceeding 500 °C (932 °F). Teflon may be used in limited applications where the minimum stack temperature exceeds 120 °C (250 °F) but never exceeds the temperature where Teflon is estimated to become unstable [approximately 210 °C (410 °F)].
6.1.3 Pitot Tube, Differential Pressure Gauge, Filter Heating System, Filter Temperature Sensor with a glass or Teflon encasement, Metering System, Barometer, Gas Density Determination Equipment. Same as Method 5, sections 6.1.1.3, 6.1.1.4, 6.1.1.6, 6.1.1.7, 6.1.1.9, 6.1.2, and 6.1.3.
6.1.4 Cyclone (Optional). Glass or Teflon. Use of the cyclone is required only when the sample gas stream is saturated with moisture; however, the cyclone is recommended to protect the filter from any liquid droplets present.
6.1.5 Filter Holder. Borosilicate or quartz glass, or Teflon filter holder, with a Teflon filter support and a sealing gasket. The sealing gasket shall be constructed of Teflon or equivalent materials. The holder design shall provide a positive seal against leakage at any point along the filter circumference. The holder shall be attached immediately to the outlet of the cyclone.
6.1.6 Impinger Train. The following system shall be used to determine the stack gas moisture content and to collect the hydrogen halides and halogens: five or six impingers connected in series with leak-free ground glass fittings or any similar leak-free noncontaminating fittings. The first impinger shown in Figure 26A-1 (knockout or condensate impinger) is optional and is recommended as a water knockout trap for use under high moisture conditions. If used, this impinger should be constructed as described below for the alkaline impingers, but with a shortened stem, and should contain 50 ml of 0.1 N H
6.1.7 Heating System. Any heating system capable of maintaining a temperature around the probe and filter holder between 120 and 134 °C (248 to 273 °F) during sampling, or such other temperature as specified by an applicable subpart of the standards or approved by the Administrator for a particular application.
6.1.8 Ambient Air Conditioning Tube (Optional). Tube tightly packed with approximately 150 g of fresh 8 to 20 mesh sodium hydroxide-coated silica, or equivalent, (Ascarite II has been found suitable) to dry and remove acid gases from the ambient air used to remove moisture from the filter and cyclone, when the cyclone is used. The inlet and outlet ends of the tube should be packed with at least 1-cm thickness of glass wool or filter material suitable to prevent escape of fines. Fit one end with flexible tubing, etc. to allow connection to probe nozzle following the test run.
6.2 Sample Recovery.
6.2.1 Probe-Liner and Probe-Nozzle Brushes, Wash Bottles, Petri Dishes, Graduated Cylinder and/or Balance, and Rubber Policeman. Same as Method 5, sections 6.2.1, 6.2.2, 6.2.4, 6.2.5, and 6.2.7.
6.2.2 Plastic Storage Containers. Screw-cap polypropylene or polyethylene containers to store silica gel. High-density polyethylene bottles with Teflon screw cap liners to store impinger reagents, 1-liter.
6.2.3 Funnels. Glass or high-density polyethylene, to aid in sample recovery.
6.2.4 Sample Storage Containers. High-density polyethylene or glass sample storage containers with Teflon screw cap liners to store impinger samples.
6.3 Sample Preparation and Analysis.
6.3.1 Volumetric Flasks. Class A, various sizes.
6.3.2 Volumetric Pipettes. Class A, assortment. To dilute samples to calibration range of the ion chromatograph (IC).
6.3.3 Ion Chromatograph (IC). Suppressed or nonsuppressed, with a conductivity detector and electronic integrator operating in the peak area mode. Other detectors, a strip chart recorder, and peak heights may be used.
Unless otherwise indicated, all reagents must conform to the specifications established by the Committee on Analytical Reagents of the American Chemical Society (ACS reagent grade). When such specifications are not available, the best available grade shall be used.
7.1 Sampling.
7.1.1 Filter. Teflon mat (e.g., Pallflex TX40HI45) filter. When the stack gas temperature exceeds 210 °C (410 °F) a quartz fiber filter may be used.
7.1.2 Water. Deionized, distilled water that conforms to American Society of Testing and Materials (ASTM) Specification D 1193-77 or 91, Type 3 (incorporated by reference – see § 60.17).
7.1.3 Acidic Absorbing Solution, 0.1 N Sulfuric Acid (H
7.1.4 Silica Gel, Crushed Ice, and Stopcock Grease. Same as Method 5, sections 7.1.2, 7.1.4, and 7.1.5, respectively.
7.1.5 Alkaline Absorbing Solution, 0.1 N Sodium Hydroxide (NaOH). To prepare 1 L, dissolve 4.00 g of solid NaOH in about 900 ml of water and adjust the final volume to 1 L using additional water. Shake well to mix the solution.
7.1.6 Sodium Thiosulfate, (Na
7.2 Sample Preparation and Analysis.
7.2.1 Water. Same as in section 7.1.2.
7.2.2 Absorbing Solution Blanks. A separate blank solution of each absorbing reagent should be prepared for analysis with the field samples. Dilute 200 ml of each absorbing solution (250 ml of the acidic absorbing solution, if a condensate impinger is used) to the same final volume as the field samples using the blank sample of rinse water. If a particulate determination is conducted, collect a blank sample of acetone.
7.2.3 Halide Salt Stock Standard Solutions. Prepare concentrated stock solutions from reagent grade sodium chloride (NaCl), sodium bromide (NaBr), and sodium fluoride (NaF). Each must be dried at 110 °C (230 °F) for two or more hours and then cooled to room temperature in a desiccator immediately before weighing. Accurately weigh 1.6 to 1.7 g of the dried NaCl to within 0.1 mg, dissolve in water, and dilute to 1 liter. Calculate the exact Cl
7.2.4 Chromatographic Eluent. Same as Method 26, section 7.2.4.
7.2.5 Water. Same as section 7.1.1.
7.2.6 Acetone. Same as Method 5, section 7.2.
Because of the complexity of this method, testers and analysts should be trained and experienced with the procedures to ensure reliable results.
8.1 Sampling.
8.1.1 Pretest Preparation. Follow the general procedure given in Method 5, section 8.1, except the filter need only be desiccated and weighed if a particulate determination will be conducted.
8.1.2 Preliminary Determinations. Same as Method 5, section 8.2.
8.1.3 Preparation of Sampling Train. Follow the general procedure given in Method 5, section 8.1.3, except for the following variations: Add 50 ml of 0.1 N H
8.1.4 Leak-Check Procedures. Follow the leak-check procedures given in Method 5, sections 8.4.2 (Pretest Leak-Check), 8.4.3 (Leak-Checks During the Sample Run), and 8.4.4 (Post-Test Leak-Check).
8.1.5 Sampling Train Operation. Follow the general procedure given in Method 5, Section 8.5. It is important to maintain a temperature around the probe, filter (and cyclone, if used) between 120 and 134 °C (248 and 273 °F) since it is extremely difficult to purge acid gases off these components. (These components are not quantitatively recovered and hence any collection of acid gases on these components would result in potential under reporting these emissions. The applicable subparts may specify alternative higher temperatures.) For each run, record the data required on a data sheet such as the one shown in Method 5, Figure 5-3. If the condensate impinger becomes too full, it may be emptied, recharged with 50 ml of 0.1 N H2SO4, and replaced during the sample run. The condensate emptied must be saved and included in the measurement of the volume of moisture collected and included in the sample for analysis. The additional 50 ml of absorbing reagent must also be considered in calculating the moisture. Before the sampling train integrity is compromised by removing the impinger, conduct a leak-check as described in Method 5, section 8.4.2.
8.1.6 Post-Test Moisture Removal (Optional). When the optional cyclone is included in the sampling train or when liquid is visible on the filter at the end of a sample run even in the absence of a cyclone, perform the following procedure. Upon completion of the test run, connect the ambient air conditioning tube at the probe inlet and operate the train with the filter heating system between 120 and 134 °C (248 and 273 °F) at a low flow rate (e.g., ΔH = 1 in. H
It is critical that this procedure is repeated until the cyclone is completely dry.
8.2 Sample Recovery. Allow the probe to cool. When the probe can be handled safely, wipe off all the external surfaces of the tip of the probe nozzle and place a cap loosely over the tip to prevent gaining or losing particulate matter. Do not cap the probe tip tightly while the sampling train is cooling down because this will create a vacuum in the filter holder, drawing water from the impingers into the holder. Before moving the sampling train to the cleanup site, remove the probe from the sample train, wipe off any silicone grease, and cap the open outlet of the impinger train, being careful not to lose any condensate that might be present. Wipe off any silicone grease and cap the filter or cyclone inlet. Remove the umbilical cord from the last impinger and cap the impinger. If a flexible line is used between the first impinger and the filter holder, disconnect it at the filter holder and let any condensed water drain into the first impinger. Wipe off any silicone grease and cap the filter holder outlet and the impinger inlet. Ground glass stoppers, plastic caps, serum caps, Teflon tape, Parafilm, or aluminum foil may be used to close these openings. Transfer the probe and filter/impinger assembly to the cleanup area. This area should be clean and protected from the weather to minimize sample contamination or loss. Inspect the train prior to and during disassembly and note any abnormal conditions. Treat samples as follows:
8.2.1 Container No. 1 (Optional; Filter Catch for Particulate Determination). Same as Method 5, section 8.7.6.1, Container No. 1.
8.2.2 Container No. 2 (Optional; Front-Half Rinse for Particulate Determination). Same as Method 5, section 8.7.6.2, Container No. 2.
8.2.3 Container No. 3 (Knockout and Acid Impinger Catch for Moisture and Hydrogen Halide Determination). Disconnect the impingers. Measure the liquid in the acid and knockout impingers to ±1 ml by using a graduated cylinder or by weighing it to ±0.5 g by using a balance. Record the volume or weight of liquid present. This information is required to calculate the moisture content of the effluent gas. Quantitatively transfer this liquid to a leak-free sample storage container. Rinse these impingers and connecting glassware including the back portion of the filter holder (and flexible tubing, if used) with water and add these rinses to the storage container. Seal the container, shake to mix, and label. The fluid level should be marked so that if any sample is lost during transport, a correction proportional to the lost volume can be applied. Retain rinse water and acidic absorbing solution blanks to be analyzed with the samples.
8.2.4 Container No. 4 (Alkaline Impinger Catch for Halogen and Moisture Determination). Measure and record the liquid in the alkaline impingers as described in section 8.2.3. Quantitatively transfer this liquid to a leak-free sample storage container. Rinse these two impingers and connecting glassware with water and add these rinses to the container. Add 25 mg of sodium thiosulfate per ppm halogen anticipated to be in the stack gas multiplied by the volume (dscm) of stack gas sampled (0.7 mg/ppm-dscf). Seal the container, shake to mix, and label; mark the fluid level. Retain alkaline absorbing solution blank to be analyzed with the samples.
25 mg per sodium thiosulfate per ppm halogen anticipated to be in the stack includes a safety factor of approximately 5 to assure complete reaction with the hypohalous acid to form a second Cl
8.2.5 Container No. 5 (Silica Gel for Moisture Determination). Same as Method 5, section 8.7.6.3, Container No. 3.
8.2.6 Container Nos. 6 through 9 (Reagent Blanks). Save portions of the absorbing reagents (0.1 N H
8.2.7 Prior to shipment, recheck all sample containers to ensure that the caps are well-secured. Seal the lids of all containers around the circumference with Teflon tape. Ship all liquid samples upright and all particulate filters with the particulate catch facing upward.
9.1 Miscellaneous Quality Control Measures.
| Section | Quality control measure | Effect |
|---|---|---|
| 8.1.4, 10.1 | Sampling equipment leak-check and calibration | Ensure accurate measurement of stack gas flow rate, sample volume. |
9.2 Volume Metering System Checks. Same as Method 5, section 9.2.
Maintain a laboratory log of all calibrations.
10.1 Probe Nozzle, Pitot Tube Assembly, Dry Gas Metering System, Probe Heater, Temperature Sensors, Leak-Check of Metering System, and Barometer. Same as Method 5, sections 10.1, 10.2, 10.3, 10.4, 10.5, 8.4.1, and 10.6, respectively.
10.2 Ion Chromatograph.
10.2.1 To prepare the calibration standards, dilute given amounts (1.0 ml or greater) of the stock standard solutions to convenient volumes, using 0.1 N H
10.2.2 Using one of the standards in each series, ensure adequate baseline separation for the peaks of interest.
10.2.3 Inject the appropriate series of calibration standards, starting with the lowest concentration standard first both before and after injection of the quality control check sample, reagent blanks, and field samples. This allows compensation for any instrument drift occurring during sample analysis. The values from duplicate injections of these calibration samples should agree within 5 percent of their mean for the analysis to be valid.
10.2.4 Determine the peak areas, or height, of the standards and plot individual values versus halide ion concentrations in µg/ml.
10.2.5 Draw a smooth curve through the points. Use linear regression to calculate a formula describing the resulting linear curve.
The liquid levels in the sample containers and confirm on the analysis sheet whether or not leakage occurred during transport. If a noticeable leakage has occurred, either void the sample or use methods, subject to the approval of the Administrator, to correct the final results.
11.1 Sample Analysis.
11.1.1 The IC conditions will depend upon analytical column type and whether suppressed or non-suppressed IC is used. An example chromatogram from a non-suppressed system using a 150-mm Hamilton PRP-X100 anion column, a 2 ml/min flow rate of a 4 mM 4-hydroxy benzoate solution adjusted to a pH of 8.6 using 1 N NaOH, a 50 µl sample loop, and a conductivity detector set on 1.0 µS full scale is shown in Figure 26-2.
11.1.2 Before sample analysis, establish a stable baseline. Next, inject a sample of water, and determine if any Cl
11.1.3 Between injections of the appropriate series of calibration standards, inject in duplicate the reagent blanks, quality control sample, and the field samples. Measure the areas or heights of the Cl
11.2 Container Nos. 1 and 2 and Acetone Blank (Optional; Particulate Determination). Same as Method 5, sections 11.2.1 and 11.2.2, respectively.
11.3 Container No. 5. Same as Method 5, section 11.2.3 for silica gel.
Retain at least one extra decimal figure beyond those contained in the available data in intermediate calculations, and round off only the final answer appropriately.
12.1 Nomenclature. Same as Method 5, section 12.1. In addition:
12.2 Calculate the exact Cl
12.3 Average Dry Gas Meter Temperature and Average Orifice Pressure Drop. See data sheet (Figure 5-3 of Method 5).
12.4 Dry Gas Volume. Calculate V
12.5 Volume of Water Vapor and Moisture Content. Calculate the volume of water vapor V
12.6 Isokinetic Variation and Acceptable Results. Use Method 5, section 12.11.
12.7 Acetone Blank Concentration, Acetone Wash Blank Residue Weight, Particulate Weight, and Particulate Concentration. For particulate determination.
12.8 Total µg HCl, HBr, or HF Per Sample.
12.9 Total µg Cl
12.10 Concentration of Hydrogen Halide or Halogen in Flue Gas.
12.11 Stack Gas Velocity and Volumetric Flow Rate. Calculate the average stack gas velocity and volumetric flow rate, if needed, using data obtained in this method and the equations in sections 12.3 and 12.4 of Method 2.
13.1 Precision and Bias. The method has a possible measurable negative bias below 20 ppm HCl perhaps due to reaction with small amounts of moisture in the probe and filter. Similar bias for the other hydrogen halides is possible.
13.2 Sample Stability. The collected Cl-samples can be stored for up to 4 weeks for analysis for HCl and Cl2.
13.3 Detection Limit. A typical analytical detection limit for HCl is 0.2 µg/ml. Detection limits for the other analyses should be similar. Assuming 300 ml of liquid recovered for the acidified impingers and a similar amounts recovered from the basic impingers, and 1 dscm of stack gas sampled, the analytical detection limits in the stack gas would be about 0.04 ppm for HCl and Cl2, respectively.
1. Steinsberger, S. C. and J. H. Margeson. Laboratory and Field Evaluation of a Methodology for Determination of Hydrogen Chloride Emissions from Municipal and Hazardous Waste Incinerators. U.S. Environmental Protection Agency, Office of Research and Development. Publication No. 600/3-89/064. April 1989. Available from National Technical Information Service, Springfield, VA 22161 as PB89220586/AS.
2. State of California Air Resources Board. Method 421 – Determination of Hydrochloric Acid Emissions from Stationary Sources. March 18, 1987.
3. Cheney, J.L. and C.R. Fortune. Improvements in the Methodology for Measuring Hydrochloric Acid in Combustion Source Emissions. J. Environ. Sci. Health. A19(3): 337-350. 1984.
4. Stern, D.A., B.M. Myatt, J.F. Lachowski, and K.T. McGregor. Speciation of Halogen and Hydrogen Halide Compounds in Gaseous Emissions. In: Incineration and Treatment of Hazardous Waste: Proceedings of the 9th Annual Research Symposium, Cincinnati, Ohio, May 2-4, 1983. Publication No. 600/9-84-015. July 1984. Available from National Technical Information Service, Springfield, VA 22161 as PB84-234525.
5. Holm, R.D. and S.A. Barksdale. Analysis of Anions in Combustion Products. In: Ion Chromatographic Analysis of Environmental Pollutants, E. Sawicki, J.D. Mulik, and E. Wittgenstein (eds.). Ann Arbor, Michigan, Ann Arbor Science Publishers. 1978. pp. 99-110.
1.1 Applicability. This method is applicable for the determination of vapor tightness of a gasoline delivery collection equipment.
2.1 Pressure and vacuum are applied alternately to the compartments of a gasoline delivery tank and the change in pressure or vacuum is recorded after a specified period of time.
3.1 Allowable pressure change (Δp) means the allowable amount of decrease in pressure during the static pressure test, within the time period t, as specified in the appropriate regulation, in mm H
3.2 Allowable vacuum change (Δv) means the allowable amount of decrease in vacuum during the static vacuum test, within the time period t, as specified in the appropriate regulation, in mm H
3.3 Compartment means a liquid-tight division of a delivery tank.
3.4 Delivery tank means a container, including associated pipes and fittings, that is attached to or forms a part of any truck, trailer, or railcar used for the transport of gasoline.
3.5 Delivery tank vapor collection equipment means any piping, hoses, and devices on the delivery tank used to collect and route gasoline vapors either from the tank to a bulk terminal vapor control system or from a bulk plant or service station into the tank.
3.6 Gasoline means a petroleum distillate or petroleum distillate/alcohol blend having a Reid vapor pressure of 27.6 kilopascals or greater which is used as a fuel for internal combustion engines.
3.7 Initial pressure (P
3.8 Initial vacuum (V
3.9 Time period of the pressure or vacuum test (t) means the time period of the test, as specified in the appropriate regulation, during which the change in pressure or vacuum is monitored, in minutes.
5.1 Gasoline contains several volatile organic compounds (e.g., benzene and hexane) which presents a potential for fire and/or explosions. It is advisable to take appropriate precautions when testing a gasoline vessel’s vapor tightness, such as refraining from smoking and using explosion-proof equipment.
5.2 This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method
The following equipment and supplies are required for testing:
6.1 Pressure Source. Pump or compressed gas cylinder of air or inert gas sufficient to pressurize the delivery tank to 500 mm (20 in.) H
6.2 Regulator. Low pressure regulator for controlling pressurization of the delivery tank.
6.3 Vacuum Source. Vacuum pump capable of evacuating the delivery tank to 250 mm (10 in.) H
6.4 Pressure-Vacuum Supply Hose.
6.5 Manometer. Liquid manometer, or equivalent instrument, capable of measuring up to 500 mm (20 in.) H
6.6 Pressure-Vacuum Relief Valves. The test apparatus shall be equipped with an inline pressure-vacuum relief valve set to activate at 675 mm (26.6 in.) H
6.7 Test Cap for Vapor Recovery Hose. This cap shall have a tap for manometer connection and a fitting with shut-off valve for connection to the pressure-vacuum supply hose.
6.8 Caps for Liquid Delivery Hoses.
8.1 Pretest Preparations.
8.1.1 Summary. Testing problems may occur due to the presence of volatile vapors and/or temperature fluctuations inside the delivery tank. Under these conditions, it is often difficult to obtain a stable initial pressure at the beginning of a test, and erroneous test results may occur. To help prevent this, it is recommended that prior to testing, volatile vapors be removed from the tank and the temperature inside the tank be allowed to stabilize. Because it is not always possible to completely attain these pretest conditions, a provision to ensure reproducible results is included. The difference in results for two consecutive runs must meet the criteria in sections 8.2.2.5 and 8.2.3.5.
8.1.2 Emptying of Tank. The delivery tank shall be emptied of all liquid.
8.1.3 Purging of Vapor. As much as possible the delivery tank shall be purged of all volatile vapors by any safe, acceptable method. One method is to carry a load of non-volatile liquid fuel, such as diesel or heating oil, immediately prior to the test, thus flushing out all the volatile gasoline vapors. A second method is to remove the volatile vapors by blowing ambient air into each tank compartment for at least 20 minutes. This second method is usually not as effective and often causes stabilization problems, requiring a much longer time for stabilization during the testing.
8.1.4 Temperature Stabilization. As much as possible, the test shall be conducted under isothermal conditions. The temperature of the delivery tank should be allowed to equilibrate in the test environment. During the test, the tank should be protected from extreme environmental and temperature variability, such as direct sunlight.
8.2 Test Procedure.
8.2.1 Preparations.
8.2.1.1 Open and close each dome cover.
8.2.1.2 Connect static electrical ground connections to the tank. Attach the liquid delivery and vapor return hoses, remove the liquid delivery elbows, and plug the liquid delivery fittings.
The purpose of testing the liquid delivery hoses is to detect tears or holes that would allow liquid leakage during a delivery. Liquid delivery hoses are not considered to be possible sources of vapor leakage, and thus, do not have to be attached for a vapor leakage test. Instead, a liquid delivery hose could be either visually inspected, or filled with water to detect any liquid leakage.
8.2.1.3 Attach the test cap to the end of the vapor recovery hose.
8.2.1.4 Connect the pressure-vacuum supply hose and the pressure-vacuum relief valve to the shut-off valve. Attach a manometer to the pressure tap.
8.2.1.5 Connect compartments of the tank internally to each other if possible. If not possible, each compartment must be tested separately, as if it were an individual delivery tank.
8.2.2 Pressure Test.
8.2.2.1 Connect the pressure source to the pressure-vacuum supply hose.
8.2.2.2 Open the shut-off valve in the vapor recovery hose cap. Apply air pressure slowly, pressurize the tank to P
8.2.2.3 Close the shut-off and allow the pressure in the tank to stabilize, adjusting the pressure if necessary to maintain pressure of P
8.2.2.4 At the end of the time period (t) specified in the regulation, record the time and final pressure.
8.2.2.5 Repeat steps 8.2.2.2 through 8.2.2.4 until the change in pressure for two consecutive runs agrees within 12.5 mm (0.5 in.) H
8.2.2.6 Compare the average measured change in pressure to the allowable pressure change, Δp, specified in the regulation. If the delivery tank does not satisfy the vapor tightness criterion specified in the regulation, repair the sources of leakage, and repeat the pressure test until the criterion is met.
8.2.2.7 Disconnect the pressure source from the pressure-vacuum supply hose, and slowly open the shut-off valve to bring the tank to atmospheric pressure.
8.2.3 Vacuum Test.
8.2.3.1 Connect the vacuum source to the pressure-vacuum supply hose.
8.2.3.2 Open the shut-off valve in the vapor recovery hose cap. Slowly evacuate the tank to V
8.2.3.3 Close the shut-off valve and allow the pressure in the tank to stabilize, adjusting the pressure if necessary to maintain a vacuum of V
8.2.3.4 At the end of the time period specified in the regulation (t), record the time and final vacuum.
8.2.3.5 Repeat steps 8.2.3.2 through 8.2.3.4 until the change in vacuum for two consecutive runs agrees within 12.5 mm (0.5 in.) H
8.2.3.6 Compare the average measured change in vacuum to the allowable vacuum change, Δv, as specified in the regulation. If the delivery tank does not satisfy the vapor tightness criterion specified in the regulation, repair the sources of leakage, and repeat the vacuum test until the criterion is met.
8.2.3.7 Disconnect the vacuum source from the pressure-vacuum supply hose, and slowly open the shut-off valve to bring the tank to atmospheric pressure.
8.2.4 Post-Test Clean-up. Disconnect all test equipment and return the delivery tank to its pretest condition.
| Section(s) | Quality control measure | Effect |
|---|---|---|
| 8.2.2.5, 8.3.3.5 | Repeat test procedures until change in pressure or vacuum for two consecutive runs agrees within ±12.5 mm (0.5 in.) H | Ensures data precision. |
13.1 Precision. The vapor tightness of a gasoline delivery tank under positive or negative pressure, as measured by this method, is precise within 12.5 mm (0.5 in.) H
13.2 Bias. No bias has been identified.
16.1 The pumping of water into the bottom of a delivery tank is an acceptable alternative to the pressure source described above. Likewise, the draining of water out of the bottom of a delivery tank may be substituted for the vacuum source. Note that some of the specific step-by-step procedures in the method must be altered slightly to accommodate these different pressure and vacuum sources.
16.2 Techniques other than specified above may be used for purging and pressurizing a delivery tank, if prior approval is obtained from the Administrator. Such approval will be based upon demonstrated equivalency with the above method.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 2, Method 3, Method 4, Method 5, Method 5G, Method 5H, Method 6, Method 6C, and Method 16A.
1.1 Analyte. Particulate matter (PM). No CAS number assigned.
1.2 Applicability. This method is applicable for the certification and auditing of wood heaters, including pellet burning wood heaters.
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 Particulate matter emissions are measured from a wood heater burning a prepared test fuel crib in a test facility maintained at a set of prescribed conditions. Procedures for determining burn rates and particulate emission rates and for reducing data are provided.
3.1 2 × 4 or 4 × 4 means two inches by four inches or four inches by four inches (50 mm by 100 mm or 100 mm by 100 mm), as nominal dimensions for lumber.
3.2 Burn rate means the rate at which test fuel is consumed in a wood heater. Measured in kilograms or lbs of wood (dry basis) per hour (kg/hr or lb/hr).
3.3 Certification or audit test means a series of at least four test runs conducted for certification or audit purposes that meets the burn rate specifications in section 8.4.
3.4 Firebox means the chamber in the wood heater in which the test fuel charge is placed and combusted.
3.5 Height means the vertical distance extending above the loading door, if fuel could reasonably occupy that space, but not more than 2 inches above the top (peak height) of the loading door, to the floor of the firebox (i.e., below a permanent grate) if the grate allows a 1-inch diameter piece of wood to pass through the grate, or, if not, to the top of the grate. Firebox height is not necessarily uniform but must account for variations caused by internal baffles, air channels, or other permanent obstructions.
3.6 Length means the longest horizontal fire chamber dimension that is parallel to a wall of the chamber.
3.7 Pellet burning wood heater means a wood heater which meets the following criteria: (1) The manufacturer makes no reference to burning cord wood in advertising or other literature, (2) the unit is safety listed for pellet fuel only, (3) the unit operating and instruction manual must state that the use of cordwood is prohibited by law, and (4) the unit must be manufactured and sold including the hopper and auger combination as integral parts.
3.8 Secondary air supply means an air supply that introduces air to the wood heater such that the burn rate is not altered by more than 25 percent when the secondary air supply is adjusted during the test run. The wood heater manufacturer can document this through design drawings that show the secondary air is introduced only into a mixing chamber or secondary chamber outside the firebox.
3.9 Test facility means the area in which the wood heater is installed, operated, and sampled for emissions.
3.10 Test fuel charge means the collection of test fuel pieces placed in the wood heater at the start of the emission test run.
3.11 Test fuel crib means the arrangement of the test fuel charge with the proper spacing requirements between adjacent fuel pieces.
3.12 Test fuel loading density means the weight of the as-fired test fuel charge per unit volume of usable firebox.
3.13 Test fuel piece means the 2 × 4 or 4 × 4 wood piece cut to the length required for the test fuel charge and used to construct the test fuel crib.
3.14 Test run means an individual emission test which encompasses the time required to consume the mass of the test fuel charge.
3.15 Usable firebox volume means the volume of the firebox determined using its height, length, and width as defined in this section.
3.16 Width means the shortest horizontal fire chamber dimension that is parallel to a wall of the chamber.
3.17 Wood heater means an enclosed, woodburning appliance capable of and intended for space heating or domestic water heating, as defined in the applicable regulation.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to performing this test method.
Same as section 6.0 of either Method 5G or Method 5H, with the addition of the following:
6.1 Insulated Solid Pack Chimney. For installation of wood heaters. Solid pack insulated chimneys shall have a minimum of 2.5 cm (1 in.) solid pack insulating material surrounding the entire flue and possess a label demonstrating conformance to U.L. 103 (incorporated by reference – see § 60.17).
6.2 Platform Scale and Monitor. For monitoring of fuel load weight change. The scale shall be capable of measuring weight to within 0.05 kg (0.1 lb) or 1 percent of the initial test fuel charge weight, whichever is greater.
6.3 Wood Heater Temperature Monitors. Seven, each capable of measuring temperature to within 1.5 percent of expected absolute temperatures.
6.4 Test Facility Temperature Monitor. A thermocouple located centrally in a vertically oriented 150 mm (6 in.) long, 50 mm (2 in.) diameter pipe shield that is open at both ends, capable of measuring temperature to within 1.5 percent of expected temperatures.
6.5 Balance (optional). Balance capable of weighing the test fuel charge to within 0.05 kg (0.1 lb).
6.6 Moisture Meter. Calibrated electrical resistance meter for measuring test fuel moisture to within 1 percent moisture content.
6.7 Anemometer. Device capable of detecting air velocities less than 0.10 m/sec (20 ft/min), for measuring air velocities near the test appliance.
6.8 Barometer. Mercury, aneroid or other barometer capable of measuring atmospheric pressure to within 2.5 mm Hg (0.1 in. Hg).
6.9 Draft Gauge. Electromanometer or other device for the determination of flue draft or static pressure readable to within 0.50 Pa (0.002 in. H
6.10 Humidity Gauge. Psychrometer or hygrometer for measuring room humidity.
6.11 Wood Heater Flue.
6.11.1 Steel flue pipe extending to 2.6 ±0.15 m (8.5 ±0.5 ft) above the top of the platform scale, and above this level, insulated solid pack type chimney extending to 4.6 ±0.3 m (15 ±1 ft) above the platform scale, and of the size specified by the wood heater manufacturer. This applies to both freestanding and insert type wood heaters.
6.11.2 Other chimney types (e.g., solid pack insulated pipe) may be used in place of the steel flue pipe if the wood heater manufacturer’s written appliance specifications require such chimney for home installation (e.g., zero clearance wood heater inserts). Such alternative chimney or flue pipe must remain and be sealed with the wood heater following the certification test.
6.12 Test Facility. The test facility shall meet the following requirements during testing:
6.12.1 The test facility temperature shall be maintained between 18 and 32 °C (65 and 90 °F) during each test run.
6.12.2 Air velocities within 0.6 m (2 ft) of the test appliance and exhaust system shall be less than 0.25 m/sec (50 ft/min) without fire in the unit.
6.12.3 The flue shall discharge into the same space or into a space freely communicating with the test facility. Any hood or similar device used to vent combustion products shall not induce a draft greater than 1.25 Pa (0.005 in. H
6.12.4 For test facilities with artificially induced barometric pressures (e.g., pressurized chambers), the barometric pressure in the test facility shall not exceed 775 mm Hg (30.5 in. Hg) during any test run.
Same as section 6.0 of either Method 5G or Method 5H, with the addition of the following:
7.1 Test Fuel. The test fuel shall conform to the following requirements:
7.1.1 Fuel Species. Untreated, air-dried, Douglas fir lumber. Kiln-dried lumber is not permitted. The lumber shall be certified C grade (standard) or better Douglas fir by a lumber grader at the mill of origin as specified in the West Coast Lumber Inspection Bureau Standard No. 16 (incorporated by reference – see § 60.17).
7.1.2 Fuel Moisture. The test fuel shall have a moisture content range between 16 to 20 percent on a wet basis (19 to 25 percent dry basis). Addition of moisture to previously dried wood is not allowed. It is recommended that the test fuel be stored in a temperature and humidity-controlled room.
7.1.3 Fuel Temperature. The test fuel shall be at the test facility temperature of 18 to 32 °C (65 to 90 °F).
7.1.4 Fuel Dimensions. The dimensions of each test fuel piece shall conform to the nominal measurements of 2 × 4 and 4 × 4 lumber. Each piece of test fuel (not including spacers) shall be of equal length, except as necessary to meet requirements in section 8.8, and shall closely approximate
7.1.4.1 If the usable firebox volume is less than or equal to 0.043 m
7.1.4.2 If the usable firebox volume is greater than 0.043 m
7.1.4.3 If the usable firebox volume is greater than 0.085 m
7.2 Test Fuel Spacers. Air-dried, Douglas fir lumber meeting the requirements outlined in sections 7.1.1 through 7.1.3. The spacers shall be 130 × 40 × 20 mm (5 × 1.5 × 0.75 in.).
8.1 Test Run Requirements.
8.1.1 Burn Rate Categories. One emission test run is required in each of the following burn rate categories:
Burn Rate Categories
[Average kg/hr (lb/hr), dry basis]
| Category 1 | Category 2 | Category 3 | Category 4 |
|---|---|---|---|
| 0.80 to 1.25 | 1.25 to 1.90 | Maximum. | |
| ( | (1.76 to 2.76) | (2.76 to 4.19) | burn rate. |
8.1.1.1 Maximum Burn Rate. For Category 4, the wood heater shall be operated with the primary air supply inlet controls fully open (or, if thermostatically controlled, the thermostat shall be set at maximum heat output) during the entire test run, or the maximum burn rate setting specified by the manufacturer’s written instructions.
8.1.1.2 Other Burn Rate Categories. For burn rates in Categories 1 through 3, the wood heater shall be operated with the primary air supply inlet control, or other mechanical control device, set at a predetermined position necessary to obtain the average burn rate required for the category.
8.1.1.3 Alternative Burn Rates for Burn Rate Categories 1 and 2.
8.1.1.3.1 If a wood heater cannot be operated at a burn rate below 0.80 kg/hr (1.76 lb/hr), two test runs shall be conducted with burn rates within Category 2. If a wood heater cannot be operated at a burn rate below 1.25 kg/hr (2.76 lb/hr), the flue shall be dampered or the air supply otherwise controlled in order to achieve two test runs within Category 2.
8.1.1.3.2 Evidence that a wood heater cannot be operated at a burn rate less than 0.80 kg/hr shall include documentation of two or more attempts to operate the wood heater in burn rate Category 1 and fuel combustion has stopped, or results of two or more test runs demonstrating that the burn rates were greater than 0.80 kg/hr when the air supply controls were adjusted to the lowest possible position or settings. Stopped fuel combustion is evidenced when an elapsed time of 30 minutes or more has occurred without a measurable ( After July 1, 1990, if a wood heater cannot be operated at a burn rate less than 0.80 kg/hr, at least one test run with an average burn rate of 1.00 kg/hr or less shall be conducted. Additionally, if flue dampering must be used to achieve burn rates below 1.25 kg/hr (or 1.0 kg/hr), results from a test run conducted at burn rates below 0.90 kg/hr need not be reported or included in the test run average provided that such results are replaced with results from a test run meeting the criteria above.
8.2 Catalytic Combustor and Wood Heater Aging. The catalyst-equipped wood heater or a wood heater of any type shall be aged before the certification test begins. The aging procedure shall be conducted and documented by a testing laboratory accredited according to procedures in § 60.535 of 40 CFR part 60.
8.2.1 Catalyst-equipped Wood Heater. Operate the catalyst-equipped wood heater using fuel meeting the specifications outlined in sections 7.1.1 through 7.1.3, or cordwood with a moisture content between 15 and 25 percent on a wet basis. Operate the wood heater at a medium burn rate (Category 2 or 3) with a new catalytic combustor in place and in operation for at least 50 hours. Record and report hourly catalyst exit temperature data (Section 8.6.2) and the hours of operation.
8.2.2 Non-Catalyst Wood Heater. Operate the wood heater using the fuel described in section 8.4.1 at a medium burn rate for at least 10 hours. Record and report the hours of operation.
8.3 Pretest Recordkeeping. Record the test fuel charge dimensions and weights, and wood heater and catalyst descriptions as shown in the example in Figure 28-1.
8.4 Wood Heater Installation. Assemble the wood heater appliance and parts in conformance with the manufacturer’s written installation instructions. Place the wood heater centrally on the platform scale and connect the wood heater to the flue described in section 6.11. Clean the flue with an appropriately sized, wire chimney brush before each certification test.
8.5 Wood Heater Temperature Monitors.
8.5.1 For catalyst-equipped wood heaters, locate a temperature monitor (optional) about 25 mm (1 in.) upstream of the catalyst at the centroid of the catalyst face area, and locate a temperature monitor (mandatory) that will indicate the catalyst exhaust temperature. This temperature monitor is centrally located within 25 mm (1 in.) downstream at the centroid of catalyst face area. Record these locations.
8.5.2 Locate wood heater surface temperature monitors at five locations on the wood heater firebox exterior surface. Position the temperature monitors centrally on the top surface, on two sidewall surfaces, and on the bottom and back surfaces. Position the monitor sensing tip on the firebox exterior surface inside of any heat shield, air circulation walls, or other wall or shield separated from the firebox exterior surface. Surface temperature locations for unusual design shapes (e.g., spherical, etc.) shall be positioned so that there are four surface temperature monitors in both the vertical and horizontal planes passing at right angles through the centroid of the firebox, not including the fuel loading door (total of five temperature monitors).
8.6 Test Facility Conditions.
8.6.1 Locate the test facility temperature monitor on the horizontal plane that includes the primary air intake opening for the wood heater. Locate the temperature monitor 1 to 2 m (3 to 6 ft) from the front of the wood heater in the 90° sector in front of the wood heater.
8.6.2 Use an anemometer to measure the air velocity. Measure and record the room air velocity before the pretest ignition period (Section 8.7) and once immediately following the test run completion.
8.6.3 Measure and record the test facility’s ambient relative humidity, barometric pressure, and temperature before and after each test run.
8.6.4 Measure and record the flue draft or static pressure in the flue at a location no greater than 0.3 m (1 ft) above the flue connector at the wood heater exhaust during the test run at the recording intervals (Section 8.8.2).
8.7 Wood Heater Firebox Volume.
8.7.1 Determine the firebox volume using the definitions for height, width, and length in section 3. Volume adjustments due to presence of firebrick and other permanent fixtures may be necessary. Adjust width and length dimensions to extend to the metal wall of the wood heater above the firebrick or permanent obstruction if the firebrick or obstruction extending the length of the side(s) or back wall extends less than one-third of the usable firebox height. Use the width or length dimensions inside the firebrick if the firebrick extends more than one-third of the usable firebox height. If a log retainer or grate is a permanent fixture and the manufacturer recommends that no fuel be placed outside the retainer, the area outside of the retainer is excluded from the firebox volume calculations.
8.7.2 In general, exclude the area above the ash lip if that area is less than 10 percent of the usable firebox volume. Otherwise, take into account consumer loading practices. For instance, if fuel is to be loaded front-to-back, an ash lip may be considered usable firebox volume.
8.7.3 Include areas adjacent to and above a baffle (up to two inches above the fuel loading opening) if four inches or more horizontal space exist between the edge of the baffle and a vertical obstruction (e.g., sidewalls or air channels).
8.8 Test Fuel Charge.
8.8.1 Prepare the test fuel pieces in accordance with the specifications outlined in sections 7.1 and 7.2. Determine the test fuel moisture content with a calibrated electrical resistance meter or other equivalent performance meter. If necessary, convert fuel moisture content values from dry basis (%M
8.8.2 Attach the spacers to the test fuel pieces with uncoated, ungalvanized nails or staples as illustrated in Figure 28-2. Attachment of spacers to the top of the test fuel piece(s) on top of the test fuel charge is optional.
8.8.3 To avoid stacking difficulties, or when a whole number of test fuel pieces does not result, all piece lengths shall be adjusted uniformly to remain within the specified loading density. The shape of the test fuel crib shall be geometrically similar to the shape of the firebox volume without resorting to special angular or round cuts on the individual fuel pieces.
8.8.4 The test fuel loading density shall be 112 ±11.2 kg/m
8.9 Sampling Equipment. Prepare the sampling equipment as defined by the selected method (i.e., either Method 5G or Method 5H). Collect one particulate emission sample for each test run.
8.10 Secondary Air Adjustment Validation.
8.10.1 If design drawings do not show the introduction of secondary air into a chamber outside the firebox (see “secondary air supply” under section 3.0, Definitions), conduct a separate test of the wood heater’s secondary air supply. Operate the wood heater at a burn rate in Category 1 (Section 8.1.1) with the secondary air supply operated following the manufacturer’s written instructions. Start the secondary air validation test run as described in section 8.8.1, except no emission sampling is necessary and burn rate data shall be recorded at 5-minute intervals.
8.10.2 After the start of the test run, operate the wood heater with the secondary air supply set as per the manufacturer’s instructions, but with no adjustments to this setting. After 25 percent of the test fuel has been consumed, adjust the secondary air supply controls to another setting, as per the manufacturer’s instructions. Record the burn rate data (5-minute intervals) for 20 minutes following the air supply adjustment.
8.10.3 Adjust the air supply control(s) to the original position(s), operate at this condition for at least 20 minutes, and repeat the air supply adjustment procedure above. Repeat the procedure three times at equal intervals over the entire burn period as defined in section 8.8. If the secondary air adjustment results in a burn rate change of more than an average of 25 percent between the 20-minute periods before and after the secondary adjustments, the secondary air supply shall be considered a primary air supply, and no adjustment to this air supply is allowed during the test run.
8.10.4 The example sequence below describes a typical secondary air adjustment validation check. The first cycle begins after at least 25 percent of the test fuel charge has been consumed.
8.11 Pretest Ignition. Build a fire in the wood heater in accordance with the manufacturer’s written instructions.
8.11.1 Pretest Fuel Charge. Crumpled newspaper loaded with kindling may be used to help ignite the pretest fuel. The pretest fuel, used to sustain the fire, shall meet the same fuel requirements prescribed in section 7.1. The pretest fuel charge shall consist of whole 2 × 4’s that are no less than
8.11.2 Wood Heater Operation and Adjustments. Set the air inlet supply controls at any position that will maintain combustion of the pretest fuel load. At least one hour before the start of the test run, set the air supply controls at the approximate positions necessary to achieve the burn rate desired for the test run. Adjustment of the air supply controls, fuel addition or subtractions, and coalbed raking shall be kept to a minimum but are allowed up to 15 minutes prior to the start of the test run. For the purposes of this method, coalbed raking is the use of a metal tool (poker) to stir coals, break burning fuel into smaller pieces, dislodge fuel pieces from positions of poor combustion, and check for the condition of uniform charcoalization. Record all adjustments made to the air supply controls, adjustments to and additions or subtractions of fuel, and any other changes to wood heater operations that occur during pretest ignition period. Record fuel weight data and wood heater temperature measurements at 10-minute intervals during the hour of the pretest ignition period preceding the start of the test run. During the 15-minute period prior to the start of the test run, the wood heater loading door shall not be open more than a total of 1 minute. Coalbed raking is the only adjustment allowed during this period.
One purpose of the pretest ignition period is to achieve uniform charcoalization of the test fuel bed prior to loading the test fuel charge. Uniform charcoalization is a general condition of the test fuel bed evidenced by an absence of large pieces of burning wood in the coal bed and the remaining fuel pieces being brittle enough to be broken into smaller charcoal pieces with a metal poker. Manipulations to the fuel bed prior to the start of the test run should be done to achieve uniform charcoalization while maintaining the desired burn rate. In addition, some wood heaters (e.g., high mass units) may require extended pretest burn time and fuel additions to reach an initial average surface temperature sufficient to meet the thermal equilibrium criteria in section 8.3.
8.11.3 The weight of pretest fuel remaining at the start of the test run is determined as the difference between the weight of the wood heater with the remaining pretest fuel and the tare weight of the cleaned, dry wood heater with or without dry ash or sand added consistent with the manufacturer’s instructions and the owner’s manual. The tare weight of the wood heater must be determined with the wood heater (and ash, if added) in a dry condition.
8.12 Test Run. Complete a test run in each burn rate category, as follows:
8.12.1 Test Run Start.
8.12.1.1 When the kindling and pretest fuel have been consumed to leave a fuel weight between 20 and 25 percent of the weight of the test fuel charge, record the weight of the fuel remaining and start the test run. Record and report any other criteria, in addition to those specified in this section, used to determine the moment of the test run start (e.g., firebox or catalyst temperature), whether such criteria are specified by the wood heater manufacturer or the testing laboratory. Record all wood heater individual surface temperatures, catalyst temperatures, any initial sampling method measurement values, and begin the particulate emission sampling. Within 1 minute following the start of the test run, open the wood heater door, load the test fuel charge, and record the test fuel charge weight. Recording of average, rather than individual, surface temperatures is acceptable for tests conducted in accordance with § 60.533(o)(3)(i) of 40 CFR part 60.
8.12.1.2 Position the fuel charge so that the spacers are parallel to the floor of the firebox, with the spacer edges abutting each other. If loading difficulties result, some fuel pieces may be placed on edge. If the usable firebox volume is between 0.043 and 0.085 m
8.12.1.3 Load the test fuel in appliances having unusual or unconventional firebox design maintaining air space intervals between the test fuel pieces and in conformance with the manufacturer’s written instructions. For any appliance that will not accommodate the loading arrangement specified in the paragraph above, the test facility personnel shall contact the Administrator for an alternative loading arrangement.
8.12.1.4 The wood heater door may remain open and the air supply controls adjusted up to five minutes after the start of the test run in order to make adjustments to the test fuel charge and to ensure ignition of the test fuel charge has occurred. Within the five minutes after the start of the test run, close the wood heater door and adjust the air supply controls to the position determined to produce the desired burn rate. No other adjustments to the air supply controls or the test fuel charge are allowed (except as specified in sections 8.12.3 and 8.12.4) after the first five minutes of the test run. Record the length of time the wood heater door remains open, the adjustments to the air supply controls, and any other operational adjustments.
8.12.2 Data Recording. Record on a data sheet similar to that shown in Figure 28-4, at intervals no greater than 10 minutes, fuel weight data, wood heater individual surface and catalyst temperature measurements, other wood heater operational data (e.g., draft), test facility temperature and sampling method data.
8.12.3 Test Fuel Charge Adjustment. The test fuel charge may be adjusted (i.e., repositioned) once during a test run if more than 60 percent of the initial test fuel charge weight has been consumed and more than 10 minutes have elapsed without a measurable (
8.12.4 Air Supply Adjustment. Secondary air supply controls may be adjusted once during the test run following the manufacturer’s written instructions (see section 8.10). No other air supply adjustments are allowed during the test run. Recording of wood heater flue draft during the test run is optional for tests conducted in accordance with § 60.533(o)(3)(i) of 40 CFR part 60.
8.12.5 Auxiliary Wood Heater Equipment Operation. Heat exchange blowers sold with the wood heater shall be operated during the test run following the manufacturer’s written instructions. If no manufacturer’s written instructions are available, operate the heat exchange blower in the “high” position. (Automatically operated blowers shall be operated as designed.) Shaker grates, by-pass controls, or other auxiliary equipment may be adjusted only one time during the test run following the manufacturer’s written instructions.
Record all adjustments on a wood heater operational written record.
If the wood heater is sold with a heat exchange blower as an option, test the wood heater with the heat exchange blower operating as described in sections 8.1 through 8.12 and report the results. As an alternative to repeating all test runs without the heat exchange blower operating, one additional test run may be without the blower operating as described in section 8.12.5 at a burn rate in Category 2 (Section 8.1.1). If the emission rate resulting from this test run without the blower operating is equal to or less than the emission rate plus 1.0 g/hr (0.0022 lb/hr) for the test run in burn rate Category 2 with the blower operating, the wood heater may be considered to have the same average emission rate with or without the blower operating. Additional test runs without the blower operating are unnecessary.
8.13 Test Run Completion. Continue emission sampling and wood heater operation for 2 hours. The test run is completed when the remaining weight of the test fuel charge is 0.00 kg (0.0 lb). End the test run when the scale has indicated a test fuel charge weight of 0.00 kg (0.0 lb) or less for 30 seconds. At the end of the test run, stop the particulate sampling, and record the final fuel weight, the run time, and all final measurement values.
8.14 Wood Heater Thermal Equilibrium. The average of the wood heater surface temperatures at the end of the test run shall agree with the average surface temperature at the start of the test run to within 70 °C (126 °F).
8.15 Consecutive Test Runs. Test runs on a wood heater may be conducted consecutively provided that a minimum one-hour interval occurs between test runs.
8.16 Additional Test Runs. The testing laboratory may conduct more than one test run in each of the burn rate categories specified in section 8.1.1. If more than one test run is conducted at a specified burn rate, the results from at least two-thirds of the test runs in that burn rate category shall be used in calculating the weighted average emission rate (see section 12.2). The measurement data and results of all test runs shall be reported regardless of which values are used in calculating the weighted average emission rate (see note in section 8.1).
Same as section 9.0 of either Method 5G or Method 5H.
Same as section 10.0 of either Method 5G or Method 5H, with the addition of the following:
10.1 Platform Scale. Perform a multi-point calibration (at least five points spanning the operational range) of the platform scale before its initial use. The scale manufacturer’s calibration results are sufficient for this purpose. Before each certification test, audit the scale with the wood heater in place by weighing at least one calibration weight (Class F) that corresponds to between 20 percent and 80 percent of the expected test fuel charge weight. If the scale cannot reproduce the value of the calibration weight within 0.05 kg (0.1 lb) or 1 percent of the expected test fuel charge weight, whichever is greater, recalibrate the scale before use with at least five calibration weights spanning the operational range of the scale.
10.2 Balance (optional). Calibrate as described in section 10.1.
10.3 Temperature Monitor. Calibrate as in Method 2, section 4.3, before the first certification test and semiannually thereafter.
10.4 Moisture Meter. Calibrate as per the manufacturer’s instructions before each certification test.
10.5 Anemometer. Calibrate the anemometer as specified by the manufacturer’s instructions before the first certification test and semiannually thereafter.
10.6 Barometer. Calibrate against a mercury barometer before the first certification test and semiannually thereafter.
10.7 Draft Gauge. Calibrate as per the manufacturer’s instructions; a liquid manometer does not require calibration.
10.8 Humidity Gauge. Calibrate as per the manufacturer’s instructions before the first certification test and semiannually thereafter.
Same as section 11.0 of either Method 5G or Method 5H.
Same as section 12.0 of either Method 5G or Method 5H, with the addition of the following:
12.1 Nomenclature.
12.2 Wet Basis Fuel Moisture Content.
12.3 Weighted Average Emission Rate. Calculate the weighted average emission rate (E
P
12.3.1 Example Calculation of Weighted Average Emission Rate.
| Burn rate category | Test No. | Burn rate (Dry-kg/hr) | Emissions (g/hr) |
|---|---|---|---|
| 1 | 1 | 0.65 | 5.0 |
| 2 1 | 2 | 0.85 | 6.7 |
| 2 | 3 | 0.90 | 4.7 |
| 2 | 4 | 1.00 | 5.3 |
| 3 | 5 | 1.45 | 3.8 |
| 4 | 6 | 2.00 | 5.1 |
1 As permitted in section 6.6, this test run may be omitted from the calculation of the weighted average emission rate because three runs were conducted for this burn rate category.
| Test No. | Burn rate | P | E | K |
|---|---|---|---|---|
| 0 | 0.000 | |||
| 1 | 0.65 | 0.121 | 5.0 | 0.300 |
| 2 | 0.90 | 0.300 | 4.7 | 0.259 |
| 3 | 1.00 | 0.380 | 5.3 | 0.422 |
| 4 | 1.45 | 0.722 | 3.8 | 0.532 |
| 5 | 2.00 | 0.912 | 5.1 | 0.278 |
| 6 | 1.000 |
K
K
K
K
K
12.4 Average Wood Heater Surface Temperatures. Calculate the average of the wood heater surface temperatures for the start of the test run (Section 8.12.1) and for the test run completion (Section 8.13). If the two average temperatures do not agree within 70 °C (125 °F), report the test run results, but do not include the test run results in the test average. Replace such test run results with results from another test run in the same burn rate category.
12.5 Burn Rate. Calculate the burn rate (BR) using Equation 28-3:
12.6 Reporting Criteria. Submit both raw and reduced test data for wood heater tests.
12.6.1 Suggested Test Report Format.
12.6.1.1 Introduction.
12.6.1.1.1 Purpose of test-certification, audit, efficiency, research and development.
12.6.1.1.2 Wood heater identification-manufacturer, model number, catalytic/noncatalytic, options.
12.6.1.1.3 Laboratory-name, location (altitude), participants.
12.6.1.1.4 Test information-date wood heater received, date of tests, sampling methods used, number of test runs.
12.6.1.2 Summary and Discussion of Results
12.6.1.2.1 Table of results (in order of increasing burn rate)-test run number, burn rate, particulate emission rate, efficiency (if determined), averages (indicate which test runs are used).
12.6.1.2.2 Summary of other data-test facility conditions, surface temperature averages, catalyst temperature averages, pretest fuel weights, test fuel charge weights, run times.
12.6.1.2.3 Discussion-Burn rate categories achieved, test run result selection, specific test run problems and solutions.
12.6.1.3 Process Description.
12.6.1.3.1 Wood heater dimensions-volume, height, width, lengths (or other linear dimensions), weight, volume adjustments.
12.6.1.3.2 Firebox configuration-air supply locations and operation, air supply introduction location, refractory location and dimensions, catalyst location, baffle and by-pass location and operation (include line drawings or photographs).
12.6.1.3.3 Process operation during test-air supply settings and adjustments, fuel bed adjustments, draft.
12.6.1.3.4 Test fuel-test fuel properties (moisture and temperature), test fuel crib description (include line drawing or photograph), test fuel loading density.
12.6.1.4 Sampling Locations.
12.6.1.4.1 Describe sampling location relative to wood heater. Include drawing or photograph.
12.6.1.5 Sampling and Analytical Procedures
12.6.1.5.1 Sampling methods-brief reference to operational and sampling procedures and optional and alternative procedures used.
12.6.1.5.2 Analytical methods-brief description of sample recovery and analysis procedures.
12.6.1.6 Quality Control and Assurance Procedures and Results
12.6.1.6.1 Calibration procedures and results-certification procedures, sampling and analysis procedures.
12.6.1.6.2 Test method quality control procedures-leak-checks, volume meter checks, stratification (velocity) checks, proportionality results.
12.6.1.7 Appendices
12.6.1.7.1 Results and Example Calculations. Complete summary tables and accompanying examples of all calculations.
12.6.1.7.2 Raw Data. Copies of all uncorrected data sheets for sampling measurements, temperature records and sample recovery data. Copies of all pretest burn rate and wood heater temperature data.
12.6.1.7.3 Sampling and Analytical Procedures. Detailed description of procedures followed by laboratory personnel in conducting the certification test, emphasizing particular parts of the procedures differing from the methods (e.g., approved alternatives).
12.6.1.7.4 Calibration Results. Summary of all calibrations, checks, and audits pertinent to certification test results with dates.
12.6.1.7.5 Participants. Test personnel, manufacturer representatives, and regulatory observers.
12.6.1.7.6 Sampling and Operation Records. Copies of uncorrected records of activities not included on raw data sheets (e.g., wood heater door open times and durations).
12.6.1.7.7 Additional Information. Wood heater manufacturer’s written instructions for operation during the certification test.
12.6.2.1 Wood Heater Identification. Report wood heater identification information. An example data form is shown in Figure 28-4.
12.6.2.2 Test Facility Information. Report test facility temperature, air velocity, and humidity information. An example data form is shown on Figure 28-4.
12.6.2.3 Test Equipment Calibration and Audit Information. Report calibration and audit results for the platform scale, test fuel balance, test fuel moisture meter, and sampling equipment including volume metering systems and gaseous analyzers.
12.6.2.4 Pretest Procedure Description. Report all pretest procedures including pretest fuel weight, burn rates, wood heater temperatures, and air supply settings. An example data form is shown on Figure 28-4.
12.6.2.5 Particulate Emission Data. Report a summary of test results for all test runs and the weighted average emission rate. Submit copies of all data sheets and other records collected during the testing. Submit examples of all calculations.
16.1 Pellet Burning Heaters. Certification testing requirements and procedures for pellet burning wood heaters are identical to those for other wood heaters, with the following exceptions:
16.1.1 Test Fuel Properties. The test fuel shall be all wood pellets with a moisture content no greater than 20 percent on a wet basis (25 percent on a dry basis). Determine the wood moisture content with either ASTM D 2016-74 or 83, (Method A), ASTM D 4444-92, or ASTM D 4442-84 or 92 (all noted ASTM standards are incorporated by reference – see § 60.17).
16.1.2 Test Fuel Charge Specifications. The test fuel charge size shall be as per the manufacturer’s written instructions for maintaining the desired burn rate.
16.1.3 Wood Heater Firebox Volume. The firebox volume need not be measured or determined for establishing the test fuel charge size. The firebox dimensions and other heater specifications needed to identify the heater for certification purposes shall be reported.
16.1.4 Heater Installation. Arrange the heater with the fuel supply hopper on the platform scale as described in section 8.6.1.
16.1.5 Pretest Ignition. Start a fire in the heater as directed by the manufacturer’s written instructions, and adjust the heater controls to achieve the desired burn rate. Operate the heater at the desired burn rate for at least 1 hour before the start of the test run.
16.1.6 Test Run. Complete a test run in each burn rate category as follows:
16.1.6.1 Test Run Start. When the wood heater has operated for at least 1 hour at the desired burn rate, add fuel to the supply hopper as necessary to complete the test run, record the weight of the fuel in the supply hopper (the wood heater weight), and start the test run. Add no additional fuel to the hopper during the test run.
Record all the wood heater surface temperatures, the initial sampling method measurement values, the time at the start of the test, and begin the emission sampling. Make no adjustments to the wood heater air supply or wood supply rate during the test run.
16.1.6.2 Data Recording. Record the fuel (wood heater) weight data, wood heater temperature and operational data, and emission sampling data as described in section 8.12.2.
16.1.6.3 Test Run Completion. Continue emission sampling and wood heater operation for 2 hours. At the end of the test run, stop the particulate sampling, and record the final fuel weight, the run time, and all final measurement values, including all wood heater individual surface temperatures.
16.1.7 Calculations. Determine the burn rate using the difference between the initial and final fuel (wood heater) weights and the procedures described in section 12.4. Complete the other calculations as described in section 12.0.
Same as Method 5G, with the addition of the following:
1. Radian Corporation. OMNI Environmental Services, Inc., Cumulative Probability for a Given Burn Rate Based on Data Generated in the CONEG and BPA Studies. Package of materials submitted to the Fifth Session of the Regulatory Negotiation Committee, July 16-17, 1986.
Table 28-1 – Burn Rate Weighted Probabilities for Calculating Weighted Average Emission Rates
| Burn rate (kg/hr-dry) | Cumulative probability (P) | Burn rate (kg/hr-dry) | Cumulative probability (P) | Burn rate (kg/hr-dry) | Cumulative probability (P) |
|---|---|---|---|---|---|
| 0.00 | 0.000 | 1.70 | 0.840 | 3.40 | 0.989 |
| 0.05 | 0.002 | 1.75 | 0.857 | 3.45 | 0.989 |
| 0.10 | 0.007 | 1.80 | 0.875 | 3.50 | 0.990 |
| 0.15 | 0.012 | 1.85 | 0.882 | 3.55 | 0.991 |
| 0.20 | 0.016 | 1.90 | 0.895 | 3.60 | 0.991 |
| 0.25 | 0.021 | 1.95 | 0.906 | 3.65 | 0.992 |
| 0.30 | 0.028 | 2.00 | 0.912 | 3.70 | 0.992 |
| 0.35 | 0.033 | 2.05 | 0.920 | 3.75 | 0.992 |
| 0.40 | 0.041 | 2.10 | 0.925 | 3.80 | 0.993 |
| 0.45 | 0.054 | 2.15 | 0.932 | 3.85 | 0.994 |
| 0.50 | 0.065 | 2.20 | 0.936 | 3.90 | 0.994 |
| 0.55 | 0.086 | 2.25 | 0.940 | 3.95 | 0.994 |
| 0.60 | 0.100 | 2.30 | 0.945 | 4.00 | 0.994 |
| 0.65 | 0.121 | 2.35 | 0.951 | 4.05 | 0.995 |
| 0.70 | 0.150 | 2.40 | 0.956 | 4.10 | 0.995 |
| 0.75 | 0.185 | 2.45 | 0.959 | 4.15 | 0.995 |
| 0.80 | 0.220 | 2.50 | 0.964 | 4.20 | 0.995 |
| 0.85 | 0.254 | 2.55 | 0.968 | 4.25 | 0.995 |
| 0.90 | 0.300 | 2.60 | 0.972 | 4.30 | 0.996 |
| 0.95 | 0.328 | 2.65 | 0.975 | 4.35 | 0.996 |
| 1.00 | 0.380 | 2.70 | 0.977 | 4.40 | 0.996 |
| 1.05 | 0.407 | 2.75 | 0.979 | 4.45 | 0.996 |
| 1.10 | 0.460 | 2.80 | 0.980 | 4.50 | 0.996 |
| 1.15 | 0.490 | 2.85 | 0.981 | 4.55 | 0.996 |
| 1.20 | 0.550 | 2.90 | 0.982 | 4.60 | 0.996 |
| 1.25 | 0.572 | 2.95 | 0.984 | 4.65 | 0.996 |
| 1.30 | 0.620 | 3.00 | 0.984 | 4.70 | 0.996 |
| 1.35 | 0.654 | 3.05 | 0.985 | 4.75 | 0.997 |
| 1.40 | 0.695 | 3.10 | 0.986 | 4.80 | 0.997 |
| 1.45 | 0.722 | 3.15 | 0.987 | 4.85 | 0.997 |
| 1.50 | 0.750 | 3.20 | 0.987 | 4.90 | 0.997 |
| 1.55 | 0.779 | 3.25 | 0.988 | 4.95 | 0.997 |
| 1.60 | 0.800 | 3.30 | 0.988 | ≥5.00 | 1.000 |
| 1.65 | 0.825 | 3.35 | 0.989 |
This method does not include all or the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should also have a thorough knowledge of at least the following additional test methods: Method 3, Method 3A, Method 5H, Method 6C, and Method 28.
1.1 Analyte. Particulate matter (PM). No CAS number assigned.
1.2 Applicability. This method is applicable for the measurement of air-to-fuel ratios and minimum achievable burn rates, for determining whether a wood-fired appliance is an affected facility, as specified in 40 CFR 60.530.
1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods.
2.1 A gas sample is extracted from a location in the stack of a wood-fired appliance while the appliance is operating at a prescribed set of conditions. The gas sample is analyzed for carbon dioxide (CO
Same as Method 28, section 3.0, with the addition of the following:
3.1 Air-to-fuel ratio means the ratio of the mass of dry combustion air introduced into the firebox to the mass of dry fuel consumed (grams of dry air per gram of dry wood burned).
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to performing this test method.
6.1 Test Facility. Insulated Solid Pack Chimney, Platform Scale and Monitor, Test Facility Temperature Monitor, Balance, Moisture Meter, Anemometer, Barometer, Draft Gauge, Humidity Gauge, Wood Heater Flue, and Test Facility. Same as Method 28, sections 6.1, 6.2, and 6.4 to 6.12, respectively.
6.2 Sampling System. Probe, Condenser, Valve, Pump, Rate Meter, Flexible Bag, Pressure Gauge, and Vacuum Gauge. Same as Method 3, sections 6.2.1 to 6.2.8, respectively. Alternatively, the sampling system described in Method 5H, section 6.1 may be used.
6.3 Exhaust Gas Analysis. Use one or both of the following:
6.3.1 Orsat Analyzer. Same as Method 3, section 6.1.3
6.3.2 Instrumental Analyzers. Same as Method 5H, sections 6.1.3.4 and 6.1.3.5, for CO
7.1 Test Fuel and Test Fuel Spacers. Same as Method 28, sections 7.1 and 7.2, respectively.
7.2 Cylinder Gases. For each of the three analyzers, use the same concentration as specified in sections 7.2.1, 7.2.2, and 7.2.3 of Method 6C.
8.1 Wood Heater Air Supply Adjustments.
8.1.1 This section describes how dampers are to be set or adjusted and air inlet ports closed or sealed during Method 28A tests. The specifications in this section are intended to ensure that affected facility determinations are made on the facility configurations that could reasonably be expected to be employed by the user. They are also intended to prevent circumvention of the standard through the addition of an air port that would often be blocked off in actual use. These specifications are based on the assumption that consumers will remove such items as dampers or other closure mechanism stops if this can be done readily with household tools; that consumers will block air inlet passages not visible during normal operation of the appliance using aluminum tape or parts generally available at retail stores; and that consumers will cap off any threaded or flanged air inlets. They also assume that air leakage around glass doors, sheet metal joints or through inlet grilles visible during normal operation of the appliance would not be further blocked or taped off by a consumer.
8.1.2 It is not the intention of this section to cause an appliance that is clearly designed, intended, and, in most normal installations, used as a fireplace to be converted into a wood heater for purposes of applicability testing. Such a fireplace would be identifiable by such features as large or multiple glass doors or panels that are not gasketed, relatively unrestricted air inlets intended, in large part, to limit smoking and fogging of glass surfaces, and other aesthetic features not normally included in wood heaters.
8.1.3 Adjustable Air Supply Mechanisms. Any commercially available flue damper, other adjustment mechanism or other air inlet port that is designed, intended or otherwise reasonably expected to be adjusted or closed by consumers, installers, or dealers and which could restrict air into the firebox shall be set so as to achieve minimum air into the firebox (i.e., closed off or set in the most closed position).
8.1.3.1 Flue dampers, mechanisms and air inlet ports which could reasonably be expected to be adjusted or closed would include:
8.1.3.1.1 All internal or externally adjustable mechanisms (including adjustments that affect the tightness of door fittings) that are accessible either before and/or after installation.
8.1.3.1.2 All mechanisms, other inlet ports, or inlet port stops that are identified in the owner’s manual or in any dealer literature as being adjustable or alterable. For example, an inlet port that could be used to provide access to an outside air duct but which is identified as being closable through use of additional materials whether or not they are supplied with the facility.
8.1.3.1.3 Any combustion air inlet port or commercially available flue damper or mechanism stop, which would readily lend itself to closure by consumers who are handy with household tools by the removal of parts or the addition of parts generally available at retail stores (e.g., addition of a pipe cap or plug, addition of a small metal plate to an inlet hole on a nondecorative sheet metal surface, or removal of riveted or screwed damper stops).
8.1.3.1.4 Any flue damper, other adjustment mechanisms or other air inlet ports that are found and documented in several (e.g., a number sufficient to reasonably conclude that the practice is not unique or uncommon) actual installations as having been adjusted to a more closed position, or closed by consumers, installers, or dealers.
8.1.4 Air Supply Adjustments During Test. The test shall be performed with all air inlets identified under this section in the closed or most closed position or in the configuration which otherwise achieves the lowest air inlet (i.e., greatest blockage).
For the purposes of this section, air flow shall not be minimized beyond the point necessary to maintain combustion or beyond the point that forces smoke into the room.
8.1.5 Notwithstanding section 8.1.1, any flue damper, adjustment mechanism, or air inlet port (whether or not equipped with flue dampers or adjusting mechanisms) that is visible during normal operation of the appliance and which could not reasonably be closed further or blocked except through means that would significantly degrade the aesthetics of the facility (e.g., through use of duct tape) will not be closed further or blocked.
8.2 Sampling System.
8.2.1 Sampling Location. Same as Method 5H, section 8.1.2.
8.2.2 Sampling System Set Up. Set up the sampling equipment as described in Method 3, section 8.1.
8.3 Wood Heater Installation, Test Facility Conditions, Wood Heater Firebox Volume, and Test Fuel Charge. Same as Method 28, sections 8.4 and 8.6 to 8.8, respectively.
8.4 Pretest Ignition. Same as Method 28, section 8.11. Set the wood heater air supply settings to achieve a burn rate in Category 1 or the lowest achievable burn rate (see section 8.1).
8.5 Test Run. Same as Method 28, section 8.12. Begin sample collection at the start of the test run as defined in Method 28, section 8.12.1.
8.5.1 Gas Analysis.
8.5.1.1 If Method 3 is used, collect a minimum of two bag samples simultaneously at a constant sampling rate for the duration of the test run. A minimum sample volume of 30 liters (1.1 ft
8.5.1.2 If instrumental gas concentration measurement procedures are used, conduct the gas measurement system performance tests, analyzer calibration, and analyzer calibration error check outlined in Method 6C, sections 8.2.3, 8.2.4, 8.5, and 10.0, respectively. Sample at a constant rate for the duration of the test run.
8.5.2 Data Recording. Record wood heater operational data, test facility temperature, sample train flow rate, and fuel weight data at intervals of no greater than 10 minutes.
8.5.3 Test Run Completion. Same as Method 28, section 8.13.
9.1 Data Validation. The following quality control procedure is suggested to provide a check on the quality of the data.
9.1.1 Calculate a fuel factor, F
9.1.2 If CO is present in quantities measurable by this method, adjust the O
9.1.3 Compare the calculated F
9.2 Method 3 Analyses. Compare the results of the analyses of the two bag samples. If all the gas components (O
11.1 Method 3 Integrated Bag Samples. Within 4 hours after the sample collection, analyze each bag sample for percent CO
11.2 Instrumental Analyzers. Average the percent CO
Carry out calculations, retaining at least one extra significant figure beyond that of the acquired data. Round off figure after the final calculation. Other forms of the equations may be used as long as they give equivalent results.
12.1 Nomenclature.
12.2 Fuel Factor. Use Equation 28A-1 to calculate the fuel factor.
12. 3 Adjusted %CO
12.4 Adjusted %O
12.5 Dry Molecular Weight. Use Equation 28A-4 to calculate the dry molecular weight of the stack gas.
The above equation does not consider argon in air (about 0.9 percent, molecular weight of 39.9). A negative error of about 0.4 percent is introduced. Argon may be included in the analysis using procedures subject to approval of the Administrator.
12.6 Dry Moles of Exhaust Gas. Use Equation 28A-5 to calculate the total moles of dry exhaust gas produced per kilogram of dry wood burned.
12.7 Air-to-Fuel Ratio. Use Equation 28A-6 to calculate the air-to-fuel ratio on a dry mass basis.
12.8 Burn Rate. Calculate the fuel burn rate as in Method 28, section 12.4.
Same as section 16.0 of Method 3 and section 17 of Method 5G.
1.1 This test method applies to certification and auditing of wood-fired room heaters and fireplace inserts.
1.2 The test method covers the fueling and operating protocol for measuring particulate emissions, as well as determining burn rates, heat output and efficiency.
1.3 Particulate emissions are measured by the dilution tunnel method as specified in ASTM E2515-11 Standard Test Method for Determination of Particulate Matter Emissions Collected in a Dilution Tunnel (IBR, see § 60.17). Upon request, four-inch filters may be used. Upon request, Teflon membrane filters or Teflon-coated glass fiber filters may be used.
2.1 This method incorporates the provisions of ASTM E2780-10 (IBR, see § 60.17) except as follows:
2.1.1 The burn rate categories, low burn rate requirement, and weightings in Method 28 shall be used.
2.1.2 The startup procedures shall be the same as in Method 28.
2.1.3 Manufacturers shall not specify a smaller volume of the firebox for testing than the full usable firebox.
2.1.4 Prior to testing, the heater must be operated for a minimum of 50 hours using a medium burn rate. The conditioning may be at the manufacturer’s facility prior to the certification test. If the conditioning is at the certification test laboratory, the pre-burn for the first test can be included as part of the conditioning requirement.
2.2 Manufacturers may use ASTM E871-82 (reapproved 2013) (IBR, see § 60.17) as an alternative to the procedures in Method 5H or Method 28 for determining total weight basis moisture in the analysis sample of particulate wood fuel.
1.1 This test method applies to wood-fired hydronic heating appliances. The units typically transfer heat through circulation of a liquid heat exchange media such as water or a water-antifreeze mixture.
1.2 The test method measures particulate emissions and delivered heating efficiency at specified heat output rates based on the appliance’s rated heating capacity.
1.3 Particulate emissions are measured by the dilution tunnel method as specified in ASTM E2515-11 Standard Test Method for Determination of Particulate Matter Emissions Collected in a Dilution Tunnel (IBR, see § 60.17). Upon request, four-inch filters may be used. Upon request, Teflon membrane filters or Teflon-coated glass fiber filters may be used. Delivered efficiency is measured by determining the heat output through measurement of the flow rate and temperature change of water circulated through a heat exchanger external to the appliance and determining the input from the mass of dry wood fuel and its higher heating value. Delivered efficiency does not attempt to account for pipeline loss.
1.4 Products covered by this test method include both pressurized and non-pressurized heating appliances intended to be fired with wood. These products are wood-fired hydronic heating appliances that the manufacturer specifies for indoor or outdoor installation. They are often connected to a heat exchanger by insulated pipes and normally include a pump to circulate heated liquid. They are used to heat structures such as homes, barns and greenhouses and can heat domestic hot water, spas or swimming pools.
1.5 Distinguishing features of products covered by this standard include:
1.5.1 Manufacturer specifies for indoor or outdoor installation.
1.5.2 A firebox with an access door for hand loading of fuel.
1.5.3 Typically, an aquastat that controls combustion air supply to maintain the liquid in the appliance within a predetermined temperature range provided sufficient fuel is available in the firebox.
1.5.4 A chimney or vent that exhausts combustion products from the appliance.
1.6 The values stated are to be regarded as the standard whether in I-P or SI units. The values given in parentheses are for information only.
2.1 Particulate matter emissions are measured from a wood-fired hydronic heating appliance burning a prepared test fuel crib in a test facility maintained at a set of prescribed conditions. Procedures for determining burn rates, and particulate emissions rates and for reducing data are provided.
2.2 Referenced Documents
2.2.1 EPA Standards
2.2.1.1 Method 28 Certification and Auditing of Wood Heaters
2.2.2 Other Standards
2.2.2.1 ASTM E2515-11 – Standard Test Method for Determination of Particulate Matter Emissions Collected in a Dilution Tunnel (IBR, see § 60.17).
2.2.2.2 CSA-B415.1-10 Performance Testing of Solid-Fuel-Burning Heating Appliances (IBR, see § 60.17).
3.1 Definitions.
3.1.1 Hydronic Heating – A heating system in which a heat source supplies energy to a liquid heat exchange media such as water that is circulated to a heating load and returned to the heat source through pipes.
3.1.2 Aquastat – A control device that opens or closes a circuit to control the rate of fuel consumption in response to the temperature of the heating media in the heating appliance.
3.1.3 Delivered Efficiency – The percentage of heat available in a test fuel charge that is delivered to a simulated heating load as specified in this test method.
3.1.4 Manufacturer’s Rated Heat Output Capacity – The value in Btu/hr (MJ/hr) that the manufacturer specifies that a particular model of hydronic heating appliance is capable of supplying at its design capacity as verified by testing, in accordance with Section 13.
3.1.5 Burn Rate – The rate at which test fuel is consumed in an appliance. Measured in pounds (lbs) or kilograms of wood (dry basis) per hour (lb/hr or kg/hr).
3.1.6 Firebox – The chamber in the appliance in which the test fuel charge is placed and combusted.
3.1.7 Test Fuel Charge – The collection of test fuel layers placed in the appliance at the start of the emission test run.
3.1.8 Test Fuel Layer – Horizontal arrangement of test fuel units.
3.1.9 Test Fuel Unit – One or more test fuel pieces with
3.1.10 Test Fuel Piece – A single 4 × 4 (4 ±0.25 inches by 4 ±0.25 inches) [100 ±6 mm by 100 ±6 mm] white or red oak wood piece cut to the length required.
3.1.11 Test Run – An individual emission test that encompasses the time required to consume the mass of the test fuel charge.
3.1.12 Overall Efficiency (SLM) – The efficiency for each test run as determined using the CSA B415.1-10 (IBR, see § 60.17) stack loss method.
3.1.13 Thermopile – A device consisting of a number of thermocouples connected in series, used for measuring differential temperature.
4.1 Dilution Tunnel. Emissions are determined using the “dilution tunnel” method specified in ASTM E2515-11 Standard Test Method for Determination of Particulate Matter Emissions Collected in a Dilution Tunnel (IBR, see § 60.17). The flow rate in the dilution tunnel is maintained at a constant level throughout the test cycle and accurately measured. Samples of the dilution tunnel flow stream are extracted at a constant flow rate and drawn through high efficiency filters. The filters are dried and weighed before and after the test to determine the emissions catch and this value is multiplied by the ratio of tunnel flow to filter flow to determine the total particulate emissions produced in the test cycle.
4.2 Efficiency. The efficiency test procedure takes advantage of the fact that this type of appliance delivers heat through circulation of the heated liquid (water) from the appliance to a remote heat exchanger and back to the appliance. Measurements of the water temperature difference as it enters and exits the heat exchanger along with the measured flow rate allow for an accurate determination of the useful heat output of the appliance. The input is determined by weight of the test fuel charge, adjusted for moisture content, multiplied by the higher heating value. Additional measurements of the appliance weight and temperature at the beginning and end of a test cycle are used to correct for heat stored in the appliance. Overall efficiency (SLM) is determined using the CSA B415.1-10 (IBR, see § 60.17) stack loss method for data quality assurance purposes.
4.3 Operation. Appliance operation is conducted on a hot-to-hot test cycle meaning that the appliance is brought to operating temperature and a coal bed is established prior to the addition of the test fuel charge and measurements are made for each test fuel charge cycle. The measurements are made under constant heat draw conditions within predetermined ranges. No attempt is made to modulate the heat demand to simulate an indoor thermostat cycling on and off in response to changes in the indoor environment. Four test categories are used. These are:
4.3.1 Category I: A heat output of 15 percent or less of manufacturer’s rated heat output capacity.
4.3.2 Category II: A heat output of 16 percent to 24 percent of manufacturer’s rated heat output capacity.
4.3.3 Category III: A heat output of 25 percent to 50 percent of manufacturer’s rated heat output capacity.
4.3.4 Category IV: Manufacturer’s rated heat output capacity.
5.1 The measurement of particulate matter emission rates is an important test method widely used in the practice of air pollution control.
5.1.1 These measurements, when approved by state or federal agencies, are often required for the purpose of determining compliance with regulations and statutes.
5.1.2 The measurements made before and after design modifications are necessary to demonstrate the effectiveness of design changes in reducing emissions and make this standard an important tool in manufacturers’ research and development programs.
5.2 Measurement of heating efficiency provides a uniform basis for comparison of product performance that is useful to the consumer. It is also required to relate emissions produced to the useful heat production.
5.3 This is a laboratory method and is not intended to be fully representative of all actual field use. It is recognized that users of hand-fired, wood-burning equipment have a great deal of influence over the performance of any wood-burning appliance. Some compromises in realism have been made in the interest of providing a reliable and repeatable test method.
6.1 Scale. A platform scale capable of weighing the appliance under test and associated parts and accessories when completely filled with water to an accuracy of ±1.0 pound (±0.5 kg).
6.2 Heat Exchanger. A water-to-water heat exchanger capable of dissipating the expected heat output from the system under test.
6.3 Water Temperature Difference Measurement. A Type – T ‘special limits’ thermopile with a minimum of 5 pairs of junctions shall be used to measure the temperature difference in water entering and leaving the heat exchanger. The temperature difference measurement uncertainty of this type of thermopile is equal to or less than ±0.50 °F (±0.25 °C). Other temperature measurement methods may be used if the temperature difference measurement uncertainty is equal to or less than ±0.50 °F (±0.25 °C).
6.4 Water Flow Meter. A water flow meter shall be installed in the inlet to the load side of the heat exchanger. The flow meter shall have an accuracy of ±1 percent of measured flow.
6.4.1 Optional – Appliance Side Water Flow Meter. A water flow meter with an accuracy of ±1 percent of the flow rate is recommended to monitor supply side water flow rate.
6.5 Optional Recirculation Pump. Circulating pump used during test to prevent stratification of liquid being heated.
6.6 Water Temperature Measurement – Thermocouples or other temperature sensors to measure the water temperature at the inlet and outlet of the load side of the heat exchanger. Must meet the calibration requirements specified in section 10.1.
6.7 Wood Moisture Meter – Calibrated electrical resistance meter capable of measuring test fuel moisture to within 1 percent moisture content. Must meet the calibration requirements specified in section 10.4.
6.8 Flue Gas Temperature Measurement – Must meet the requirements of CSA B415.1-10 (IBR, see § 60.17), clause 6.2.2.
6.9 Test Room Temperature Measurement – Must meet the requirements of CSA B415.1-10 (IBR, see § 60.17), clause 6.2.1.
6.10 Flue Gas Composition Measurement – Must meet the requirements of CSA B415.1-10 (IBR, see § 60.17), clauses 6.3.1 through 6.3.3.
7.1 These tests involve combustion of wood fuel and substantial release of heat and products of combustion. The heating system also produces large quantities of very hot water and the potential for steam production and system pressurization. Appropriate precautions must be taken to protect personnel from burn hazards and respiration of products of combustion.
8.1 Test specimens shall be supplied as complete appliances including all controls and accessories necessary for installation in the test facility. A full set of specifications and design and assembly drawings shall be provided when the product is to be placed under certification of a third-party agency. The manufacturer’s written installation and operating instructions are to be used as a guide in the set-up and testing of the appliance.
9.1 The appliance is to be placed on a scale capable of weighing the appliance fully loaded with a resolution of ±1.0 lb (0.5 kg).
9.2 The appliance shall be fitted with the type of chimney recommended or provided by the manufacturer and extending to 15 ±0.5 feet (4.6 ±0.15 m) from the upper surface of the scale. If no flue or chimney system is recommended or provided by the manufacturer, connect the appliance to a flue of a diameter equal to the flue outlet of the appliance. The flue section from the appliance flue collar to 8 ±0.5 feet above the scale shall be single wall stove pipe and the remainder of the flue shall be double wall insulated class A chimney.
9.3 Optional Equipment Use
9.3.1 A recirculation pump may be installed between connections at the top and bottom of the appliance to minimize thermal stratification if specified by the manufacturer. The pump shall not be installed in such a way as to change or affect the flow rate between the appliance and the heat exchanger.
9.3.2 If the manufacturer specifies that a thermal control valve or other device be installed and set to control the return water temperature to a specific set point, the valve or other device shall be installed and set per the manufacturer’s written instructions.
9.4 Prior to filling the tank, weigh and record the appliance mass.
9.5 Heat Exchanger
9.5.1 Plumb the unit to a water-to-water heat exchanger with sufficient capacity to draw off heat at the maximum rate anticipated. Route hoses, electrical cables, and instrument wires in a manner that does not influence the weighing accuracy of the scale as indicated by placing dead weights on the platform and verifying the scale’s accuracy.
9.5.2 Locate thermocouples to measure the water temperature at the inlet and outlet of the load side of the heat exchanger.
9.5.3 Install a thermopile meeting the requirements of section 6.3 to measure the water temperature difference between the inlet and outlet of the load side of the heat exchanger.
9.5.4 Install a calibrated water flow meter in the heat exchanger load side supply line. The water flow meter is to be installed on the cooling water inlet side of the heat exchanger so that it will operate at the temperature at which it is calibrated.
9.5.5 Place the heat exchanger in a box with 2 in. (50 mm) of expanded polystyrene (EPS) foam insulation surrounding it to minimize heat losses from the heat exchanger.
9.5.6 The reported efficiency and heat output rate shall be based on measurements made on the load side of the heat exchanger.
9.5.7 Temperature instrumentation per section 6.6 shall be installed in the appliance outlet and return lines. The average of the outlet and return water temperature on the supply side of the system shall be considered the average appliance temperature for calculation of heat storage in the appliance (TF
9.6 Fill the system with water. Determine the total weight of the water in the appliance when the water is circulating. Verify that the scale indicates a stable weight under operating conditions. Make sure air is purged properly.
10.1 Water Temperature Sensors. Temperature measuring equipment shall be calibrated before initial use and at least semi-annually thereafter. Calibrations shall be in compliance with National Institute of Standards and Technology (NIST) Monograph 175, Standard Limits of Error.
10.2 Heat Exchanger Load Side Water Flow Meter.
10.2.1 The heat exchanger load side water flow meter shall be calibrated within the flow range used for the test run using NIST traceable methods. Verify the calibration of the water flow meter before and after each test run and at least once during each test run by comparing the water flow rate indicated by the flow meter to the mass of water collected from the outlet of the heat exchanger over a timed interval. Volume of the collected water shall be determined based on the water density calculated from section 13, Eq. 8, using the water temperature measured at the flow meter. The uncertainty in the verification procedure used shall be 1 percent or less. The water flow rate determined by the collection and weighing method shall be within 1 percent of the flow rate indicated by the water flow meter.
10.3 Scales. The scales used to weigh the appliance and test fuel charge shall be calibrated using NIST traceable methods at least once every 6 months.
10.4 Moisture Meter. The moisture meter shall be calibrated per the manufacturer’s instructions and checked before each use.
10.5 Flue Gas Analyzers – In accordance with CSA B415.1-10 (IBR, see § 60.17), clause 6.8.
11.1 Prior to testing, the appliance is to be operated for a minimum of 50 hours using a medium heat draw rate. The conditioning may be at the manufacturer’s facility prior to the certification test. If the conditioning is at the certification test laboratory, the pre-burn for the first test can be included as part of the conditioning requirement. If conditioning is included in pre-burn, then the appliance shall be aged with fuel meeting the specifications outlined in sections 12.2 with a moisture content between 19 and 25 percent on a dry basis. Operate the appliance at a medium burn rate (Category II or III) for at least 10 hours for noncatalytic appliances and 50 hours for catalytic appliances. Record and report hourly flue gas exit temperature data and the hours of operation. The aging procedure shall be conducted and documented by a testing laboratory.
12.1 Appliance Installation. Assemble the appliance and parts in conformance with the manufacturer’s written installation instructions. Clean the flue with an appropriately sized, wire chimney brush before each certification test series.
12.2 Fuel. Test fuel charge fuel shall be red (Quercus ruba L.) or white (Quercus alba) oak 19 to 25 percent moisture content on a dry basis. Piece length shall be 80 percent of the firebox depth rounded down to the nearest 1 inch (25mm) increment. For example, if the firebox depth is 46 inches (1168mm) the 4 × 4 piece length would be 36 inches (46 inches × 0.8 = 36.8 inches rounded down to 36 inches). Pieces are to be placed in the firebox parallel to the longest firebox dimension. For fireboxes with sloped surfaces that create a non-uniform firebox length, the piece length shall be adjusted for each layer based on 80 percent of the length at the level where the layer is placed. Pieces are to be spaced
12.2.1 Using a fuel moisture meter as specified in section 6.7 of the test method, determine the fuel moisture for each test fuel piece used for the test fuel load by averaging at least five fuel moisture meter readings measured parallel to the wood grain. Penetration of the moisture meter insulated electrodes for all readings shall be
12.2.2 Firebox Volume. Determine the firebox volume in cubic feet. Firebox volume shall include all areas accessible through the fuel loading door where firewood could reasonably be placed up to the horizontal plane defined by the top of the loading door. A drawing of the firebox showing front, side and plan views or an isometric view with interior dimensions shall be provided by the manufacturer and verified by the laboratory. Calculations for firebox volume from computer aided design (CAD) software programs are acceptable and shall be included in the test report if used. If the firebox volume is calculated by the laboratory the firebox drawings and calculations shall be included in the test report.
12.2.3 Test Fuel Charge. Test fuel charges shall be determined by multiplying the firebox volume by 10 pounds (4.54 kg) per ft
12.3 Sampling Equipment. Prepare the particulate emission sampling equipment as defined by ASTM E2515-11 Standard Test Method for Determination of Particulate Matter Emissions Collected in a Dilution Tunnel (IBR, see § 60.17). Upon request, four-inch filters may be used. Upon request, Teflon membrane filters or Teflon-coated glass fiber filters may be used.
12.4 Appliance Startup. The appliance shall be fired with wood fuel of any species, size and moisture content at the laboratories’ discretion to bring it up to operating temperature. Operate the appliance until the water is heated to the upper operating control limit and has cycled at least two times. Then remove all unburned fuel, zero the scale and verify the scales accuracy using dead weights.
12.4.1 Pretest Burn Cycle. Reload appliance with oak wood and allow it to burn down to the specified coal bed weight. The pretest burn cycle fuel charge weight shall be within ±10 percent of the test fuel charge weight. Piece size and length shall be selected such that charcoalization is achieved by the time the fuel charge has burned down to the required coal bed weight. Pieces with a maximum thickness of approximately 2 inches have been found to be suitable. Charcoalization is a general condition of the test fuel bed evidenced by an absence of large pieces of burning wood in the coal bed and the remaining fuel pieces being brittle enough to be broken into smaller charcoal pieces with a metal poker. Manipulations to the fuel bed prior to the start of the test run are to be done to achieve charcoalization while maintaining the desired heat output rate. During the pre-test burn cycle and at least one hour prior to starting the test run, adjust water flow to the heat exchanger to establish the target heat draw for the test. For the first test run the heat draw rate shall be equal to the manufacturer’s rated heat output capacity.
12.4.1.1 Allowable Adjustments. Fuel addition or subtractions, and coal bed raking shall be kept to a minimum but are allowed up to 15 minutes prior to the start of the test run. For the purposes of this method, coal bed raking is the use of a metal tool (poker) to stir coals, break burning fuel into smaller pieces, dislodge fuel pieces from positions of poor combustion, and check for the condition of charcoalization. Record all adjustments to and additions or subtractions of fuel, and any other changes to the appliance operations that occur during pretest ignition period. During the 15-minute period prior to the start of the test run, the wood heater loading door shall not be open more than a total of 1 minute. Coal bed raking is the only adjustment allowed during this period.
12.4.2 Coal Bed Weight. The appliance is to be loaded with the test fuel charge when the coal bed weight is between 10 percent and 20 percent of the test fuel charge weight. Coals may be raked as necessary to level the coal bed but may only be raked and stirred once between 15 to 20 minutes prior to the addition of the test fuel charge.
12.5 Test Runs. For all test runs, the return water temperature to the hydronic heater must be equal to or greater than 120 °F. Aquastat or other heater output control device settings that are adjustable shall be set using manufacturer specifications, either as factory set or in accordance with the owner’s manual, and shall remain the same for all burn categories.
Complete a test run in each heat output rate category, as follows:
12.5.1 Test Run Start. Once the appliance is operating normally and the pretest coal bed weight has reached the target value per section 12.4.2, tare the scale and load the full test charge into the appliance. Time for loading shall not exceed 5 minutes. The actual weight of the test fuel charge shall be measured and recorded within 30 minutes prior to loading. Start all sampling systems.
12.5.1.1 Record all water temperatures, differential water temperatures and water flow rates at time intervals of one minute or less.
12.5.1.2 Record particulate emissions data per the requirements of ASTM E2515 (IBR, see § 60.17).
12.5.1.3 Record data needed to determine overall efficiency (SLM) per the requirements of CSA B415.1-10 (IBR, see § 60.17), clauses 6.2.1, 6.2.2, 6.3, 8.5.7, 10.4.3 (a), 10.4.3(f), and 13.7.9.3
12.5.1.3.1 Measure and record the test room air temperature in accordance with the requirements of CSA B415.1-10 (IBR, see § 60.17), clauses 6.2.1, 8.5.7 and 10.4.3 (g).
12.5.1.3.2 Measure and record the flue gas temperature in accordance with the requirements of CSA B415.1-10 (IBR, see § 60.17), clauses 6.2.2, 8.5.7 and 10.4.3 (f).
12.5.1.3.3 Determine and record the carbon monoxide (CO) and carbon dioxide (CO
12.5.1.3.4 Measure and record the test fuel weight per the requirements of CSA B415.1-10 (IBR, see § 60.17), clauses 8.5.7 and 10.4.3 (h).
12.5.1.3.5 Record the test run time per the requirements of CSA B415.1-10 (IBR, see § 60.17), clauses 10.4.3 (a).
12.5.1.4 Monitor the average heat output rate on the load side of the heat exchanger. If the heat output rate gets close to the upper or lower limit of the target range (±5 percent) adjust the water flow through the heat exchanger to compensate. Make changes as infrequently as possible while maintaining the target heat output rate. The first test run shall be conducted at the Category IV heat output rate to validate that the appliance is capable of producing the manufacturer’s rated heat output capacity.
12.5.2 Test Fuel Charge Adjustment. It is acceptable to adjust the test fuel charge (i.e., reposition) once during a test run if more than 60 percent of the initial test fuel charge weight has been consumed and more than 10 minutes have elapsed without a measurable (1 lb or 0. 5 kg) weight change while the operating control is in the demand mode. The time used to make this adjustment shall be less than 60 seconds.
12.5.3 Test Run Completion. The test run is completed when the remaining weight of the test fuel charge is 0.0 lb (0.0 kg). End the test run when the scale has indicated a test fuel charge weight of 0.0 lb (0.0 kg) or less for 30 seconds.
12.5.3.1 At the end of the test run, stop the particulate sampling train and overall efficiency (SLM) measurements, and record the run time, and all final measurement values.
12.5.4 Heat Output Capacity Validation. The first test run must produce a heat output rate that is within 10 percent of the manufacturer’s rated heat output capacity (Category IV) throughout the test run and an average heat output rate within 5 percent of the manufacturer’s rated heat output capacity. If the appliance is not capable of producing a heat output within these limits, the manufacturer’s rated heat output capacity is considered not validated and testing is to be terminated. In such cases, the tests may be restarted using a lower heat output capacity if requested by the manufacturer.
12.5.5 Additional Test Runs. Using the manufacturer’s rated heat output capacity as a basis, conduct a test for additional heat output categories as specified in section 4.3. It is not required to run these tests in any particular order.
12.5.6 Alternative Heat Output Rate for Category I. If an appliance cannot be operated in the Category I heat output range due to stopped combustion, two test runs shall be conducted at heat output rates within Category II, provided that the completed test run burn rate is no greater than the burn rate expected in home use. If this rate cannot be achieved, the test is not valid.
When the alternative heat output rate is used, the weightings for the weighted averages indicated in Table 2 shall be the average of the Category I and II weightings and shall be applied to both Category II results. The two completed runs in Category II will be deemed to meet the requirement for runs completed in both Category I and Category II. Appliances that are not capable of operation within Category II (
12.5.6.1 Stopped Fuel Combustion. Evidence that an appliance cannot be operated at a Category I heat output rate due to stopped fuel combustion shall include documentation of two or more attempts to operate the appliance in burn rate Category I and fuel combustion has stopped prior to complete consumption of the test fuel charge. Stopped fuel combustion is evidenced when an elapsed time of 60 minutes or more has occurred without a measurable (1 lb or 0.5 kg) weight change in the test fuel charge while the appliance operating control is in the demand mode. Report the evidence and the reasoning used to determine that a test in burn rate Category I cannot be achieved. For example, two unsuccessful attempts to operate at an output rate of 10 percent of the rated output capacity are not sufficient evidence that burn rate Category I cannot be achieved. Note that section 12.5.6 requires that the completed test run burn rate can be no greater than the burn rate expected in home use. If this rate cannot be achieved, the test is not valid.
12.5.7 Appliance Overheating. Appliances shall be capable of operating in all heat output categories without overheating to be rated by this test method. Appliance overheating occurs when the rate of heat withdrawal from the appliance is lower than the rate of heat production when the unit control is in the idle mode. This condition results in the water in the appliance continuing to increase in temperature well above the upper limit setting of the operating control. Evidence of overheating includes: 1 hour or more of appliance water temperature increase above the upper temperature set-point of the operating control, exceeding the temperature limit of a safety control device (independent from the operating control), boiling water in a non-pressurized system or activation of a pressure or temperature relief valve in a pressurized system.
12.6 Additional Test Runs. The testing laboratory may conduct more than one test run in each of the heat output categories specified in section 4.3.1. If more than one test run is conducted at a specified heat output rate, the results from at least two-thirds of the test runs in that heat output rate category shall be used in calculating the weighted average emission rate (See section 14.1.14). The measurement data and results of all test runs shall be reported regardless of which values are used in calculating the weighted average emission rate.
13.2 After the test is completed, determine the particulate emissions E
The subscript (i) indicates the parameter value for sampling time interval t
Vi is the total water volume at the end of interval i and Vi-1 is the total water volume at the beginning of the time interval. This calculation is necessary when a totalizing type water meter is used.
For determination of the average overall thermal efficiency (η
13.5.5.1 Whenever the CSA B415.1-10 (IBR, see § 60.17) overall efficiency is found to be lower than the overall efficiency based on load side measurements, as determined by Eq. 16 of this method, section 14.1.7 of the test report must include a discussion of the reasons for this result.
13.6.1 Determine the weighted average emission rate and delivered efficiency from the individual tests in the specified heat output categories. The weighting factors (Fi) are derived from an analysis of ASHRAE bin data which provides details of normal building heating requirements in terms of percent of design capacity and time in a particular capacity range – or “bin” – over the course of a heating season. The values used in this method represent an average of data from several cities located in the northern United States.
13.7 Average Heat Output (Q
13.7.1 Units tested under this standard typically require infrequent fuelling, 8 to 12 hours intervals being typical. Rating unit’s based on an average output sustainable over an 8 hour duration will assist consumers in appropriately sizing units to match the theoretical heat demand of their application.
13.7.2 Calculations:
13.7.2.1 Determine the test durations and actual load for each category as recorded in Table 1A.
13.7.2.2 Determine the data point that has the nearest duration greater than 8 hrs.
13.7.2.3 Determine the data point that has the nearest duration less than 8 hours.
13.7.2.4 Example:
Category Actual Load Duration
[Category Actual Load Duration ηdel]
| (Btu/Hr) | (Hr) | (%) |
|---|---|---|
| 1 15,000 | 10.2 | 70.0 |
| 2 26,000 | 8.4 | 75.5 |
| 3 50,000 | 6.4 | 80.1 |
| 4 100,000 | 4.7 | 80.9 |
Category 2 duration is just above 8 hours, therefore: X1 = 26,000 Btu/hr, η
Category 3 duration is just below 8 hours, therefore: X2 = 50,000 Btu/hr, η
For each minute of the test period, the carbon monoxide emission rate shall be calculated as:
Total CO emissions for each of the three test periods (CO
Total CO emission for the test run, CO
14.1.1 The report shall include the following.
14.1.2 Name and location of the laboratory conducting the test.
14.1.3 A description of the appliance tested and its condition, date of receipt and dates of tests.
14.1.4 A statement that the test results apply only to the specific appliance tested.
14.1.5 A statement that the test report shall not be reproduced except in full, without the written approval of the laboratory.
14.1.6 A description of the test procedures and test equipment including a schematic or other drawing showing the location of all required test equipment. Also, a description of test fuel sourcing, handling and storage practices shall be included.
14.1.7 Details of deviations from, additions to or exclusions from the test method, and their data quality implications on the test results (if any), as well as information on specific test conditions, such as environmental conditions.
14.1.8 A list of participants and observers present for the tests.
14.1.9 Data and drawings indicating the fire box size and location of the fuel charge.
14.1.10 Drawings and calculations used to determine firebox volume.
14.1.11 Information for each test run fuel charge including piece size, moisture content, and weight.
14.1.12 All required data for each test run shall be provided in spreadsheet format. Formulae used for all calculations shall be accessible for review.
14.1.13 Test run duration for each test.
14.1.14 Calculated results for delivered efficiency at each burn rate and the weighted average emissions reported as total emissions in grams, pounds per mm Btu of delivered heat, grams per MJ of delivered heat, grams per kilogram of dry fuel and grams per hour. Results shall be reported for each heat output category and the weighted average.
14.1.15 Tables 1A, 1B, 1C and Table 2 must be used for presentation of results in test reports.
14.1.16 A statement of the estimated uncertainty of measurement of the emissions and efficiency test results.
14.1.17 Raw data, calibration records, and other relevant documentation shall be retained by the laboratory for a minimum of 7 years.
15.1 Precision – It is not possible to specify the precision of the procedure in Method 28WHH because the appliance operation and fueling protocols and the appliances themselves produce variable amounts of emissions and cannot be used to determine reproducibility or repeatability of this measurement method.
15.2 Bias – No definitive information can be presented on the bias of the procedure in Method 28WHH for measuring solid fuel burning hydronic heater emissions because no material having an accepted reference value is available.
16.1 Solid fuel, hydronic heating appliances, wood-burning hydronic heaters.
1.1 This test method applies to wood-fired hydronic heating appliances with heat storage external to the appliance. The units typically transfer heat through circulation of a liquid heat exchange media such as water or a water-antifreeze mixture. Throughout this document, the term “water” will be used to denote any of the heat transfer liquids approved for use by the manufacturer.
1.2 The test method measures PM and CO emissions and delivered heating efficiency at specified heat output rates referenced against the appliance’s rated heating capacity as specified by the manufacturer and verified under this test method.
1.3 PM emissions are measured by the dilution tunnel method as specified in the EPA Method 28WHH and the standards referenced therein with the exceptions noted in section 12.5.9. Delivered efficiency is measured by determining the fuel energy input and appliance output. Heat output is determined through measurement of the flow rate and temperature change of water circulated through a heat exchanger external to the appliance and the increase in energy of the external storage. Heat input is determined from the mass of dry wood fuel and its higher heating value (HHV). Delivered efficiency does not attempt to account for pipeline loss.
1.4 Products covered by this test method include both pressurized and non-pressurized hydronic heating appliances intended to be fired with wood and for which the manufacturer specifies for indoor or outdoor installation. The system, which includes the heating appliance and external storage, is commonly connected to a heat exchanger by insulated pipes and normally includes a pump to circulate heated liquid. These systems are used to heat structures such as homes, barns and greenhouses. They also provide heat for domestic hot water, spas and swimming pools.
1.5 Distinguishing features of products covered by this standard include:
1.5.1 The manufacturer specifies the application for either indoor or outdoor installation.
1.5.2 A firebox with an access door for hand loading of fuel.
1.5.3 Typically an aquastat mounted as part of the appliance that controls combustion air supply to maintain the liquid in the appliance within a predetermined temperature range provided sufficient fuel is available in the firebox. The appliance may be equipped with other devices to control combustion.
1.5.4 A chimney or vent that exhausts combustion products from the appliance.
1.5.5 A liquid storage system, typically water, which is not large enough to accept all of the heat produced when a full load of wood is burned and the storage system starts a burn cycle at 125 °F.
1.5.6 The heating appliances require external thermal storage and these units will only be installed as part of a system which includes thermal storage. The manufacturer specifies the minimum amount of thermal storage required. However, the storage system shall be large enough to ensure that the boiler (heater) does not cycle, slumber, or go into an off-mode when operated in a Category III load condition (See section 4.3).
1.6 The values stated are to be regarded as the standard whether in I-P or SI units. The values given in parentheses are for information only.
2.1 PM and CO emissions are measured from a wood-fired hydronic heating appliance burning a prepared test fuel charge in a test facility maintained at a set of prescribed conditions. Procedures for determining heat output rates, PM and CO emissions, and efficiency and for reducing data are provided.
2.2.1 EPA Standards
2.2.1.1 Method 28 Certification and Auditing of Wood Heaters
2.2.1.2 Method 28WHH Measurement of Particulate Emissions and Heating Efficiency of Wood-Fired Hydronic Heating Appliances and the Standards Referenced therein.
2.2.2 Other Standards
2.2.2.1 CSA-B415.1-10 Performance Testing of Solid-Fuel-Burning Heating Appliances
3.1.1 Hydronic Heating – A heating system in which a heat source supplies energy to a liquid heat exchange media such as water that is circulated to a heating load and returned to the heat source through pipes.
3.1.2 Aquastat – A control device that opens or closes a circuit to control the rate of fuel consumption in response to the temperature of the heating media in the heating appliance.
3.1.3 Delivered Efficiency – The percentage of heat available in a test fuel charge that is delivered to a simulated heating load or the storage system as specified in this test method.
3.1.4 Emission Factor – The emission of a pollutant expressed in mass per unit of energy (typically) output from the boiler/heater.
3.1.5 Emission Index – The emission of a pollutant expressed in mass per unit mass of fuel used.
3.1.6 Emission Rate – The emission of a pollutant expressed in mass per unit time
3.1.7 Manufacturer’s Rated Heat Output Capacity – The value in Btu/hr (MJ/hr) that the manufacturer specifies that a particular model of hydronic heating appliance is capable of supplying at its design capacity as verified by testing, in accordance with section 12.5.4.
3.1.8 Heat Output Rate – The average rate of energy output from the appliance during a specific test period in Btu/hr (MJ/hr).
3.1.9 Firebox – The chamber in the appliance in which the test fuel charge is placed and combusted.
3.1.10 NIST – National Institute of Standards and Technology.
3.1.11 Test Fuel Charge – The collection of test fuel placed in the appliance at the start of the emission test run.
3.1.12 Test Run – An individual emission test which encompasses the time required to consume the mass of the test fuel charge. The time of the test run also considers the time for the energy to be drawn from the thermal storage.
3.1.13 Test Run Under “Cold-to-Cold” Condition – Under this test condition the test fuel is added into an empty chamber along with kindling and ignition materials (paper). The boiler/heater at the start of this test is typically 125° to 130 °F.
3.1.14 Test Run Under “Hot-to-Hot” Condition – Under this test condition the test fuel is added onto a still-burning bed of charcoals produced in a pre-burn period. The boiler/heater water is near its operating control limit at the start of the test.
3.1.15 Overall Efficiency, also known as Stack Loss Efficiency – The efficiency for each test run as determined using the CSA B415.1-10 (IBR, see § 60.17) stack loss method (SLM).
3.1.16 Phases of a Burn Cycle – The “startup phase” is defined as the period from the start of the test until 15 percent of the test fuel charge is consumed. The “steady-state phase” is defined as the period from the end of the startup phase to a point at which 80 percent of the test fuel charge is consumed. The “end phase” is defined as the time from the end of the steady-state period to the end of the test.
3.1.17 Thermopile – A device consisting of a number of thermocouples connected in series, used for measuring differential temperature.
3.1.18 Slumber Mode – This is a mode in which the temperature of the water in the boiler/heater has exceeded the operating control limit and the control has changed the boiler/heater fan speed, dampers, and/or other operating parameters to minimize the heat output of the boiler/heater.
4.1 Dilution Tunnel. Emissions are determined using the “dilution tunnel” method specified in EPA Method 28WHH and the standards referenced therein. The flow rate in the dilution tunnel is maintained at a constant level throughout the test cycle and accurately measured. Samples of the dilution tunnel flow stream are extracted at a constant flow rate and drawn through high efficiency filters. The filters are dried and weighed before and after the test to determine the emissions collected and this value is multiplied by the ratio of tunnel flow to filter flow to determine the total particulate emissions produced in the test cycle.
4.2 Efficiency. The efficiency test procedure takes advantage of the fact that this type of system delivers heat through circulation of the heated liquid (water) from the system to a remote heat exchanger (e.g. baseboard radiators in a room) and back to the system. Measurements of the cooling water temperature difference as it enters and exits the test system heat exchanger along with the measured flow rate allow for an accurate determination of the useful heat output of the appliance. Also included in the heat output is the change in the energy content in the storage system during a test run. Energy input to the appliance during the test run is determined by weight of the test fuel charge, adjusted for moisture content, multiplied by the higher heating value. Additional measurements of the appliance weight and temperature at the beginning and end of a test cycle are used to correct for heat stored in the appliance. Overall efficiency (SLM) is determined using the CSA B415.1-10 (IBR, see § 60.17) stack loss method for data quality assurance purposes.
4.3 Operation. Four test categories are defined for use in this method. These are:
4.3.1 Category I: A heat output of 15 percent or less of manufacturer’s rated heat output capacity.
4.3.2 Category II: A heat output of 16 percent to 24 percent of manufacturer’s rated heat output capacity.
4.3.3 Category III: A heat output of 25 percent to 50 percent of manufacturer’s rated heat output capacity.
4.3.4 Category IV: Manufacturer’s Rated Heat Output Capacity. These heat output categories refer to the output from the system by way of the load heat exchanger installed for the test. The output from just the boiler/heater part of the system may be higher for all or part of a test, as part of this boiler/heater output goes to storage.
For the Category III and IV runs, appliance operation is conducted on a hot-to-hot test cycle meaning that the appliance is brought to operating temperature and a coal bed is established prior to the addition of the test fuel charge and measurements are made for each test fuel charge cycle. The measurements are made under constant heat draw conditions within pre-determined ranges. No attempt is made to modulate the heat demand to simulate an indoor thermostat cycling on and off in response to changes in the indoor environment.
For the Category I and II runs, the unit is tested with a “cold start.” At the manufacturer’s option, the Category II and III runs may be waived and it may be assumed that the particulate emission values and efficiency values determined in the startup, steady-state, and end phases of Category I are applicable in Categories II and III for the purpose of determining the annual averages in lb/mmBtu and g/MJ (See section 13). For the annual average in g/hr, the length of time for stored heat to be drawn from thermal storage shall be determined for the test load requirements of the respective category.
All test operations and measurements shall be conducted by personnel of the laboratory responsible for the submission of the test report.
5.1 The measurement of particulate matter emission and CO rates is an important test method widely used in the practice of air pollution control.
5.1.1 These measurements, when approved by state or federal agencies, are often required for the purpose of determining compliance with regulations and statutes.
5.1.2 The measurements made before and after design modifications are necessary to demonstrate the effectiveness of design changes in reducing emissions and make this standard an important tool in manufacturers’ research and development programs.
5.2 Measurement of heating efficiency provides a uniform basis for comparison of product performance that is useful to the consumer. It is also required to relate emissions produced to the useful heat production.
5.3 This is a laboratory method and is not intended to be fully representative of all actual field use. It is recognized that users of hand-fired, wood-burning equipment have a great deal of influence over the performance of any wood-burning appliance. Some compromises in realism have been made in the interest of providing a reliable and repeatable test method.
6.1 Scale. A platform scale capable of weighing the boiler/heater under test and associated parts and accessories when completely filled with water to an accuracy of ±1.0 pound (±0.5 kg) and a readout resolution of ±0.2 pound (±0.1 kg).
6.2 Heat Exchanger. A water-to-water heat exchanger capable of dissipating the expected heat output from the system under test.
6.3 Water Temperature Difference Measurement. A Type – T ‘special limits’ thermopile with a minimum of 5 pairs of junctions shall be used to measure the temperature difference in water entering and leaving the heat exchanger. The temperature difference measurement uncertainty of this type of thermopile is equal to or less than ±0.50 °F (±0.25 °C). Other temperature measurement methods may be used if the temperature difference measurement uncertainty is equal to or less than ±0.50 °F (±0.25 °C). This measurement uncertainty shall include the temperature sensor, sensor well arrangement, piping arrangements, lead wire, and measurement/recording system. The response time of the temperature measurement system shall be less than half of the time interval at which temperature measurements are recorded.
6.4 Water Flow Meter. A water flow meter shall be installed in the inlet to the load side of the heat exchanger. The flow meter shall have an accuracy of ±1 percent of measured flow.
6.4.1 Optional – Appliance Side Water Flow Meter. A water flow meter with an accuracy of ±1 percent of the flow rate is recommended to monitor supply side water flow rate.
6.5 Optional Recirculation Pump. Circulating pump used during test to prevent stratification, in the boiler/heater, of liquid being heated.
6.6 Water Temperature Measurement. Thermocouples or other temperature sensors to measure the water temperature at the inlet and outlet of the load side of the heat exchanger must meet the calibration requirements specified in 10.1 of this method.
6.7 Lab Scale. For measuring the moisture content of wood slices as part of the overall wood moisture determination. Accuracy of ±0.01 pounds.
6.8 Flue Gas Temperature Measurement. Must meet the requirements of CSA B415.1-10 (IBR, see § 60.17), clause 6.2.2.
6.9 Test Room Temperature Measurement. Must meet the requirements of CSA B415.1-10 (IBR, see § 60.17), clause 6.2.1.
6.10 Flue Gas Composition Measurement. Must meet the requirements of CSA B415.1-10 (IBR, see § 60.17), clauses 6.3.1 through 6.3.3.
6.11 Dilution Tunnel CO Measurement. In parallel with the flue gas composition measurements, the CO concentration in the dilution tunnel shall also be measured and reported at time intervals not to exceed one minute. This analyzer shall meet the zero and span drift requirements of CSA B415.1-10 (IBR, see § 60.17). In addition the measurement repeatability shall be better than ±15 ppm over the range of CO levels observed in the dilution tunnel.
7.1 These tests involve combustion of wood fuel and substantial release of heat and products of combustion. The heating system also produces large quantities of very hot water and the potential for steam production and system pressurization. Appropriate precautions must be taken to protect personnel from burn hazards and respiration of products of combustion.
8.1 Test specimens shall be supplied as complete appliances, as described in marketing materials, including all controls and accessories necessary for installation in the test facility. A full set of specifications, installation and operating instructions, and design and assembly drawings shall be provided when the product is to be placed under certification of a third-party agency. The manufacturer’s written installation and operating instructions are to be used as a guide in the set-up and testing of the appliance and shall be part of the test record.
8.2 The size, connection arrangement, and control arrangement for the thermal storage shall be as specified in the manufacturer’s documentation. It is not necessary to use the specific storage system that the boiler/heater will be marketed with. However, the capacity of the system used in the test cannot be greater than that specified as the minimum allowable for the boiler/heater.
8.3 All system control settings shall be the as-shipped, default settings. These default settings shall be the same as those communicated in a document to the installer or end user. These control settings and the documentation of the control settings as to be provided to the installer or end user shall be part of the test record.
8.4 Where the manufacturer defines several alternatives for the connection and loading arrangement, one shall be defined in the appliance documentation as the default or standard installation. It is expected that this will be the configuration for use with a simple baseboard heating system. This is the configuration to be followed for these tests. The manufacturer’s documentation shall define the other arrangements as optional or alternative arrangements.
9.1 The appliance is to be placed on a scale capable of weighing the appliance fully loaded with a resolution of ±0.2 lb (0.1 kg).
9.2 The appliance shall be fitted with the type of chimney recommended or provided by the manufacturer and extending to 15 ±0.5 feet (4.6 ±0.15 m) from the upper surface of the scale. If no flue or chimney system is recommended or provided by the manufacturer, connect the appliance to a flue of a diameter equal to the flue outlet of the appliance. The flue section from the appliance flue collar to 8 ±0.5 feet above the scale shall be single wall stove pipe and the remainder of the flue shall be double wall insulated class A chimney.
9.3 Optional Equipment Use
9.3.1 A recirculation pump may be installed between connections at the top and bottom of the appliance to minimize thermal stratification if specified by the manufacturer. The pump shall not be installed in such a way as to change or affect the flow rate between the appliance and the heat exchanger.
9.3.2 If the manufacturer specifies that a thermal control valve or other device be installed and set to control the return water temperature to a specific set point, the valve or other device shall be installed and set per the manufacturer’s written instructions.
9.4 Prior to filling the boiler/heater with water, weigh and record the appliance mass.
9.5 Heat Exchanger
9.5.1 Plumb the unit to a water-to-water heat exchanger with sufficient capacity to draw off heat at the maximum rate anticipated. Route hoses and electrical cables and instrument wires in a manner that does not influence the weighing accuracy of the scale as indicated by placing dead weights on the platform and verifying the scale’s accuracy.
9.5.2 Locate thermocouples to measure the water temperature at the inlet and outlet of the load side of the heat exchanger.
9.5.3 Install a thermopile (or equivalent instrumentation) meeting the requirements of section 6.3 to measure the water temperature difference between the inlet and outlet of the load side of the heat exchanger
9.5.4 Install a calibrated water flow meter in the heat exchanger load side supply line. The water flow meter is to be installed on the cooling water inlet side of the heat exchanger so that it will operate at the temperature at which it is calibrated.
9.5.5 Place the heat exchanger in a box with 2 in. (50 mm) of expanded polystyrene (EPS) foam insulation surrounding it to minimize heat losses from the heat exchanger.
9.5.6 The reported efficiency and heat output rate shall be based on measurements made on the load side of the heat exchanger.
9.5.7 Temperature instrumentation per section 6.6 shall be installed in the appliance outlet and return lines. The average of the outlet and return water temperature on the supply side of the system shall be considered the average appliance temperature for calculation of heat storage in the appliance (TF
9.6 Storage Tank. The storage tank shall include a destratification pump as illustrated in Figure 1. The pump will draw from the bottom of the tank and return to the top as illustrated. Temperature sensors (TS1 and TS2 in Figure 1) shall be included to measure the temperature in the recirculation loop. The valve plan in Figure 1 allows the tank recirculation loop to operate and the boiler/heater-to-heat exchanger loop to operate at the same time but in isolation. This would typically be done before the start of a test or following completion of a test to determine the end of test average tank temperature. The nominal flow rate in the storage tank recirculation loop can be estimated based on pump manufacturers’ performance curves and any significant restriction in the recirculation loop.
9.7 Fill the system with water. Determine the total weight of the water in the appliance when the water is circulating. Verify that the scale indicates a stable weight under operating conditions. Make sure air is purged properly.
10.1 Water Temperature Sensors. Temperature measuring equipment shall be calibrated before initial use and at least semi-annually thereafter. Calibrations shall be in compliance with National Institute of Standards and Technology (NIST) Monograph 175, Standard Limits of Error.
10.2 Heat Exchanger Load Side Water Flow Meter.
10.2.1 The heat exchanger load side water flow meter shall be calibrated within the flow range used for the test run using NIST-traceable methods. Verify the calibration of the water flow meter before and after each test run and at least once during each test run by comparing the water flow rate indicated by the flow meter to the mass of water collected from the outlet of the heat exchanger over a timed interval. Volume of the collected water shall be determined based on the water density calculated from section 13, Eq. 12, using the water temperature measured at the flow meter. The uncertainty in the verification procedure used shall be 1 percent or less. The water flow rate determined by the collection and weighing method shall be within 1 percent of the flow rate indicated by the water flow meter.
10.3 Scales. The scales used to weigh the appliance and test fuel charge shall be calibrated using NIST-traceable methods at least once every 6 months.
10.4 Flue Gas Analyzers – In accordance with CSA B415.1-10 (IBR, see § 60.17), clause 6.8.
11.1 Prior to testing, an appliance is to be operated for a minimum of 50 hours using a medium heat draw rate. The conditioning may be at the manufacturer’s facility prior to the certification test. If the conditioning is at the certification test laboratory, the pre-burn for the first test can be included as part of the conditioning requirement. If conditioning is included in pre-burn, then the appliance shall be aged with fuel meeting the specifications outlined in section 12.2 with a moisture content between 19 and 25 percent on a dry basis. Operate the appliance at a medium heat output rate (Category II or III) for at least 10 hours for non-catalytic appliances and 50 hours for catalytic appliances. Record and report hourly flue gas exit temperature data and the hours of operation. The aging procedure shall be conducted and documented by a testing laboratory.
12.1 Appliance Installation. Assemble the appliance and parts in conformance with the manufacturer’s written installation instructions. Clean the flue with an appropriately sized, wire chimney brush before each certification test series.
12.2 Fuel. Test fuel charge fuel shall be red (Quercus ruba L.) or white (Quercus Alba) oak 19 to 25 percent moisture content on a dry basis. Piece length shall be 80 percent of the firebox depth rounded down to the nearest 1 inch (25mm) increment. For example, if the firebox depth is 46 inches (1168mm) the piece length would be 36 inches (46 inches × 0.8 = 36.8 inches, rounded down to 36 inches). Pieces are to be placed in the firebox parallel to the longest firebox dimension. For fireboxes with sloped surfaces that create a non-uniform firebox length, the piece length shall be adjusted for each layer based on 80 percent of the length at the level where the layer is placed. The test fuel shall be cord wood with cross section dimensions and weight limits as defined in CSA B415.1-10 (IBR, see § 60.17), section 8.3, Table 4. The use of dimensional lumber is not allowed.
12.2.1 Select three pieces of cord wood from the same batch of wood as the test fuel and the same weight as the average weight of the pieces in the test load ±1.0 lb. From each of these three pieces, cut three slices. Each slice shall be
The moisture content of each slice, on a dry basis, shall be calculated as:
The average moisture content of the entire test load (MC) shall be determined using Eq. 6. Each individual slice shall have a moisture content in the range of 18 percent to 28 percent on a dry basis. The average moisture content for the test fuel load shall be in the range of 19 percent to 25 percent. Moisture shall not be added to previously dried fuel pieces except by storage under high humidity conditions and temperature up to 100 °F. Fuel moisture measurement shall begin within 4 hours of using the fuel batch for a test. Use of a pin-type meter to estimate the moisture content prior to a test is recommended.
12.2.2 Firebox Volume. Determine the firebox volume in cubic feet. Firebox volume shall include all areas accessible through the fuel loading door where firewood could reasonably be placed up to the horizontal plane defined by the top of the loading door. A drawing of the firebox showing front, side and plan views or an isometric view with interior dimensions shall be provided by the manufacturer and verified by the laboratory. Calculations for firebox volume from computer aided design (CAD) software programs are acceptable and shall be included in the test report if used. If the firebox volume is calculated by the laboratory the firebox drawings and calculations shall be included in the test report.
12.2.3 Test Fuel charge. Test fuel charges shall be determined by multiplying the firebox volume by 10 pounds (4.54 kg) per ft
12.3 Sampling Equipment. Prepare the particulate emission sampling equipment as defined by EPA Method 28WHH and the standards referenced therein.
12.4 Appliance Startup. The appliance shall be fired with wood fuel of any species, size and moisture content, at the laboratory’s discretion, to bring it up to operating temperature. Operate the appliance until the water is heated to the upper operating control limit and has cycled at least two times. Then remove all unburned fuel, zero the scale and verify the scales accuracy using dead weights.
12.4.1 Startup Procedure for Category III and IV Test Runs, “Hot-to-Hot.”
12.4.1.1 Pretest t Burn Cycle. Following appliance startup (section 12.4), reload appliance with oak cord wood and allow it to burn down to the specified coal bed weight. The pre-test burn cycle fuel charge weight shall be within ±10 percent of the test fuel charge weight. Piece size and length shall be selected such that charcoalization is achieved by the time the fuel charge has burned down to the required coal bed weight. Pieces with a maximum thickness of approximately 2 inches have been found to be suitable. Charcoalization is a general condition of the test fuel bed evidenced by an absence of large pieces of burning wood in the coal bed and the remaining fuel pieces being brittle enough to be broken into smaller charcoal pieces with a metal poker. Manipulations to the fuel bed prior to the start of the test run are to be done to achieve charcoalization while maintaining the desired heat output rate. During the pre-test burn cycle and at least one hour prior to starting the test run, adjust water flow to the heat exchanger to establish the target heat draw for the test. For the first test run the heat draw rate shall be equal to the manufacturer’s rated heat output capacity.
12.4.1.2 Allowable Adjustments. Fuel addition or subtractions, and coal bed raking shall be kept to a minimum but are allowed up to 15 minutes prior to the start of the test run. For the purposes of this method, coal bed raking is the use of a metal tool (poker) to stir coals, break burning fuel into smaller pieces, dislodge fuel pieces from positions of poor combustion, and check for the condition of charcoalization. Record all adjustments to and additions or subtractions of fuel, and any other changes to the appliance operations that occur during pretest ignition period. During the 15-minute period prior to the start of the test run, the wood heater loading door shall not be open more than a total of 1 minute. Coal bed raking is the only adjustment allowed during this period.
12.4.1.3 Coal Bed Weight. The appliance is to be loaded with the test fuel charge when the coal bed weight is between 10 percent and 20 percent of the test fuel charge weight. Coals may be raked as necessary to level the coal bed but may only be raked and stirred once between 15 to 20 minutes prior to the addition of the test fuel charge.
12.4.1.4 Storage. The Category III and IV test runs may be done either with or without the thermal storage. If thermal storage is used, the initial temperature of the storage must be 125 °F or greater at the start of the test. The storage may be heated during the pre-test burn cycle or it may be heated by external means. If thermal storage is used, prior to the start of the test run, the storage tank destratification pump, shown in Figure 1, shall be operated until the total volume pumped exceeds 1.5 times the tank volume and the difference between the temperature at the top and bottom of the storage tank (TS
12.4.2 Startup Procedure for Category I and II Test Runs, “Cold-to-Cold.”
12.4.2.1 Initial Temperatures. This test shall be started with both the boiler/heater and the storage at a minimum temperature of 125 °F. The boiler/heater maximum temperature at the start of this test shall be 135 °F. The boiler/heater and storage may be heated through a pre-burn or it may be heated by external means.
12.4.2.2 Firebox Condition at Test Start. Prior to the start of this test remove all ash and charcoal from the combustion chamber(s). The loading of the test fuel and kindling should follow the manufacturer’s recommendations, subject to the following constraints: Up to 10 percent kindling and paper may be used which is in addition to the fuel load. Further, up to 10 percent of the fuel load (i.e., included in the 10 lb/ft
12.4.2.3 Storage. The Category I and II test runs shall be done with thermal storage. The initial temperature of the storage must be 125 °F or greater at the start of the test. The storage may be heated during the pre-test burn cycle or it may be heated by external means. Prior to the start of the test run, the storage tank destratification pump, shown in Figure 1, shall be operated until the total volume pumped exceeds 1.5 times the tank volume and the difference between the temperature at the top and bottom of the storage tank (TS
12.5 Test Runs. For all test runs, the return water temperature to the hydronic heater must be equal to or greater than 120 °F (this is lower than the initial tank temperature to allow for any pipeline losses). Where the storage system is used, flow of water from the boiler/heater shall be divided between the storage tank and the heat exchanger such that the temperature change of the circulating water across the heat exchanger shall be 30 ±5 °F, averaged over the entire test run. This is typically adjusted using the system valves.
Complete a test run in each heat output rate category, as follows:
12.5.1 Test Run Start. For Category III and IV runs: Once the appliance is operating normally and the pretest coal bed weight has reached the target value per section 12.4.1, tare the scale and load the full test charge into the appliance. Time for loading shall not exceed 5 minutes. The actual weight of the test fuel charge shall be measured and recorded within 30 minutes prior to loading. Start all sampling systems.
For Category I and II runs: Once the appliance has reached the starting temperature, tare the scale and load the full test charge, including kindling into the appliance. The actual weight of the test fuel charge shall be measured and recorded within 30 minutes prior to loading. Light the fire following the manufacturer’s written normal startup procedure. Start all sampling systems.
12.5.1.1 Record all water temperatures, differential water temperatures and water flow rates at time intervals of one minute or less.
12.5.1.2 Record particulate emissions data per the requirements of EPA Method 28WHH and the standards referenced therein.
12.5.1.3 Record data needed to determine overall efficiency (SLM) per the requirements of CSA B415.1-10 (IBR, see § 60.17) clauses 6.2.1, 6.2.2, 6.3, 8.5.7, 10.4.3(a), 10.4.3(f), and 13.7.9.3
12.5.1.3.1 Measure and record the test room air temperature in accordance with the requirements of CSA B415.1-10 (IBR, see § 60.17), clauses 6.2.1, 8.5.7 and 10.4.3(g).
12.5.1.3.2 Measure and record the flue gas temperature in accordance with the requirements of CSA B415.1-10 (IBR, see § 60.17), clauses 6.2.2, 8.5.7 and 10.4.3(f).
12.5.1.3.3 Determine and record the carbon monoxide (CO) and carbon dioxide (CO
12.5.1.3.4 Measure and record the test fuel weight per the requirements of CSA B415.1-10 (IBR, see § 60.17), clauses 8.5.7 and 10.4.3(h).
12.5.1.3.5 Record the test run time per the requirements of CSA B415.1-10 (IBR, see § 60.17), clause 10.4.3(a).
12.5.1.3.6 Record and document all settings and adjustments, if any, made to the boiler/heater as recommended/required by manufacturer’s instruction manual for different combustion conditions or heat loads. These may include temperature setpoints, under and over-fire air adjustment, or other adjustments that could be made by an operator to optimize or alter combustion. All such settings shall be included in the report for each test run.
12.5.1.4 Monitor the average heat output rate on the load side of the heat exchanger based on water temperatures and flow. If the heat output rate over a 10 minute averaging period gets close to the upper or lower limit of the target range (±5 percent), adjust the water flow through the heat exchanger to compensate. Make changes as infrequently as possible while maintaining the target heat output rate. The first test run shall be conducted at the Category IV heat output rate to validate that the appliance is capable of producing the manufacturer’s rated heat output capacity.
12.5.2 Test Fuel Charge Adjustment. It is acceptable to adjust the test fuel charge (i.e., reposition) once during a test run if more than 60 percent of the initial test fuel charge weight has been consumed and more than 10 minutes have elapsed without a measurable (1 lb or 0.5 kg) weight change while the operating control is in the demand mode. The time used to make this adjustment shall be less than 60 seconds.
12.5.3 Test Run Completion. For the Category III and IV, “hot-to-hot” test runs, the test run is completed when the remaining weight of the test fuel charge is 0.0 lb (0.0 kg). (W
For the Category I and II “cold-to-cold” test runs, the test run is completed; and the end of a test is defined at the first occurrence of any one of the following:
(a) The remaining weight of the test fuel charge is less than 1 percent of the total test fuel weight (W
(b) The automatic control system on the boiler/heater switches to an off mode. In this case, the boiler/heater fan (if used) is typically stopped and all air flow dampers are closed by the control system. Note that this off mode cannot be an “overheat” or emergency shutdown which typically requires a manual reset; or
(c) If the boiler/heater does not have an automatic off mode: After 90 percent of the fuel load has been consumed and the scale has indicated a rate of change of the test fuel charge of less than 1.0 lb/hr for a period of 10 minutes or longer. Note – this is not considered “stopped fuel combustion,” See section 12.5.6.1.
12.5.3.1 At the end of the test run, stop the particulate sampling train and overall efficiency (SLM) measurements, and record the run time, and all final measurement values.
12.5.3.2 At the end of the test run, continue to operate the storage tank destratification pump until the total volume pumped exceeds 1.5 times the tank volume. The maximum average of the top and bottom temperatures measured after this time may be taken as the average tank temperature at the end of the tests (TFSavg, See section 13.1). The total volume pumped may be based on the nominal flow rate of the destratification pump (See section 9.6).
12.5.3.3 For the Category I and II test runs, there is a need to determine the energy content of the unburned fuel remaining in the chamber if the remaining mass in the chamber is greater than 1 percent of the test fuel weight. Following the completion of the test, as soon as safely practical, this remaining fuel is removed from the chamber, separated from the remaining ash and weighed. This separation could be implemented with a slotted “scoop” or similar tool. A
12.5.4 Heat Output Capacity Validation. The first test run must produce a heat output rate that is within 10 percent of the manufacturer’s rated heat output capacity (Category IV) throughout the test run and an average heat output rate within 5 percent of the manufacturer’s rated heat output capacity. If the appliance is not capable of producing a heat output within these limits, the manufacturer’s rated heat output capacity is considered not validated and testing is to be terminated. In such cases, the tests may be restarted using a lower heat output capacity if requested by the manufacturer. Alternatively, during the Category IV run, if the rated output cannot be maintained for a 15 minute interval, the manufacturer may elect to reduce the rated output to match the test and complete the Category IV run on this basis. The target outputs for Categories I, II, and III shall then be recalculated based on this change in rated output capacity.
12.5.5 Additional Test Runs. Using the manufacturer’s rated heat output capacity as a basis, conduct a test for additional heat output categories as specified in section 4.3. It is not required to run these tests in any particular order.
12.5.6 Alternative Heat Output Rate for Category I. If an appliance cannot be operated in the Category I heat output range due to stopped combustion, two test runs shall be conducted at heat output rates within Category II. When this is the case, the weightings for the weighted averages indicated in section 14.1.15 shall be the average of the Category I and II weighting’s and shall be applied to both Category II results. Appliances that are not capable of operation within Category II (
12.5.6.1 Stopped Fuel Combustion. Evidence that an appliance cannot be operated at a Category I heat output rate due to stopped fuel combustion shall include documentation of two or more attempts to operate the appliance in heat output rate Category I and fuel combustion has stopped prior to complete consumption of the test fuel charge. Stopped fuel combustion is evidenced when an elapsed time of 60 minutes or more has occurred without a measurable (1 lb or 0.5 kg) weight change in the test fuel charge while the appliance operating control is in the demand mode. Report the evidence and the reasoning used to determine that a test in heat output rate Category I cannot be achieved. For example, two unsuccessful attempts to operate at an output rate of 10 percent of the rated output capacity are not sufficient evidence that heat output rate Category I cannot be achieved.
12.5.7 Appliance Overheating. Appliances with their associated thermal storage shall be capable of operating in all heat output categories without overheating to be rated by this test method. Appliance overheating occurs when the rate of heat withdrawal from the appliance is lower than the rate of heat production when the unit control is in the idle mode. This condition results in the water in the appliance continuing to increase in temperature well above the upper limit setting of the operating control. Evidence of overheating includes: 1 hour or more of appliance water temperature increase above the upper temperature set-point of the operating control, exceeding the temperature limit of a safety control device (independent from the operating control – typically requires manual reset), boiling water in a non-pressurized system or activation of a pressure or temperature relief valve in a pressurized system.
12.5.8 Option to Eliminate Tests in Category II and III. Following successful completion of a test run in Category I, the manufacturer may eliminate the Category II and III tests. For the purpose of calculating the annual averages for particulates and efficiency, the values obtained in the Category I run shall be assumed to apply also to Category II and Category III. It is envisioned that this option would be applicable to systems which have sufficient thermal storage such that the fuel load in the Category I test can be completely consumed without the system reaching its upper operating temperature limit. In this case, the boiler/heater would likely be operating at maximum thermal output during the entire test and this output rate may be higher than the manufacturer’s rated heat output capacity. The Category II and III runs would then be the same as the Category I run. It may be assumed that the particulate emission values and efficiency values determined in the startup, steady-state, and end phases of Category I are applicable in Categories II and III, for the purpose of determining the annual averages in lb/mmBtu and g/MJ (See section 13). For the annual average in g/hr, the length of time for stored heat to be drawn from thermal storage shall be determined for the test load requirements of the respective category.
12.5.9 Modification to Measurement Procedure in EPA Method 28WHH to Determine Emissions Separately During the Startup, Steady-State and End Phases. With one of the two particulate sampling trains used, filter changes shall be made at the end of the startup phase and the steady-state phase (See section 3.0). This shall be done to determine the particulate emission rate and particulate emission index for the startup, steady-state, and end phases individually. For this one train, the particulates measured during each of these three phases shall be added together to also determine the particulate emissions for the whole run.
12.5.10 Modification to Measurement Procedure in EPA Method 28WHH and the Standards Referenced therein on Averaging Period for Determination of Efficiency by the Stack Loss Method. The methods currently defined in Method 28WHH allow averaging over 10-minute time periods for flue gas temperature, flue gas CO
12.6 Additional Test Runs. The testing laboratory may conduct more than one test run in each of the heat output categories specified in section 4.3. If more than one test run is conducted at a specified heat output rate, the results from at least two-thirds of the test runs in that heat output rate category shall be used in calculating the weighted average emission rate. The measurement data and results of all test runs shall be reported regardless of which values are used in calculating the weighted average emission rate.
13.2 After the test is completed, determine the particulate emissions E
13.3 Determination of the weight of fuel that has been burned at an arbitrary time.
For the purpose of tracking the consumption of the test fuel load during a test run the following may be used to calculate the weight of fuel that burned since the start of the test:
13.5.1 Correction to Q
13.6 Determine Heat Output, Efficiency, and Emissions.
13.6.1 Determine heat output as:
Q
The subscript (i) indicates the parameter value for sampling time interval t
V
13.6.2 Determine Heat Output Rate Over Burn Period (Θ
13.6.3 Determine Emission Rates and Emission Factors as:
If thermal storage is not used in a Category III or IV run, then Θ
E
E
E
E
E
E
13.6.4 Determine delivered efficiency as:
13.6.5 Determine η
For determination of the average overall thermal efficiency (η
13.6.5.1 Whenever the CSA B415.1-10 (IBR, see § 60.17) overall efficiency is found to be lower than the overall efficiency based on load side measurements, as determined by Eq. 22 of this method, section 14.1.7 of the test report must include a discussion of the reasons for this result. For a test where the CSA B415.1-10 overall efficiency SLM is less than 2 percentage points lower than the overall efficiency based on load side measurements, the efficiency based on load side measurements shall be considered invalid. [Note on the rationale for the 2 percentage points limit. The SLM method does not include boiler/heater jacket losses and, for this reason, should provide an efficiency which is actually higher than the efficiency based on the energy input and output measurements or “delivered efficiency.” A delivered efficiency that is higher than the efficiency based on the SLM could be considered suspect. A delivered efficiency greater than 2 percentage points higher than the efficiency based on the SLM, then, clearly indicates a measurement error.]
13.6.6 Carbon Monoxide Emissions
For each minute of the test period, the carbon monoxide emission rate shall be calculated as:
Total CO emissions for each of the three test periods (CO
13.7 Weighted Average Emissions and Efficiency.
13.7.1 Determine the weighted average emission rate and delivered efficiency from the individual tests in the specified heat output categories. The weighting factors (F
If, as discussed in section 12.5.8, the option to eliminate tests in Category II and III is elected, the values of efficiency and particulate emission rate as measured in Category I, shall be assigned also to Category II and III for the purpose of determining the annual averages.
14.1.1 The report shall include the following:
14.1.2 Name and location of the laboratory conducting the test.
14.1.3 A description of the appliance tested and its condition, date of receipt and dates of tests.
14.1.4 A description of the minimum amount of external thermal storage that is required for use with this system. This shall be specified both in terms of volume in gallons and stored energy content in Btu with a storage temperature ranging from 125 °F to the manufacturer’s specified setpoint temperature.
14.1.5 A statement that the test results apply only to the specific appliance tested.
14.1.6 A statement that the test report shall not be reproduced except in full, without the written approval of the laboratory.
14.1.7 A description of the test procedures and test equipment including a schematic or other drawing showing the location of all required test equipment. Also, a description of test fuel sourcing, handling and storage practices shall be included.
14.1.8 Details of deviations from, additions to or exclusions from the test method, and their data quality implications on the test results (if any), as well as information on specific test conditions, such as environmental conditions.
14.1.9 A list of participants and their roles and observers present for the tests.
14.1.10 Data and drawings indicating the fire box size and location of the fuel charge.
14.1.11 Drawings and calculations used to determine firebox volume.
14.1.12 Information for each test run fuel charge including piece size, moisture content and weight.
14.1.13 All required data and applicable blanks for each test run shall be provided in spreadsheet format both in the printed report and in a computer file such that the data can be easily analyzed and calculations easily verified. Formulas used for all calculations shall be accessible for review.
14.1.14 For each test run, Θ
14.1.15 Calculated results for delivered efficiency at each heat output rate and the weighted average emissions reported as total emissions in grams, pounds per mm Btu of delivered heat, grams per MJ of delivered heat, grams per kilogram of dry fuel and grams per hour. Results shall be reported for each heat output category and the weighted average.
14.1.16 Tables 1A, 1B, 1C, 1D, 1E and Table 2 must be used for presentation of results in test reports.
14.1.17 A statement of the estimated uncertainty of measurement of the emissions and efficiency test results.
14.1.18 A plot of CO emission rate in grams/minute vs. time, based on 1 minute averages, for the entire test period, for each run.
14.1.19 A plot of estimated boiler/heater energy release rate in Btu/hr based on 10 minute averages, for the entire test period, for each run. This will be calculated from the fuel used, the wood heating value and moisture content, and the SLM efficiency during each 10 minute period.
14.1.20 Raw data, calibration records, and other relevant documentation shall be retained by the laboratory for a minimum of 7 years.
15.1 Precision – It is not possible to specify the precision of the procedure in this test method because the appliance operation and fueling protocols and the appliances themselves produce variable amounts of emissions and cannot be used to determine reproducibility or repeatability of this test method.
15.2 Bias – No definitive information can be presented on the bias of the procedure in this test method for measuring solid fuel burning hydronic heater emissions because no material having an accepted reference value is available.
16.1 Solid fuel, hydronic heating appliances, wood-burning hydronic heaters, partial thermal storage.
This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 5 and Method 12.
1.1 Analytes.
| Analyte | CAS No. |
|---|---|
| Antimony (Sb) | 7440-36-0 |
| Arsenic (As) | 7440-38-2 |
| Barium (Ba) | 7440-39-3 |
| Beryllium (Be) | 7440-41-7 |
| Cadmium (Cd) | 7440-43-9 |
| Chromium (Cr) | 7440-47-3 |
| Cobalt (Co) | 7440-48-4 |
| Copper (Cu) | 7440-50-8 |
| Lead (Pb) | 7439-92-1 |
| Manganese (Mn) | 7439-96-5 |
| Mercury (Hg) | 7439-97-6 |
| Nickel (Ni) | 7440-02-0 |
| Phosphorus (P) | 7723-14-0 |
| Selenium (Se) | 7782-49-2 |
| Silver (Ag) | 7440-22-4 |
| Thallium (Tl) | 7440-28-0 |
| Zinc (Zn) | 7440-66-6 |
1.2 Applicability. This method is applicable to the determination of metals emissions from stationary sources. This method may be used to determine particulate emissions in addition to the metals emissions if the prescribed procedures and precautions are followed.
1.2.1 Hg emissions can be measured, alternatively, using EPA Method 101A of Appendix B, 40 CFR Part 61. Method 101-A measures only Hg but it can be of special interest to sources which need to measure both Hg and Mn emissions.
2.1 Principle. A stack sample is withdrawn isokinetically from the source, particulate emissions are collected in the probe and on a heated filter, and gaseous emissions are then collected in an aqueous acidic solution of hydrogen peroxide (analyzed for all metals including Hg) and an aqueous acidic solution of potassium permanganate (analyzed only for Hg). The recovered samples are digested, and appropriate fractions are analyzed for Hg by cold vapor atomic absorption spectroscopy (CVAAS) and for Sb, As, Ba, Be, Cd, Cr, Co, Cu, Pb, Mn, Ni, P, Se, Ag, Tl, and Zn by inductively coupled argon plasma emission spectroscopy (ICAP) or atomic absorption spectroscopy (AAS). Graphite furnace atomic absorption spectroscopy (GFAAS) is used for analysis of Sb, As, Cd, Co, Pb, Se, and Tl if these elements require greater analytical sensitivity than can be obtained by ICAP. If one so chooses, AAS may be used for analysis of all listed metals if the resulting in-stack method detection limits meet the goal of the testing program. Similarly, inductively coupled plasma-mass spectroscopy (ICP-MS) may be used for analysis of Sb, As, Ba, Be, Cd, Cr, Co, Cu, Pb, Mn, Ni, Ag, Tl and Zn.
4.1 Iron (Fe) can be a spectral interference during the analysis of As, Cr, and Cd by ICAP. Aluminum (Al) can be a spectral interference during the analysis of As and Pb by ICAP. Generally, these interferences can be reduced by diluting the analytical sample, but such dilution raises the in-stack detection limits. Background and overlap corrections may be used to adjust for spectral interferences. Refer to Method 6010 of Reference 2 in section 16.0 or the other analytical methods used for details on potential interferences to this method. For all GFAAS analyses, use matrix modifiers to limit interferences, and matrix match all standards.
5.1 Disclaimer. This method may involve hazardous materials, operations, and equipment. This test method may not address all of the safety problems associated with its use. It is the responsibility of the user of this test method to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to performing this test method.
5.2 Corrosive Reagents. The following reagents are hazardous. Personal protective equipment and safe procedures are useful in preventing chemical splashes. If contact occurs, immediately flush with copious amounts of water at least 15 minutes. Remove clothing under shower and decontaminate. Treat residual chemical burn as thermal burn.
5.2.1 Nitric Acid (HNO
5.2.2 Sulfuric Acid (H
5.2.3 Hydrochloric Acid (HC1). Highly corrosive liquid with toxic vapors. Vapors are highly irritating to eyes, skin, nose, and lungs, causing severe damage. May cause bronchitis, pneumonia, or edema of lungs. Exposure to concentrations of 0.13 to 0.2 percent can be lethal to humans in a few minutes. Provide ventilation to limit exposure. Reacts with metals, producing hydrogen gas.
5.2.4 Hydrofluoric Acid (HF). Highly corrosive to eyes, skin, nose, throat, and lungs. Reaction to exposure may be delayed by 24 hours or more. Provide ventilation to limit exposure.
5.2.5 Hydrogen Peroxide (H
5.2.6 Potassium Permanganate (KMnO
5.2.7 Potassium Persulfate. Strong oxidizer. Avoid bodily contact with. Keep containers well closed and in a cool place.
5.3 Reaction Pressure. Due to the potential reaction of the potassium permanganate with the acid, there could be pressure buildup in the acidic KMnO
6.1 Sampling. A schematic of the sampling train is shown in Figure 29-1. It has general similarities to the Method 5 train.
6.1.1 Probe Nozzle (Probe Tip) and Borosilicate or Quartz Glass Probe Liner. Same as Method 5, sections 6.1.1.1 and 6.1.1.2, except that glass nozzles are required unless alternate tips are constructed of materials that are free from contamination and will not interfere with the sample. If a probe tip other than glass is used, no correction to the sample test results to compensate for the nozzle’s effect on the sample is allowed. Probe fittings of plastic such as Teflon, polypropylene, etc. are recommended instead of metal fittings to prevent contamination. If one chooses to do so, a single glass piece consisting of a combined probe tip and probe liner may be used.
6.1.2 Pitot Tube and Differential Pressure Gauge. Same as Method 2, sections 6.1 and 6.2, respectively.
6.1.3 Filter Holder. Glass, same as Method 5, section 6.1.1.5, except use a Teflon filter support or other non-metallic, non-contaminating support in place of the glass frit.
6.1.4 Filter Heating System. Same as Method 5, section 6.1.1.6.
6.1.5 Condenser. Use the following system for condensing and collecting gaseous metals and determining the moisture content of the stack gas. The condensing system shall consist of four to seven impingers connected in series with leak-free ground glass fittings or other leak-free, non-contaminating fittings. Use the first impinger as a moisture trap. The second impinger (which is the first HNO
6.1.6 Metering System, Barometer, and Gas Density Determination Equipment. Same as Method 5, sections 6.1.1.9, 6.1.2, and 6.1.3, respectively.
6.1.7 Teflon Tape. For capping openings and sealing connections, if necessary, on the sampling train.
6.2 Sample Recovery. Same as Method 5, sections 6.2.1 through 6.2.8 (Probe-Liner and Probe-Nozzle Brushes or Swabs, Wash Bottles, Sample Storage Containers, Petri Dishes, Glass Graduated Cylinder, Plastic Storage Containers, Funnel and Rubber Policeman, and Glass Funnel), respectively, with the following exceptions and additions:
6.2.1 Non-metallic Probe-Liner and Probe-Nozzle Brushes or Swabs. Use non-metallic probe-liner and probe-nozzle brushes or swabs for quantitative recovery of materials collected in the front-half of the sampling train.
6.2.2 Sample Storage Containers. Use glass bottles (see section 8.1 of this Method) with Teflon-lined caps that are non-reactive to the oxidizing solutions, with capacities of 1000- and 500-ml, for storage of acidified KMnO
6.2.3 Graduated Cylinder. Glass or equivalent.
6.2.4 Funnel. Glass or equivalent.
6.2.5 Labels. For identifying samples.
6.2.6 Polypropylene Tweezers and/or Plastic Gloves. For recovery of the filter from the sampling train filter holder.
6.3 Sample Preparation and Analysis.
6.3.1 Volumetric Flasks, 100-ml, 250-ml, and 1000-ml. For preparation of standards and sample dilutions.
6.3.2 Graduated Cylinders. For preparation of reagents.
6.3.3 Parr Bombs or Microwave Pressure Relief Vessels with Capping Station (CEM Corporation model or equivalent). For sample digestion.
6.3.4 Beakers and Watch Glasses. 250-ml beakers, with watch glass covers, for sample digestion.
6.3.5 Ring Stands and Clamps. For securing equipment such as filtration apparatus.
6.3.6 Filter Funnels. For holding filter paper.
6.3.7 Disposable Pasteur Pipets and Bulbs.
6.3.8 Volumetric Pipets.
6.3.9 Analytical Balance. Accurate to within 0.1 mg.
6.3.10 Microwave or Conventional Oven. For heating samples at fixed power levels or temperatures, respectively.
6.3.11 Hot Plates.
6.3.12 Atomic Absorption Spectrometer (AAS). Equipped with a background corrector.
6.3.12.1 Graphite Furnace Attachment. With Sb, As, Cd, Co, Pb, Se, and Tl hollow cathode lamps (HCLs) or electrodeless discharge lamps (EDLs). Same as Reference 2 in section 16.0. Methods 7041 (Sb), 7060 (As), 7131 (Cd), 7201 (Co), 7421 (Pb), 7740 (Se), and 7841 (Tl).
6.3.12.2 Cold Vapor Mercury Attachment. With a mercury HCL or EDL, an air recirculation pump, a quartz cell, an aerator apparatus, and a heat lamp or desiccator tube. The heat lamp shall be capable of raising the temperature at the quartz cell by 10 °C above ambient, so that no condensation forms on the wall of the quartz cell. Same as Method 7470 in Reference 2 in section 16.0. See note 2: section 11.1.3 for other acceptable approaches for analysis of Hg in which analytical detection limits of 0.002 ng/ml were obtained.
6.3.13 Inductively Coupled Argon Plasma Spectrometer. With either a direct or sequential reader and an alumina torch. Same as EPA Method 6010 in Reference 2 in section 16.0.
6.3.14 Inductively Coupled Plasma-Mass Spectrometer.
Same as EPA Method 6020 in Reference 2 in section 16.0.
7.1 Unless otherwise indicated, it is intended that all reagents conform to the specifications established by the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available. Otherwise, use the best available grade.
7.2 Sampling Reagents.
7.2.1 Sample Filters. Without organic binders. The filters shall contain less than 1.3 µg/in.
7.2.2 Water. To conform to ASTM Specification D1193-77 or 91, Type II (incorporated by reference – see § 60.17). If necessary, analyze the water for all target metals prior to field use. All target metals should be less than 1 ng/ml.
7.2.3 HNO
7.2.4 HCl, Concentrated. Baker Instra-analyzed or equivalent.
7.2.5 H
7.2.6 KMnO
7.2.7 H
7.2.8 Silica Gel and Crushed Ice. Same as Method 5, sections 7.1.2 and 7.1.4, respectively.
7.3 Pretest Preparation of Sampling Reagents.
7.3.1 HNO
7.3.2 Acidic KMnO
Precaution: To prevent autocatalytic decomposition of the permanganate solution, filter the solution through Whatman 541 filter paper.
7.3.3 HNO
7.3.4 HCl, 8 N. Carefully add with stirring 690 ml of concentrated HCl to a flask containing 250 ml of water. Dilute to 1000 ml with water. Mix well. This reagent shall contain less than 2 ng/ml of Hg.
7.4 Glassware Cleaning Reagents.
7.4.1 HNO
7.4.2 Water. To conform to ASTM Specifications D1193, Type II.
7.4.3 HNO
7.5 Sample Digestion and Analysis Reagents. The metals standards, except Hg, may also be made from solid chemicals as described in Reference 3 in section 16.0. Refer to References 1, 2, or 5 in section 16.0 for additional information on Hg standards. The 1000 µg/ml Hg stock solution standard may be made according to section 7.2.7 of Method 101A.
7.5.1 HCl, Concentrated.
7.5.2 HF, Concentrated.
7.5.3 HNO
7.5.4 HNO
7.5.5 HNO
7.5.6 Water. To conform to ASTM Specifications D1193, Type II.
7.5.7 Hydroxylamine Hydrochloride and Sodium Chloride Solution. See Reference 2 In section 16.0 for preparation.
7.5.8 Stannous Chloride. See Reference 2 in section 16.0 for preparation.
7.5.9 KMnO
7.5.10 H
7.5.11 Potassium Persulfate, 5 Percent (W/V). See Reference 2 in section 16.0 for preparation.
7.5.12 Nickel Nitrate, Ni(N0
7.5.13 Lanthanum Oxide, La
7.5.14 Hg Standard (AAS Grade), 1000 µg/ml.
7.5.15 Pb Standard (AAS Grade), 1000 µg/ml.
7.5.16 As Standard (AAS Grade), 1000 µg/ml.
7.5.17 Cd Standard (AAS Grade), 1000 µg/ml.
7.5.18 Cr Standard (AAS Grade), 1000 µg/ml.
7.5.19 Sb Standard (AAS Grade), 1000 µg/ml.
7.5.20 Ba Standard (AAS Grade), 1000 µg/ml.
7.5.21 Be Standard (AAS Grade), 1000 µg/ml.
7.5.22 Co Standard (AAS Grade), 1000 µg/ml.
7.5.23 Cu Standard (AAS Grade), 1000 µg/ml.
7.5.24 Mn Standard (AAS Grade), 1000 µg/ml.
7.5.25 Ni Standard (AAS Grade), 1000 µg/ml.
7.5.26 P Standard (AAS Grade), 1000 µg/ml.
7.5.27 Se Standard (AAS Grade), 1000 µg/ml.
7.5.28 Ag Standard (AAS Grade), 1000 µg/ml.
7.5.29 Tl Standard (AAS Grade), 1000 µg/ml.
7.5.30 Zn Standard (AAS Grade), 1000 µg/ml.
7.5.31 Al Standard (AAS Grade), 1000 µg/ml.
7.5.32 Fe Standard (AAS Grade), 1000 µg/ml.
7.5.33 Hg Standards and Quality Control Samples. Prepare fresh weekly a 10 µg/ml intermediate Hg standard by adding 5 ml of 1000 µg/ml Hg stock solution prepared according to Method 101A to a 500-ml volumetric flask; dilute with stirring to 500 ml by first carefully adding 20 ml of 15 percent HNO
7.5.34 ICAP Standards and Quality Control Samples. Calibration standards for ICAP analysis can be combined into four different mixed standard solutions as follows:
Mixed Standard Solutions for ICAP Analysis
| Solution | Elements |
|---|---|
| I | As, Be, Cd, Mn, Pb, Se, Zn. |
| II | Ba, Co, Cu, Fe. |
| III | Al, Cr, Ni. |
| IV | Ag, P, Sb, Tl. |
Prepare these standards by combining and diluting the appropriate volumes of the 1000 µg/ml solutions with 5 percent HNO
7.5.35 GFAAS Standards. Sb, As, Cd, Co, Pb, Se, and Tl. Prepare a 10 µg/ml standard by adding 1 ml of 1000 µg/ml standard to a 100-ml volumetric flask. Dilute with stirring to 100 ml with 10 percent HNO
7.5.36 Matrix Modifiers.
7.5.36.1 Nickel Nitrate, 1 Percent (V/V). Dissolve 4.956 g of Ni(N0
7.5.36.2 Nickel Nitrate, 0.1 Percent (V/V). Dilute 10 ml of 1 percent nickel nitrate solution to 100 ml with water. Inject an equal amount of sample and this modifier into the graphite furnace during GFAAS analysis for As.
7.5.36.3 Lanthanum. Carefully dissolve 0.5864 g of La
7.5.37 Whatman 40 and 541 Filter Papers (or equivalent). For filtration of digested samples.
8.1 Sampling. The complexity of this method is such that, to obtain reliable results, both testers and analysts must be trained and experienced with the test procedures, including source sampling; reagent preparation and handling; sample handling; safety equipment and procedures; analytical calculations; reporting; and the specific procedural descriptions throughout this method.
8.1.1 Pretest Preparation. Follow the same general procedure given in Method 5, section 8.1, except that, unless particulate emissions are to be determined, the filter need not be desiccated or weighed. First, rinse all sampling train glassware with hot tap water and then wash in hot soapy water. Next, rinse glassware three times with tap water, followed by three additional rinses with water. Then soak all glassware in a 10 percent (V/V) nitric acid solution for a minimum of 4 hours, rinse three times with water, rinse a final time with acetone, and allow to air dry. Cover all glassware openings where contamination can occur until the sampling train is assembled for sampling.
8.1.2 Preliminary Determinations. Same as Method 5, section 8.1.2.
8.1.3 Preparation of Sampling Train.
8.1.3.1 Set up the sampling train as shown in Figure 29-1. Follow the same general procedures given in Method 5, section 8.3, except place 100 ml of the HNO
8.1.3.2 Based on the specific source sampling conditions, the use of an empty first impinger can be eliminated if the moisture to be collected in the impingers will be less than approximately 100 ml.
8.1.3.3 If Hg analysis will not be performed, the fourth, fifth, and sixth impingers as shown in Figure 29-1 are not required.
8.1.3.4 To insure leak-free sampling train connections and to prevent possible sample contamination problems, use Teflon tape or other non-contaminating material instead of silicone grease.
Precaution: Exercise extreme care to prevent contamination within the train. Prevent the acidic KMnO
8.1.4 Leak-Check Procedures. Follow the leak-check procedures given in Method 5, section 8.4.2 (Pretest Leak-Check), section 8.4.3 (Leak-Checks During the Sample Run), and section 8.4.4 (Post-Test Leak-Checks).
8.1.5 Sampling Train Operation. Follow the procedures given in Method 5, section 8.5. When sampling for Hg, use a procedure analogous to that described in section 8.1 of Method 101A, 40 CFR Part 61, Appendix B, if necessary to maintain the desired color in the last acidified permanganate impinger. For each run, record the data required on a data sheet such as the one shown in Figure 5-3 of Method 5.
8.1.6 Calculation of Percent Isokinetic. Same as Method 5, section 12.11.
8.2 Sample Recovery.
8.2.1 Begin cleanup procedures as soon as the probe is removed from the stack at the end of a sampling period. The probe should be allowed to cool prior to sample recovery. When it can be safely handled, wipe off all external particulate matter near the tip of the probe nozzle and place a rinsed, non-contaminating cap over the probe nozzle to prevent losing or gaining particulate matter. Do not cap the probe tip tightly while the sampling train is cooling; a vacuum can form in the filter holder with the undesired result of drawing liquid from the impingers onto the filter.
8.2.2 Before moving the sampling train to the cleanup site, remove the probe from the sampling train and cap the open outlet. Be careful not to lose any condensate that might be present. Cap the filter inlet where the probe was fastened. Remove the umbilical cord from the last impinger and cap the impinger. Cap the filter holder outlet and impinger inlet. Use non-contaminating caps, whether ground-glass stoppers, plastic caps, serum caps, or Teflon ® tape to close these openings.
8.2.3 Alternatively, the following procedure may be used to disassemble the train before the probe and filter holder/oven are completely cooled: Initially disconnect the filter holder outlet/impinger inlet and loosely cap the open ends. Then disconnect the probe from the filter holder or cyclone inlet and loosely cap the open ends. Cap the probe tip and remove the umbilical cord as previously described.
8.2.4 Transfer the probe and filter-impinger assembly to a cleanup area that is clean and protected from the wind and other potential causes of contamination or loss of sample. Inspect the train before and during disassembly and note any abnormal conditions. Take special precautions to assure that all the items necessary for recovery do not contaminate the samples. The sample is recovered and treated as follows (see schematic in Figures 29-2a and 29-2b):
8.2.5 Container No. 1 (Sample Filter). Carefully remove the filter from the filter holder and place it in its labeled petri dish container. To handle the filter, use either acid-washed polypropylene or Teflon coated tweezers or clean, disposable surgical gloves rinsed with water and dried. If it is necessary to fold the filter, make certain the particulate cake is inside the fold. Carefully transfer the filter and any particulate matter or filter fibers that adhere to the filter holder gasket to the petri dish by using a dry (acid-cleaned) nylon bristle brush. Do not use any metal-containing materials when recovering this train. Seal the labeled petri dish.
8.2.6 Container No. 2 (Acetone Rinse). Perform this procedure only if a determination of particulate emissions is to be made. Quantitatively recover particulate matter and any condensate from the probe nozzle, probe fitting, probe liner, and front half of the filter holder by washing these components with a total of 100 ml of acetone, while simultaneously taking great care to see that no dust on the outside of the probe or other surfaces gets in the sample. The use of exactly 100 ml is necessary for the subsequent blank correction procedures. Distilled water may be used instead of acetone when approved by the Administrator and shall be used when specified by the Administrator; in these cases, save a water blank and follow the Administrator’s directions on analysis.
8.2.6.1 Carefully remove the probe nozzle, and clean the inside surface by rinsing with acetone from a wash bottle while brushing with a non-metallic brush. Brush until the acetone rinse shows no visible particles, then make a final rinse of the inside surface with acetone.
8.2.6.2 Brush and rinse the sample exposed inside parts of the probe fitting with acetone in a similar way until no visible particles remain. Rinse the probe liner with acetone by tilting and rotating the probe while squirting acetone into its upper end so that all inside surfaces will be wetted with acetone. Allow the acetone to drain from the lower end into the sample container. A funnel may be used to aid in transferring liquid washings to the container. Follow the acetone rinse with a non-metallic probe brush. Hold the probe in an inclined position, squirt acetone into the upper end as the probe brush is being pushed with a twisting action three times through the probe. Hold a sample container underneath the lower end of the probe, and catch any acetone and particulate matter which is brushed through the probe until no visible particulate matter is carried out with the acetone or until none remains in the probe liner on visual inspection. Rinse the brush with acetone, and quantitatively collect these washings in the sample container. After the brushing, make a final acetone rinse of the probe as described above.
8.2.6.3 It is recommended that two people clean the probe to minimize sample losses. Between sampling runs, keep brushes clean and protected from contamination. Clean the inside of the front-half of the filter holder by rubbing the surfaces with a non-metallic brush and rinsing with acetone. Rinse each surface three times or more if needed to remove visible particulate. Make a final rinse of the brush and filter holder. After all acetone washings and particulate matter have been collected in the sample container, tighten the lid so that acetone will not leak out when shipped to the laboratory. Mark the height of the fluid level to determine whether or not leakage occurred during transport. Clearly label the container to identify its contents.
8.2.7 Container No. 3 (Probe Rinse). Keep the probe assembly clean and free from contamination during the probe rinse. Rinse the probe nozzle and fitting, probe liner, and front-half of the filter holder thoroughly with a total of 100 ml of 0.1 N HNO
The use of a total of exactly 100 ml is necessary for the subsequent blank correction procedures.
8.2.8 Container No. 4 (Impingers 1 through 3, Moisture Knockout Impinger, when used, HNO
The use of exactly 100 ml of 0.1 N HNO
8.2.9 Container Nos. 5A (0.1 N HNO
8.2.9.1 When sampling for Hg, pour all the liquid from the impinger (normally impinger No. 4) that immediately preceded the two permanganate impingers into a graduated cylinder and measure the volume to within 0.5 ml. This information is required to calculate the moisture content of the sampled flue gas. Place the liquid in Container No. 5A. Rinse the impinger with exactly 100 ml of 0.1 N HNO
8.2.9.2 Pour all the liquid from the two permanganate impingers into a graduated cylinder and measure the volume to within 0.5 ml. This information is required to calculate the moisture content of the sampled flue gas. Place this acidic KMnO
Due to the potential reaction of KMnO
8.2.9.3 Wash the two permanganate impingers with 25 ml of 8 N HCl, and place the wash in a separate sample container labeled No. 5C containing 200 ml of water. First, place 200 ml of water in the container. Then wash the impinger walls and stem with the 8 N HCl by turning the impinger on its side and rotating it so that the HCl contacts all inside surfaces. Use a total of only 25 ml of 8 N HCl for rinsing both permanganate impingers combined. Rinse the first impinger, then pour the actual rinse used for the first impinger into the second impinger for its rinse. Finally, pour the 25 ml of 8 N HCl rinse carefully into the container with the 200 ml of water. Mark the height of the fluid level on the outside of the container in order to determine if leakage occurs during transport.
8.2.10 Container No. 6 (Silica Gel). Note the color of the indicating silica gel to determine whether it has been completely spent and make a notation of its condition. Transfer the silica gel from its impinger to its original container and seal it. The tester may use a funnel to pour the silica gel and a rubber policeman to remove the silica gel from the impinger. The small amount of particles that might adhere to the impinger wall need not be removed. Do not use water or other liquids to transfer the silica gel since weight gained in the silica gel impinger is used for moisture calculations. Alternatively, if a balance is available in the field, record the weight of the spent silica gel (or silica gel plus impinger) to the nearest 0.5 g.
8.2.11 Container No. 7 (Acetone Blank). If particulate emissions are to be determined, at least once during each field test, place a 100-ml portion of the acetone used in the sample recovery process into a container labeled No. 7. Seal the container.
8.2.12 Container No. 8A (0.1 N HNO
8.2.13 Container No. 8B (Water Blank). At least once during each field test, place 100 ml of the water used in the sample recovery process into a container labeled No. 8B. Seal the container.
8.2.14 Container No. 9 (5 Percent HNO
8.2.15 Container No. 10 (Acidified KMnO
8.2.16 Container No. 11 (8 N HCl Blank). At least once during each field test, place 200 ml of water into a sample container labeled No. 11. Then carefully add with stirring 25 ml of 8 N HCl. Mix well and seal the container.
8.2.17 Container No. 12 (Sample Filter Blank). Once during each field test, place into a petri dish labeled No. 12 three unused blank filters from the same lot as the sampling filters. Seal the petri dish.
8.3 Sample Preparation. Note the level of the liquid in each of the containers and determine if any sample was lost during shipment. If a noticeable amount of leakage has occurred, either void the sample or use methods, subject to the approval of the Administrator, to correct the final results. A diagram illustrating sample preparation and analysis procedures for each of the sample train components is shown in Figure 29-3.
8.3.1 Container No. 1 (Sample Filter).
8.3.1.1 If particulate emissions are being determined, first desiccate the filter and filter catch without added heat (do not heat the filters to speed the drying) and weigh to a constant weight as described in section 11.2.1 of Method 5.
8.3.1.2 Following this procedure, or initially, if particulate emissions are not being determined in addition to metals analysis, divide the filter with its filter catch into portions containing approximately 0.5 g each. Place the pieces in the analyst’s choice of either individual microwave pressure relief vessels or Parr Bombs. Add 6 ml of concentrated HNO
8.3.1.3 If the sampling train includes an optional glass cyclone in front of the filter, prepare and digest the cyclone catch by the procedures described in section 8.3.1.2 and then combine the digestate with the digested filter sample.
8.3.2 Container No. 2 (Acetone Rinse). Note the level of liquid in the container and confirm on the analysis sheet whether or not leakage occurred during transport. If a noticeable amount of leakage has occurred, either void the sample or use methods, subject to the approval of the Administrator, to correct the final results. Measure the liquid in this container either volumetrically within 1 ml or gravimetrically within 0.5 g. Transfer the contents to an acid-cleaned, tared 250-ml beaker and evaporate to dryness at ambient temperature and pressure. If particulate emissions are being determined, desiccate for 24 hours without added heat, weigh to a constant weight according to the procedures described in section 11.2.1 of Method 5, and report the results to the nearest 0.1 mg. Redissolve the residue with 10 ml of concentrated HNO
8.3.3 Container No. 3 (Probe Rinse). Verify that the pH of this sample is 2 or lower. If it is not, acidify the sample by careful addition with stirring of concentrated HNO
8.3.4 Container No. 4 (Impingers 1-3). Measure and record the total volume of this sample to within 0.5 ml and label it “Sample Fraction 2”. Remove a 75- to 100-ml aliquot for Hg analysis and label the aliquot “Analytical Fraction 2B”. Label the remaining portion of Container No. 4 as “Sample Fraction 2A”. Sample Fraction 2A defines the volume of Analytical Fraction 2A prior to digestion. All of Sample Fraction 2A is digested to produce “Analytical Fraction 2A”. Analytical Fraction 2A defines the volume of Sample Fraction 2A after its digestion and the volume of Analytical Fraction 2A is normally 150 ml. Analytical Fraction 2A is analyzed for all metals except Hg. Verify that the pH of Sample Fraction 2A is 2 or lower. If necessary, use concentrated HNO
8.3.4.1 Conventional Digestion Procedure. Add 30 ml of 50 percent HNO
8.3.4.2 Microwave Digestion Procedure. Add 10 ml of 50 percent HNO
All microwave heating times given are approximate and are dependent upon the number of samples being digested at a time. Heating times as given above have been found acceptable for simultaneous digestion of up to 12 individual samples. Sufficient heating is evidenced by solvent reflux within the vessel.
8.3.5 Container No. 5A (Impinger 4), Container Nos. 5B and 5C (Impingers 5 and 6). Keep the samples in Containers Nos. 5A, 5B, and 5C separate from each other. Measure and record the volume of 5A to within 0.5 ml. Label the contents of Container No. 5A to be Analytical Fraction 3A. To remove any brown MnO
8.3.6 Container No. 6 (Silica Gel). Weigh the spent silica gel (or silica gel plus impinger) to the nearest 0.5 g using a balance.
9.1 Field Reagent Blanks, if analyzed. Perform the digestion and analysis of the blanks in Container Nos. 7 through 12 that were produced in sections 8.2.11 through 8.2.17, respectively. For Hg field reagent blanks, use a 10 ml aliquot for digestion and analysis.
9.1.1 Digest and analyze one of the filters from Container No. 12 per section 8.3.1, 100 ml from Container No. 7 per section 8.3.2, and 100 ml from Container No. 8A per section 8.3.3. This step produces blanks for Analytical Fractions 1A and 1B.
9.1.2 Combine 100 ml of Container No. 8A with 200 ml from Container No. 9, and digest and analyze the resultant volume per section 8.3.4. This step produces blanks for Analytical Fractions 2A and 2B.
9.1.3 Digest and analyze a 100-ml portion of Container No. 8A to produce a blank for Analytical Fraction 3A.
9.1.4 Combine 100 ml from Container No. 10 with 33 ml from Container No. 8B to produce a blank for Analytical Fraction 3B. Filter the resultant 133 ml as described for Container No. 5B in section 8.3.5, except do not dilute the 133 ml. Analyze this blank for Hg within 48 hr of the filtration step, and use 400 ml as the blank volume when calculating the blank mass value. Use the actual volumes of the other analytical blanks when calculating their mass values.
9.1.5 Digest the filter that was used to remove any brown MnO
9.1.6 Analyze the blanks for Analytical Fraction Blanks 1A and 2A per section 11.1.1 and/or section 11.1.2. Analyze the blanks for Analytical Fractions 1B, 2B, 3A, 3B, and 3C per section 11.1.3. Analysis of the blank for Analytical Fraction 1A produces the front-half reagent blank correction values for the desired metals except for Hg; Analysis of the blank for Analytical Fraction 1B produces the front-half reagent blank correction value for Hg. Analysis of the blank for Analytical Fraction 2A produces the back-half reagent blank correction values for all of the desired metals except for Hg, while separate analyses of the blanks for Analytical Fractions 2B, 3A, 3B, and 3C produce the back-half reagent blank correction value for Hg.
9.2 Quality Control Samples. Analyze the following quality control samples.
9.2.1 ICAP and ICP-MS Analysis. Follow the respective quality control descriptions in section 8 of Methods 6010 and 6020 in EPA Publication SW-846 Third Edition (November 1986) including updates I, II, IIA, IIB and III, as incorporated by reference in § 60.17(i). For the purposes of a source test that consists of three sample runs, modify those requirements to include the following: two instrument check standard runs, two calibration blank runs, one interference check sample at the beginning of the analysis (analyze by Method of Standard Additions unless within 25 percent), one quality control sample to check the accuracy of the calibration standards (required to be within 25 percent of calibration), and one duplicate analysis (required to be within 20 percent of average or repeat all analyses).
9.2.2 Direct Aspiration AAS and/or GFAAS Analysis for Sb, As, Ba, Be, Cd, Cu, Cr, Co, Pb, Ni, Mn, Hg, P, Se, Ag, Tl, and Zn. Analyze all samples in duplicate. Perform a matrix spike on at least one front-half sample and one back-half sample, or one combined sample. If recoveries of less than 75 percent or greater than 125 percent are obtained for the matrix spike, analyze each sample by the Method of Standard Additions. Analyze a quality control sample to check the accuracy of the calibration standards. If the results are not within 20 percent, repeat the calibration.
9.2.3 CVAAS Analysis for Hg. Analyze all samples in duplicate. Analyze a quality control sample to check the accuracy of the calibration standards (if not within 15 percent, repeat calibration). Perform a matrix spike on one sample (if not within 25 percent, analyze all samples by the Method of Standard Additions). Additional information on quality control can be obtained from Method 7470 in EPA Publication SW-846 Third Edition (November 1986) including updates I, II, IIA, IIB and III, as incorporated by reference in § 60.17(i), or in Standard Methods for Water and Wastewater Method 303F.
Maintain a laboratory log of all calibrations.
10.1 Sampling Train Calibration. Calibrate the sampling train components according to the indicated sections of Method 5: Probe Nozzle (Section 10.1); Pitot Tube (Section 10.2); Metering System (Section 10.3); Probe Heater (Section 10.4); Temperature Sensors (Section 10.5); Leak-Check of the Metering System (Section 8.4.1); and Barometer (Section 10.6).
10.2 Inductively Coupled Argon Plasma Spectrometer Calibration. Prepare standards as outlined in section 7.5. Profile and calibrate the instrument according to the manufacturer’s recommended procedures using those standards. Check the calibration once per hour. If the instrument does not reproduce the standard concentrations within 10 percent, perform the complete calibration procedures. Perform ICP-MS analysis by following Method 6020 in EPA Publication SW-846 Third Edition (November 1986) including updates I, II, IIA, IIB and III, as incorporated by reference in § 60.17(i).
10.3 Atomic Absorption Spectrometer – Direct Aspiration AAS, GFAAS, and CVAAS analyses. Prepare the standards as outlined in section 7.5 and use them to calibrate the spectrometer. Calibration procedures are also outlined in the EPA methods referred to in Table 29-2 and in Method 7470 in EPA Publication SW-846 Third Edition (November 1986) including updates I, II, IIA, IIB and III, as incorporated by reference in § 60.17(i), or in Standard Methods for Water and Wastewater Method 303F (for Hg). Run each standard curve in duplicate and use the mean values to calculate the calibration line. Recalibrate the instrument approximately once every 10 to 12 samples.
10.4 Field Balance Calibration Check. Check the calibration of the balance used to weigh impingers with a weight that is at least 500g or within 50g of a loaded impinger. The weight must be ASTM E617-13 “Standard Specification for Laboratory Weights and Precision Mass Standards” (incorporated by reference-see 40 CFR 60.17) Class 6 (or better). Daily before use, the field balance must measure the weight within ±0.5g of the certified mass. If the daily balance calibration check fails, perform corrective measures and repeat the check before using balance.
10.5 Analytical Balance Calibration. Perform a multipoint calibration (at least five points spanning the operational range) of the analytical balance before the first use, and semiannually thereafter. The calibration of the analytical balance must be conducted using ASTM E617-13 “Standard Specification for Laboratory Weights and Precision Mass Standards” (incorporated by reference – see 40 CFR 60.17) Class 2 (or better) tolerance weights. Audit the balance each day it is used for gravimetric measurements by weighing at least one ASTM E617-13 Class 2 tolerance (or better) calibration weight that corresponds to 50 to 150 percent of the weight of one filter or between 1g and 5g. If the scale cannot reproduce the value of the calibration weight to within 0.5 mg of the certified mass, perform corrective measures, and conduct the multipoint calibration before use.
11.1 Sample Analysis. For each sampling train sample run, seven individual analytical samples are generated; two for all desired metals except Hg, and five for Hg. A schematic identifying each sample container and the prescribed analytical preparation and analysis scheme is shown in Figure 29-3. The first two analytical samples, labeled Analytical Fractions 1A and 1B, consist of the digested samples from the front-half of the train. Analytical Fraction 1A is for ICAP, ICP-MS or AAS analysis as described in sections 11.1.1 and 11.1.2, respectively. Analytical Fraction 1B is for front-half Hg analysis as described in section 11.1.3. The contents of the back-half of the train are used to prepare the third through seventh analytical samples. The third and fourth analytical samples, labeled Analytical Fractions 2A and 2B, contain the samples from the moisture removal impinger No. 1, if used, and HNO
11.1.1 ICAP and ICP-MS Analysis. Analyze Analytical Fractions 1A and 2A by ICAP using Method 6010 or Method 200.7 (40 CFR 136, Appendix C). Calibrate the ICAP, and set up an analysis program as described in Method 6010 or Method 200.7. Follow the quality control procedures described in section 9.2.1. Recommended wavelengths for analysis are as shown in Table 29-2. These wavelengths represent the best combination of specificity and potential detection limit. Other wavelengths may be substituted if they can provide the needed specificity and detection limit, and are treated with the same corrective techniques for spectral interference. Initially, analyze all samples for the target metals (except Hg) plus Fe and Al. If Fe and Al are present, the sample might have to be diluted so that each of these elements is at a concentration of less than 50 ppm so as to reduce their spectral interferences on As, Cd, Cr, and Pb. Perform ICP-MS analysis by following Method 6020 in EPA Publication SW-846 Third Edition (November 1986) including updates I, II, IIA, IIB and III, as incorporated by reference in § 60.17(i).
When analyzing samples in a HF matrix, an alumina torch should be used; since all front-half samples will contain HF, use an alumina torch.
11.1.2 AAS by Direct Aspiration and/or GFAAS. If analysis of metals in Analytical Fractions 1A and 2A by using GFAAS or direct aspiration AAS is needed, use Table 29-3 to determine which techniques and procedures to apply for each target metal. Use Table 29-3, if necessary, to determine techniques for minimization of interferences. Calibrate the instrument according to section 10.3 and follow the quality control procedures specified in section 9.2.2.
11.1.3 CVAAS Hg analysis. Analyze Analytical Fractions 1B, 2B, 3A, 3B, and 3C separately for Hg using CVAAS following the method outlined in Method 7470 in EPA Publication SW-846 Third Edition (November 1986) including updates I, II, IIA, IIB and III, as incorporated by reference in § 60.17(i), or in Standard Methods for Water and Wastewater Analysis, 15th Edition, Method 303F, or, optionally using note no. 2 at the end of this section. Set up the calibration curve (zero to 1000 ng) as described in Method 7470 or similar to Method 303F using 300-ml BOD bottles instead of Erlenmeyers. Perform the following for each Hg analysis. From each original sample, select and record an aliquot in the size range from 1 ml to 10 ml. If no prior knowledge of the expected amount of Hg in the sample exists, a 5 ml aliquot is suggested for the first dilution to 100 ml (see note no. 1 at end of this section). The total amount of Hg in the aliquot shall be less than 1 µg and within the range (zero to 1000 ng) of the calibration curve. Place the sample aliquot into a separate 300-ml BOD bottle, and add enough water to make a total volume of 100 ml. Next add to it sequentially the sample digestion solutions and perform the sample preparation described in the procedures of Method 7470 or Method 303F. (See note no. 2 at the end of this section). If the maximum readings are off-scale (because Hg in the aliquot exceeded the calibration range; including the situation where only a 1-ml aliquot of the original sample was digested), then dilute the original sample (or a portion of it) with 0.15 percent HNO
When Hg levels in the sample fractions are below the in-stack detection limit given in Table 29-1, select a 10 ml aliquot for digestion and analysis as described.
Optionally, Hg can be analyzed by using the CVAAS analytical procedures given by some instrument manufacturer’s directions. These include calibration and quality control procedures for the Leeman Model PS200, the Perkin Elmer FIAS systems, and similar models, if available, of other instrument manufacturers. For digestion and analyses by these instruments, perform the following two steps: (1), Digest the sample aliquot through the addition of the aqueous hydroxylamine hydrochloride/sodium chloride solution the same as described in this section: (The Leeman, Perkin Elmer, and similar instruments described in this note add automatically the necessary stannous chloride solution during the automated analysis of Hg.); (2), Upon completion of the digestion described in (1), analyze the sample according to the instrument manufacturer’s directions. This approach allows multiple (including duplicate) automated analyses of a digested sample aliquot.
12.1 Nomenclature.
For example, if a 10 ml aliquot of Analytical Fraction 2B is taken and digested and analyzed (according to section 11.1.3 and its notes nos. 1 and 2), then calculate and use the total amount of Hg in the 10 ml aliquot for Q
For example, if a 10 ml aliquot of Analytical Fraction 1B is taken and digested and analyzed (according to section 11.1.3 and its notes nos. 1 and 2), then calculate and use the total amount of Hg in the 10 ml aliquot for Q
For example, if a 1 ml aliquot of Analytical Fraction 1B was diluted to 50 ml with 0.15 percent HNO
For example, if 1 ml of Analytical Fraction 2B was diluted to 10 ml with 0.15 percent HNO
V
12.2 Dry Gas Volume. Using the data from this test, calculate V
12.3 Volume of Water Vapor and Moisture Content. Using the total volume of condensate collected during the source sampling, calculate the volume of water vapor V
12.4 Stack Gas Velocity. Using the data from this test and Equation 2-9 of Method 2, calculate the average stack gas velocity.
12.5 In-Stack Detection Limits. Calculate the in-stack method detection limits shown in Table 29-4 using the conditions described in section 13.3.1 as follows:
12.6 Metals (Except Hg) in Source Sample.
12.6.1 Analytical Fraction 1A, Front-Half, Metals (except Hg). Calculate separately the amount of each metal collected in Sample Fraction 1 of the sampling train using the following equation:
If Analytical Fractions 1A and 2A are combined, use proportional aliquots. Then make appropriate changes in Equations 29-2 through 29-4 to reflect this approach.
12.6.2 Analytical Fraction 2A, Back-Half, Metals (except Hg). Calculate separately the amount of each metal collected in Fraction 2 of the sampling train using the following equation:
12.6.3 Total Train, Metals (except Hg). Calculate the total amount of each of the quantified metals collected in the sampling train as follows:
If the measured blank value for the front half (M
I. “A” µg.
II. The lesser of (a) M
I. 1 µg.
II. The lesser of (a) M
12.7 Hg in Source Sample.
12.7.1 Analytical Fraction 1B; Front-Half Hg. Calculate the amount ofHg collected in the front-half, Sample Fraction 1, of the sampling train by using Equation 29-5:
12.7.2 Analytical Fractions 2B, 3A, 3B, and 3C; Back Half Hg.
12.7.2.1 Calculate the amount of Hg collected in Sample Fraction 2 by using Equation 29-6:
12.7.2.2 Calculate each of the back-half Hg values for Analytical Fractions 3A, 3B, and 3C by using Equation 29-7:
12.7.2.3 Calculate the total amount of Hg collected in the back-half of the sampling train by using Equation 29-8:
12.7.3 Total Train Hg Catch. Calculate the total amount of Hg collected in the sampling train by using Equation 29-9:
If the total of the measured blank values (Hg
I. 0.6 µg.
II. The lesser of (a) (Hg
12.8 Individual Metal Concentrations in Stack Gas. Calculate the concentration of each metal in the stack gas (dry basis, adjusted to standard conditions) by using Equation 29-10:
12.9 Isokinetic Variation and Acceptable Results. Same as Method 5, sections 12.11 and 12.12, respectively.
13.1 Range. For the analysis described and for similar analyses, the ICAP response is linear over several orders of magnitude. Samples containing metal concentrations in the nanograms per ml (ng/ml) to micrograms per ml (µg/ml) range in the final analytical solution can be analyzed using this method. Samples containing greater than approximately 50 µg/ml As, Cr, or Pb should be diluted to that level or lower for final analysis. Samples containing greater than approximately 20 µg/ml of Cd should be diluted to that level before analysis.
13.2 Analytical Detection Limits.
See section 13.3 for the description of in-stack detection limits.
13.2.1 ICAP analytical detection limits for the sample solutions (based on SW-846, Method 6010) are approximately as follows: Sb (32 ng/ml), As (53 ng/ml), Ba (2 ng/ml), Be (0.3 ng/ml), Cd (4 ng/ml), Cr (7 ng/ml), Co (7 ng/ml), Cu (6 ng/ml), Pb (42 ng/ml), Mn (2 ng/ml), Ni (15 ng/ml), P (75 ng/ml), Se (75 ng/ml), Ag (7 ng/ml), Tl (40 ng/ml), and Zn (2 ng/ml). ICP-MS analytical detection limits (based on SW-846, Method 6020) are lower generally by a factor of ten or more. Be is lower by a factor of three. The actual sample analytical detection limits are sample dependent and may vary due to the sample matrix.
13.2.2 The analytical detection limits for analysis by direct aspiration AAS (based on SW-846, Method 7000 series) are approximately as follows: Sb (200 ng/ml), As (2 ng/ml), Ba (100 ng/ml), Be (5 ng/ml), Cd (5 ng/ml), Cr (50 ng/ml), Co (50 ng/ml), Cu (20 ng/ml), Pb (100 ng/ml), Mn (10 ng/ml), Ni (40 ng/ml), Se (2 ng/ml), Ag (10 ng/ml), Tl (100 ng/ml), and Zn (5 ng/ml).
13.2.3 The detection limit for Hg by CVAAS (on the resultant volume of the digestion of the aliquots taken for Hg analyses) can be approximately 0.02 to 0.2 ng/ml, depending upon the type of CVAAS analytical instrument used. 13.2.4 The use of GFAAS can enhance the detection limits compared to direct aspiration AAS as follows: Sb (3 ng/ml), As (1 ng/ml), Be (0.2 ng/ml), Cd (0.1 ng/ml), Cr (1 ng/ml), Co (1 ng/ml), Pb (1 ng/ml), Se (2 ng/ml), and Tl (1 ng/ml).
13.3 In-stack Detection Limits.
13.3.1 For test planning purposes in-stack detection limits can be developed by using the following information: (1) The procedures described in this method, (2) the analytical detection limits described in section 13.2 and in SW-846,(3) the normal volumes of 300 ml (Analytical Fraction 1) for the front-half and 150 ml (Analytical Fraction 2A) for the back-half samples, and (4) a stack gas sample volume of 1.25 m
13.3.2 To ensure optimum precision/resolution in the analyses, the target concentrations of metals in the analytical solutions should be at least ten times their respective analytical detection limits. Under certain conditions, and with greater care in the analytical procedure, these concentrations can be as low as approximately three times the respective analytical detection limits without seriously impairing the precision of the analyses. On at least one sample run in the source test, and for each metal analyzed, perform either repetitive analyses, Method of Standard Additions, serial dilution, or matrix spike addition, etc., to document the quality of the data.
13.3.3 Actual in-stack method detection limits are based on actual source sampling parameters and analytical results as described above. If required, the method in-stack detection limits can be improved over those shown in Table 29-1 for a specific test by either increasing the sampled stack gas volume, reducing the total volume of the digested samples, improving the analytical detection limits, or any combination of the three. For extremely low levels of Hg only, the aliquot size selected for digestion and analysis can be increased to as much as 10 ml, thus improving the in-stack detection limit by a factor of ten compared to a 1 ml aliquot size.
13.3.3.1 A nominal one hour sampling run will collect a stack gas sampling volume of about 1.25 m
13.3.3.2 The in-stack detection limits assume that all of the sample is digested and the final liquid volumes for analysis are the normal values of 300 ml for Analytical Fraction 1, and 150 ml for Analytical Fraction 2A. If the volume of Analytical Fraction 1 is reduced from 300 to 30 ml, the in-stack detection limits for that fraction of the sample would be improved by a factor of ten. If the volume of Analytical Fraction 2A is reduced from 150 to 25 ml, the in-stack detection limits for that fraction of the sample would be improved by a factor of six. Matrix effect checks are necessary on sample analyses and typically are of much greater significance for samples that have been concentrated to less than the normal original sample volume. Reduction of Analytical Fractions 1 and 2A to volumes of less than 30 and 25 ml, respectively, could interfere with the redissolving of the residue and could increase interference by other compounds to an intolerable level.
13.3.3.3 When both of the modifications described in sections 13.3.3.1 and 13.3.3.2 are used simultaneously on one sample, the resultant improvements are multiplicative. For example, an increase in stack gas volume by a factor of four and a reduction in the total liquid sample digested volume of both Analytical Fractions 1 and 2A by a factor of six would result in an improvement by a factor of twenty-four of the in-stack method detection limit.
13.4 Precision. The precision (relative standard deviation) for each metal detected in a method development test performed at a sewage sludge incinerator were found to be as follows:
16.1 Alternative Analyzer. Samples may also be analyzed by cold vapor atomic fluorescence spectrometry.
16.2 [Reserved]
1. Method 303F in Standard Methods for the Examination of Water Wastewater, 15th Edition, 1980. Available from the American Public Health Association, 1015 18th Street N.W., Washington, D.C. 20036.
2. EPA Methods 6010, 6020, 7000, 7041, 7060, 7131, 7421, 7470, 7740, and 7841, Test Methods for Evaluating Solid Waste: Physical/Chemical Methods. SW-846, Third Edition, November 1986, with updates I, II, IIA, IIB and III. Office of Solid Waste and Emergency Response, U. S. Environmental Protection Agency, Washington, DC 20460.
3. EPA Method 200.7, Code of Federal Regulations, Title 40, Part 136, Appendix C. July 1, 1987.
4. EPA Methods 1 through 5, Code of Federal Regulations, Title 40, Part 60, Appendix A, July 1, 1991.
5. EPA Method 101A, Code of Federal Regulations, Title 40, Part 61, Appendix B, July 1, 1991.
Table 29-1 – In Stack Method Detection Limits (ug/m
3) for the Front-Half, the Back Half, and the Total Sampling Train Using ICAP, GFAAS, and CVAAS
| Metal | Front-half: probe and filter | Back-half: impinters 1-3 | Back-half: impringers 4-6 a | Total train |
|---|---|---|---|---|
| Antimony | 1 7.7 (0.7) | 1 3.8 (0.4) | 1 11.5 (1.1) | |
| Arsenic | 1 12.7 (0.3) | 1 6.4 (0.1) | 1 19.1 (0.4) | |
| Barium | 0.5 | 0.3 | 0.8 | |
| Beryllium | 1 0.07 (0.05) | 1 0.04 (0.03) | 1 0.11 (0.08) | |
| Cadmium | 1 1.0 (0.02) | 1 0.5 (0.01) | 1 1.5 (0.03) | |
| Chromium | 1 1.7 (0.2) | 1 0.8 (0.1) | 1 2.5 (0.3) | |
| Cobalt | 1 1.7 (0.2) | 1 0.8 (0.1) | 1 2.5 (0.3) | |
| Copper | 1.4 | 0.7 | 2.1 | |
| Lead | 1 10.1 (0.2) | 1 5.0 (0.1) | 1 15.1 (0.3) | |
| Manganese | 1 0.5 (0.2) | 1 0.2 (0.1) | 1 0.7 (0.3) | |
| Mercury | 2 0.06 | 2 0.3 | 2 0.2 | 2 0.56 |
| Nickel | 3.6 | 1.8 | 5.4 | |
| Phosphorus | 18 | 9 | 27 | |
| Selenium | 1 18 (0.5) | 1 9 (0.3) | 1 27 (0.8) | |
| Silver | 1.7 | 0.9 (0.7) | 2.6 | |
| Thallium | 1 9.6 (0.2) | 1 4.8 (0.1) | 1 14.4 (0.3) | |
| Zinc | 0.5 | 0.3 | 0.8 |
a Mercury analysis only.
1 Detection limit when analyzed by ICAP or GFAAS as shown in parentheses (see section 11.1.2).
2 Detection limit when anaylzed by CVAAS, estimated for Back-half and Total Train. See sections 13.2 and 11.1.3. Note: Actual method in-stack detection limits may vary from these values, as described in section 13.3.3.
Table 29-2 – Recommended Wavelengths for ICAP Analysis
| Analyte | Wavelength (nm) |
|---|---|
| Aluminum (Al) | 308.215 |
| Antimony (Sb) | 206.833 |
| Arsenic (As) | 193.696 |
| Barium (Ba) | 455.403 |
| Beryllium (Be) | 313.042 |
| Cadmium (Cd) | 226.502 |
| Chromium (Cr) | 267.716 |
| Cobalt (Co) | 228.616 |
| Copper (Cu) | 328.754 |
| Iron (Fe) | 259.940 |
| Lead (Pb) | 220.353 |
| Manganese (Mn) | 257.610 |
| Nickel (Ni) | 231.604 |
| Phosphorus (P) | 214.914 |
| Selenium (Se) | 196.026 |
| Silver (Ag) | 328.068 |
| Thallium (T | 190,864 |
| Zinc (Zn) | 213,856 |
Table 29-3 – Applicable Techniques, Methods and Minimization of Interferences for AAS Analysis
| Metal | Technique | SW-846 1 Methods No. | Wavelength (nm) | Interferences | |
|---|---|---|---|---|---|
| Cause | Minimization | ||||
| Fe | Aspiration | 7380 | 248.3 | Contamination | Great care taken to avoid contamination. |
| Pb | Aspiration | 7420 | 283.3 | 217.0 nm alternate | Background correction required. |
| Pb | Furnace | 7421 | 283.3 | Poor recoveries | Matrix modifier, add 10 µl of phosphorus acid to 1 ml of prepared sample in sampler cup. |
| Mn | Aspiration | 7460 | 279.5 | 403.1 nm alternate | Background correction required. |
| Ni | Aspiration | 7520 | 232.0 | 352.4 nm alternate Fe, Co, and Cr Nonlinear response | Background correction required. Matrix matching or nitrous-oxide/acetylene flame Sample dilution or use 352.3 nm line |
| Se | Furnace | 7740 | 196.0 | Volatility | Spike samples and reference materials and add nickel nitrate to minimize volatilization. |
| Adsorption & scatter | Background correction is required and Zeeman background correction can be useful. | ||||
| Ag | Aspiration | 7760 | 328.1 | Adsorption & scatter AgCl insoluble | Background correction is required. Avoid hydrochloric acid unless silver is in solution as a chloride complex. Sample and standards monitored for aspiration rate. |
| Tl | Aspiration | 7840 | 276.8 | Background correction is required. Hydrochloric acid should not be used. | |
| Tl | Furnace | 7841 | 276.8 | Hydrochloric acid or chloride | Background correction is required. Verify that losses are not occurring for volatilization by spiked samples or standard addition; Palladium is a suitable matrix modifier. |
| Zn | Aspiration | 7950 | 213.9 | High Si, Cu, & P Contamination | Strontium removes Cu and phosphate. Great care taken to avoid contamination. |
| Sb | Aspiration | 7040 | 217.6 | 1000 mg/ml Pb, Ni, Cu, or acid | Use secondary wavelength of 231.1 nm; match sample & standards acid concentration or use nitrous oxide/acetylene flame. |
| Sb | Furnace | 7041 | 217.6 | High Pb | Secondary wavelength or Zeeman correction. |
| As | Furnace | 7060 | 193.7 | Arsenic Volatilization Aluminum | Spike samples and add nickel nitrate solution to digestates prior to analysis. Use Zeeman background correction. |
| Ba | Aspiration | 7080 | 553.6 | ||
| Calcium | |||||
| Barium Ionization | High hollow cathode current and narrow band set. 2 ml of KCl per 100 m1 of sample. | ||||
| Be | Aspiration | 7090 | 234.9 | 500 ppm Al. High Mg and Si | Add 0.1% fluoride. |
| Be | Furnace | 7091 | 234.9 | Be in optical path | Optimize parameters to minimize effects. |
| Cd | Aspiration | 7130 | 228.8 | Absorption and light scattering | Background correction is required. |
| Cd | Furnace | 7131 | 228.8 | As above Excess Chloride Pipet Tips | As above. Ammonium phosphate used as a matrix modifier. Use cadmium-free tips. |
| Cr | Aspiration | 7190 | 357.9 | Alkali metal | KCl ionization suppressant in samples and standards – Consult mfgs’ literature. |
| Co | Furnace | 7201 | 240.7 | Excess chloride | Use Method of Standard Additions. |
| Cr | Furnace | 7191 | 357.9 | 200 mg/L Ca and P | All calcium nitrate for a know constant effect and to eliminate effect of phosphate. |
| Cu | Aspiration | 7210 | 324.7 | Absorption and Scatter | Consult manufacturer’s manual. |
1 Refer to EPA publication SW-846 (Reference 2 in section 16.0).
Method 30A is a procedure for measuring total vapor phase mercury (Hg) emissions from stationary sources using an instrumental analyzer. This method is particularly appropriate for performing emissions testing and for conducting relative accuracy test audits (RATAs) of mercury continuous emissions monitoring systems (Hg CEMS) and sorbent trap monitoring systems at coal-fired combustion sources. Quality assurance and quality control requirements are included to assure that you, the tester, collect data of known and acceptable quality for each testing site. This method does not completely describe all equipment, supplies, and sampling procedures and analytical procedures you will need but refers to other test methods for some of the details. Therefore, to obtain reliable results, you should also have a thorough knowledge of these additional methods which are also found in appendices A-1 and A-3 to this part:
(a) Method 1 – Sample and Velocity Traverses for Stationary Sources.
(b) Method 4 – Determination of Moisture Content in Stack Gases.
1.1 Analytes. What does this method determine? This method is designed to measure the mass concentration of total vapor phase Hg in flue gas, which represents the sum of elemental Hg (Hg
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| Elemental Hg (Hg 0) | 7439-97-6 | Typically |
| Oxidized Hg (Hg | (Same). |
1.2 Applicability. When is this method required? Method 30A is offered as a reference method for emission testing and for RATAs of Hg CEMS and sorbent trap monitoring systems at coal-fired boilers. Method 30A may also be specified for other source categories in the future, either by New Source Performance Standards (NSPS), National Emission Standards for Hazardous Air Pollutants (NESHAP), emissions trading programs, State Implementation Plans (SIP), or operating permits that require measurement of Hg concentrations in stationary source emissions to determine compliance with an applicable emission standard or limit, or to conduct RATAs of Hg CEMS and sorbent trap monitoring systems.
1.3 Data Quality Objectives (DQO). How good must my collected data be? Method 30A has been designed to provide data of high and known quality for Hg emission testing and for relative accuracy testing of Hg monitoring systems including Hg CEMS and sorbent trap monitoring systems. In these and other applications, the principle objective is to ensure the accuracy of the data at the actual emission levels encountered. To meet this objective, calibration standards prepared according to an EPA traceability protocol must be used and measurement system performance tests are required.
In this method, a sample of the effluent gas is continuously extracted and conveyed to an analyzer capable of measuring the total vapor phase Hg concentration. Elemental and oxidized mercury (i.e., Hg
3.1 Calibration Curve means the relationship between an analyzer’s response to the injection of a series of calibration gases and the actual concentrations of those gases.
3.2 Calibration Gas means a gas standard containing Hg
3.2.1 Zero Gas means a calibration gas with a concentration that is below the level detectable by the measurement system.
3.2.2 Low-Level Gas means a calibration gas with a concentration that is 10 to 30 percent of the calibration span.
3.2.3 Mid-Level Gas means a calibration gas with a concentration that is 40 to 60 percent of the calibration span.
3.2.4 High-Level Gas means a calibration gas whose concentration is equal to the calibration span.
3.3 Converter means a device that reduces oxidized mercury (Hg
3.4 Calibration Span means the upper limit of valid instrument response during sampling. To the extent practicable the measured emissions are to be between 10 and 100 percent of the selected calibration span (i.e., the measured emissions should be within the calibrated range determined by the Low- and High-Level gas standards). It is recommended that the calibration span be at least twice the native concentration to accommodate the dynamic spiking procedure.
3.5 Centroidal Area means the central area that has the same shape as the stack or duct cross section and is no greater than one percent of the stack or duct total cross-sectional area.
3.6 Data Recorder means the equipment that permanently records the concentrations reported by the analyzer.
3.7 Drift Check means the test to determine the difference between the measurement system readings obtained in a post-run system integrity check and the prior pre-run system integrity check at a specific calibration gas concentration level (i.e., zero, mid-level, or high-level).
3.8 Dynamic Spiking means a procedure in which a known mass or concentration of vapor phase HgCl
3.9 Gas Analyzer means the equipment that detects the total vapor phase Hg being measured and generates an output proportional to its concentration.
3.10 Interference Test means the test to detect analyzer responses to compounds other than Hg, usually gases present in the measured gas stream, that are not adequately accounted for in the calibration procedure and may cause measurement bias.
3.11 Measurement System means all of the equipment used to determine the Hg concentration. The measurement system may generally include the following major subsystems: sample acquisition, Hg
3.12 Native Concentration means the total vapor phase Hg concentration in the effluent gas stream.
3.13 NIST means the National Institute of Standards and Technology, located in Gaithersburg, Maryland.
3.14 Response Time means the time it takes for the measurement system, while operating normally at its target sample flow rate or dilution ratio, to respond to a known step change in gas concentration (from a low-level to a high-level gas) and to read within 5 percent of the stable high-level gas response.
3.15 Run means a series of gas samples taken successively from the stack or duct. A test normally consists of a specific number of runs.
3.16 System Calibration Error means the difference between the measured concentration of a low-, mid-, or high-level Hg
3.17 System Calibration Mode means introducing the calibration gases into the measurement system at the probe, upstream of all sample conditioning components.
3.18 Test refers to the series of runs required by the applicable regulation.
Interferences will vary among instruments and potential instrument-specific spectral and matrix interferences must be evaluated through the interference test and the dynamic spiking tests.
This method may require you to work with hazardous materials and in hazardous conditions. You are encouraged to establish safety procedures before using the method. Among other precautions, you should become familiar with the safety recommendations in the gas analyzer user’s manual. Occupational Safety and Health Administration (OSHA) regulations concerning use of compressed gas cylinders and noxious gases may apply.
6.1 What do I need for the measurement system? This method is intended to be applicable to multiple instrumental technologies. You may use any equipment and supplies that meet the following specifications.
6.1.1 All wetted sampling system components, including probe components prior to the point at which the calibration gas is introduced, must be chemically inert to all Hg species. Materials such as perfluoroalkoxy (PFA) Teflon
6.1.2 The interference, system calibration error, system integrity, drift and dynamic spiking test criteria must all be met by the system used.
6.1.3 The system must be capable of measuring and controlling sample flow rate.
6.1.4 All system components prior to the Hg
6.2 Measurement System Components. Figure 30A-1 in section 17.0 is an example schematic of a Method 30A measurement system.
6.2.1 Sample Probe. The probe must be made of the appropriate materials as noted in section 6.1.1, heated when necessary (see section 6.1.4), configured with ports for introduction of calibration and spiking gases, and of sufficient length to traverse all of the sample points.
6.2.2 Filter or Other Particulate Removal Device. The filter or other particulate removal device is considered to be a part of the measurement system, must be made of appropriate materials as noted in section 6.1.1, and must be included in all system tests.
6.2.3 Sample Line. The sample line that connects the probe to the converter, conditioning system and analyzer must be made of appropriate materials as noted in section 6.1.1.
6.2.4 Conditioning Equipment. For dry basis measurements, a condenser, dryer or other suitable device is required to remove moisture continuously from the sample gas. Any equipment needed to heat the probe, or sample line to avoid condensation prior to the moisture removal component is also required. For wet basis systems, you must keep the sample above its dew point either by: (1) Heating the sample line and all sample transport components up to the inlet of the analyzer (and, for hot-wet extractive systems, also heating the analyzer) or (2) by diluting the sample prior to analysis using a dilution probe system. The components required to do either of the above are considered to be conditioning equipment.
6.2.5 Sampling Pump. A pump is needed to push or pull the sample gas through the system at a flow rate sufficient to minimize the response time of the measurement system. If a mechanical sample pump is used and its surfaces are in contact with the sample gas prior to detection, the pump must be leak free and must be constructed of a material that is non-reactive to the gas being sampled (see section 6.1.1). For dilution-type measurement systems, an ejector pump (eductor) may be used to create a sufficient vacuum that sample gas will be drawn through a critical orifice at a constant rate. The ejector pump may be constructed of any material that is non-reactive to the gas being sampled.
6.2.6 Calibration Gas System(s). One or more systems may be needed to introduce calibration gases into the measurement system. A system should be able to flood the sampling probe sufficiently to prevent entry of gas from the effluent stream.
6.2.7 Dynamic Spiking Port. For the purposes of the dynamic spiking procedure described in section 8.2.7, the measurement system must be equipped with a port to allow introduction of the dynamic spike gas stream with the sample gas stream, at a point as close as possible to the inlet of the probe so as to ensure adequate mixing. The same port used for system calibrations and calibration error checks may be used for dynamic spiking purposes.
6.2.8 Sample Gas Delivery. The sample line may feed directly to a converter, to a by-pass valve (for speciating systems), or to a sample manifold. All valve and/or manifold components must be made of material that is non-reactive to the gas sampled and the calibration gas, and must be configured to safely discharge any excess gas.
6.2.9 Hg Analyzer. An instrument is required that continuously measures the total vapor phase Hg in the gas stream and meets the applicable specifications in section 13.0.
6.2.10 Data Recorder. A recorder, such as a computerized data acquisition and handling system (DAHS), digital recorder, strip chart, or data logger, is required for recording measurement data.
6.3 Moisture Measurement System. If correction of the measured Hg emissions for moisture is required (see section 8.5), either Method 4 in appendix A-3 to this part or other moisture measurement methods approved by the Administrator will be needed to measure stack gas moisture content.
7.1 Calibration Gases. What calibration gases do I need? You will need calibration gases of known concentrations of Hg
The following calibration gas concentrations are required:
7.1.1 High-Level Gas. Equal to the selected calibration span.
7.1.2 Mid-Level Gas. 40 to 60 percent of the calibration span.
7.1.3 Low-Level Gas. 10 to 30 percent of the calibration span.
7.1.4 Zero Gas. No detectable Hg.
7.1.5 Dynamic Spike Gas. The exact concentration of the HgCl
7.2 Interference Test. What reagents do I need for the interference test? Use the appropriate test gases listed in Table 30A-3 in section 17.0 (i.e., the potential interferents for the source to be tested, as identified by the instrument manufacturer) to conduct the interference check. These gases need not be of protocol gas quality.
Figure 30A-2 in section 17.0 presents an overview of the test procedures required by this method. Since you may choose different options to comply with certain performance criteria, you must identify the specific options and associated frequencies you select and document your results in regard to the performance criteria.
8.1 Selection of Sampling Sites and Sampling Points. What sampling site and sampling points do I select?
8.1.1 When this method is used solely for Hg emission testing (e.g., to determine compliance with an emission standard or limit), use twelve sampling points located according to Table 1-1 or Table 1-2 of Method 1 in appendix A-1 to this part. Alternatively, you may conduct a stratification test as described in section 8.1.3 to determine the number and location of the sampling points.
8.1.2 When this method is used for relative accuracy testing of a Hg CEMS or sorbent trap monitoring system, follow the sampling site selection and sampling point layout procedures for gas monitor RATA testing described in the appropriate performance specification or applicable regulation (e.g., Performance Specification 2, section 8.1.3 of appendix B to this part or section 6.5.6 of appendix A to part 75 of this chapter), with one exception. If you elect to perform stratification testing as part of the sampling point selection process, perform the testing in accordance with section 8.1.3 of this method (see also “Summary Table of QA/QC Requirements” in section 9.0).
8.1.3 Determination of Stratification. If you elect to perform stratification testing as part of the sampling point selection process and the test results show your effluent gas stream to be unstratified or minimally stratified, you may be allowed to sample at fewer points or at different points than would otherwise be required.
8.1.3.1 Test Procedure. To test for stratification, use a probe of appropriate length to measure the total vapor phase Hg concentration at twelve traverse points located according to Table 1-1 or Table 1-2 of Method 1 in appendix A-1 to this part. Alternatively, for a sampling location where stratification is expected (e.g., after a wet scrubber or at a point where dissimilar gas streams are combined together), if a 12-point Hg stratification test has been previously performed at that location and the results of the test showed the location to be minimally stratified or unstratified according to the criteria in section 8.1.3.2, you may perform an abbreviated 3-point or 6-point Hg stratification test at the points specified in section 6.5.6.2(a) of appendix A to part 75 of this chapter in lieu of performing the 12-point test. Sample for a minimum of twice the system response time (see section 8.2.6) at each traverse point. Calculate the individual point and mean Hg concentrations.
8.1.3.2 Acceptance Criteria and Sampling Point Location.
8.1.3.2.1 If the Hg concentration at each traverse point differs from the mean concentration for all traverse points by no more than: (a) ±5 percent of the mean concentration; or (b) ±0.2 µg/m
8.1.3.2.2 If the 5 percent or 0.2 µg/m
8.1.3.2.3 If the gas stream is found to be stratified because the 10 percent or 0.5 µg/m
8.1.3.3 Temporal Variations. Temporal variations in the source Hg concentration during a stratification test may complicate the determination of stratification. If temporal variations are a concern, you may use the following procedure to normalize the stratification test data. A second Hg measurement system, i.e., either an installed Hg CEMS or another Method 30A system, is required to perform this procedure. Position the sampling probe of the second Hg measurement system at a fixed point in the stack or duct, at least one meter from the stack or duct wall. Then, each time that the Hg concentration is measured at one of the stratification test points, make a concurrent measurement of Hg concentration at the fixed point. Normalize the Hg concentration measured at each traverse point, by multiplying it by the ratio of C
8.1.3.4 Stratification Testing Exemption. Stratification testing need not be performed at a test location where it would otherwise be required to justify using fewer sample points or different sample points, if the owner or operator documents that the Hg concentration in the stack gas is expected to be 3 µg/m
8.1.3.5 Interim Alternative Stratification Test Procedures. In the time period between the effective date of this method and January 1, 2009, you may follow one of the following two procedures. Substitute a stratification test for sulfur dioxide (SO
8.2 Initial Measurement System Performance Tests. What initial performance criteria must my system meet before I begin sampling? Before measuring emissions, perform the following procedures:
(a) Interference Test;
(b) Calibration Gas Verification;
(c) Measurement System Preparation;
(d) 3-Point System Calibration Error Test;
(e) System Integrity Check;
(f) Measurement System Response Time Test; and
(g) Dynamic Spiking Test.
8.2.1 Interference Test (Optional). Your measurement system should be free of known interferences. It is recommended that you conduct this interference test of your measurement system prior to its initial use in the field to verify that the candidate test instrument is free from inherent biases or interferences resulting from common combustion emission constituents. If you have multiple measurement systems with components of the same make and model numbers, you need only perform this interference check on one system and you may also rely on an interference test conducted by the manufacturer on a system having components of the same make and model(s) of the system that you use. The interference test procedure is found in section 8.6 of this method.
8.2.2 Calibration Gas Verification. How must I verify the concentrations of my calibration gases?
8.2.2.1 Cylinder Gas Standards. When cylinder gas standards are used for Hg
8.2.2.2 Other Calibration Standards. All other calibration standards for HgCl
8.2.2.3 Calibration Span. Select the calibration span (i.e., high-level gas concentration) so that the measured source emissions are 10 to 100 percent of the calibration span. This requirement is waived for applications in which the Hg concentrations are consistently below 1 µg/m
8.2.3 Measurement System Preparation. How do I prepare my measurement system for use? Assemble, prepare, and precondition the measurement system according to your standard operating procedure. Adjust the system to achieve the correct sampling rate or dilution ratio (as applicable). Then, conduct a 3-point system calibration error test using Hg
8.2.4 System Calibration Error Test. Conduct a 3-point system calibration error test before the first test run. Use Hg
8.2.5 System Integrity Check. Perform a two-point system integrity check before the first test run. Use the zero gas and either the mid- or high-level HgCl
8.2.6 Measurement System Response Time. The measurement system response time is used to determine the minimum sampling time for each sampling point and is equal to the time that is required for the measured Hg concentration to increase from the stable low-level calibration gas response to a value within 5 percent of the stable high-level calibration gas response during the system calibration error test in section 8.2.4. Round off the measured system response time to the nearest minute.
8.2.7 Dynamic Spiking Test. You must perform dynamic spiking prior to the first test run to validate your test data. The purpose of this procedure is to demonstrate that the site-specific flue gas matrix does not adversely affect the accuracy of the measurement system. The specifications in section 13.5 must be met to validate your data. If these specifications are not met for the pre-test dynamic spiking, you may not proceed with the test until satisfactory results are obtained. For the time period between the effective date of this method and January 1, 2009, the dynamic spiking requirement is waived.
8.2.7.1 How do I perform dynamic spiking? Dynamic spiking is a gas phase application of the method of standard additions, which involves injecting a known quantity of Hg into the measurement system upstream of all sample conditioning components, similar to system calibration mode, except the probe is not flooded and the resulting sample stream includes both effluent gas and the spike gas. You must follow a written procedure that details how the spike is added to the system, how the spike dilution factor (DF) is measured, and how the Hg concentration data are collected and processed.
8.2.7.2 Spiking Procedure Requirements.
8.2.7.2.1 Spiking Gas Requirements. The spike gas must also be a HgCl
8.2.7.2.2 Target Spiking Level. The target level for spiking must be 150 to 200 percent of the native Hg concentration; however, if the native Hg concentration is 3, set the target level to add between 1 and 4 µg/m
8.2.7.2.3 Spike Injections. You must inject spikes in such a manner that the spiking does not alter the total volumetric sample system flow rate and dilution ratio (if applicable). You must collect at least 3 data points, and the relative standard deviation (RSD) specification in section 13.5 must be met. Each data point represents a single spike injection, and pre- and post-injection measurements of the native Hg concentration (or diluted native concentration, as applicable) are required for each spike injection.
8.2.7.2.4 Spike Dilution Factor (DF). For each spike injection, DF, the dilution factor must be determined. DF is the ratio of the total volumetric flow rate of gas through the measurement system to the spike gas flow rate. This factor must be ≥5. The spiking mass balance calculation is directly dependent on the accuracy of the DF determination. As a result, high accuracy total volumetric flow rate and spike gas flowrate measurements are required. These flow rates may be determined by direct or indirect measurement. Calibrated flow meters, venturies, orifices or tracer gas measurements are examples of potential flow measurement techniques.
8.2.7.2.5 Concentrations. The measurement system must record total vapor phase Hg concentrations continuously during the dynamic spiking procedure. It is possible that dynamic spiking at a level close to 200 percent of the native Hg concentration may cause the measured Hg concentration to exceed the calibration span value. Avoid this by choosing a lower spiking level or by recalibration at a higher span. The measurements shall not exceed 120 percent of the calibration span. The “baseline” measurements made between spikes may represent the native Hg concentration (if spike gas flow is stopped between injections) or the native Hg concentration diluted by blank or carrier gas flowing at the same rate as the spike gas (if gas flow cannot be stopped between injections). Each baseline measurement must include at least 4 readings or 1 minute (whichever is greater) of stable responses. Use Equation 30A-10 or 30A-11 in section 12.10 (as applicable) to convert baseline measurements to native concentration.
8.2.7.2.6 Recovery. Calculate spike recoveries using Equation 30A-7 in section 12.7. Mass recoveries may be calculated from stable responses based on injected mass flows or from integrated response peaks based on total mass injected. Calculate the mean and RSD for the three (or more) spike injections and compare to the specifications in section 13.5.
8.2.7.2.7 Error Adjustment Option. You may adjust the measurement data collected during dynamic spiking for the system calibration error using Equation 30A-3 in section 12. To do this, perform the initial system integrity check prior to the dynamic spiking test, and perform another system integrity check following the dynamic spiking test and before the first test run. If you choose this option, you must apply Equation 30A-3 to both the spiked sample concentration measurement (C
8.2.7.3 Example Spiking Procedure Using a Hot Vapor Calibration Source Generator.
(a) Introduce the spike gas into the probe using a hot vapor calibration source generator and a solution of HgCl
(b) If applicable, monitor the measurement system to make sure the total sampling system flow rate and the sample dilution ratio do not change during this procedure. Record all data on a data sheet similar to Table 30A-5 in section 17.0. If the Hg measurement system design makes it impractical to measure the total volumetric flow rate through the system, use a spike gas that includes a tracer for measuring the dilution factor, DF (see Equation 30A-9 in section 12.9). Allow the measurements to stabilize between each spike injection, average the pre- and post-injection baseline measurements, and calculate the native concentration. If this measurement shifts by more than 5 percent during any injection, it may be necessary to discard that data point and repeat the injection to achieve the required RSD among the injections. If the spikes persistently show poor repeatability, or if the recoveries are not within the range specified in section 13.5, take corrective action.
8.2.8 Run Validation. How do I confirm that each run I conduct is valid?
8.2.8.1 System Integrity Checks.
(a) Before and after each test run, perform a two-point system integrity check using the same procedure as the initial system integrity check described in section 8.2.5. You may use data from that initial system integrity check as the pre-run data for the first test run, provided it is the most recent system integrity check done before the first run. You may also use the results of a successful post-run system integrity check as the pre-run data for the next test run. Do not make any adjustments to the measurement system during these checks, other than to maintain the target calibration gas flow rate and the proper dilution ratio.
(b) As a time-saving alternative, you may, at the risk of invalidating multiple test runs, skip one or more integrity checks during a test day. Provided there have been no auto-calibrations or other instrument alterations, a single integrity check may suffice as a post-run check to validate (or invalidate) as many consecutive test runs as can be completed during a single test day. All subsequent test days must begin with a pre-run system integrity check subject to the same performance criteria and corrective action requirements as a post-run system integrity check.
(c) Each system integrity check must meet the criteria for system integrity checks in section 13.2. If a post-run system integrity check is failed, all test runs since the last passed system integrity check are invalid. If a post-run or a pre-run system integrity check is failed, you must take corrective action and pass another 3-point Hg
8.2.8.2 Drift Check. Using the data from the successful pre- and post-run system integrity checks, calculate the zero and upscale drift, using Equation 30A-2 in section 12.3. Exceeding the section 13.3 specification does not invalidate the run, but corrective action must be taken and a new 3-point Hg
8.3 Dilution-Type Systems – Special Considerations. When a dilution-type measurement system is used, there are three important considerations that must be taken into account to ensure the quality of the emissions data. First, the critical orifice size and dilution ratio must be selected properly so that the sample dew point will be below the sample line and analyzer temperatures. Second, a high-quality, accurate dilution controller must be used to maintain the correct dilution ratio during sampling. The dilution controller should be capable of monitoring the dilution air pressure, orifice upstream pressure, eductor vacuum, and sample flow rates. Third, differences between the molecular weight of calibration gas mixtures, dilution air, and the stack gas molecular weight must be considered because these can affect the dilution ratio and introduce measurement bias.
8.4 Sampling.
(a) Position the probe at the first sampling point. Allow the system to flush and equilibrate for at least two times the measurement system response time before recording any data. Then, traverse and record measurements at all required sampling points. Sample at each traverse point for an equal length of time, maintaining the appropriate sample flow rate or dilution ratio (as applicable). For all Hg instrumental method systems, the minimum sampling time at each sampling point must be at least two times the system response time, but not less than 10 minutes. For concentrating systems, the minimum sampling time must also include at least 4 concentration measurement cycles.
(b) After recording data for the appropriate period of time at the first traverse point, you may move the sample probe to the next point and continue recording, omitting the requirement to allow the system to equilibrate for two times the system response time before recording data at the subsequent traverse points. You must, however, sample at this and all subsequent traverse points for the required minimum amount of time specified in this section. If you must remove the probe from the stack for any reason, you must again allow the sampling system to equilibrate for at least two times the system response time prior to resuming data recording.
(c) If at any point the measured Hg concentration exceeds the calibration span value, you must at a minimum identify and report this as a deviation from the method. Depending on the data quality objectives of the test, this event may require corrective action before proceeding. If the average Hg concentration for any run exceeds the calibration span value, the run is invalidated.
8.5 Moisture Correction. If the moisture basis (wet or dry) of the measurements made with this method is different from the moisture basis of either: (1) The applicable emission limit; or (2) a Hg CEMS or sorbent trap monitoring system being evaluated for relative accuracy, you must determine the moisture content of the flue gas and correct the measured gas concentrations to a dry basis using Method 4 in appendix A-3 of this part or other appropriate methods, subject to the approval of the Administrator.
8.6 Optional Interference Test Procedure.
(a) Select an appropriate calibration span that reflects the source(s) to be tested and perform the interference check at 40 percent of the lowest calibration span value anticipated, e.g., 10 µg/m
(b) Introduce the interference test gases listed in Table 30A-3 in section 17.0 into the measurement system separately or as a mixture. The interference test gases HCl and NO must be introduced as a mixture. The interference test gases must be introduced into the sampling system at the probe such that the interference gas mixtures pass through all filters, scrubbers, conditioners, and other components as would be configured for normal sampling.
(c) The interference test must be performed using HgCl
(d) The duration of each test should be for a sufficient period of time to ensure the Hg measurement system surfaces are conditioned and a stable output is obtained. Measure the Hg response of the analyzer to these gases in µg/m3. Record the responses and determine the overall interference response using Table 30A-4 in section 17.0 and the equations presented in section 12.11. The specification in section 13.4 must be met.
(e) A copy of these data, including the date completed and a signed certification, must be included with each test report. The intent of this test is that the interference test results are intended to be valid for the life of the system. As a result, the Hg measurement system should be operated and tested in a configuration consistent with the configuration that will be used for field applications. However, if the system used for field testing is not consistent with the system that was interference-tested, the interference test must be repeated before it is used for any field applications. Examples of such conditions include, but are not limited to: major changes in dilution ratio (for dilution based systems), changes in catalyst materials, changes in filtering device design or materials, changes in probe design or configuration, and changes in gas conditioning materials or approaches.
The table which follows is a summary of the mandatory, suggested, and alternative quality assurance and quality control measures and the associated frequency and acceptance criteria. All of the QC data, along with the run data, must be documented and included in the test report.
Summary Table of QA/QC Requirements
| Status 1 | Process or element | QA/QC specification | Acceptance criteria | Checking frequency |
|---|---|---|---|---|
| S | Identify Data User | Regulatory Agency or other primary end user of data | Before designing test. | |
| M | Analyzer Design | Analyzer range | Sufficiently >high-level gas to allow determination of system calibration error | |
| S | Analyzer resolution or sensitivity | Manufacturer design. | ||
| S | Interference response | Overall response ≤3% of calibration span Alternatively, overall response ≤0.3 µg/m 3 | ||
| M | Calibration Gases | Traceability protocol | Validation of concentration required | |
| M | High-level Hg 0 gas | Equal to the calibration span | Each calibration error test. | |
| M | Mid-level Hg 0 gas | 40 to 60% of calibration span | Each calibration error test. | |
| M | Low-level Hg 0 gas | 10 to 30% of calibration span | Each calibration error test. | |
| M | High-level HgCl | Equal to the calibration span | Each system integrity check (if it better represents C | |
| M | Mid-level HgCl | 40 to 60% of calibration span | Each system gas integrity check (if it better represents C | |
| M | Zero gas | Each system integrity check. | ||
| M | Dynamic spike gas (C 3) | A high-concentration HgCl | Pre-test; dynamic spiking not required until 1/1/09. | |
| M | Dynamic spike gas (C | A high-concentration HgCl 3 above the native concentration | Pre-test; dynamic spiking not required until 1/1/09. | |
| S | Data Recorder Design | Data resolution | ≤0.5% of full-scale | Manufacturer design. |
| M | Sample Extraction | Probe material | Inert to sample constituents (e.g., PFA Teflon, or quartz if stack >500 °F) | Each run. |
| M | Sample Extraction | Probe, filter and sample line temperature | For dry-basis analyzers, keep sample above the dew point, by heating prior to moisture removal For wet-basis analyzers, keep sample above dew point at all times, by heating or dilution | Each run. |
| M | Sample Extraction | Calibration valve material | Inert to sample constituents (e.g., PFA Teflon or PFA Teflon coated) | Each test. |
| S | Sample Extraction | Sample pump material | Inert to sample constituents | Each test. |
| M | Sample Extraction | Manifold material | Inert to sample constituents | Each test. |
| M | Particulate Removal | Filter inertness | Pass calibration error check | Each calibration error check. |
| M | System Calibration Performance | System calibration error (CE) test | CE ≤5.0 % of the calibration span for the low-, mid-or high-level Hg 0 calibration gas Alternative specification: ≤0.5 µg/m 3 absolute difference between system response and reference value | Before initial run and after a failed system integrity check or drift test. |
| M | System Calibration Performance | System integrity check | Error ≤5.0% of the calibration span for the zero and mid- or high-level HgCl Alternative specification: ≤0.5 µg/m 3 absolute difference between system response and reference value | Before initial run, after each run, at the beginning of subsequent test days, and after a failed system integrity check or drift test. |
| M | System Performance | System response time | Used to determine minimum sampling time per point | During initial 3-point system calibration error test. |
| M | System Performance | Drift | ≤3.0% of calibration span for the zero and mid- or high-level gas Alternative specification: ≤0.3 µg/m 3 absolute difference between pre- and post-run system calibration error percentages. | At least once per test day. |
| M | System Performance | Minimum sampling time | The greater of two times the system response time or 10 minutes. Concentrating systems must also include at least 4 cycles | Each sampling point. |
| M | System Performance | Percentage spike recovery and relative standard deviation | Percentage spike recovery, at the target level: 100 ±10% Relative standard deviation: ≤5 percent Alternative specification: absolute difference between calculated and measured spike values ≤0.5 µg/m 3 | Before initial run; dynamic spiking not required until 1/1/09. |
| M | Sample Point Selection | Number and Location of Sample Points | For emission testing applications, use 12 points, located according to Method 1 in appendix A-1 to this part, unless the results of a stratification test allow fewer points to be used | Prior to first run. |
| For Part 60 RATAs, follow the procedures in Performance Specification 2, section 8.1.3, and for Part 75 RATAs, follow the procedures in section 6.5.6 of appendix A to Part 75. That is: | ||||
| • At | ||||
| • At | ||||
| • At a location where stratification is not expected and the measurement line is >2.4 m (7.8 ft), you may use 3 sample points located along a “short” measurement line at 0.4, 1.0, and 2.0 m from the stack or duct wall or, for Part 75 only, sample points may be located at 4.4, 14.6, and 29.6% of the measurement line; or | ||||
| • After a wet scrubber or at a point where dissimilar gas streams are combined, either locate 3 sample points along the “long” measurement line or locate 6 Method 1 points along a diameter (Part 75, only), unless the results of a stratification test allow you to use a “short” 3-point measurement line or to sample at a single point | ||||
| • If it can be demonstrated that stack gas concentration is ≤3 µg/m 3, then the test site is exempted from stratification testing. Use the 3-point “short” measurement line if the stack diameter is >2.4 m (7.8 ft) and the 3-point “long” line for stack diameters ≤2.4 m (7.8 ft) | ||||
| A | Sample Point Selection | Stratification Test (See section 8.1.3). | If the Hg concentration 2 at each traverse point during the stratification test is: • Within ±5% of mean, use 1-point sampling (at the point closest to the mean); or • Not within ±5% of mean, but is within ±10% of mean, use 3-point sampling. Locate points according to section 8.1.3.2.2 of this method. Alternatively, if the Hg concentration at each point is: • Within ±0.2 µg/m 3 of mean, use 1-point sampling (at the point closest to the mean); or • Not within ±0.2 µg/m 3 of mean, but is within ±0.5 µg/m 3 of mean, use 3-point sampling. Locate points according to section 8.1.3.2.2 of this method. | Prior to first run. Prior to 1/1/09, you may (1) forgo stratification testing and use 3 sampling points (as per section 8.1.3.2.2) or (2) perform a SO |
| M | Data Recording | Frequency | Once per cycle | During run. |
| S | Data Parameters | Sample concentration and calibration span | All analyzer readings during each run within calibration span | Each run. |
| M | Data Parameters | Sample concentration and calibration span | All analyzer readings during dynamic spiking tests within 120% of calibration span | Each spike injection. |
| M | Data Parameters | Sample concentration and calibration span | Average Hg concentration for the run ≤calibration span | Each run. |
1 M = Mandatory; S = Suggested; A = Alternative.
2 These may either be the unadjusted Hg concentrations or concentrations normalized to account for temporal variations.
Your analyzer must be calibrated with Hg° standards. The initial 3-point system calibration error test described in section 8.2.4 is required before you start the test. Also, prior to and following test runs, the two-point system integrity checks described in sections 8.2.5 and 8.2.8 are required. On and after January 1, 2009, the pre-test dynamic spiking procedure described in section 8.2.7 is also required to verify that the accuracy of the measurement system is suitable and not adversely affected by the flue gas matrix.
Because sample collection and analysis are performed together (see section 8), additional discussion of the analytical procedure is not necessary.
You must follow the procedures for calculations and data analysis listed in this section.
12.1 Nomenclature. The terms used in the equations are defined as follows:
12.2 System Calibration Error. Use Equation 30A-1 to calculate the system calibration error. Equation 30A-1 applies to: 3-point system calibration error tests performed with Hg° standards; and pre- and post-run two-point system integrity checks performed with HgCl
12.3 Drift Assessment. Use Equation 30A-2 to separately calculate the zero and upscale drift for each test run.
12.3 Effluent Hg Concentration. For each test run, calculate C
12.4 Moisture Correction. Use Equation 30A-4a if your measurements need to be corrected to a dry basis.
Use Equation 30A-4b if your measurements need to be corrected to a wet basis.
12.5 Dynamic Spike Gas Concentrations. Use Equation 30A-5 to determine the spike gas concentration needed to produce a spiked sample with a certain “target” Hg concentration.
12.6 Spiked Sample Concentration. Use Equation 30A-6 to determine the expected or theoretical Hg concentration of a spiked sample.
12.7 Spike Recovery. Use Equation 30A-7 to calculate the percentage recovery of each spike.
12.8 Relative Standard Deviation. Use Equation 30A-8 to calculate the relative standard deviation of the individual percentage spike recovery values from the mean.
12.9 Spike Dilution Factor. Use Equation 30A-9 to calculate the spike dilution factor, using either direct flow measurements or tracer gas measurements.
12.10 Native Concentration. For spiking procedures that inject blank or carrier gases (at the spiking flow rate, Q
For spiking procedures that halt all injections between spikes, the native concentration equals the average baseline concentration (see Equation 30A-11).
12.11 Overall Interference Response. Use equation 30A-12 to calculate the overall interference response.
Where, for each interference gas (or mixture):
13.1 System Calibration Error Test. This specification applies to the 3-point system calibration error tests using Hg
13.2 System Integrity Checks. This specification applies to all pre- and post-run 2-point system integrity checks using HgCl
13.3 Drift. For each run, the low-level and upscale drift must be less than or equal to 3.0 percent of the calibration span. The drift is also acceptable if the pre- and post-run system integrity check responses do not differ by more than 0.3 µg/m
13.4 Interference Test. Summarize the results following the format contained in Table 30A-4. For each interference gas (or mixture), calculate the mean difference between the measurement system responses with and without the interference test gas(es). The overall interference response for the analyzer that was used for the test (calculated according to Equation 30A-12), must not be greater than 3.0 percent of the calibration span used for the test (see section 8.6). The results of the interference test are also acceptable if the sum of the absolute average differences for all interference gases (i.e., Σ C
13.5 Dynamic Spiking Test. For the pre-test dynamic spiking, the mean value of the percentage spike recovery must be 100 ±10 percent. In addition, the relative standard deviation (RSD) of the individual percentage spike recovery values from the mean must be ≤5.0 percent. Alternatively, if the mean percentage recovery is not met, the results are acceptable if the absolute difference between the theoretical spiked sample concentration (see section 12.6) and the actual average value of the spiked sample concentration is ≤0.5 µg/m
1. EPA Traceability Protocol for Qualification and Certification of Elemental Mercury Gas Generators, expected publication date December 2008, see www.epa.gov/ttn/emc.
2. EPA Traceability Protocol for Qualification and Certification of Oxidized Mercury Gas Generators, expected publication date December 2008, see www.epa.gov/ttn/emc.
3. EPA Traceability Protocol for Assay and Certification of Gaseous Calibration Standards, expected revision publication date December 2008, see www.epa.gov/ttn/emc.
Table 30A-3 – Interference Check Gas Concentrations
| Potential interferent gas 1 | Concentration, tentative – (balance N |
|---|---|
| CO | 15% ±1% CO |
| CO | 100 ±20 ppm |
| HCl 2 | 100 ±20 ppm |
| NO 2 | 250 ±50 ppm |
| SO | 200 ±20 ppm |
| O | 3% ±1% O |
| H | 10% ±1% H |
| Nitrogen | Balance |
| Other |
1 Any of these specific gases can be tested at a lower level if the manufacturer has provided reliable means for limiting or scrubbing that gas to a specified level.
2 HCl and NO must be tested as a mixture.
Method 30B is a procedure for measuring total vapor phase mercury (Hg) emissions from coal-fired combustion sources using sorbent trap sampling and an extractive or thermal analytical technique. This method is only intended for use only under relatively low particulate conditions (e.g., sampling after all pollution control devices). Quality assurance and quality control requirements are included to assure that you, the tester, collect data of known and acceptable quality for each testing program. This method does not completely describe all equipment, supplies, and sampling and analytical procedures you will need, but instead refers to other test methods for some of the details. Therefore, to obtain reliable results, you should also have a thorough knowledge of these additional methods which are found in Appendices A-1 and A-3 to this part:
(a) Method 1 – Sample and Velocity Traverses for Stationary Sources.
(b) Method 4 – Determination of Moisture Content in Stack Gases.
(c) Method 5 – Determination of Particulate Matter Emissions from Stationary Sources
1.1 Analytes. What does this method determine? This method is designed to measure the mass concentration of total vapor phase Hg in flue gas, including elemental Hg (Hg
| Analyte | CAS No. | Analytical range and sensitivity |
|---|---|---|
| Elemental Hg (Hg 0 ) | 7439-97-6 | Typically 0.1 µg/dscm to >50 µg/dscm. |
| Oxidized Hg (Hg | (Same) |
1.2 Applicability. When is this method required? Method 30B is a reference method for relative accuracy test audits (RATAs) of vapor phase Hg CEMS and sorbent trap monitoring systems installed at coal-fired boilers and is also appropriate for Hg emissions testing at such boilers. It is intended for use only under relatively low particulate conditions (i.e., sampling after all pollution control devices); in cases where significant amounts of particle-bound Hg may be present, an isokinetic sampling method for Hg should be used. Method 30B may also be specified by New Source Performance Standards (NSPS), National Emission Standards for Hazardous Air Pollutants (NESHAP), emissions trading programs, State Implementation Plans (SIPs), and operating permits that require measurement of Hg concentrations in stationary source emissions, either to determine compliance with an applicable emission standard or limit, or to conduct RATAs of Hg CEMS and sorbent trap monitoring systems.
1.3 Data Quality Objectives (DQO). How good must my collected data be? Method 30B has been designed to provide data of high and known quality for Hg emissions testing and for RATA testing of Hg monitoring systems, including CEMS and sorbent trap monitors. In these and other applications, the principal objective is to ensure the accuracy of the data at the actual emissions levels and in the actual emissions matrix encountered. To meet this objective, NIST-traceable calibration standards must be used and method performance tests are required.
Known volumes of flue gas are extracted from a stack or duct through paired, in-stack sorbent media traps at an appropriate flow rate. Collection of mercury on the sorbent media in the stack mitigates potential loss of mercury during transport through a probe/sample line. For each test run, paired train sampling is required to determine measurement precision and verify acceptability of the measured emissions data. A field recovery test which assesses recovery of an elemental Hg spike to determine measurement bias is also used to verify data acceptability. The sorbent traps are recovered from the sampling system, prepared for analysis as needed, and analyzed by any suitable determinative technique that can meet the performance criteria.
3.1 Analytical System is the combined equipment and apparatus used to perform sample analyses. This includes any associated sample preparation apparatus e.g., digestion equipment, spiking systems, reduction devices, etc., as well as analytical instrumentation such as UV AA and UV AF cold vapor analyzers.
3.2 Calibration Standards are the Hg containing solutions prepared from NIST traceable standards and are used to directly calibrate analytical systems.
3.3 Independent Calibration Standard is a NIST traceable standard obtained from a source or supplier independent of that for the calibration standards and is used to confirm the integrity of the calibration standards used.
3.4 Method Detection Limit (MDL) is the lowest mass of Hg greater than zero that can be estimated and reported by your candidate analytical technique. The MDL is statistically derived from replicate low level measurements near your analytical instrument’s detection level.
3.5 NIST means the National Institute of Standards and Technology, located in Gaithersburg, Maryland.
3.6 Run means a series of gas samples taken successively from the stack or duct. A test normally consists of a specific number of runs.
3.7 Sorbent Trap means a cartridge or sleeve containing a sorbent media (typically activated carbon treated with iodine or some other halogen) with multiple sections separated by an inert material such as glass wool. These sorbent traps are optimized for the quantitative capture of elemental and oxidized forms of Hg and can be analyzed by multiple techniques.
3.8 Test refers to the series of runs required by the applicable regulation.
3.9 Thermal Analysis means an analytical technique where the contents of the sorbent traps are analyzed using a thermal technique (desorption or combustion) to release the captured Hg in a detectable form for quantification.
3.10 Wet Analysis means an analytical technique where the contents of the sorbent tube are first leached or digested to quantitatively transfer the captured Hg to liquid solution for subsequent analysis.
Interferences may result from the sorbent trap material used as well as from the measurement environment itself. The iodine present on some sorbent traps may impart a negative measurement bias. High levels of sulfur trioxide (SO
What safety measures should I consider when using this method? This method may require you to work with hazardous materials and in hazardous conditions. You are encouraged to establish safety procedures before using the method. Among other precautions, you should become familiar with the safety recommendations in the gas analyzer user’s manual. Occupational Safety and Health Administration (OSHA) regulations concerning use of compressed gas cylinders and noxious gases may apply.
5.1 Site Hazards. Prior to applying these procedures/specifications in the field, the potential hazards at the test site should be considered; advance coordination with the site is critical to understand the conditions and applicable safety policies. At a minimum, portions of the sampling system will be hot, requiring appropriate gloves, long sleeves, and caution in handling this equipment.
5.2 Laboratory Safety. Policies should be in place to minimize risk of chemical exposure and to properly handle waste disposal in the laboratory. Personnel shall wear appropriate laboratory attire according to a Chemical Hygiene Plan established by the laboratory.
5.3 Reagent Toxicity/Carcinogenicity. The toxicity and carcinogenicity of any reagents used must be considered. Depending upon the sampling and analytical technologies selected, this measurement may involve hazardous materials, operations, and equipment and this method does not address all of the safety problems associated with implementing this approach. It is the responsibility of the user to establish appropriate safety and health practices and determine the applicable regulatory limitations prior to performance. Any chemical should be regarded as a potential health hazard and exposure to these compounds should be minimized. Chemists should refer to the Material Safety Data Sheet (MSDS) for each chemical used.
5.4 Waste Disposal. Any waste generated by this procedure must be disposed of according to a hazardous materials management plan that details and tracks various waste streams and disposal procedures.
The following list is presented as an example of key equipment and supplies likely required to measure vapor-phase Hg using a sorbent trap sampling system. It is recognized that additional equipment and supplies may be needed. Collection of paired samples is required.
6.1 Sorbent Trap Sampling System. A typical sorbent trap sampling system is shown in Figure 30B-1 in section 17.0. The sorbent trap sampling system shall include the following components:
6.1.1 Sorbent Traps. The sorbent media used to collect Hg must be configured in a trap with at least two distinct segments or sections, connected in series, that are amenable to separate analyses. section 1 is designated for primary capture of gaseous Hg. section 2 is designated as a backup section for determination of vapor phase Hg breakthrough. Each sorbent trap must be inscribed or otherwise permanently marked with a unique identification number, for tracking purposes. The sorbent media may be any collection material (e.g., carbon, chemically-treated filter, etc.) capable of quantitatively capturing and recovering for subsequent analysis, all gaseous forms of Hg in the emissions from the intended application. Selection of the sorbent media shall be based on the material’s ability to achieve the performance criteria contained in this method as well as the sorbent’s vapor phase Hg capture efficiency for the emissions matrix and the expected sampling duration at the test site. The sorbent media must be obtained from a source that can demonstrate their quality assurance and quality control (see section 7.2). The paired sorbent traps are supported on a probe (or probes) and inserted directly into the flue gas stream.
6.1.2 Sampling Probe Assembly. Each probe assembly shall have a leak-free attachment to the sorbent trap(s). Each sorbent trap must be mounted at the entrance of or within the probe such that the gas sampled enters the trap directly. Each probe/sorbent trap assembly must be heated to a temperature sufficient to prevent liquid condensation in the sorbent trap(s). Auxiliary heating is required only where the stack temperature is too low to prevent condensation. Use a calibrated thermocouple to monitor the stack temperature. A single probe capable of operating the paired sorbent traps may be used. Alternatively, individual probe/sorbent trap assemblies may be used, provided that the individual sorbent traps are co-located to ensure representative Hg monitoring.
6.1.3 Moisture Removal Device. A moisture removal device or system shall be used to remove water vapor from the gas stream prior to entering dry gas flow metering devices.
6.1.4 Vacuum Pump. Use a leak-tight, vacuum pump capable of operating within the system’s flow range.
6.1.5 Gas Flow Meter. A gas flow meter (such as a dry gas meter, thermal mass flow meter, or other suitable measurement device) shall be used to determine the total sample volume on a dry basis, in units of standard cubic meters. The meter must be sufficiently accurate to measure the total sample volume to within 2 percent and must be calibrated at selected flow rates across the range of sample flow rates at which the sampling train will be operated. The gas flow meter shall be equipped with any necessary auxiliary measurement devices (e.g., temperature sensors, pressure measurement devices) needed to correct the sample volume to standard conditions.
6.1.6 Sample Flow Rate Meter and Controller. Use a flow rate indicator and controller for maintaining necessary sampling flow rates.
6.1.7 Temperature Sensor. Same as section 6.1.1.7 of Method 5 in Appendix A-3 to this part.
6.1.8 Barometer. Same as section 6.1.2 of Method 5 in Appendix A-3 to this part.
6.1.9 Data Logger (optional). Device for recording associated and necessary ancillary information (e.g., temperatures, pressures, flow, time, etc.).
6.2 Gaseous Hg
6.3 Sample Analysis Equipment. Any analytical system capable of quantitatively recovering and quantifying total Hg from the sorbent media selected is acceptable provided that the analysis can meet the performance criteria described in this method. Example recovery techniques include acid leaching, digestion, and thermal desorption/direct combustion. Example analytical techniques include, but are not limited to, ultraviolet atomic fluorescence (UV AF), ultraviolet atomic absorption (UV AA) with and without gold trapping, and X-ray fluorescence (XRF) analysis.
6.3 Moisture Measurement System. If correction of the measured Hg emissions for moisture is required (see section 8.3.3.7), either Method 4 in Appendix A-3 to this part or other moisture measurement methods approved by the Administrator will be needed to measure stack gas moisture content.
7.1 Reagents and Standards. Only NIST-certified or NIST-traceable calibration standards, standard reference materials, and reagents shall be used for the tests and procedures required by this method.
7.2 Sorbent Trap Media. The sorbent trap media shall be prepared such that the material used for testing is of known and acceptable quality. Sorbent supplier quality assurance/quality control measures to ensure appropriate and consistent performance such as sorptive capacity, uniformity of preparation treatments, and background levels shall be considered.
This section presents the sample collection and handling procedures along with the pretest and on-site performance tests required by this method. Since you may choose different options to comply with certain performance criteria, each test report must identify the specific options selected and document the results with respect to the performance criteria of this method.
8.1 Selection of Sampling Sites and Sampling Points. What sampling site and sampling points do I select? Same as section 8.1 of Method 30A of this appendix.
8.2 Measurement System Performance Tests. What performance criteria must my measurement system meet? The following laboratory and field procedures and associated criteria of this section are designed to ensure (1) selection of a sorbent and analytical technique combination capable of quantitative collection and analysis of gaseous Hg, (2) collection of an adequate amount of Hg on each sorbent trap during field tests, and (3) adequate performance of the method for each test program: The primary objectives of these performance tests are to characterize and verify the performance of your intended analytical system and associated sampling and analytical procedures, and to define the minimum amount of Hg (as the sample collection target) that can be quantified reliably.
(a) Analytical Matrix Interference Test;
(b) Determination of Minimum Sample Mass;
(c) Hg
(d) Determination of Nominal Sample Volume;
(e) Field Recovery Test.
8.2.1 Analytical Matrix Interference Test and Minimum Sample Dilution.
(a) The analytical matrix interference test is a laboratory procedure. It is required only if you elect to use a liquid digestion analytical approach and needs to be performed only once for each sorbent material used. The purpose of the test is to verify the presence or absence of known and potential analytical matrix interferences, including the potential negative bias associated with iodine common to many sorbent trap materials. The analytical matrix interference test determines the minimum dilution (if any) necessary to mitigate matrix effects on the sample digestate solutions.
(b) The result of the analytical matrix interference test, i.e., the minimum sample dilution required (if any) for all sample analyses, is used to establish the minimum sample mass needed for the Hg
8.2.1.1 Analytical Matrix Interference Test Procedures. Digest and prepare for analysis a representative mass of sorbent material (unsampled) according to your intended laboratory techniques for field samples. Analyze the digestate according to your intended analytical conditions at the least diluted level you intend to use for sample analysis (e.g., undiluted, 1 in 10 dilution, etc.). Determine the Hg concentration of the undiluted digestate solution. Prepare a series of solutions with a fixed final volume containing graduated aliquots of the sample digestate and, a fixed aliquot of a calibration standard (with the balance being Hg-free reagent or H
8.2.1.2 Analytical Matrix Interference Test Acceptance Criteria. Compare the measured concentration of each solution containing digestate to the measured concentration of the digestate-free solution. The lowest dilution ratio of any solution having a Hg concentration within ±5 percent of the digestate-free solution is the minimum dilution ratio required for analysis of all samples. If you desire to measure the digestate without dilution, the ±5 percent criterion must be met at a dilution ratio of at least 9:10 (i.e., ≥90% digestate).
8.2.1.3 Example Analytical Matrix Interference Test. An example analytical matrix interference test is presented below. Additional information on the conduct of the analytical matrix interference test will be posted at http://www.epa.gov/ttn/emc. Determine the most sensitive working range for the analyzer to be used. This will be a narrow range of concentrations. Digest and prepare for analysis a representative mass of sorbent material (unsampled) according to your intended laboratory techniques for sample preparation and analysis. Prepare a calibration curve for the most sensitive analytical region, e.g., 0.0, 0.5, 1.0, 3.0, 5.0, 10 ppb. Using the highest calibration standard, e.g., 10.0 ppb, prepare a series of solutions by adding successively smaller increments of the digestate to a fixed volume of the calibration standard and bringing each solution to a final fixed volume with mercury-free deionized water (diH
8.2.2 Determination of Minimum Sample Mass. The minimum mass of Hg that must be collected per sample must be determined. This information is necessary in order to effectively perform the Hg
8.2.2.1 Determination of Minimum Calibration Concentration or Mass. Based on your instrument’s sensitivity and linearity, determine the calibration concentrations or masses that make up a representative low level calibration range. Verify that you are able to meet the multipoint calibration performance criteria in section 11.0 of this method. Select a calibration concentration or mass that is no less than 2 times the lowest concentration or mass in your calibration curve. The lowest point in your calibration curve must be at least 5, and preferably 10, times the Method Detection Limit (MDL), which is the minimum amount of the analyte that can be detected and reported. The MDL must be determined at least once for the analytical system using an MDL study such as that found in section 15.0 to Method 301 of appendix A to part 63 of this chapter.
While it might be desirable to base the minimum calibration concentration or mass on the lowest point in the calibration curve, selecting a higher concentration or mass is necessary to ensure that all analyses of the field samples will fall within the calibration curve. Therefore, it is strongly recommended that you select a minimum calibration concentration or mass that is sufficiently above the lowest point of the calibration curve (see examples in sections 8.2.2.2.1 and 8.2.2.2.2 below).
8.2.2.2 Determination of Minimum Sample Mass. Based on your minimum calibration concentration or mass and other sample treatments including, but not limited to, final digestate volume and minimum sample dilution, determine the minimum sample mass. Consideration should also be given to the Hg levels expected to be measured in section 2 of the sorbent traps and to the breakthrough criteria presented in Table 9-1.
8.2.2.2.1 Example Determination of Minimum Sample Mass for Thermal Desorption Analysis. A thermal analysis system has been calibrated at five Hg mass levels: 10 ng, 20 ng, 50 ng, 100 ng, 200 ng, and shown to meet the calibration performance criteria in this method. Based on 2 times the lowest point in the calibration curve, 20 ng is selected as the minimum calibration mass. Because the entire sample is analyzed and there are no dilutions involved, the minimum sample mass is also 20 ng.
In this example, if the typical background (blank) Hg levels in section 2 were relatively high (e.g., 3 to 5 ng), a sample mass of 20 ng might not have been sufficient to ensure that the breakthrough criteria in Table 9-1 would be met, thereby necessitating the use of a higher point on the calibration curve (e.g., 50 ng) as the minimum calibration and sample mass.
8.2.2.2.2 Example Determination of Minimum Sample Mass for Acid Leachate/Digestate Analysis. A cold vapor analysis system has been calibrated at four Hg concentration levels: 2 ng/L, 5 ng, 10 ng/L, 20 ng/L, and shown to meet the calibration performance criteria in this method. Based on 2 times the lowest point in the calibration curve, 4 ng/L was selected as the minimum calibration concentration. The final sample volume of a digestate is nominally 50 ml (0.05 L) and the minimum dilution necessary was determined to be 1:100 by the Analytical Matrix Interference Test of section 8.2.1. The following calculation would be used to determine the minimum sample mass.
In this example, if the typical background (blank) Hg levels in section 2 were relatively high (e.g., 3 to 5 ng), a sample mass of 20 ng might not have been sufficient to ensure that the breakthrough criterion in Table 9-1 would be met, thereby necessitating the use of a higher point on the calibration curve (e.g., 10 ng/L) as the minimum calibration concentration.
8.2.3 Hg
8.2.3.1 Hg
8.2.3.1.1 Hg
8.2.3.1.2 HgCl
8.2.4 Determination of Target Sample Volume. The target sample volume is an estimate of the sample volume needed to ensure that valid emissions data are collected (i.e., that sample mass Hg loadings fall within the analytical calibration curve and are within the upper and lower bounds set by the analytical bias tests). The target sample volume and minimum sample mass can also be determined by performing a diagnostic test run prior to initiation of formal testing.
For the purposes of relative accuracy testing of Hg monitoring systems under subpart UUUUU of part 63 of this chapter and Performance Specifications 12A and 12B in appendix B to this part, when the stack gas Hg concentration is expected to be very low (
8.2.5 Determination of Sample Run Time. Sample run time will be a function of minimum sample mass (see section 8.2.2), target sample volume and nominal equipment sample flow rate. The minimum sample run time for conducting relative accuracy test audits of Hg monitoring systems is 30 minutes and for emissions testing to characterize an emission source is 1 hour. The target sample run time can be calculated using the following example.
8.2.6 Field Recovery Test. The field recovery test provides a test program-specific verification of the performance of the combined sampling and analytical approach. Three sets of paired samples, one of each pair which is spiked with a known level of Hg, are collected and analyzed and the average recovery of the spiked samples is used to verify performance of the measurement system under field conditions during that test program. The conduct of this test requires an estimate or confirmation of the stack Hg concentrations at the time of testing.
8.2.6.1 Calculation of Pre-sampling Spiking Level. Determine the sorbent trap spiking level for the field recovery test using estimates of the stack Hg concentration, the target sample flow rate, and the planned sample duration. First, determine the Hg mass expected to be collected in section 1 of the sorbent trap. The pre-sampling spike must be within 50 to 150 percent of this expected mass.
A Hg spike of 60 to 180 ng (50-150% of 120 ng) would be appropriate.
8.2.6.2 Procedures. Set up two identical sampling trains. One of the sampling trains shall be designated the spiked train and the other the unspiked train. Spike Hg
It is acceptable to perform the field recovery test concurrent with actual test runs (e.g., through the use of a quad probe). It is also acceptable to use the field recovery test runs as test runs for emissions testing or for the RATA of a Hg monitoring system under subpart UUUUU of part 63 of this chapter and Performance Specifications 12A and 12B in appendix B to this part, if certain conditions are met. To determine whether a particular field recovery test run may be used as a RATA run, subtract the mass of the Hg
8.3 Sampling. This section describes the procedures and criteria for collecting the field samples for analysis. As noted in section 8.2.6, the field recovery test samples are also collected using these procedures.
8.3.1 Pre-test leak check. Perform a leak check of the sampling system with the sorbent traps in place. For each of the paired sampling trains, draw a vacuum in the train, and adjust the vacuum to ∼15″ Hg; and, using the gas flow meter, determine leak rate. The leak rate for an individual train must not exceed 4 percent of the target sampling rate. Once the leak check passes this criterion, carefully release the vacuum in the sample train, then seal the sorbent trap inlet until the probe is ready for insertion into the stack or duct.
8.3.2 Determination of Flue Gas Characteristics. Determine or measure the flue gas measurement environment characteristics (gas temperature, static pressure, gas velocity, stack moisture, etc.) in order to determine ancillary requirements such as probe heating requirements (if any), initial sampling rate, moisture management, etc.
8.3.3 Sample Collection
8.3.3.1 Remove the plug from the end of each sorbent trap and store each plug in a clean sorbent trap storage container. Remove the stack or duct port cap and insert the probe(s). Secure the probe(s) and ensure that no leakage occurs between the duct and environment.
8.3.3.2 Record initial data including the sorbent trap ID, date, and the run start time.
8.3.3.3 Record the initial gas flow meter reading, stack temperature, meter temperatures (if needed), and any other appropriate information, before beginning sampling. Begin sampling and target a sampling flow rate similar to that for the field recovery test. Then, at regular intervals (≤5 minutes) during the sampling period, record the date and time, the sample flow rate, the gas meter reading, the stack temperature, the flow meter temperatures (if using a dry gas meter), temperatures of heated equipment such as the vacuum lines and the probes (if heated), and the sampling system vacuum readings. Adjust the sampling flow rate as necessary to maintain the initial sample flow rate. Ensure that the total volume sampled for each run is within 20 percent of the total volume sampled for the field recovery test.
8.3.3.4 Data Recording. Obtain and record any essential operating data for the facility during the test period, e.g., the barometric pressure must be obtained for correcting sample volume to standard conditions when using a dry gas meter. At the end of the data collection period, record the final gas flow meter reading and the final values of all other essential parameters.
8.3.3.5 Post-Test Leak Check. When sampling is completed, turn off the sample pump, remove the probe(s) with sorbent traps from the port, and carefully seal the end of each sorbent trap. Perform another leak check of each sampling train with the sorbent trap in place, at the maximum vacuum reached during the sampling period. Record the leakage rates and vacuums. The leakage rate for each train must not exceed 4 percent of the average sampling rate for the data collection period. Following each leak check, carefully release the vacuum in the sample train.
8.3.3.6 Sample Recovery. Recover each sampled sorbent trap by removing it from the probe and sealing both ends. Wipe any deposited material from the outside of the sorbent trap. Place the sorbent trap into an appropriate sample storage container and store/preserve in appropriate manner (see section 8.3.3.8).
8.3.3.7 Stack Gas Moisture Determination. If the moisture basis of the measurements made with this method (dry) is different from the moisture basis of either: (1) the applicable emission limit; or (2) a Hg CEMS being evaluated for relative accuracy, you must determine the moisture content of the flue gas and correct for moisture using Method 4 in appendix A-3 to this part. If correction of the measured Hg concentrations for moisture is required, at least one Method 4 moisture determination shall be made during each test run.
8.3.3.8 Sample Handling, Preservation, Storage, and Transport. While the performance criteria of this approach provides for verification of appropriate sample handling, it is still important that the user consider, determine and plan for suitable sample preservation, storage, transport, and holding times for these measurements. Therefore, procedures in ASTM D6911-15 “Standard Guide for Packaging and Shipping Environmental Samples for Laboratory Analysis” (incorporated by reference-see 40 CFR 60.17) shall be followed for all samples, where appropriate. To avoid Hg contamination of the samples, special attention should be paid to cleanliness during transport, field handling, sampling, recovery, and laboratory analysis, as well as during preparation of the sorbent cartridges. Collection and analysis of blank samples (e.g., reagent, sorbent, field, etc.) is useful in verifying the absence or source of contaminant Hg.
8.3.3.9 Sample Custody. Proper procedures and documentation for sample chain of custody are critical to ensuring data integrity. The chain of custody procedures in ASTM D4840-99 “Standard Guide for Sampling Chain-of-Custody Procedures” shall be followed for all samples (including field samples and blanks).
Table 9-1 summarizes the QA/QC performance criteria that are used to validate the Hg emissions data from Method 30B sorbent trap measurement systems.
Table 9-1 – Quality Assurance/Quality Control Criteria for Method 30B
| QA/QC test or specification | Acceptance criteria | Frequency | Consequences if not met |
|---|---|---|---|
| Gas flow meter calibration (At 3 settings or points) | Calibration factor (Y | Prior to initial use and when post-test check is not within ±5% of Y | Recalibrate at 3 points until the acceptance criteria are met. |
| Gas flow meter post-test calibration check (Single-point) | Calibration factor (Y | After each field test. For mass flow meters, must be done on-site, using stack gas | Recalibrate gas flow meter at 3 points to determine a new value of Y. For mass flow meters, must be done on-site, using stack gas. Apply the new Y value to the field test data. |
| Temperature sensor calibration | Absolute temperature measures by sensor within ±1.5% of a reference sensor | Prior to initial use and before each test thereafter | Recalibrate; sensor may not be used until specification is met. |
| Barometer calibration | Absolute pressure measured by instrument within ±10 mm Hg of reading with a mercury barometer or NIST traceable barometer | Prior to initial use and before each test thereafter | Recalibrate; instrument may not be used until specification is met. |
| Pre-test leak check | ≤4% of target sampling rate | Prior to sampling | Sampling shall not commence until the leak check is passed. |
| Post-test leak check | ≤4% of average sampling rate | After sampling | Sample invalidated.* |
| Analytical matrix interference test (wet chemical analysis, only) | Establish minimum dilution (if any) needed to eliminate sorbent matrix interferences | Prior to analyzing any field samples; repeat for each type of sorbent used | Field sample results not validated. |
| Analytical bias test | Average recovery between 90% and 110% for Hg 0 and HgCl | Prior to analyzing field samples and prior to use of new sorbent media | Field samples shall not be analyzed until the percent recovery criteria has been met. |
| Multipoint analyzer calibration | Each analyzer reading within ±10% of true value 2≥0.99 | On the day of analysis, before analyzing any samples | Recalibrate until successful. |
| Analysis of independent calibration standard | Within ±10% of true value | Following daily calibration, prior to analyzing field samples | Recalibrate and repeat independent standard analysis until successful. |
| Analysis of continuing calibration verification standard (CCVS) | Within ±10% of true value | Following daily calibration, after analyzing ≤10 field samples, and at end of each set of analyses | Recalibrate and repeat independent standard analysis, reanalyze samples until successful, if possible; for destructive techniques, samples invalidated. |
| Test run total sample volume | Within ±20% of total volume sampled during field recovery test | Each individual sample | Sample invalidated. |
| Sorbent trap section 2 breakthrough | For compliance/emissions testing: | Every sample | Sample invalidated.* |
| ≤10% of section 1 Hg mass for Hg concentrations >1 µg/dscm; | |||
| ≤20% of section 1 Hg mass for Hg concentrations ≤1 µg/dscm | |||
| ≤50% of section 1 Hg mass if the stack Hg concentration is ≤30% of the Hg concentration that is equivalent to the applicable emission limit | |||
| For relative accuracy testing: | |||
| ≤10% of section 1 Hg mass for Hg concentrations >1 µg/dscm; | |||
| ≤20% of section 1 Hg mass for Hg concentrations ≤1 µg/dscm and >0.5 µg/dscm; | |||
| ≤50% of section 1 Hg mass for Hg concentrations ≤0.5 µg/dscm >0.1 µg/dscm; | |||
| no criterion for Hg concentrations ≤0.1 µg/dscm (must meet all other QA/QC specifications) | |||
| Paired sorbent trap agreement | ≤10% Relative Deviation (RD) mass for Hg concentrations >1 µg/dscm; | Every run | Run invalidated.* |
| ≤20% RD or ≤0.2 µg/dscm absolute difference for Hg concentrations ≤1 µg/dscm | |||
| Sample analysis | Within valid calibration range (within calibration curve) | All Section 1 samples where stack Hg concentration is ≥0.02 µg/dscm except in case where stack Hg concentration is ≤30% of the applicable emission limit | Reanalyze at more concentrated level if possible, samples invalidated if not within calibrated range. |
| Sample analysis | Within bounds of Hg 0 and HgCl | All Section 1 samples where stack Hg concentration is ≥0.5 µg/dscm | Expand bounds of Hg 0 and HgCl |
| Field recovery test | Average recovery between 85% and 115% for Hg 0 | Once per field test | Field sample runs not validated without successful field recovery test. |
* And data from the pair of sorbent traps are also invalidated.
10.1 Only NIST-certified and NIST-traceable calibration standards (i.e., calibration gases, solutions, etc.) shall be used for the spiking and analytical procedures in this method.
10.2 Gas Flow Meter Calibration.
10.2.1 Preliminaries. The manufacturer or equipment supplier of the gas flow meter should perform all necessary set-up, testing, programming, etc., and should provide the end user with any necessary instructions, to ensure that the meter will give an accurate readout of dry gas volume in standard cubic meters for this method.
10.2.2 Initial Calibration. Prior to its initial use, a calibration of the gas flow meter shall be performed. The initial calibration may be done by the manufacturer, by the equipment supplier, or by the end user. If the flow meter is volumetric in nature (e.g., a dry gas meter), the manufacturer or end user may perform a direct volumetric calibration using any gas. For a mass flow meter, the manufacturer, equipment supplier, or end user may calibrate the meter using either: (1) A bottled gas mixture containing 12 ±0.5% CO
10.2.2.1 Initial Calibration Procedures. Determine an average calibration factor (Y) for the gas flow meter by calibrating it at three sample flow rate settings covering the range of sample flow rates at which the sampling system will be operated. You may either follow the procedures in section 10.3.1 of Method 5 in appendix A-3 to this part or in section 16 of Method 5 in appendix A-3 to this part. If a dry gas meter is being calibrated, use at least five revolutions of the meter at each flow rate.
10.2.2.2 Alternative Initial Calibration Procedures. Alternatively, you may perform the initial calibration of the gas flow meter using a reference gas flow meter (RGFM). The RGFM may be: (1) A wet test meter calibrated according to section 10.3.1 of Method 5 in appendix A-3 to this part; (2) a gas flow metering device calibrated at multiple flow rates using the procedures in section 16 of Method 5 in appendix A-3 to this part; or (3) a NIST-traceable calibration device capable of measuring volumetric flow to an accuracy of 1 percent. To calibrate the gas flow meter using the RGFM, proceed as follows: While the Method 30B sampling system is sampling the actual stack gas or a compressed gas mixture that simulates the stack gas composition (as applicable), connect the RGFM to the discharge of the system. Care should be taken to minimize the dead volume between the gas flow meter being tested and the RGFM. Concurrently measure dry stack gas volume with the RGFM and the flow meter being calibrated for at least 10 minutes at each of three flow rates covering the typical range of operation of the sampling system. For each set of concurrent measurements, record the total sample volume, in units of dry standard cubic meters (dscm), measured by the RGFM and the gas flow meter being tested.
10.2.2.3 Initial Calibration Factor. Calculate an individual calibration factor Y
10.2.2.4 Pretest On-Site Calibration Check (Optional). For a mass flow meter, if the most recent 3-point calibration of the flow meter was performed using a compressed gas mixture, you may want to conduct the following on-site calibration check prior to testing, to ensure that the flow meter will accurately measure the volume of the stack gas: While sampling stack gas, check the calibration of the flow meter at one intermediate flow rate setting representative of normal operation of the sampling system. If the pretest calibration check shows that the value of Y
10.2.2.5 Post-Test Calibration Check. Check the calibration of the gas flow meter following each field test at one intermediate flow rate setting, either at, or in close proximity to, the average sample flow rate during the field test. For dry gas meters, ensure at least three revolutions of the meter during the calibration check. For mass flow meters, this check must be performed before leaving the test site, while sampling stack gas. If a one-point calibration check shows that the value of Y
10.3 Thermocouples and Other Temperature Sensors. Use the procedures and criteria in Section 10.3 of Method 2 in appendix A-1 to this part to calibrate in-stack temperature sensors and thermocouples. Dial thermometers shall be calibrated against mercury-in-glass thermometers or equivalent. Calibrations must be performed prior to initial use and before each field test thereafter. At each calibration point, the absolute temperature measured by the temperature sensor must agree to within ±1.5 percent of the temperature measured with the reference sensor, otherwise the sensor may not continue to be used.
10.4 Barometer. Calibrate against a mercury barometer or other NIST-traceable barometer as per Section 10.6 of Method 5 in appendix A-3 to this part. Calibration must be performed prior to initial use and before each test program, and the absolute pressure measured by the barometer must agree to within ±10 mm Hg of the pressure measured by the mercury or other NIST-traceable barometer, otherwise the barometer may not continue to be used.
10.5 Other Sensors and Gauges. Calibrate all other sensors and gauges according to the procedures specified by the instrument manufacturer(s).
10.6 Analytical System Calibration. See section 11.1 of this method.
The analysis of Hg in the field and quality control samples may be conducted using any instrument or technology capable of quantifying total Hg from the sorbent media and meeting the performance criteria in this method. Because multiple analytical approaches, equipment and techniques are appropriate for the analysis of sorbent traps, it is not possible to provide detailed, technique-specific analytical procedures. As they become available, detailed procedures for a variety of candidate analytical approaches will be posted at http://www.epa.gov/ttn/emc.
11.1 Analytical System Calibration. Perform a multipoint calibration of the analyzer at three or more upscale points over the desired quantitative range (multiple calibration ranges shall be calibrated, if necessary). The field samples analyzed must fall within a calibrated, quantitative range and meet the performance criteria specified below. For samples suitable for aliquotting, a series of dilutions may be needed to ensure that the samples fall within a calibrated range. However, for sorbent media samples consumed during analysis (e.g., when using thermal desorption techniques), extra care must be taken to ensure that the analytical system is appropriately calibrated prior to sample analysis. The calibration curve range(s) should be determined such that the levels of Hg mass expected to be collected and measured will fall within the calibrated range. The calibration curve may be generated by directly introducing standard solutions into the analyzer or by spiking the standards onto the sorbent media and then introducing into the analyzer after preparing the sorbent/standard according to the particular analytical technique. For each calibration curve, the value of the square of the linear correlation coefficient, i.e., r
11.2 Sample Preparation. Carefully separate the sections of each sorbent trap. Combine for analysis all materials associated with each section; any supporting substrate that the sample gas passes through prior to entering a media section (e.g., glass wool separators, acid gas traps, etc.) must be analyzed with that segment.
11.3 Field Sample Analyses. Analyze the sorbent trap samples following the same procedures that were used for conducting the Hg
11.4 Analysis of Continuing Calibration Verification Standard (CCVS). After no more than 10 samples and at the end of each set of analyses, a continuing calibration verification standard must be analyzed. The measured value of the continuing calibration standard must be within ±10 percent of the expected value.
11.5 Blanks. The analysis of blanks is optional. The analysis of blanks is useful to verify the absence of, or an acceptable level of, Hg contamination. Blank levels should be considered when quantifying low Hg levels and their potential contribution to meeting the sorbent trap section 2 breakthrough requirements; however, correcting sorbent trap results for blank levels is prohibited.
You must follow the procedures for calculation and data analysis listed in this section.
12.1 Nomenclature. The terms used in the equations are defined as follows:
12.2 Calculation of Spike Recovery (Analytical Bias Test). Calculate the percent recovery of Hg
12.3 Calculation of Breakthrough. Use Equation 30B-2 to calculate the percent breakthrough to the second section of the sorbent trap.
12.4 Calculation of Hg Concentration. Calculate the Hg concentration measured with sorbent trap “a”, using Equation 30B-3.
For sorbent trap “b”, replace “C
12.5 Moisture Correction. Use Equation 30B-4 if your measurements need to be corrected to a wet basis.
12.6 Calculation of Paired Trap Agreement. Calculate the relative deviation (RD) between the Hg concentrations measured with the paired sorbent traps using Equation 30B-5.
12.7 Calculation of Measured Spike Hg Concentration (Field Recovery Test). Calculate the measured spike concentration using Equation 30B-6.
Then calculate the spiked Hg recovery, R, using Equation 30B-7.
How do I validate my data? Measurement data are validated using initial, one-time laboratory tests coupled with test program-specific tests and procedures. The analytical matrix interference test and the Hg
1. EPA Traceability Protocol for Qualification and Certification of Elemental Mercury Gas Generators, expected publication date December 2008, see www.epa.gov/ttn/emc.
2. EPA Traceability Protocol for Qualification and Certification of Oxidized Mercury Gas Generators, expected publication date December 2008, see www.epa.gov/ttn/emc.
3. EPA Traceability Protocol for Assay and Certification of Gaseous Calibration Standards, expected revision publication date December 2008, see www.epa.gov/ttn/emc.
Appendix B to Part 60 – Performance Specifications
Performance Specification 1 (PS-1) provides (1) requirements for the design, performance, and installation of a continuous opacity monitoring system (COMS) and (2) data computation procedures for evaluating the acceptability of a COMS. It specifies activities for two groups (1) the owner or operator and (2) the opacity monitor manufacturer.
1.1 Measurement Parameter. PS-1 covers the instrumental measurement of opacity caused by attenuation of projected light due to absorption and scatter of the light by particulate matter in the effluent gas stream.
1.2 What COMS must comply with PS-1? If you are an owner or operator of a facility with a COMS as a result of this Part, then PS-1 applies to your COMS if one of the following is true:
(1) Your facility has a new COMS installed after February 6, 2001; or
(2) Your COMS is replaced, relocated, or substantially refurbished (in the opinion of the regulatory authority) after February 6, 2001; or
(3) Your COMS was installed before February 6, 2001 and is specifically required by regulatory action other than the promulgation of PS-1 to be recertified.
If you are an opacity monitor manufacturer, then paragraph 8.2 applies to you.
1.3 Does PS-1 apply to a facility with an applicable opacity limit less than 10 percent? If you are an owner or operator of a facility with a COMS as a result of this Part and the applicable opacity limit is less than 10 percent, then PS-1 applies to your COMS as described in section 1.2; taking into account (through statistical procedures or otherwise) the uncertainties associated with opacity measurements, and following the conditions for attenuators selection for low opacity applications as outlined in section 8.1(3)(ii). At your option, you, the source owner or operator, may select to establish a reduced full scale range of no less than 50 percent opacity instead of the 80 percent as prescribed in section 3.5, if the applicable opacity limit for your facility is less than 10 percent. The EPA recognizes that reducing the range of the analyzer to 50 percent does not necessarily result in any measurable improvement in measurement accuracy at opacity levels less than 10 percent; however, it may allow improved chart recorder interpretation.
1.4 What data uncertainty issues apply to COMS data? The measurement uncertainties associated with COMS data result from several design and performance factors including limitations on the availability of calibration attenuators for opacities less than about 6 percent (3 percent for single-pass instruments), calibration error tolerances, zero and upscale drift tolerances, and allowance for dust compensation that are significant relative to low opacity levels. The full scale requirements of this PS may also contribute to measurement uncertainty for opacity measurements where the applicable limits are below 10 percent opacity.
PS-1 requires (1) opacity monitor manufacturers comply with a comprehensive series of design and performance specifications and test procedures to certify opacity monitoring equipment before shipment to the end user, (2) the owner or operator to follow installation guidelines, and (3) the owner or operator to conduct a set of field performance tests that confirm the acceptability of the COMS after it is installed.
2.1 ASTM D6216-12 (incorporated by reference, see § 60.17) is the reference for design specifications, manufacturer’s performance specifications, and test procedures. The opacity monitor manufacturer must periodically select and test an opacity monitor, that is representative of a group of monitors produced during a specified period or lot, for conformance with the design specifications in ASTM D6216-12. The opacity monitor manufacturer must test each opacity monitor for conformance with the manufacturer’s performance specifications in ASTM D6216-12. Note: If the initial certification of the opacity monitor occurred before November 14, 2018 using D6216-98, D6216-03, or D6216-07, it is not necessary to recertify using D6216-12.
2.2 section 8.1(2) provides guidance for locating an opacity monitor in vertical and horizontal ducts. You are encouraged to seek approval for the opacity monitor location from the appropriate regulatory authority prior to installation.
2.3 After the COMS is installed and calibrated, the owner or operator must test the COMS for conformance with the field performance specifications in PS-1.
3.1 All definitions and discussions from section 3 of ASTM D6216-12 are applicable to PS-1.
3.2 Centroid Area. A concentric area that is geometrically similar to the stack or duct cross-section and is no greater than 1 percent of the stack or duct cross-sectional area.
3.3 Data Recorder. That portion of the installed COMS that provides a permanent record of the opacity monitor output in terms of opacity. The data recorder may include automatic data reduction capabilities.
3.4 External Audit Device. The inherent design, equipment, or accommodation of the opacity monitor allowing the independent assessment of the COMS’s calibration and operation.
3.5 Full Scale. The maximum data display output of the COMS. For purposes of recordkeeping and reporting, full scale will be greater than 80 percent opacity.
3.6 Operational Test Period. A period of time (168 hours) during which the COMS is expected to operate within the established performance specifications without any unscheduled maintenance, repair, or adjustment.
3.7 Primary Attenuators. Those devices (glass or grid filter that reduce the transmission of light) calibrated according to procedures in section 7.1.
3.8 Secondary Attenuators. Those devices (glass or grid filter that reduce the transmission of light) calibrated against primary attenuators according to procedures in section 7.2.
3.9 System Response Time. The amount of time the COMS takes to display 95 percent of a step change in opacity on the COMS data recorder.
The procedures required under PS-1 may involve hazardous materials, operations, and equipment. PS-1 does not purport to address all of the safety problems associated with these procedures. Before performing these procedures, you must establish appropriate safety and health practices, and you must determine the applicable regulatory limitations. You should consult the COMS user’s manual for specific precautions to take.
6.1 Continuous Opacity Monitoring System. You, as owner or operator, are responsible for purchasing an opacity monitor that meets the specifications of ASTM D6216-12, including a suitable data recorder or automated data acquisition handling system. Example data recorders include an analog strip chart recorder or more appropriately an electronic data acquisition and reporting system with an input signal range compatible with the analyzer output.
6.2 Calibration Attenuators. You, as owner or operator, are responsible for purchasing a minimum of three calibration attenuators that meet the requirements of PS-1. Calibration attenuators are optical filters with neutral spectral characteristics. Calibration attenuators must meet the requirements in section 7 and must be of sufficient size to attenuate the entire light beam received by the detector of the COMS. For transmissometers operating over a narrow bandwidth (e.g., laser), a calibration attenuator’s value is determined for the actual operating wavelengths of the transmissometer. Some filters may not be uniform across the face. If errors result in the daily calibration drift or calibration error test, you may want to examine the across-face uniformity of the filter.
6.3 Calibration Spectrophotometer. Whoever calibrates the attenuators must have a spectrophotometer that meets the following minimum design specifications:
| Parameter | Specification |
|---|---|
| Wavelength range | 300-800 nm. |
| Detector angle of view | |
| Accuracy |
You will need to use attenuators (i.e., neutral density filters) to check the daily calibration drift and calibration error of a COMS. Attenuators are designated as either primary or secondary based on how they are calibrated.
7.1 Attenuators are designated primary in one of two ways:
(1) They are calibrated by NIST; or
(2) They are calibrated on a 6-month frequency through the assignment of a luminous transmittance value in the following manner:
(i) Use a spectrophotometer meeting the specifications of section 6.3 to calibrate the required filters. Verify the spectrophotometer calibration through use of a NIST 930D Standard Reference Material (SRM). A SRM 930D consists of three neutral density glass filters and a blank, each mounted in a cuvette. The wavelengths and temperature to be used in the calibration are listed on the NIST certificate that accompanies the reported values. Determine and record a transmittance of the SRM values at the NIST wavelengths (three filters at five wavelengths each for a total of 15 determinations). Calculate a percent difference between the NIST certified values and the spectrophotometer response. At least 12 of the 15 differences (in percent) must be within ±0.5 percent of the NIST SRM values. No difference can be greater than ±1.0 percent. Recalibrate the SRM or service the spectrophotometer if the calibration results fail the criteria.
(ii) Scan the filter to be tested and the NIST blank from wavelength 380 to 780 nm, and record the spectrophotometer percent transmittance responses at 10 nm intervals. Test in this sequence: blank filter, tested filter, tested filter rotated 90 degrees in the plane of the filter, blank filter. Calculate the average transmittance at each 10 nm interval. If any pair of the tested filter transmittance values (for the same filter and wavelength) differ by more than ±0.25 percent, rescan the tested filter. If the filter fails to achieve this tolerance, do not use the filter in the calibration tests of the COMS.
(iii) Correct the tested filter transmittance values by dividing the average tested filter transmittance by the average blank filter transmittance at each 10 nm interval.
(iv) Calculate the weighted (to the response of the human eye), tested filter transmittance by multiplying the transmittance value by the corresponding response factor shown in table 1-1, to obtain the Source C Human Eye Response.
(v) Recalibrate the primary attenuators semi-annually if they are used for the required calibration error test. Recalibrate the primary attenuators annually if they are used only for calibration of secondary attenuators.
7.2 Attenuators are designated secondary if the filter calibration is done using a laboratory-based transmissometer. Conduct the secondary attenuator calibration using a laboratory-based transmissometer calibrated as follows:
(i) Use at least three primary filters of nominal luminous transmittance 50, 70 and 90 percent, calibrated as specified in section 7.1(2)(i), to calibrate the laboratory-based transmissometer. Determine and record the slope of the calibration line using linear regression through zero opacity. The slope of the calibration line must be between 0.99 and 1.01, and the laboratory-based transmissometer reading for each primary filter must not deviate by more than ±2 percent from the linear regression line. If the calibration of the laboratory-based transmissometer yields a slope or individual readings outside the specified ranges, secondary filter calibrations cannot be performed. Determine the source of the variations (either transmissometer performance or changes in the primary filters) and repeat the transmissometer calibration before proceeding with the attenuator calibration.
(ii) Immediately following the laboratory-based transmissometer calibration, insert the secondary attenuators and determine and record the percent effective opacity value per secondary attenuator from the calibration curve (linear regression line).
(iii) Recalibrate the secondary attenuators semi-annually if they are used for the required calibration error test.
Procedures to verify the performance of the COMS are divided into those completed by the owner or operator and those completed by the opacity monitor manufacturer.
8.1 What procedures must I follow as the Owner or Operator?
(1) You must purchase an opacity monitor that complies with ASTM D6216-12 and obtain a certificate of conformance from the opacity monitor manufacturer.
(2) You must install the opacity monitor at a location where the opacity measurements are representative of the total emissions from the affected facility. You must meet this requirement by choosing a measurement location and a light beam path as follows:
(i) Measurement Location. Select a measurement location that is (1) at least 4 duct diameters downstream from all particulate control equipment or flow disturbance, (2) at least 2 duct diameters upstream of a flow disturbance, (3) where condensed water vapor is not present, and (4) accessible in order to permit maintenance. Alternatively, you may select a measurement location specified in paragraph 8.1(2)(ii) or 8.1(2)(iii).
(ii) Light Beam Path. Select a light beam path that passes through the centroidal area of the stack or duct. Also, you must follow these additional requirements or modifications for these measurement locations:
| If your measurement location is in a: | And is: | Then use a light beam path that is: |
|---|---|---|
| 1. Straight vertical section of stack or duct | Less than 4 equivalent diameters downstream from a bend | In the plane defined by the upstream bend (see figure 1-1). |
| 2. Straight vertical section of stack or duct | Less than 4 equivalent diameters upstream from a bend | In the plane defined by the downstream bend (see figure 1-2). |
| 3. Straight vertical section of stack or duct | Less than 4 equivalent diameters downstream and is also less than 1 diameter upstream from a bend | In the plane defined by the upstream bend (see figure 1-3). |
| 4. Horizontal section of stack or duct | At least 4 equivalent diameters downstream from a vertical bend | In the horizontal plane that is between |
| 5. Horizontal section of duct | Less than 4 equivalent diameters downstream from a vertical bend | In the horizontal plane that is between |
(iii) Alternative Locations and Light Beam Paths. You may select locations and light beam paths, other than those cited above, if you demonstrate, to the satisfaction of the Administrator or delegated agent, that the average opacity measured at the alternative location or path is equivalent to the opacity as measured at a location meeting the criteria of sections 8.1(2)(i) and 8.1(2)(ii). The opacity at the alternative location is considered equivalent if (1) the average opacity value measured at the alternative location is within ±10 percent of the average opacity value measured at the location meeting the installation criteria, and (2) the difference between any two average opacity values is less than 2 percent opacity (absolute). You use the following procedure to conduct this demonstration: simultaneously measure the opacities at the two locations or paths for a minimum period of time (e.g., 180-minutes) covering the range of normal operating conditions and compare the results. The opacities of the two locations or paths may be measured at different times, but must represent the same process operating conditions. You may use alternative procedures for determining acceptable locations if those procedures are approved by the Administrator.
(3) Field Audit Performance Tests. After you install the COMS, you must perform the following procedures and tests on the COMS.
(i) Optical Alignment Assessment. Verify and record that all alignment indicator devices show proper alignment. A clear indication of alignment is one that is objectively apparent relative to reference marks or conditions.
(ii) Calibration Error Check. Conduct a three-point calibration error test using three calibration attenuators that produce outlet pathlength corrected, single-pass opacity values shown in ASTM D6216-12, section 7.5. If your applicable limit is less than 10 percent opacity, use attenuators as described in ASTM D6216-12, section 7.5 for applicable standards of 10 to 19 percent opacity. Confirm the external audit device produces the proper zero value on the COMS data recorder. Separately, insert each calibration attenuators (low, mid, and high-level) into the external audit device. While inserting each attenuator, (1) ensure that the entire light beam passes through the attenuator, (2) minimize interference from reflected light, and (3) leave the attenuator in place for at least two times the shortest recording interval on the COMS data recorder. Make a total of five nonconsecutive readings for each attenuator. At the end of the test, correlate each attenuator insertion to the corresponding value from the data recorder. Subtract the single-pass calibration attenuator values corrected to the stack exit conditions from the COMS responses. Calculate the arithmetic mean difference, standard deviation, and confidence coefficient of the five measurements value using equations 1-3, 1-4, and 1-5. Calculate the calibration error as the sum of the absolute value of the mean difference and the 95 percent confidence coefficient for each of the three test attenuators using equation 1-6. Report the calibration error test results for each of the three attenuators.
(iii) System Response Time Check. Using a high-level calibration attenuator, alternately insert the filter five times and remove it from the external audit device. For each filter insertion and removal, measure the amount of time required for the COMS to display 95 percent of the step change in opacity on the COMS data recorder. For the upscale response time, measure the time from insertion to display of 95 percent of the final, steady upscale reading. For the downscale response time, measure the time from removal to display 5 percent of the initial upscale reading. Calculate the mean of the five upscale response time measurements and the mean of the five downscale response time measurements. Report both the upscale and downscale response times.
(iv) Averaging Period Calculation and Recording Check. After the calibration error check, conduct a check of the averaging period calculation (e.g., 6-minute integrated average). Consecutively insert each of the calibration error check attenuators (low, mid, and high-level) into the external audit device for a period of two times the averaging period plus 1 minute (e.g., 13 minutes for a 6-minute averaging period). Compare the path length corrected opacity value of each attenuator to the valid average value calculated by the COMS data recording device for that attenuator.
(4) Operational Test Period. Before conducting the operational testing, you must have successfully completed the field audit tests described in sections 8.1(3)(i) through 8.1(3)(iv). Then, you operate the COMS for an initial 168-hour test period while the source is operating under normal operating conditions. If normal operations contain routine source shutdowns, include the source’s down periods in the 168-hour operational test period. However, you must ensure that the following minimum source operating time is included in the operational test period: (1) For a batch operation, the operational test period must include at least one full cycle of batch operation during the 168-hour period unless the batch operation is longer than 168 hours or (2) for continuous operating processes, the unit must be operating for at least 50 percent of the 168-hour period. Except during times of instrument zero and upscale calibration drift checks, you must analyze the effluent gas for opacity and produce a permanent record of the COMS output. During this period, you may not perform unscheduled maintenance, repair, or adjustment to the COMS. Automatic zero and calibration adjustments (i.e., intrinsic adjustments), made by the COMS without operator intervention or initiation, are allowable at any time. At the end of the operational test period, verify and record that the COMS optical alignment is still correct. If the test period is interrupted because of COMS failure, record the time when the failure occurred. After the failure is corrected, you restart the 168-hour period and tests from the beginning (0-hour). During the operational test period, perform the following test procedures:
(i) Zero Calibration Drift Test. At the outset of the 168-hour operational test period and at each 24-hour interval, the automatic calibration check system must initiate the simulated zero device to allow the zero drift to be determined. Record the COMS response to the simulated zero device. After each 24-hour period, subtract the COMS zero reading from the nominal value of the simulated zero device to calculate the 24-hour zero drift (ZD). At the end of the 168-hour period, calculate the arithmetic mean, standard deviation, and confidence coefficient of the 24-hour ZDs using equations 1-3, 1-4, and 1-5. Calculate the sum of the absolute value of the mean and the absolute value of the confidence coefficient using equation 1-6, and report this value as the 24-hour ZD error.
(ii) Upscale Calibration Drift Test. At each 24-hour interval after the simulated zero device value has been checked, check and record the COMS response to the upscale calibration device. After each 24-hour period, subtract the COMS upscale reading from the nominal value of the upscale calibration device to calculate the 24-hour calibration drift (CD). At the end of the 168-hour period, calculate the arithmetic mean, standard deviation, and confidence coefficient of the 24-hour CD using equations 1-3, 1-4, and 1-5. Calculate the sum of the absolute value of the mean and the absolute value of the confidence coefficient using equation 1-6, and report this value as the 24-hour CD error.
(5) Retesting. If the COMS fails to meet the specifications for the tests conducted under the operational test period, make the necessary corrections and restart the operational test period. Depending on the opinion of the enforcing agency, you may have to repeat some or all of the field audit tests.
8.2 What are the responsibilities of the Opacity Monitor Manufacturer?
You, the manufacturer, must carry out the following activities:
(1) Conduct the verification procedures for design specifications in section 6 of ASTM D6216-12.
(2) Conduct the verification procedures for performance specifications in section 7 of ASTM D6216-12.
(3) Provide to the owner or operator, a report of the opacity monitor’s conformance to the design and performance specifications required in sections 6 and 7 of ASTM D6216-12 in accordance with the reporting requirements of section 9 in ASTM D6216-12.
Opacity monitor manufacturers must initiate a quality program following the requirements of ASTM D6216-12, section 8. The quality program must include (1) a quality system and (2) a corrective action program.
12.1 Desired Attenuator Values. Calculate the desired attenuator value corrected to the emission outlet pathlength as follows:
12.2 Luminous Transmittance Value of a Filter. Calculate the luminous transmittance of a filter as follows:
12.3 Arithmetic Mean. Calculate the arithmetic mean of a data set as follows:
12.4 Standard Deviation. Calculate the standard deviation as follows:
12.5 Confidence Coefficient. Calculate the 2.5 percent error confidence coefficient (one-tailed) as follows:
12.6 Calibration Error. Calculate the error (calibration error, zero drift error, and calibration drift error) as follows:
12.7 Conversion of Opacity Values for Monitor Pathlength to Emission Outlet Pathlength. When the monitor pathlength is different from the emission outlet pathlength, use either of the following equations to convert from one basis to the other (this conversion may be automatically calculated by the monitoring system):
12.8 Mean Response Wavelength. Calculate the mean of the effective spectral response curve from the individual responses at the specified wavelength values as follows:
A COMS must meet the following design, manufacturer’s performance, and field audit performance specifications:
13.1 Design Specifications. The opacity monitoring equipment must comply with the design specifications of ASTM D6216-12.
13.2 Manufacturer’s Performance Specifications. The opacity monitor must comply with the manufacturer’s performance specifications of ASTM D6216-12.
13.3 Field Audit Performance Specifications. The installed COMS must comply with the following performance specifications:
(1) Optical Alignment. Objectively indicate proper alignment relative to reference marks (e.g., bull’s-eye) or conditions.
(2) Calibration Error. The calibration error must be ≤3 percent opacity for each of the three calibration attenuators.
(3) System Response Time. The COMS upscale and downscale response times must be ≤10 seconds as measured at the COMS data recorder.
(4) Averaging Period Calculation and Recording. The COMS data recorder must average and record each calibration attenuator value to within ±2 percent opacity of the certified value of the attenuator.
(5) Operational Test Period. The COMS must be able to measure and record opacity and to perform daily calibration drift assessments for 168 hours without unscheduled maintenance, repair, or adjustment.
(6) Zero and Upscale Calibration Drift Error. The COMS zero and upscale calibration drift error must not exceed 2 percent opacity over a 24 hour period.
1. Experimental Statistics. Department of Commerce. National Bureau of Standards Handbook 91. Paragraph 3-3.1.4. 1963. 3-31 p.
2. Performance Specifications for Stationary Source Monitoring Systems for Gases and Visible Emissions, EPA-650/2-74-013, January 1974, U. S. Environmental Protection Agency, Research Triangle Park, NC.
3. Koontz, E.C., Walton, J. Quality Assurance Programs for Visible Emission Evaluations. Tennessee Division of Air Pollution Control. Nashville, TN. 78th Meeting of the Air Pollution Control Association. Detroit, MI. June 16-21, 1985.
4. Evaluation of Opacity CEMS Reliability and Quality Assurance Procedures. Volume 1. U. S. Environmental Protection Agency. Research Triangle Park, NC. EPA-340/1-86-009a.
5. Nimeroff, I. “Colorimetry Precision Measurement and Calibration.” NBS Special Publication 300. Volume 9. June 1972.
6. Technical Assistance Document: Performance Audit Procedures for Opacity Monitors. U. S. Environmental Protection Agency. Research Triangle Park, NC. EPA-600/8-87-025. April 1987.
7. Technical Assistance Document: Performance Audit Procedures for Opacity Monitors. U. S. Environmental Protection Agency. Research Triangle Park, NC. EPA-450/4-92-010. April 1992.
8. ASTM D6216-12: Standard Practice for Opacity Monitor Manufacturers to Certify Conformance with Design and Performance Specifications. ASTM. October 2012.
17.1 Reference Tables.
Table 1-1 – Source C, Human Eye Response Factor
| Wavelength nanometers | Weighting factor a | Wavelength nanometers | Weighting factor a |
|---|---|---|---|
| 380 | 0 | 590 | 6627 |
| 390 | 0 | 600 | 5316 |
| 400 | 2 | 610 | 4176 |
| 410 | 9 | 620 | 3153 |
| 420 | 37 | 630 | 2190 |
| 430 | 122 | 640 | 1443 |
| 440 | 262 | 650 | 886 |
| 450 | 443 | 660 | 504 |
| 460 | 694 | 670 | 259 |
| 470 | 1058 | 680 | 134 |
| 480 | 1618 | 690 | 62 |
| 490 | 2358 | 700 | 29 |
| 500 | 3401 | 720 | 14 |
| 510 | 4833 | 720 | 6 |
| 520 | 6462 | 730 | 3 |
| 530 | 7934 | 740 | 2 |
| 540 | 9194 | 750 | 1 |
| 550 | 9832 | 760 | 1 |
| 560 | 9841 | 770 | 0 |
| 570 | 9147 | 780 | 0 |
| 580 | 7992 |
1 Total of weighting factors = 100,000.
Table 1-2
T Values
| n a | t 0.975 | n a | t 0.975 | n a | t 0.975 |
|---|---|---|---|---|---|
| 2 | 12.706 | 7 | 2.447 | 12 | 2.201 |
| 3 | 4.303 | 8 | 2.365 | 13 | 2.179 |
| 4 | 3.182 | 9 | 2.306 | 14 | 2.160 |
| 5 | 2.776 | 10 | 2.262 | 15 | 2.145 |
| 6 | 2.571 | 11 | 2.228 | 16 | 2.131 |
a The values in this table are already corrected for n-1 degrees of freedom. Use n equal to the number of individual values.
17.2 Diagrams.
1.1 Analytes
| Analyte | CAS Nos. |
|---|---|
| Sulfur Dioxide (SO | 7449-09-5 |
| Nitrogen Oxides (NO | 10102-44-0 (NO |
1.2 Applicability.
1.2.1 This specification is for evaluating the acceptability of SO
1.2.2 This specification is not designed to evaluate the installed CEMS performance over an extended period of time nor does it identify specific calibration techniques and other auxiliary procedures to assess the CEMS performance. The source owner or operator is responsible to calibrate, maintain, and operate the CEMS properly. The Administrator may require, under section 114 of the Act, the operator to conduct CEMS performance evaluations at other times besides the initial test to evaluate the CEMS performance. See 40 CFR Part 60, § 60.13(c).
Procedures for measuring CEMS relative accuracy and calibration drift are outlined. CEMS installation and measurement location specifications, equipment specifications, performance specifications, and data reduction procedures are included. Conformance of the CEMS with the Performance Specification is determined.
3.1 Calibration Drift (CD) means the difference in the CEMS output readings from the established reference value after a stated period of operation during which no unscheduled maintenance, repair, or adjustment took place.
3.2 Centroidal Area means a concentric area that is geometrically similar to the stack or duct cross section and is no greater than l percent of the stack or duct cross-sectional area.
3.3 Continuous Emission Monitoring System means the total equipment required for the determination of a gas concentration or emission rate. The sample interface, pollutant analyzer, diluent analyzer, and data recorder are the major subsystems of the CEMS.
3.4 Data Recorder means that portion of the CEMS that provides a permanent record of the analyzer output. The data recorder may include automatic data reduction capabilities.
3.5 Diluent Analyzer means that portion of the CEMS that senses the diluent gas (i.e., CO
3.6 Path CEMS means a CEMS that measures the gas concentration along a path greater than 10 percent of the equivalent diameter of the stack or duct cross section.
3.7 Point CEMS means a CEMS that measures the gas concentration either at a single point or along a path equal to or less than 10 percent of the equivalent diameter of the stack or duct cross section.
3.8 Pollutant Analyzer means that portion of the CEMS that senses the pollutant gas and generates an output proportional to the gas concentration.
3.9 Relative Accuracy (RA) means the absolute mean difference between the gas concentration or emission rate determined by the CEMS and the value determined by the reference method (RM), plus the 2.5 percent error confidence coefficient of a series of tests, divided by the mean of the RM tests or the applicable emission limit.
3.10 Sample Interface means that portion of the CEMS used for one or more of the following: sample acquisition, sample delivery, sample conditioning, or protection of the monitor from the effects of the stack effluent.
3.11 Span Value means the calibration portion of the measurement range as specified in the applicable regulation or other requirement. If the span is not specified in the applicable regulation or other requirement, then it must be a value approximately equivalent to two times the emission standard. For spans less than 500 ppm, the span value may either be rounded upward to the next highest multiple of 10 ppm, or to the next highest multiple of 100 ppm such that the equivalent emission concentration is not less than 30 percent of the selected span value.
The procedures required under this performance specification may involve hazardous materials, operations, and equipment. This performance specification may not address all of the safety problems associated with these procedures. It is the responsibility of the user to establish appropriate safety and health practices and determine the applicable regulatory limitations prior to performing these procedures. The CEMS user’s manual and materials recommended by the reference method should be consulted for specific precautions to be taken.
6.1 CEMS Equipment Specifications.
6.1.1 Data Recorder. The portion of the CEMS that provides a record of analyzer output. The data recorder may record other pertinent data such as effluent flow rates, various instrument temperatures or abnormal CEMS operation. The data recorder output range must include the full range of expected concentration values in the gas stream to be sampled including zero and span values.
6.1.2 The CEMS design should also allow the determination of calibration drift at the zero and span values. If this is not possible or practical, the design must allow these determinations to be conducted at a low-level value (zero to 20 percent of the span value) and at a value between 50 and 100 percent of the span value. In special cases, the Administrator may approve a single-point calibration drift determination.
6.2 Other equipment and supplies, as needed by the applicable reference method(s) (see section 8.4.2 of this Performance Specification), may be required.
7.1 Reference Gases, Gas Cells, or Optical Filters. As specified by the CEMS manufacturer for calibration of the CEMS (these need not be certified).
7.2 Reagents and Standards. May be required as needed by the applicable reference method(s) (see section 8.4.2 of this Performance Specification).
8.1 Installation and Measurement Location Specifications.
8.1.1 CEMS Installation. Install the CEMS at an accessible location where the pollutant concentration or emission rate measurements are directly representative or can be corrected so as to be representative of the total emissions from the affected facility or at the measurement location cross section. Then select representative measurement points or paths for monitoring in locations that the CEMS will pass the RA test (see section 8.4). If the cause of failure to meet the RA test is determined to be the measurement location and a satisfactory correction technique cannot be established, the Administrator may require the CEMS to be relocated. Suggested measurement locations and points or paths that are most likely to provide data that will meet the RA requirements are listed below.
8.1.2 CEMS Measurement Location. It is suggested that the measurement location be (1) at least two equivalent diameters downstream from the nearest control device, the point of pollutant generation, or other point at which a change in the pollutant concentration or emission rate may occur and (2) at least a half equivalent diameter upstream from the effluent exhaust or control device.
8.1.2.1 Point CEMS. It is suggested that the measurement point be (1) no less than 1.0 meter (3.3 ft) from the stack or duct wall or (2) within or centrally located over the centroidal area of the stack or duct cross section.
8.1.2.2 Path CEMS. It is suggested that the effective measurement path (1) be totally within the inner area bounded by a line 1.0 meter (3.3 ft) from the stack or duct wall, or (2) have at least 70 percent of the path within the inner 50 percent of the stack or duct cross-sectional area, or (3) be centrally located over any part of the centroidal area.
8.1.3 Reference Method Measurement Location and Traverse Points.
8.1.3.1 Select, as appropriate, an accessible RM measurement point at least two equivalent diameters downstream from the nearest control device, the point of pollutant generation, or other point at which a change in the pollutant concentration or emission rate may occur, and at least a half equivalent diameter upstream from the effluent exhaust or control device. When pollutant concentration changes are due solely to diluent leakage (e.g., air heater leakages) and pollutants and diluents are simultaneously measured at the same location, a half diameter may be used in lieu of two equivalent diameters. The CEMS and RM locations need not be the same.
8.1.3.2 Select traverse points that assure acquisition of representative samples over the stack or duct cross section. The minimum requirements are as follows: Establish a “measurement line” that passes through the centroidal area and in the direction of any expected stratification. If this line interferes with the CEMS measurements, displace the line up to 30 cm (12 in.) (or 5 percent of the equivalent diameter of the cross section, whichever is less) from the centroidal area. Locate three traverse points at 16.7, 50.0, and 83.3 percent of the measurement line. If the measurement line is longer than 2.4 meters (7.8 ft) and pollutant stratification is not expected, the three traverse points may be located on the line at 0.4, 1.2, and 2.0 meters from the stack or duct wall. This option must not be used after wet scrubbers or at points where two streams with different pollutant concentrations are combined. If stratification is suspected, the following procedure is suggested. For rectangular ducts, locate at least nine sample points in the cross section such that sample points are the centroids of similarly-shaped, equal area divisions of the cross section. Measure the pollutant concentration, and, if applicable, the diluent concentration at each point using appropriate reference methods or other appropriate instrument methods that give responses relative to pollutant concentrations. Then calculate the mean value for all sample points. For circular ducts, conduct a 12-point traverse (i.e., six points on each of the two perpendicular diameters) locating the sample points as described in 40 CFR 60, Appendix A, Method 1. Perform the measurements and calculations as described above. Determine if the mean pollutant concentration is more than 10% different from any single point. If so, the cross section is considered to be stratified, and the tester may not use the alternative traverse point locations (…0.4, 1.2, and 2.0 meters from the stack or duct wall.) but must use the three traverse points at 16.7, 50.0, and 83.3 percent of the entire measurement line. Other traverse points may be selected, provided that they can be shown to the satisfaction of the Administrator to provide a representative sample over the stack or duct cross section. Conduct all necessary RM tests within 3 cm (1.2 in.) of the traverse points, but no closer than 3 cm (1.2 in.) to the stack or duct wall.
8.2 Pretest Preparation. Install the CEMS, prepare the RM test site according to the specifications in section 8.1, and prepare the CEMS for operation according to the manufacturer’s written instructions.
8.3 Calibration Drift Test Procedure.
8.3.1 CD Test Period. While the affected facility is operating, determine the magnitude of the CD once each day (at 24-hour intervals) for 7 consecutive calendar days according to the procedure given in sections 8.3.2 through 8.3.4. Alternatively, the CD test may be conducted over 7 consecutive unit operating days.
8.3.2 The purpose of the CD measurement is to verify the ability of the CEMS to conform to the established CEMS calibration used for determining the emission concentration or emission rate. Therefore, if periodic automatic or manual adjustments are made to the CEMS zero and calibration settings, conduct the CD test immediately before these adjustments, or conduct it in such a way that the CD can be determined.
8.3.3 Conduct the CD test at the two points specified in section 6.1.2. Introduce to the CEMS the reference gases, gas cells, or optical filters (these need not be certified). Record the CEMS response and subtract this value from the reference value (see example data sheet in Figure 2-1).
8.4 Relative Accuracy Test Procedure.
8.4.1 RA Test Period. Conduct the RA test according to the procedure given in sections 8.4.2 through 8.4.6 while the affected facility is operating at more than 50 percent of normal load, or as specified in an applicable subpart. The RA test may be conducted during the CD test period.
8.4.2 Reference Methods. Unless otherwise specified in an applicable subpart of the regulations, Methods 3B, 4, 6, and 7, or their approved alternatives, are the reference methods for diluent (O
8.4.3 Sampling Strategy for RM Tests. Conduct the RM tests in such a way that they will yield results representative of the emissions from the source and can be correlated to the CEMS data. It is preferable to conduct the diluent (if applicable), moisture (if needed), and pollutant measurements simultaneously. However, diluent and moisture measurements that are taken within an hour of the pollutant measurements may be used to calculate dry pollutant concentration and emission rates. In order to correlate the CEMS and RM data properly, note the beginning and end of each RM test period of each run (including the exact time of day) on the CEMS chart recordings or other permanent record of output. Use the following strategies for the RM tests:
8.4.3.1 For integrated samples (e.g., Methods 6 and Method 4), make a sample traverse of at least 21 minutes, sampling for an equal time at each traverse point (see section 8.1.3.2 for discussion of traverse points.
8.4.3.2 For grab samples (e.g., Method 7), take one sample at each traverse point, scheduling the grab samples so that they are taken simultaneously (within a 3-minute period) or at an equal interval of time apart over the span of time the CEM pollutant is measured. A test run for grab samples must be made up of at least three separate measurements.
At times, CEMS RA tests are conducted during new source performance standards performance tests. In these cases, RM results obtained during CEMS RA tests may be used to determine compliance as long as the source and test conditions are consistent with the applicable regulations.
8.4.4 Number of RM Tests. Conduct a minimum of nine sets of all necessary RM test runs.
More than nine sets of RM tests may be performed. If this option is chosen, a maximum of three sets of the test results may be rejected so long as the total number of test results used to determine the RA is greater than or equal to nine. However, all data must be reported, including the rejected data.
8.4.5 Correlation of RM and CEMS Data. Correlate the CEMS and the RM test data as to the time and duration by first determining from the CEMS final output (the one used for reporting) the integrated average pollutant concentration or emission rate for each pollutant RM test period. Consider system response time, if important, and confirm that the pair of results are on a consistent moisture, temperature, and diluent concentration basis. Then, compare each integrated CEMS value against the corresponding average RM value. Use the following guidelines to make these comparisons.
8.4.5.1 If the RM has an integrated sampling technique, make a direct comparison of the RM results and CEMS integrated average value.
8.4.5.2 If the RM has a grab sampling technique, first average the results from all grab samples taken during the test run, and then compare this average value against the integrated value obtained from the CEMS chart recording or output during the run. If the pollutant concentration is varying with time over the run, the arithmetic average of the CEMS value recorded at the time of each grab sample may be used.
8.4.6 Calculate the mean difference between the RM and CEMS values in the units of the emission standard, the standard deviation, the confidence coefficient, and the relative accuracy according to the procedures in section 12.0.
8.5 Reporting. At a minimum (check with the appropriate regional office, State, or Local agency for additional requirements, if any), summarize in tabular form the results of the CD tests and the RA tests or alternative RA procedure, as appropriate. Include all data sheets, calculations, charts (records of CEMS responses), cylinder gas concentration certifications, and calibration cell response certifications (if applicable) necessary to confirm that the performance of the CEMS met the performance specifications.
Sample collection and analysis are concurrent for this Performance Specification (see section 8.0). Refer to the RM for specific analytical procedures.
Summarize the results on a data sheet similar to that shown in Figure 2-2 (in section 18.0).
12.1 All data from the RM and CEMS must be on a consistent dry basis and, as applicable, on a consistent diluent basis and in the units of the emission standard. Correct the RM and CEMS data for moisture and diluent as follows:
12.1.1 Moisture Correction (as applicable). Correct each wet RM run for moisture with the corresponding Method 4 data; correct each wet CEMS run using the corresponding CEMS moisture monitor date using Equation 2-1.
12.1.2 Correction to Units of Standard (as applicable). Correct each dry RM run to the units of the emission standard with the corresponding Method 3B data; correct each dry CEMS run using the corresponding CEMS diluent monitor data as follows:
12.1.2.1 Correct to Diluent Basis. The following is an example of concentration (ppm) correction to 7% oxygen.
The following is an example of mass/gross calorific value (lbs/million Btu) correction.
12.2 Arithmetic Mean. Calculate the arithmetic mean of the difference, d, of a data set as follows:
12.3 Standard Deviation. Calculate the standard deviation, S
12.4 Confidence Coefficient. Calculate the 2.5 percent error confidence coefficient (one-tailed), CC, as follows:
12.5 Relative Accuracy. Calculate the RA of a set of data as follows:
13.1 Calibration Drift Performance Specification. The CEMS calibration must not drift or deviate from the reference value of the gas cylinder, gas cell, or optical filter by more than 2.5 percent of the span value. If the CEMS includes pollutant and diluent monitors, the CD must be determined separately for each in terms of concentrations (See Performance Specification 3 for the diluent specifications), and none of the CDs may exceed the specification.
13.2 Relative Accuracy Performance Specification.
| Calculate . . . | RA criteria (%) | |
|---|---|---|
| If average emissions during the RATA are ≥50% of emission standard | Use Eq. 2-6, with RM in the denominator | ≤20.0 |
| If average emissions during the RATA are | Use Eq. 2-6, emission standard in the denominator | ≤10.0 |
| For SO | Use Eq. 2-6, emission standard in the denominator | ≤15.0 |
| For SO | Use Eq. 2-6, emission standard in the denominator | ≤20.0 |
13.3 For instruments that use common components to measure more than one effluent gas constituent, all channels must simultaneously pass the RA requirement, unless it can be demonstrated that any adjustments made to one channel did not affect the others.
Paragraphs 60.13(j)(1) and (2) of 40 CFR part 60 contain criteria for which the reference method procedure for determining relative accuracy (see section 8.4 of this Performance Specification) may be waived and the following procedure substituted.
16.1 Conduct a complete CEMS status check following the manufacturer’s written instructions. The check should include operation of the light source, signal receiver, timing mechanism functions, data acquisition and data reduction functions, data recorders, mechanically operated functions (mirror movements, zero pipe operation, calibration gas valve operations, etc.), sample filters, sample line heaters, moisture traps, and other related functions of the CEMS, as applicable. All parts of the CEMS shall be functioning properly before proceeding to the alternative RA procedure.
16.2 Alternative RA Procedure.
16.2.1 Challenge each monitor (both pollutant and diluent, if applicable) with cylinder gases of known concentrations or calibration cells that produce known responses at two measurement points within the ranges shown in Table 2-2 (Section 18).
16.2.2 Use a separate cylinder gas (for point CEMS only) or calibration cell (for path CEMS or where compressed gas cylinders can not be used) for measurement points 1 and 2. Challenge the CEMS and record the responses three times at each measurement point. The Administrator may allow dilution of cylinder gas using the performance criteria in Test Method 205, 40 CFR Part 51, Appendix M. Use the average of the three responses in determining relative accuracy.
16.2.3 Operate each monitor in its normal sampling mode as nearly as possible. When using cylinder gases, pass the cylinder gas through all filters, scrubbers, conditioners, and other monitor components used during normal sampling and as much of the sampling probe as practical. When using calibration cells, the CEMS components used in the normal sampling mode should not be by-passed during the RA determination. These include light sources, lenses, detectors, and reference cells. The CEMS should be challenged at each measurement point for a sufficient period of time to assure adsorption-desorption reactions on the CEMS surfaces have stabilized.
16.2.4 Use cylinder gases that have been certified by comparison to National Institute of Standards and Technology (NIST) gaseous standard reference material (SRM) or NIST/EPA approved gas manufacturer’s certified reference material (CRM) (See Reference 2 in section 17.0) following EPA Traceability Protocol Number 1 (See Reference 3 in section 17.0). As an alternative to Protocol Number 1 gases, CRM’s may be used directly as alternative RA cylinder gases. A list of gas manufacturers that have prepared approved CRM’s is available from EPA at the address shown in Reference 2. Procedures for preparation of CRM’s are described in Reference 2.
16.2.5 Use calibration cells certified by the manufacturer to produce a known response in the CEMS. The cell certification procedure shall include determination of CEMS response produced by the calibration cell in direct comparison with measurement of gases of known concentration. This can be accomplished using SRM or CRM gases in a laboratory source simulator or through extended tests using reference methods at the CEMS location in the exhaust stack. These procedures are discussed in Reference 4 in section 17.0. The calibration cell certification procedure is subject to approval of the Administrator.
16.3 The differences between the known concentrations of the cylinder gases and the concentrations indicated by the CEMS are used to assess the accuracy of the CEMS. The calculations and limits of acceptable relative accuracy are as follows:
16.3.1 For pollutant CEMS:
16.3.2 For diluent CEMS:
Waiver of the relative accuracy test in favor of the alternative RA procedure does not preclude the requirements to complete the CD tests nor any other requirements specified in an applicable subpart for reporting CEMS data and performing CEMS drift checks or audits.
1. Department of Commerce. Experimental Statistics. Handbook 91. Washington, D.C. p. 3-31, paragraphs 3-3.1.4.
2. “A Procedure for Establishing Traceability of Gas Mixtures to Certain National Bureau of Standards Standard Reference Materials.” Joint publication by NBS and EPA. EPA 600/7-81-010. Available from U.S. Environmental Protection Agency, Quality Assurance Division (MD-77), Research Triangle Park, North Carolina 27711.
3. “Traceability Protocol for Establishing True Concentrations of Gases Used for Calibration and Audits of Continuous Source Emission Monitors. (Protocol Number 1).” June 1978. Protocol Number 1 is included in the Quality Assurance Handbook for Air Pollution Measurement Systems, Volume III, Stationary Source Specific Methods. EPA-600/4-77-027b. August 1977.
4. “Gaseous Continuous Emission Monitoring Systems – Performance Specification Guidelines for SO
Table 2-1 –
| n a | t | n a | t | n a | t |
|---|---|---|---|---|---|
| 2 | 12.706 | 7 | 2.447 | 12 | 2.201 |
| 3 | 4.303 | 8 | 2.365 | 13 | 2.179 |
| 4 | 3.182 | 9 | 2.306 | 14 | 2.160 |
| 5 | 2.776 | 10 | 2.262 | 15 | 2.145 |
| 6 | 2.571 | 11 | 2.228 | 16 | 2.131 |
a The values in this table are already corrected for n−1 degrees of freedom. Use n equal to the number of individual values.
Table 2-2 – Measurement Range
| Measurement point | Pollutant monitor | Diluent monitor for | |
|---|---|---|---|
| CO | O | ||
| 1 | 20-30% of span value | 5-8% by volume | 4-6% by volume. |
| 2 | 50-60% of span value | 10-14% by volume | 8-12% by volume. |
a For Steam generators.
b Average of three samples.
c Make sure that RM and CEMS data are on a consistent basis, either wet or dry.
1.1 Analytes.
| Analytes | CAS No. |
|---|---|
| Carbon Dioxide (CO | 124-38-9 |
| Oxygen (O | 7782-44-7 |
1.2 Applicability.
1.2.1 This specification is for evaluating acceptability of O
1.2.2 This specification is not designed to evaluate the installed CEMS performance over an extended period of time, nor does it identify specific calibration techniques and other auxiliary procedures to assess the CEMS performance. The source owner or operator, is responsible to calibrate, maintain, and operate the CEMS properly. The Administrator may require, under section 114 of the Act, the operator to conduct CEMS performance evaluations at other times besides the initial test to evaluate the CEMS performance. See 40 CFR part 60, section 60.13(c).
1.2.3 The definitions, installation and measurement location specifications, calculations and data analysis, and references are the same as in PS 2, sections 3, 8.1, 12, and 17, respectively, and also apply to O
The RA and calibration drift (CD) tests are conducted to determine conformance of the CEMS to the specification.
Same as in section 3.0 of PS 2.
This performance specification may involve hazardous materials, operations, and equipment. This performance specification may not address all of the safety problems associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and determine the applicable regulatory limitations prior to performing this performance specification. The CEMS users manual should be consulted for specific precautions to be taken with regard to the analytical procedures.
Same as section 6.0 of PS2.
Same as section 7.0 of PS2.
8.1 Relative Accuracy Test Procedure. Sampling Strategy for reference method (RM) Tests, Correlation of RM and CEMS Data, and Number of RM Tests. Same as PS 2, sections 8.4.3, 8.4.5, and 8.4.4, respectively.
8.2 Reference Method. Unless otherwise specified in an applicable subpart of the regulations, Method 3B or other approved alternative is the RM for O
Sample collection and analyses are concurrent for this performance specification (see section 8). Refer to the RM for specific analytical procedures.
Calculate the RA using equations 3-1 and 3-2. Summarize the results on a data sheet similar to that shown in Figure 2.2 of PS2.
13.1 Calibration Drift Performance Specification. The CEMS calibration must not drift by more than 0.5 percent O
13.2 CEMS Relative Accuracy Performance Specification. The RA of the CEMS must be no greater than 20.0 percent of the mean value of the reference method (RM) data when calculated using equation 3-1. The results are also acceptable if the result of Equation 3-2 is less than or equal to 1.0 percent O
Same as in section 17.0 of PS 2.
1.1 Analytes.
| Analyte | CAS No. |
|---|---|
| Carbon Monoxide (CO) | 630-08-0 |
1.2 Applicability.
1.2.1 This specification is for evaluating the acceptability of carbon monoxide (CO) continuous emission monitoring systems (CEMS) at the time of installation or soon after and whenever specified in an applicable subpart of the regulations. This specification was developed primarily for CEMS having span values of 1,000 ppmv CO.
1.2.2 This specification is not designed to evaluate the installed CEMS performance over an extended period of time nor does it identify specific calibration techniques and other auxiliary procedures to assess CEMS performance. The source owner or operator, is responsible to calibrate, maintain, and operate the CEMS. The Administrator may require, under section 114 of the Act, the source owner or operator to conduct CEMS performance evaluations at other times besides the initial test to evaluate the CEMS performance. See 40 CFR part 60, section 60.13(c).
1.2.3 The definitions, performance specification test procedures, calculations, and data analysis procedures for determining calibration drift (CD) and relative accuracy (RA) of Performance Specification 2 (PS 2), sections 3, 8.0, and 12, respectively, apply to this specification.
The CD and RA tests are conducted to determine conformance of the CEMS to the specification.
Same as in section 3.0 of PS 2.
This performance specification may involve hazardous materials, operations, and equipment. This performance specification may not address all of the safety problems associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and determine the applicable regulatory limitations prior to performing this performance specification. The CEMS users manual should be consulted for specific precautions to be taken with regard to the analytical procedures.
Same as section 6.0 of PS 2.
Same as section 7.0 of PS 2.
8.1 Relative Accuracy Test Procedure. Sampling Strategy for reference method (RM) Tests, Number of RM Tests, and Correlation of RM and CEMS Data are the same as PS 2, sections 8.4.3, 8.4.4, and 8.4.5, respectively.
8.2 Reference Methods. Unless otherwise specified in an applicable subpart of the regulation, Method 10, 10A, 10B or other approved alternative are the RM for this PS.
Sample collection and analysis are concurrent for this performance specification (see section 8.0). Refer to the RM for specific analytical procedures.
Same as section 12.0 of PS 2.
13.1 Calibration Drift. The CEMS calibration must not drift or deviate from the reference value of the calibration gas, gas cell, or optical filter by more than 5 percent of the established span value for 6 out of 7 test days (e.g., the established span value is 1000 ppm for Subpart J affected facilities).
13.2 Relative Accuracy. The RA of the CEMS must be no greater than 10 percent when the average RM value is used to calculate RA or 5 percent when the applicable emission standard is used to calculate RA.
1. Ferguson, B.B., R.E. Lester, and W.J. Mitchell. Field Evaluation of Carbon Monoxide and Hydrogen Sulfide Continuous Emission Monitors at an Oil Refinery. U.S. Environmental Protection Agency. Research Triangle Park, N.C. Publication No. EPA-600/4-82-054. August 1982. 100 p.
2. “Gaseous Continuous Emission Monitoring Systems – Performance Specification Guidelines for SO
3. Repp, M. Evaluation of Continuous Monitors for Carbon Monoxide in Stationary Sources. U.S. Environmental Protection Agency. Research Triangle Park, N.C. Publication No. EPA-600/2-77-063. March 1977. 155 p.
4. Smith, F., D.E. Wagoner, and R.P. Donovan. Guidelines for Development of a Quality Assurance Program: Volume VIII – Determination of CO Emissions from Stationary Sources by NDIR Spectrometry. U.S. Environmental Protection Agency. Research Triangle Park, N.C. Publication No. EPA-650/4-74-005-h. February 1975. 96 p.
Same as section 18.0 of PS 2.
1.1 Analytes.
| Analyte | CAS No. |
|---|---|
| Carbon Monoxide (CO) | 630-80-0 |
1.2 Applicability.
1.2.1 This specification is for evaluating the acceptability of carbon monoxide (CO) continuous emission monitoring systems (CEMS) at the time of installation or soon after and whenever specified in an applicable subpart of the regulations. This specification was developed primarily for CEMS that comply with low emission standards (less than 200 ppmv).
1.2.2 This specification is not designed to evaluate the installed CEMS performance over an extended period of time nor does it identify specific calibration techniques and other auxiliary procedures to assess CEMS performance. The source owner or operator is responsible to calibrate, maintain, and operate the CEMS. The Administrator may require, under section 114 of the Act, the source owner or operator to conduct CEMS performance evaluations at other times besides the initial test to evaluate CEMS performance. See 40 CFR Part 60, section 60.13(c).
1.2.3 The definitions, performance specification, test procedures, calculations and data analysis procedures for determining calibration drifts (CD) and relative accuracy (RA), of Performance Specification 2 (PS 2), sections 3, 8.0, and 12, respectively, apply to this specification.
The CD and RA tests are conducted to determine conformance of the CEMS to the specification.
Same as in section 3.0 of PS 2.
This performance specification may involve hazardous materials, operations, and equipment. This performance specification may not address all of the safety problems associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and determine the applicable regulatory limitations prior to performing this performance specification. The CEMS users manual should be consulted for specific precautions to be taken with regard to the analytical procedures.
Same as section 6.0 of PS 2 with the following additions.
6.1 Data Recorder Scale.
6.1.1 This specification is the same as section 6.1 of PS 2. The CEMS shall be capable of measuring emission levels under normal conditions and under periods of short-duration peaks of high concentrations. This dual-range capability may be met using two separate analyzers (one for each range) or by using dual-range units which have the capability of measuring both levels with a single unit. In the latter case, when the reading goes above the full-scale measurement value of the lower range, the higher-range operation shall be started automatically. The CEMS recorder range must include zero and a high-level value. Under applications of consistent low emissions, a single-range analyzer is allowed provided normal and spike emissions can be quantified. In this case, set an appropriate high-level value to include all emissions.
6.1.2 For the low-range scale of dual-range units, the high-level value shall be between 1.5 times the pollutant concentration corresponding to the emission standard level and the span value. For the high-range scale, the high-level value shall be set at 2000 ppm, as a minimum, and the range shall include the level of the span value. There shall be no concentration gap between the low-and high-range scales.
Same as section 7.0 of PS 2.
8.1 Relative Accuracy Test Procedure. Sampling Strategy for reference method (RM) Tests, Number of RM Tests, and Correlation of RM and CEMS Data are the same as PS 2, sections 8.4.3, 8.4.4, and 8.4.5, respectively.
8.2 Reference Methods. Unless otherwise specified in an applicable subpart of the regulation, Methods 10, 10A, 10B, or other approved alternative is the RM for this PS. When evaluating nondispersive infrared CEMS using Method 10 as the RM, the alternative interference trap specified in section 16.0 of Method 10 shall be used.
8.3 Response Time Test Procedure. The response time test applies to all types of CEMS, but will generally have significance only for extractive systems. The entire system is checked with this procedure including applicable sample extraction and transport, sample conditioning, gas analyses, and data recording.
8.3.1 Introduce zero gas into the system. When the system output has stabilized (no change greater than 1 percent of full scale for 30 sec), introduce an upscale calibration gas and wait for a stable value. Record the time (upscale response time) required to reach 95 percent of the final stable value. Next, reintroduce the zero gas and wait for a stable reading before recording the response time (downscale response time). Repeat the entire procedure until you have three sets of data to determine the mean upscale and downscale response times. The slower or longer of the two means is the system response time.
8.4 Interference Check. The CEMS must be shown to be free from the effects of any interferences.
Sample collection and analysis are concurrent for this performance specification (see section 8.0). Refer to the RM for specific analytical procedures.
13.1 Calibration Drift. The CEMS calibration must not drift or deviate from the reference value of the calibration gas, gas cell, or optical filter by more than 5 percent of the established span value for 6 out of 7 test days.
13.2 Relative Accuracy. The RA of the CEMS must be no greater than 10 percent when the average RM value is used to calculate RA, 5 percent when the applicable emission standard is used to calculate RA, or within 5 ppmv when the RA is calculated as the absolute average difference between the RM and CEMS plus the 2.5 percent confidence coefficient.
13.3 Response Time. The CEMS response time shall not exceed 240 seconds to achieve 95 percent of the final stable value.
16.1 Under conditions where the average CO emissions are less than 10 percent of the standard and this is verified by Method 10, a cylinder gas audit may be performed in place of the RA test to determine compliance with these limits. In this case, the cylinder gas shall contain CO in 12 percent carbon dioxide as an interference check. If this option is exercised, Method 10 must be used to verify that emission levels are less than 10 percent of the standard.
Same as section 17 of PS 4.
Same as section 18.0 of PS 2.
1.1 Applicability. a. This specification is to be used for evaluating the acceptability of carbon monoxide (CO) and oxygen (O
b. This specification is not designed to evaluate the installed CEMS’ performance over an extended period of time nor does it identify specific calibration techniques and auxiliary procedures to assess the CEMS’ performance. The source owner or operator, however, is responsible to properly calibrate, maintain, and operate the CEMS. To evaluate the CEMS’ performance, the Administrator may require, under section 114 of the Act, the operator to conduct CEMS performance evaluations at times other than the initial test.
c. The definitions, installation and measurement location specifications, test procedures, data reduction procedures, reporting requirements, and bibliography are the same as in PS 3 (for O
1.2 Principle. Installation and measurement location specifications, performance specifications, test procedures, and data reduction procedures are included in this specification. Reference method tests, calibration error tests, calibration drift tests, and interferant tests are conducted to determine conformance of the CEMS with the specification.
2.1 Continuous Emission Monitoring System (CEMS). This definition is the same as PS 2 section 2.1 with the following addition. A continuous monitor is one in which the sample to be analyzed passes the measurement section of the analyzer without interruption.
2.2 Response Time. The time interval between the start of a step change in the system input and when the pollutant analyzer output reaches 95 percent of the final value.
2.3 Calibration Error (CE). The difference between the concentration indicated by the CEMS and the known concentration generated by a calibration source when the entire CEMS, including the sampling interface is challenged. A CE test procedure is performed to document the accuracy and linearity of the CEMS over the entire measurement range.
3.1 The CEMS Installation and Measurement Location. This specification is the same as PS 2 section 3.1 with the following additions. Both the CO and O
3.1.1 Measurement Location. Same as PS 2 section 3.1.1.
3.1.2 Point CEMS. The measurement point should be within or centrally located over the centroidal area of the stack or duct cross section.
3.1.3 Path CEMS. The effective measurement path should: (1) Have at least 70 percent of the path within the inner 50 percent of the stack or duct cross sectional area, or (2) be centrally located over any part of the centroidal area.
3.2 Reference Method (RM) Measurement Location and Traverse Points. This specification is the same as PS 2 section 3.2 with the following additions. When pollutant concentration changes are due solely to diluent leakage and CO and O
3.3 Stratification Test Procedure. Stratification is defined as the difference in excess of 10 percent between the average concentration in the duct or stack and the concentration at any point more than 1.0 meter from the duct or stack wall. To determine whether effluent stratification exists, a dual probe system should be used to determine the average effluent concentration while measurements at each traverse point are being made. One probe, located at the stack or duct centroid, is used as a stationary reference point to indicate change in the effluent concentration over time. The second probe is used for sampling at the traverse points specified in Method 1 (40 CFR part 60 appendix A). The monitoring system samples sequentially at the reference and traverse points throughout the testing period for five minutes at each point.
4.1 Data Recorder Scale. For O
4.2 Calibration Drift. For O
4.3 Relative Accuracy (RA). For O
4.4 Calibration Error (CE). The mean difference between the CEMS and reference values at all three test points (see Table I) must be no greater than 5 percent of span value for CO monitors and 0.5 percent for O
4.5 Response Time. The response time for the CO or O
5.1 Calibration Error Test and Response Time Test Periods. Conduct the CE and response time tests during the CD test period.
The response time test procedure is given in PS 4A, and must be carried out for both the CO and O
7. Relative Accuracy and Calibration Error Test Procedures
7.1 Calibration Error Test Procedure. Challenge each monitor (both low and high range CO and O
Table I. Calibration Error Concentration Ranges
| Measurement point | CO Low range (ppm) | CO High range (ppm) | O |
|---|---|---|---|
| 1 | 0-40 | 0-600 | 0-2 |
| 2 | 60-80 | 900-1200 | 8-10 |
| 3 | 140-160 | 2100-2400 | 14-16 |
7.1.1 Calculations. Summarize the results on a data sheet. Average the differences between the instrument response and the certified cylinder gas value for each gas. Calculate the CE results for the CO monitor according to:
7.2 Relative Accuracy Test Procedure. Follow the RA test procedures in PS 3 (for O
7.3 Alternative RA Procedure. Under some operating conditions, it may not be possible to obtain meaningful results using the RA test procedure. This includes conditions where consistent, very low CO emission or low CO emissions interrupted periodically by short duration, high level spikes are observed. It may be appropriate in these circumstances to waive the RA test and substitute the following procedure.
Conduct a complete CEMS status check following the manufacturer’s written instructions. The check should include operation of the light source, signal receiver, timing mechanism functions, data acquisition and data reduction functions, data recorders, mechanically operated functions, sample filters, sample line heaters, moisture traps, and other related functions of the CEMS, as applicable. All parts of the CEMS must be functioning properly before the RA requirement can be waived. The instrument must also successfully passed the CE and CD specifications. Substitution of the alternate procedure requires approval of the Regional Administrator.
8. Bibliography
1. 40 CFR Part 266, Appendix IX, section 2, “Performance Specifications for Continuous Emission Monitoring Systems.”
1.1 Analytes.
| Analyte | CAS No. |
|---|---|
| Total Reduced Sulfur (TRS) | NA |
1.2 Applicability. This specification is for evaluating the applicability of TRS continuous emission monitoring systems (CEMS) at the time of installation or soon after and whenever specified in an applicable subpart of the regulations. The CEMS may include oxygen monitors which are subject to Performance Specification 3 (PS 3).
1.3 The definitions, performance specification, test procedures, calculations and data analysis procedures for determining calibration drifts (CD) and relative accuracy (RA) of PS 2, sections 3.0, 8.0, and 12.0, respectively, apply to this specification.
The CD and RA tests are conducted to determine conformance of the CEMS to the specification.
Same as in section 3.0 of PS 2.
This performance specification may involve hazardous materials, operations, and equipment. This performance specification may not address all of the safety problems associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and determine the applicable regulatory limitations prior to performing this performance specification. The CEMS user’s manual should be consulted for specific precautions to be taken with regard to the analytical procedures.
Same as section 6.0 of PS 2.
Same as section 7.0 of PS 2.
8.1 Relative Accuracy Test Procedure. Sampling Strategy for reference method (RM) Tests, Number of RM Tests, and Correlation of RM and CEMS Data are the same as PS 2, sections 8.4.3, 8.4.4, and 8.4.5, respectively.
For Method 16, a sample is made up of at least three separate injects equally spaced over time. For Method 16A, a sample is collected for at least 1 hour. For Method 16B, you must analyze a minimum of three aliquots spaced evenly over the test period.
8.2 Reference Methods. Unless otherwise specified in the applicable subpart of the regulations, Method 16, Method 16A, 16B or other approved alternative is the RM for TRS.
Sample collection and analysis are concurrent for this performance specification (see section 8.0). Refer to the reference method for specific analytical procedures.
Same as section 12.0 of PS 2.
13.1 Calibration Drift. The CEMS detector calibration must not drift or deviate from the reference value of the calibration gas by more than 5 percent of the established span value for 6 out of 7 test days. This corresponds to 1.5 ppm drift for Subpart BB sources where the span value is 30 ppm. If the CEMS includes pollutant and diluent monitors, the CD must be determined separately for each in terms of concentrations (see PS 3 for the diluent specifications).
13.2 Relative Accuracy. The RA of the CEMS must be no greater than 20 percent when the average RM value is used to calculate RA or 10 percent when the applicable emission standard is used to calculate RA.
1. Department of Commerce. Experimental Statistics, National Bureau of Standards, Handbook 91. 1963. Paragraphs 3-3.1.4, p. 3-31.
2. A Guide to the Design, Maintenance and Operation of TRS Monitoring Systems. National Council for Air and Stream Improvement Technical Bulletin No. 89. September 1977.
3. Observation of Field Performance of TRS Monitors on a Kraft Recovery Furnace. National Council for Air and Stream Improvement Technical Bulletin No. 91. January 1978.
Same as section 18.0 of PS 2.
1.1 Applicability. This specification is used for evaluating the acceptability of continuous emission rate monitoring systems (CERMSs).
1.2 The installation and measurement location specifications, performance specification test procedure, calculations, and data analysis procedures, of Performance Specifications (PS 2), sections 8.0 and 12, respectively, apply to this specification.
The calibration drift (CD) and relative accuracy (RA) tests are conducted to determine conformance of the CERMS to the specification.
The definitions are the same as in section 3 of PS 2, except this specification refers to the continuous emission rate monitoring system rather than the continuous emission monitoring system. The following definitions are added:
3.1 Continuous Emission Rate Monitoring System (CERMS). The total equipment required for the determining and recording the pollutant mass emission rate (in terms of mass per unit of time).
3.2 Flow Rate Sensor. That portion of the CERMS that senses the volumetric flow rate and generates an output proportional to that flow rate. The flow rate sensor shall have provisions to check the CD for each flow rate parameter that it measures individually (e.g., velocity, pressure).
This performance specification may involve hazardous materials, operations, and equipment. This performance specification may not address all of the safety problems associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and determine the applicable regulatory limitations prior to performing this performance specification. The CERMS users manual should be consulted for specific precautions to be taken with regard to the analytical procedures.
Same as section 6.0 of PS 2.
Same as section 7.0 of PS 2.
8.1 Calibration Drift Test Procedure.
8.1.1 The CD measurements are to verify the ability of the CERMS to conform to the established CERMS calibrations used for determining the emission rate. Therefore, if periodic automatic or manual adjustments are made to the CERMS zero and calibration settings, conduct the CD tests immediately before these adjustments, or conduct them in such a way that CD can be determined.
8.1.2 Conduct the CD tests for pollutant concentration at the two values specified in section 6.1.2 of PS 2. For other parameters that are selectively measured by the CERMS (e.g., velocity, pressure, flow rate), use two analogous values (e.g., Low: 0-20% of full scale, High: 50-100% of full scale). Introduce to the CERMS the reference signals (these need not be certified). Record the CERMS response to each and subtract this value from the respective reference value (see example data sheet in Figure 6-1).
8.2 Relative Accuracy Test Procedure.
8.2.1 Sampling Strategy for reference method (RM) Tests, Correlation of RM and CERMS Data, and Number of RM Tests are the same as PS 2, sections 8.4.3, 8.4.5, and 8.4.4, respectively. Summarize the results on a data sheet. An example is shown in Figure 6-1. The RA test may be conducted during the CD test period.
8.2.2 Reference Methods. Unless otherwise specified in the applicable subpart of the regulations, the RM for the pollutant gas is the Appendix A method that is cited for compliance test purposes, or its approved alternatives. Methods 2, 2A, 2B, 2C, or 2D, as applicable, are the RMs for the determination of volumetric flow rate.
Same as section 11.0 of PS 2.
Same as section 12.0 of PS 2.
13.1 Calibration Drift. Since the CERMS includes analyzers for several measurements, the CD shall be determined separately for each analyzer in terms of its specific measurement. The calibration for each analyzer associated with the measurement of flow rate shall not drift or deviate from each reference value of flow rate by more than 3 percent of the respective high-level reference value over the CD test period (e.g., seven-day) associated with the pollutant analyzer. The CD specification for each analyzer for which other PSs have been established (e.g., PS 2 for SO
13.2 CERMS Relative Accuracy. Calculate the CERMS Relative Accuracy using Eq. 2-6 of section 12 of Performance Specification 2. The RA of the CERMS shall be no greater than 20 percent of the mean value of the RM’s test data in terms of the units of the emission standard, or in cases where the average emissions for the test are less than 50 percent of the applicable standard, substitute the emission standard value in the denominator of Eq. 2-6 in place of the RM.
Same as in section 16.0 of PS 2.
1. Brooks, E.F., E.C. Beder, C.A. Flegal, D.J. Luciani, and R. Williams. Continuous Measurement of Total Gas Flow Rate from Stationary Sources. U.S. Environmental Protection Agency. Research Triangle Park, North Carolina. Publication No. EPA-650/2-75-020. February 1975. 248 p.
| Run No. | Date and time | Emission rate (kg/hr) a | ||
|---|---|---|---|---|
| CERMS | RMs | Difference (RMs-CERMS) | ||
| 1 | ||||
| 2 | ||||
| 3 | ||||
| 4 | ||||
| 5 | ||||
| 6 | ||||
| 7 | ||||
| 8 | ||||
| 9 | ||||
a The RMs and CERMS data as corrected to a consistent basis (
1.1 Analytes.
| Analyte | CAS No. |
|---|---|
| Hydrogen Sulfide | 7783-06-4 |
1.2 Applicability.
1.2.1 This specification is to be used for evaluating the acceptability of hydrogen sulfide (H
1.2.2 This specification is not designed to evaluate the installed CEMS performance over an extended period of time nor does it identify specific calibration techniques and other auxiliary procedures to assess CEMS performance. The source owner or operator, however, is responsible to calibrate, maintain, and operate the CEMS. To evaluate CEMS performance, the Administrator may require, under section 114 of the Act, the source owner or operator to conduct CEMS performance evaluations at other times besides the initial test. See section 60.13(c).
Calibration drift (CD) and relative accuracy (RA) tests are conducted to determine that the CEMS conforms to the specification.
Same as section 3.0 of PS 2.
The procedures required under this performance specification may involve hazardous materials, operations, and equipment. This performance specification may not address all of the safety problems associated with these procedures. It is the responsibility of the user to establish appropriate safety problems associated with these procedures. It is the responsibility of the user to establish appropriate safety and health practices and determine the application regulatory limitations prior to performing these procedures. The CEMS user’s manual and materials recommended by the reference method should be consulted for specific precautions to be taken.
6.1 Instrument Zero and Span. This specification is the same as section 6.1 of PS 2.
6.2 Calibration Drift. The CEMS calibration must not drift or deviate from the reference value of the calibration gas or reference source by more than 5 percent of the established span value for 6 out of 7 test days (e.g., the established span value is 300 ppm for Subpart J fuel gas combustion devices).
6.3 Relative Accuracy. The RA of the CEMS must be no greater than 20 percent when the average reference method (RM) value is used to calculate RA or 10 percent when the applicable emission standard is used to calculate RA.
Same as section 7.0 of PS 2.
8.1 Installation and Measurement Location Specification. Same as section 8.1 of PS 2.
8.2 Pretest Preparation. Same as section 8.2 of PS 2.
8.3 Calibration Drift Test Procedure. Same as section 8.3 of PS 2.
8.4 Relative Accuracy Test Procedure.
8.4.1 Sampling Strategy for RM Tests, Number of RM Tests, Correlation of RM and CEMS Data, and Calculations. These are the same as that in PS-2, Sections 8.4.3 (except as specified below), 8.4.4, 8.4.5, and 8.4.6, respectively.
8.4.2 Reference Methods. Unless otherwise specified in an applicable subpart of the regulation, Methods 11, 15, and 16 may be used for the RM for this PS.
8.4.2.1 Sampling Time Per Run – Method 11. A sampling run, when Method 11 (integrated sampling) is used, shall consist of a single measurement for at least 10 minutes and 0.010 dscm (0.35 dscf). Each sample shall be taken at approximately 30-minute intervals.
8.4.2.2 Sampling Time Per Run – Methods 15 and 16. The sampling run shall consist of two injections equally spaced over a 30-minute period following the procedures described in the particular method.
8.5 Reporting. Same as section 8.5 of PS 2.
Sample Collection and analysis are concurrent for this PS (see section 8.0). Refer to the RM for specific analytical procedures.
Same as section 12.0 of PS 2.
1. U.S. Environmental Protection Agency. Standards of Performance for New Stationary Sources; Appendix B; Performance Specifications 2 and 3 for SO
2. U.S. Government Printing Office. Gaseous Continuous Emission Monitoring Systems – Performance Specification Guidelines for SO
3. Maines, G.D., W.C. Kelly (Scott Environmental Technology, Inc.), and J.B. Homolya. Evaluation of Monitors for Measuring H
4. Ferguson, B.B., R.E. Lester (Harmon Engineering and Testing), and W.J. Mitchell. Field Evaluation of Carbon Monoxide and Hydrogen Sulfide Continuous Emission Monitors at an Oil Refinery. Prepared for the U.S. Environmental Protection Agency. Research Triangle Park, N.C. Publication No. EPA-600/4-82-054. August 1982. 100 p.
5. Letter to RAMCON Environmental Corp. from Robert Kellam, December 27, 1992.
Same as section 18.0 of PS 2.
1.1 Analytes. Volatile Organic Compounds (VOCs).
1.2 Applicability.
1.2.1 This specification is to be used for evaluating a continuous emission monitoring system (CEMS) that measures a mixture of VOC’s and generates a single combined response value. The VOC detection principle may be flame ionization (FI), photoionization (PI), non-dispersive infrared absorption (NDIR), or any other detection principle that is appropriate for the VOC species present in the emission gases and that meets this performance specification. The performance specification includes procedures to evaluate the acceptability of the CEMS at the time of or soon after its installation and whenever specified in emission regulations or permits. This specification is not designed to evaluate the installed CEMS performance over an extended period of time, nor does it identify specific calibration techniques and other auxiliary procedures to assess the CEMS performance. The source owner or operator, however, is responsible to calibrate, maintain, and operate the CEMS properly. To evaluate the CEMS performance, the Administrator may require, under section 114 of the Act, the operator to conduct CEMS performance evaluations in addition to the initial test. See section 60.13(c).
1.2.2 In most emission circumstances, most VOC monitors can provide only a relative measure of the total mass or volume concentration of a mixture of organic gases, rather than an accurate quantification. This problem is removed when an emission standard is based on a total VOC measurement as obtained with a particular detection principle. In those situations where a true mass or volume VOC concentration is needed, the problem can be mitigated by using the VOC CEMS as a relative indicator of total VOC concentration if statistical analysis indicates that a sufficient margin of compliance exists for this approach to be acceptable. Otherwise, consideration can be given to calibrating the CEMS with a mixture of the same VOC’s in the same proportions as they actually occur in the measured source. In those circumstances where only one organic species is present in the source, or where equal incremental amounts of each of the organic species present generate equal CEMS responses, the latter choice can be more easily achieved.
2.1 Calibration drift and relative accuracy tests are conducted to determine adherence of the CEMS with specifications given for those items. The performance specifications include criteria for installation and measurement location, equipment and performance, and procedures for testing and data reduction.
Same as section 3.0 of PS 2.
The procedures required under this performance specification may involve hazardous materials, operations, and equipment. This performance specification may not address all of the safety problems associated with these procedures. It is the responsibility of the user to establish appropriate safety problems associated with these procedures. It is the responsibility of the user to establish appropriate safety and health practices and determine the application regulatory limitations prior to performing these procedures. The CEMS user’s manual and materials recommended by the reference method should be consulted for specific precautions to be taken.
6.1 VOC CEMS Selection. When possible, select a VOC CEMS with the detection principle of the reference method specified in the regulation or permit (usually either FI, NDIR, or PI). Otherwise, use knowledge of the source process chemistry, previous emission studies, or gas chromatographic analysis of the source gas to select an appropriate VOC CEMS. Exercise extreme caution in choosing and installing any CEMS in an area with explosive hazard potential.
6.2 Data Recorder Scale. Same as section 6.1 of PS 2.
8.1 Installation and Measurement Location Specifications. Same as section 8.1 of PS 2.
8.2 Pretest Preparation. Same as section 8.2 of PS 2.
8.3 Calibration Drift Test Procedure. Same as section 8.3 of PS 2.
8.4 Reference Method (RM). Use the method specified in the applicable regulation or permit, or any approved alternative, as the RM.
8.5 Sampling Strategy for RM Tests, Correlation of RM and CEMS Data, and Number of RM Tests. Follow PS 2, sections 8.4.3, 8.4.5, and 8.4.4, respectively.
8.6 Reporting. Same as section 8.5 of PS 2.
Sample collection and analysis are concurrent for this PS (see section 8.0). Refer to the RM for specific analytical procedures.
Same as section 12.0 of PS 2.
13.1 Calibration Drift. The CEMS calibration must not drift by more than 2.5 percent of the span value.
13.2 CEMS Relative Accuracy. Unless stated otherwise in the regulation or permit, the RA of the CEMS must not be greater than 20 percent of the mean value of the RM test data in terms of the units of the emission standard, or 10 percent of the applicable standard, whichever is greater.
Same as section 17.0 of PS 2.
1.1 Applicability. These performance specifications apply to hydrocarbon (HC) continuous emission monitoring systems (CEMS) installed on stationary sources. The specifications include procedures which are intended to be used to evaluate the acceptability of the CEMS at the time of its installation or whenever specified in regulations or permits. The procedures are not designed to evaluate CEMS performance over an extended period of time. The source owner or operator is responsible for the proper calibration, maintenance, and operation of the CEMS at all times.
1.2 Principle. A gas sample is extracted from the source through a heated sample line and heated filter to a flame ionization detector (FID). Results are reported as volume concentration equivalents of propane. Installation and measurement location specifications, performance and equipment specifications, test and data reduction procedures, and brief quality assurance guidelines are included in the specifications. Calibration drift, calibration error, and response time tests are conducted to determine conformance of the CEMS with the specifications.
2.1 Continuous Emission Monitoring System (CEMS). The total equipment used to acquire data, which includes sample extraction and transport hardware, analyzer, data recording and processing hardware, and software. The system consists of the following major subsystems:
2.1.1 Sample Interface. That portion of the system that is used for one or more of the following: Sample acquisition, sample transportation, sample conditioning, or protection of the analyzer from the effects of the stack effluent.
2.1.2 Organic Analyzer. That portion of the system that senses organic concentration and generates an output proportional to the gas concentration.
2.1.3 Data Recorder. That portion of the system that records a permanent record of the measurement values. The data recorder may include automatic data reduction capabilities.
2.2 Instrument Measurement Range. The difference between the minimum and maximum concentration that can be measured by a specific instrument. The minimum is often stated or assumed to be zero and the range expressed only as the maximum.
2.3 Span or Span Value. Full scale instrument measurement range. The span value must be documented by the CEMS manufacturer with laboratory data.
2.4 Calibration Gas. A known concentration of a gas in an appropriate diluent gas.
2.5 Calibration Drift (CD). The difference in the CEMS output readings from the established reference value after a stated period of operation during which no unscheduled maintenance, repair, or adjustment takes place. A CD test is performed to demonstrate the stability of the CEMS calibration over time.
2.6 Response Time. The time interval between the start of a step change in the system input (e.g., change of calibration gas) and the time when the data recorder displays 95 percent of the final value.
2.7 Accuracy. A measurement of agreement between a measured value and an accepted or true value, expressed as the percentage difference between the true and measured values relative to the true value. For these performance specifications, accuracy is checked by conducting a calibration error (CE) test.
2.8 Calibration Error (CE). The difference between the concentration indicated by the CEMS and the known concentration of the cylinder gas. A CE test procedure is performed to document the accuracy and linearity of the monitoring equipment over the entire measurement range.
2.9 Performance Specification Test (PST) Period. The period during which CD, CE, and response time tests are conducted.
2.10 Centroidal Area. A concentric area that is geometrically similar to the stack or duct cross section and is no greater than 1 percent of the stack or duct cross-sectional area.
3.1 CEMS Installation and Measurement Locations. The CEMS must be installed in a location in which measurements representative of the source’s emissions can be obtained. The optimum location of the sample interface for the CEMS is determined by a number of factors, including ease of access for calibration and maintenance, the degree to which sample conditioning will be required, the degree to which it represents total emissions, and the degree to which it represents the combustion situation in the firebox (where applicable). The location should be as free from in-leakage influences as possible and reasonably free from severe flow disturbances. The sample location should be at least two equivalent duct diameters downstream from the nearest control device, point of pollutant generation, or other point at which a change in the pollutant concentration or emission rate occurs and at least 0.5 diameter upstream from the exhaust or control device. The equivalent duct diameter is calculated as per 40 CFR part 60, appendix A, method 1, section 2.1. If these criteria are not achievable or if the location is otherwise less than optimum, the possibility of stratification should be investigated as described in section 3.2. The measurement point must be within the centroidal area of the stack or duct cross section.
3.2 Stratification Test Procedure. Stratification is defined as a difference in excess of 10 percent between the average concentration in the duct or stack and the concentration at any point more than 1.0 meter from the duct or stack wall. To determine whether effluent stratification exists, a dual probe system should be used to determine the average effluent concentration while measurements at each traverse point are being made. One probe, located at the stack or duct centroid, is used as a stationary reference point to indicate the change in effluent concentration over time. The second probe is used for sampling at the traverse points specified in 40 CFR part 60 appendix A, method 1. The monitoring system samples sequentially at the reference and traverse points throughout the testing period for five minutes at each point.
If this method is applied in highly explosive areas, caution and care must be exercised in choice of equipment and installation.
4.1 Flame Ionization Detector (FID) Analyzer. A heated FID analyzer capable of meeting or exceeding the requirements of these specifications. Heated systems must maintain the temperature of the sample gas between 150 °C (300 °F) and 175 °C (350 °F) throughout the system. This requires all system components such as the probe, calibration valve, filter, sample lines, pump, and the FID to be kept heated at all times such that no moisture is condensed out of the system. The essential components of the measurement system are described below:
4.1.1 Sample Probe. Stainless steel, or equivalent, to collect a gas sample from the centroidal area of the stack cross-section.
4.1.2 Sample Line. Stainless steel or Teflon tubing to transport the sample to the analyzer.
Mention of trade names or specific products does not constitute endorsement by the Environmental Protection Agency.
4.1.3 Calibration Valve Assembly. A heated three-way valve assembly to direct the zero and calibration gases to the analyzer is recommended. Other methods, such as quick-connect lines, to route calibration gas to the analyzers are applicable.
4.1.4 Particulate Filter. An in-stack or out-of-stack sintered stainless steel filter is recommended if exhaust gas particulate loading is significant. An out-of-stack filter must be heated.
4.1.5 Fuel. The fuel specified by the manufacturer (e.g., 40 percent hydrogen/60 percent helium, 40 percent hydrogen/60 percent nitrogen gas mixtures, or pure hydrogen) should be used.
4.1.6 Zero Gas. High purity air with less than 0.1 parts per million by volume (ppm) HC as methane or carbon equivalent or less than 0.1 percent of the span value, whichever is greater.
4.1.7 Calibration Gases. Appropriate concentrations of propane gas (in air or nitrogen). Preparation of the calibration gases should be done according to the procedures in EPA Protocol 1. In addition, the manufacturer of the cylinder gas should provide a recommended shelf life for each calibration gas cylinder over which the concentration does not change by more than ±2 percent from the certified value.
4.2 CEMS Span Value. 100 ppm propane. The span value must be documented by the CEMS manufacturer with laboratory data.
4.3 Daily Calibration Gas Values. The owner or operator must choose calibration gas concentrations that include zero and high-level calibration values.
4.3.1 The zero level may be between zero and 0.1 ppm (zero and 0.1 percent of the span value).
4.3.2 The high-level concentration must be between 50 and 90 ppm (50 and 90 percent of the span value).
4.4 Data Recorder Scale. The strip chart recorder, computer, or digital recorder must be capable of recording all readings within the CEMS’ measurement range and must have a resolution of 0.5 ppm (0.5 percent of span value).
4.5 Response Time. The response time for the CEMS must not exceed 2 minutes to achieve 95 percent of the final stable value.
4.6 Calibration Drift. The CEMS must allow the determination of CD at the zero and high-level values. The CEMS calibration response must not differ by more than ±3 ppm (±3 percent of the span value) after each 24-hour period of the 7-day test at both zero and high levels.
4.7 Calibration Error. The mean difference between the CEMS and reference values at all three test points listed below must be no greater than 5 ppm (±5 percent of the span value).
4.7.1 Zero Level. Zero to 0.1 ppm (0 to 0.1 percent of span value).
4.7.2 Mid-Level. 30 to 40 ppm (30 to 40 percent of span value).
4.7.3 High-Level. 70 to 80 ppm (70 to 80 percent of span value).
4.8 Measurement and Recording Frequency. The sample to be analyzed must pass through the measurement section of the analyzer without interruption. The detector must measure the sample concentration at least once every 15 seconds. An average emission rate must be computed and recorded at least once every 60 seconds.
4.9 Hourly Rolling Average Calculation. The CEMS must calculate every minute an hourly rolling average, which is the arithmetic mean of the 60 most recent 1-minute average values.
4.10 Retest. If the CEMS produces results within the specified criteria, the test is successful. If the CEMS does not meet one or more of the criteria, necessary corrections must be made and the performance tests repeated.
5.1 Pretest Preparation Period. Install the CEMS, prepare the PTM test site according to the specifications in section 3, and prepare the CEMS for operation and calibration according to the manufacturer’s written instructions. A pretest conditioning period similar to that of the 7-day CD test is recommended to verify the operational status of the CEMS.
5.2 Calibration Drift Test Period. While the facility is operating under normal conditions, determine the magnitude of the CD at 24-hour intervals for seven consecutive days according to the procedure given in section 6.1. All CD determinations must be made following a 24-hour period during which no unscheduled maintenance, repair, or adjustment takes place. If the combustion unit is taken out of service during the test period, record the onset and duration of the downtime and continue the CD test when the unit resumes operation.
5.3 Calibration Error Test and Response Time Test Periods. Conduct the CE and response time tests during the CD test period.
6.1 Relative Accuracy Test Audit (RATA) and Absolute Calibration Audits (ACA). The test procedures described in this section are in lieu of a RATA and ACA.
6.2 Calibration Drift Test.
6.2.1 Sampling Strategy. Conduct the CD test at 24-hour intervals for seven consecutive days using calibration gases at the two daily concentration levels specified in section 4.3. Introduce the two calibration gases into the sampling system as close to the sampling probe outlet as practical. The gas must pass through all CEM components used during normal sampling. If periodic automatic or manual adjustments are made to the CEMS zero and calibration settings, conduct the CD test immediately before these adjustments, or conduct it in such a way that the CD can be determined. Record the CEMS response and subtract this value from the reference (calibration gas) value. To meet the specification, none of the differences may exceed 3 percent of the span of the CEM.
6.2.2 Calculations. Summarize the results on a data sheet. An example is shown in Figure 1. Calculate the differences between the CEMS responses and the reference values.
6.3 Response Time. The entire system including sample extraction and transport, sample conditioning, gas analyses, and the data recording is checked with this procedure.
6.3.1 Introduce the calibration gases at the probe as near to the sample location as possible. Introduce the zero gas into the system. When the system output has stabilized (no change greater than 1 percent of full scale for 30 sec), switch to monitor stack effluent and wait for a stable value. Record the time (upscale response time) required to reach 95 percent of the final stable value.
6.3.2 Next, introduce a high-level calibration gas and repeat the above procedure. Repeat the entire procedure three times and determine the mean upscale and downscale response times. The longer of the two means is the system response time.
6.4 Calibration Error Test Procedure.
6.4.1 Sampling Strategy. Challenge the CEMS with zero gas and EPA Protocol 1 cylinder gases at measurement points within the ranges specified in section 4.7.
6.4.1.1 The daily calibration gases, if Protocol 1, may be used for this test.
6.4.1.2 Operate the CEMS as nearly as possible in its normal sampling mode. The calibration gas should be injected into the sampling system as close to the sampling probe outlet as practical and must pass through all filters, scrubbers, conditioners, and other monitor components used during normal sampling. Challenge the CEMS three non-consecutive times at each measurement point and record the responses. The duration of each gas injection should be for a sufficient period of time to ensure that the CEMS surfaces are conditioned.
6.4.2 Calculations. Summarize the results on a data sheet. An example data sheet is shown in Figure 2. Average the differences between the instrument response and the certified cylinder gas value for each gas. Calculate three CE results according to Equation 1. No confidence coefficient is used in CE calculations.
Calibration Error. Calculate CE using Equation 1.
At a minimum, summarize in tabular form the results of the CD, response time, and CE test, as appropriate. Include all data sheets, calculations, CEMS data records, and cylinder gas or reference material certifications.
1. Measurement of Volatile Organic Compounds-Guideline Series. U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, 27711, EPA-450/2-78-041, June 1978.
2. Traceability Protocol for Establishing True Concentrations of Gases Used for Calibration and Audits of Continuous Source Emission Monitors (Protocol No. 1). U.S. Environmental Protection Agency ORD/EMSL, Research Triangle Park, North Carolina, 27711, June 1978.
3. Gasoline Vapor Emission Laboratory Evaluation-Part 2. U.S. Environmental Protection Agency, OAQPS, Research Triangle Park, North Carolina, 27711, EMB Report No. 76-GAS-6, August 1975.
1.1 Applicability. These requirements apply to continuous emission monitoring systems (CEMSs) that use gas chromatography (GC) to measure gaseous organic compound emissions. The requirements include procedures intended to evaluate the acceptability of the CEMS at the time of its installation and whenever specified in regulations or permits. Quality assurance procedures for calibrating, maintaining, and operating the CEMS properly at all times are also given in this procedure.
2.1 Calibration precision, calibration error, and performance audit tests are conducted to determine conformance of the CEMS with these specifications. Daily calibration and maintenance requirements are also specified.
3.1 Gas Chromatograph (GC). That portion of the system that separates and detects organic analytes and generates an output proportional to the gas concentration. The GC must be temperature controlled.
The term temperature controlled refers to the ability to maintain a certain temperature around the column. Temperature-programmable GC is not required for this performance specification, as long as all other requirements for precision, linearity and accuracy listed in this performance specification are met. It should be noted that temperature programming a GC will speed up peak elution, thus allowing increased sampling frequency.
3.1.1 Column. Analytical column capable of separating the analytes of interest.
3.1.2 Detector. A detection system capable of detecting and quantifying all analytes of interest.
3.1.3 Integrator. That portion of the system that quantifies the area under a particular sample peak generated by the GC.
3.1.4 Data Recorder. A strip chart recorder, computer, or digital recorder capable of recording all readings within the instrument’s calibration range.
3.2 Calibration Precision. The error between triplicate injections of each calibration standard.
The procedures required under this performance specification may involve hazardous materials, operations, and equipment. This performance specification does not purport to address all of the safety problems associated with these procedures. It is the responsibility of the user to establish appropriate safety problems associated with these procedures. It is the responsibility of the user to establish appropriate safety and health practices and determine the application regulatory limitations prior to performing these procedures. The CEMS user’s manual and materials recommended by the reference method should be consulted for specific precautions to be taken.
6.1 Presurvey Sample Analysis and GC Selection. Determine the pollutants to be monitored from the applicable regulation or permit and determine the approximate concentration of each pollutant (this information can be based on past compliance test results). Select an appropriate GC configuration to measure the organic compounds. The GC components should include a heated sample injection loop (or other sample introduction systems), separatory column, temperature-controlled oven, and detector. If the source chooses dual column and/or dual detector configurations, each column/detector is considered a separate instrument for the purpose of this performance specification and thus the procedures in this performance specification shall be carried out on each system. If this method is applied in highly explosive areas, caution should be exercised in selecting the equipment and method of installation.
6.2 Sampling System. The sampling system shall be heat traced and maintained at a minimum of 120 °C with no cold spots. All system components shall be heated, including the probe, calibration valve, sample lines, sampling loop (or sample introduction system), GC oven, and the detector block (when appropriate for the type of detector being utilized, e.g., flame ionization detector).
7.1 Calibration Gases. Obtain three concentrations of calibration gases certified by the manufacturer to be accurate to within 2 percent of the value on the label. A gas dilution system may be used to prepare the calibration gases from a high concentration certified standard if the gas dilution system meets the requirements specified in Test Method 205, 40 CFR Part 51, Appendix M. The performance test specified in Test Method 205 shall be repeated quarterly, and the results of the Method 205 test shall be included in the report. The calibration gas concentration of each target analyte shall be as follows (measured concentration is based on the presurvey concentration determined in section 6.1).
If the low level calibration gas concentration falls at or below the limit of detection for the instrument for any target pollutant, a calibration gas with a concentration at 4 to 5 times the limit of detection for the instrument may be substituted for the low-level calibration gas listed in section 7.1.1.
7.1.1 Low-level. 40-60 percent of measured concentration.
7.1.2 Mid-level. 90-110 percent of measured concentration.
7.1.3 High-level. 140-160 percent of measured concentration, or select highest expected concentration.
7.2 Performance Audit Gas. Performance Audit Gas is an independent cylinder gas or cylinder gas mixture. A certified EPA audit gas shall be used, when possible. A gas mixture containing all the target compounds within the calibration range and certified by EPA’s Traceability Protocol for Assay and Certification of Gaseous Calibration Standards may be used when EPA performance audit materials are not available. If a certified EPA audit gas or a traceability protocol gas is not available, use a gas manufacturer standard accurate to 2 percent.
8.1 Installation and Measurement Location Specifications. Install the CEMs in a location where the measurements are representative of the source emissions. Consider other factors, such as ease of access for calibration and maintenance purposes. The location should not be close to air in-leakages. The sampling location should be at least two equivalent duct diameters downstream from the nearest control device, point of pollutant generation, or other point at which a change in the pollutant concentration or emission rate occurs. The location should be at least 0.5 diameter upstream from the exhaust or control device. To calculate equivalent duct diameter, see section 12.2 of Method 1 (40 CFR Part 60, Appendix A). Sampling locations not conforming to the requirements in this section may be used if necessary upon approval of the Administrator.
8.2 Pretest Preparation Period. Using the procedures described in Method 18
8.3 Seven (7)-Day Calibration Error (CE) Test Period. At the beginning of each 24-hour period, set the initial instrument set points by conducting a multi-point calibration for each compound. The multi-point calibration shall meet the requirements in sections 13.1, 13.2, and 13.3. Throughout the 24-hour period, sample and analyze the stack gas at the sampling intervals prescribed in the regulation or permit. At the end of the 24-hour period, inject the calibration gases at three concentrations for each compound in triplicate and determine the average instrument response. Determine the CE for each pollutant at each concentration using Equation 9-2. Each CE shall be ≤10 percent. Repeat this procedure six more times for a total of 7 consecutive days.
8.4 Performance Audit Test Periods. Conduct the performance audit once during the initial 7-day CE test and quarterly thereafter. Performance Audit Tests must be conducted through the entire sampling and analyzer system. Sample and analyze the EPA audit gas(es) (or the gas mixture) three times. Calculate the average instrument response. Results from the performance audit test must meet the requirements in sections 13.3 and 13.4.
8.5 Reporting. Follow the reporting requirements of the applicable regulation or permit. If the reporting requirements include the results of this performance specification, summarize in tabular form the results of the CE tests. Include all data sheets, calculations, CEMS data records, performance audit results, and calibration gas concentrations and certifications.
10.1 Multi-Point Calibration. After initial startup of the GC, after routine maintenance or repair, or at least once per month, conduct a multi-point calibration of the GC for each target analyte. Calibration is performed at the instrument independent of the sample transport system. The multi-point calibration for each analyte shall meet the requirements in sections 13.1, 13.2, and 13.3.
10.2 Daily Calibration. Once every 24 hours, analyze the mid-level calibration standard for each analyte in triplicate. Calibration is performed at the instrument independent of the sample transport system. Calculate the average instrument response for each analyte. The average instrument response shall not vary by more than 10 percent from the certified concentration value of the cylinder for each analyte. If the difference between the analyzer response and the cylinder concentration for any target compound is greater than 10 percent, immediately inspect the instrument making any necessary adjustments, and conduct an initial multi-point calibration as described in section 10.1.
12.1 Nomenclature.
12.2 Coefficient of Determination. Calculate r
12.3 Calibration Error Determination. Determine the percent calibration error (CE) at each concentration for each pollutant using the following equation.
12.4 Sampling System Time Constant (T).
13.1 Calibration Error (CE). The CEMS must allow the determination of CE at all three calibration levels. The average CEMS calibration response must not differ by more than 10 percent of calibration gas value at each level after each 24-hour period and after any triplicate calibration response check.
13.2 Calibration Precision and Linearity. For each triplicate injection at each concentration level for each target analyte, any one injection shall not deviate more than 5 percent from the average concentration measured at that level. When the CEMS response is evaluated over three concentration levels, the linear regression curve for each organic compound shall be determined using Equation 9-1 and must have an r
13.3 Measurement Frequency. The sample to be analyzed shall flow continuously through the sampling system. The sampling system time constant shall be ≤5 minutes or the sampling frequency specified in the applicable regulation, whichever is less. Use Equation 9-3 to determine T. The analytical system shall be capable of measuring the effluent stream at the frequency specified in the appropriate regulation or permit.
13.4 Audit Test Error. Determine the error for each average pollutant measurement using the Equation 9-2 in section 12.3. Each error shall be less than or equal to 10 percent of the cylinder gas certified value. Report the audit results including the average measured concentration, the error and the certified cylinder concentration of each pollutant as part of the reporting requirements in the appropriate regulation or permit.
The purpose of Performance Specification 11 (PS-11) is to establish the initial installation and performance procedures that are required for evaluating the acceptability of a particulate matter (PM) continuous emission monitoring system (CEMS); it is not to evaluate the ongoing performance of your PM CEMS over an extended period of time, nor to identify specific calibration techniques and auxiliary procedures to assess CEMS performance. You will find procedures for evaluating the ongoing performance of a PM CEMS in Procedure 2 of Appendix F – Quality Assurance Requirements for Particulate Matter Continuous Emission Monitoring Systems Used at Stationary Sources.
1.1 Under what conditions does PS-11 apply to my PM CEMS? The PS-11 applies to your PM CEMS if you are required by any provision of Title 40 of the Code of Federal Regulations (CFR) to install and operate PM CEMS.
1.2 When must I comply with PS-11? You must comply with PS-11 when directed by the applicable rule that requires you to install and operate a PM CEMS.
1.3 What other monitoring must I perform? To report your PM emissions in units of the emission standard, you may need to monitor additional parameters to correct the PM concentration reported by your PM CEMS. Your CEMS may include the components listed in paragraphs (1) through (3) of this section:
(1) A diluent monitor (i.e., O
(2) Auxiliary monitoring equipment to allow measurement, determination, or input of the flue gas temperature, pressure, moisture content, and/or dry volume of stack effluent sampled, and
(3) An automatic sampling system. The performance of your PM CEMS and the establishment of its correlation to manual reference method measurements must be determined in units of mass concentration as measured by your PM CEMS (e.g., milligrams per actual cubic meter (mg/acm) or milligrams per dry standard cubic meter (mg/dscm)).
The PS-11 requires you to perform initial installation and calibration procedures that confirm the acceptability of your CEMS when it is installed and placed into operation. You must develop a site-specific correlation of your PM CEMS response against manual gravimetric reference method measurements (including those made using EPA Methods 5, 5I, or 17).
2.1 What types of PM CEMS technologies are covered? Several different types of PM CEMS technologies (e.g., light scattering, Beta attenuation, etc.) can be designed with in-situ or extractive sample gas handling systems. Each PM CEMS technology and sample gas handling technology has certain site-specific advantages. You should select and install a PM CEMS that is appropriate for the flue gas conditions at your source.
2.2 How is PS-11 different from other performance specifications? The PS-11 is based on a technique of correlating PM CEMS responses relative to emission concentrations determined by the reference method. This technique is called “the correlation.” This differs from CEMS used to measure gaseous pollutants that have available calibration gases of known concentration. Because the type and characteristics of PM vary from source to source, a single PM correlation, applicable to all sources, is not possible.
2.3 How are the correlation data handled? You must carefully review your manual reference method data and your PM CEMS responses to include only valid, high-quality data. For the correlation, you must convert the manual reference method data to measurement conditions (e.g., wet or dry basis) that are consistent with your PM CEMS. Then, you must correlate the manual method and PM CEMS data in terms of the output as received from the monitor (e.g., milliamps). At the appropriate PM CEMS response specified in section 13.2 of this performance specification, you must calculate the confidence interval half range and tolerance interval half range as a percentage of the applicable PM concentration emission limit and compare the confidence interval and tolerance interval percentages with the performance criteria. Also, you must calculate the correlation coefficient and compare the correlation coefficient with the applicable performance criterion specified in section 13.2 of this performance specification.
Situations may arise where you will need two or more correlations. If you need multiple correlations, you must collect sufficient data for each correlation, and each correlation must satisfy the performance criteria specified in section 13.2 of this performance specification.
2.4 How do I design my PM CEMS correlation program? When planning your PM CEMS correlation effort, you must address each of the items in paragraphs (1) through (7) of this section to enhance the probability of success. You will find each of these elements further described in this performance specification or in the applicable reference method procedure.
(1) What type of PM CEMS should I select? You should select a PM CEMS that is appropriate for your source with technical consideration for potential factors such as interferences, site-specific configurations, installation location, flue gas conditions, PM concentration range, and other PM characteristics. You can find guidance on which technology is best suited for specific situations in our report “Current Knowledge of Particulate Matter (PM) Continuous Emission Monitoring” (PM CEMS Knowledge Document, see section 16.5).
(2) Where should I install my PM CEMS? Your PM CEMS must be installed in a location that is most representative of PM emissions, as determined by the reference method, such that the correlation between PM CEMS response and emissions determined by the reference method will meet these performance specifications. Care must be taken in selecting a location and measurement point to minimize problems due to flow disturbances, cyclonic flow, and varying PM stratification.
(3) How should I record my CEMS data? You need to ensure that your PM CEMS and data logger are set up to collect and record all normal emission levels and excursions. You must ensure that your data logger and PM CEMS have been properly programmed to accept and transfer status signals of valid monitor operation (e.g., flags for internal calibration, suspect data, or maintenance periods).
(4) What CEMS data should I review? You must review drift data daily to document proper operation. You must also ensure that any audit material is appropriate for the typical operating range of your PM CEMS.
(5) How long should I operate my PM CEMS before conducting the initial correlation test? You should allow sufficient time for your PM CEMS to operate for you to become familiar with your PM CEMS.
(i) You should observe PM CEMS response over time during normal and varying process conditions. This will ensure that your PM CEMS has been properly set up to operate at a range that is compatible with the concentrations and characteristics of PM emissions for your source. You should use this information to establish the range of operating conditions necessary to determine the correlations of PM CEMS data to manual reference method measurements over a wide operating range.
(ii) You must determine the types of process changes that will influence, on a definable and repeatable basis, flue gas PM concentrations and the resulting PM CEMS responses. You may find this period useful to make adjustments to your planned approach for operating your PM CEMS at your source. For instance, you may change the measurement range or batch sampling period to something other than those you initially planned to use.
(6) How do I conduct the initial correlation test? When conducting the initial correlation test of your PM CEMS response to PM emissions determined by the reference method, you must pay close attention to accuracy and details. Your PM CEMS must be operating properly. You must perform the manual reference method testing accurately, with attention to eliminating site-specific systemic errors. You must coordinate the timing of the manual reference method testing with the sampling cycle of your PM CEMS. You must complete a minimum of 15 manual reference method tests. You must perform the manual reference method testing over the full range of PM CEMS responses that correspond to normal operating conditions for your source and control device and will result in the widest range of emission concentrations.
(7) How should I perform the manual reference method testing? You must perform the manual reference method testing in accordance with specific rule requirements, coordinated closely with PM CEMS and process operations. It is highly recommended that you use paired trains for the manual reference method testing. You must perform the manual reference method testing over a suitable PM concentration range that corresponds to the full range of normal process and control device operating conditions. Because the manual reference method testing for this correlation test is not for compliance reporting purposes, you may conduct the reference method test runs for less than the typical minimum test run duration of 1 hour.
(8) What do I do with the manual reference method data and PM CEMS data? You must complete each of the activities in paragraphs (8)(i) through (v) of this section.
(i) Screen the manual reference method data for validity (e.g., isokinetics, leak checks), quality assurance, and quality control (e.g., outlier identification).
(ii) Screen your PM CEMS data for validity (e.g., daily drift check requirements) and quality assurance (e.g., flagged data).
(iii) Convert the manual reference method test data into measurement units (e.g., mg/acm) consistent with the measurement conditions of your PM CEMS.
(iv) Calculate the correlation equation(s) as specified in section 12.3.
(v) Calculate the correlation coefficient, confidence interval half range, and tolerance interval half range for the complete set of PM CEMS and reference method correlation data for comparison with the correlation performance criteria specified in section 13.2.
2.5 What other procedures must I perform? Before conducting the initial correlation test, you must successfully complete a 7-day drift test (See section 8.5).
3.1 “Appropriate Measurement Range of your PM CEMS” means a measurement range that is capable of recording readings over the complete range of your source’s PM emission concentrations during routine operations. The appropriate range is determined during the pretest preparations as specified in section 8.4.
3.2 “Appropriate Data Range for PM CEMS Correlation” means the data range that reflects the full range of your source’s PM emission concentrations recorded by your PM CEMS during the correlation test planning period or other normal operations as defined in the applicable regulations.
3.3 “Batch Sampling” means that gas is sampled on an intermittent basis and concentrated on a collection medium before intermittent analysis and follow-up reporting. Beta gauge PM CEMS are an example of batch sampling devices.
3.4 “Confidence Interval Half Range (CI)” is a statistical term and means one-half of the width of the 95 percent confidence interval around the predicted mean PM concentration (y value) calculated at the PM CEMS response value (x value) where the confidence interval is narrowest. Procedures for calculating CI are specified in section 12.3. The CI as a percent of the emission limit value (CI%) is calculated at the appropriate PM CEMS response value and must satisfy the criteria specified in section 13.2 (2).
3.5 “Continuous Emission Monitoring System (CEMS)” means all of the equipment required for determination of PM mass concentration in units of the emission standard. The sample interface, pollutant monitor, diluent monitor, other auxiliary data monitor(s), and data recorder are the major subsystems of your CEMS.
3.6 “Correlation” means the primary mathematical relationship for correlating the output from your PM CEMS to a PM concentration, as determined by the PM reference method. The correlation is expressed in the measurement units that are consistent with the measurement conditions (e.g., mg/dscm, mg/acm) of your PM CEMS.
3.7 “Correlation Coefficient (r)” means a quantitative measure of the association between your PM CEMS outputs and the reference method measurements. Equations for calculating the r value are provided in section 12.3(1)(iv) for linear correlations and in section 12.3(2)(iv) for polynomial correlations.
3.8 “Cycle Time” means the time required to complete one sampling, measurement, and reporting cycle. For a batch sampling PM CEMS, the cycle time would start when sample gas is first extracted from the stack/duct and end when the measurement of that batch sample is complete and a new result for that batch sample is produced on the data recorder.
3.9 “Data Recorder” means the portion of your CEMS that provides a permanent record of the monitor output in terms of response and status (flags). The data recorder may also provide automatic data reduction and CEMS control capabilities (see section 6.6).
3.10 “Diluent Monitor and Other Auxiliary Data Monitor(s) (if applicable)” means the portion of your CEMS that provides the diluent gas concentration (such as O
3.11 “Drift Check” means a check of the difference between your PM CEMS output readings and the established reference value of a reference standard or procedure after a stated period of operation during which no unscheduled maintenance, repair, or adjustment took place. The procedures used to determine drift are specific to the operating principles of your specific PM CEMS. A drift check includes both a zero drift check and an upscale drift check.
3.12 “Exponential Correlation” means an exponential equation used to define the relationship between your PM CEMS output and the reference method PM concentration, as indicated by Equation 11-37.
3.13 “Flagged Data” means data marked by your CEMS indicating that the response value(s) from one or more CEMS subsystems is suspect or invalid or that your PM CEMS is not in source-measurement operating mode.
3.14 “Linear Correlation” means a first-order mathematical relationship between your PM CEMS output and the reference method PM concentration that is linear in form, as indicated by Equation 11-3.
3.15 “Logarithmic Correlation” means a first-order mathematical relationship between the natural logarithm of your PM CEMS output and the reference method PM concentration that is linear in form, as indicated by Equation 11-34.
3.16 “Low-Emitting Source” means a source that operated at no more than 50 percent of the emission limit during the most recent performance test, and, based on the PM CEMS correlation, the daily average emissions for the source, measured in the units of the applicable emission limit, have not exceeded 50 percent of the emission limit for any day since the most recent performance test.
3.17 “Paired Trains” means two reference method trains that are used to conduct simultaneous measurements of PM concentrations. Guidance on the use of paired sampling trains can be found in the PM CEMS Knowledge Document (see section 16.5).
3.18 “Polynomial Correlation” means a second-order equation used to define the relationship between your PM CEMS output and reference method PM concentration, as indicated by Equation 11-16.
3.19 “Power Correlation” means an equation used to define a power function relationship between your PM CEMS output and the reference method concentration, as indicated by Equation 11-42.
3.20 “Reference Method” means the method defined in the applicable regulations, but commonly refers to those methods collectively known as EPA Methods 5, 5I, and 17 (for particulate matter), found in Appendix A of 40 CFR 60. Only the front half and dry filter catch portions of the reference method can be correlated to your PM CEMS output.
3.21 “Reference Standard” means a reference material or procedure that produces a known and unchanging response when presented to the pollutant monitor portion of your CEMS. You must use these standards to evaluate the overall operation of your PM CEMS, but not to develop a PM CEMS correlation.
3.22 “Response Time” means the time interval between the start of a step change in the system input and the time when the pollutant monitor output reaches 95 percent of the final value (see sections 6.5 and 13.3 for procedures and acceptance criteria).
3.23 “Sample Interface” means the portion of your CEMS used for one or more of the following: sample acquisition, sample delivery, sample conditioning, or protection of the monitor from the effects of the stack effluent.
3.24 “Sample Volume Check” means a check of the difference between your PM CEMS sample volume reading and the sample volume reference value.
3.25 “Tolerance Interval half range (TI)” means one-half of the width of the tolerance interval with upper and lower limits, within which a specified percentage of the future data population is contained with a given level of confidence, as defined by the respective tolerance interval half range equations in section 12.3(1)(iii) for linear correlations and in section 12.3(2)(iii) for polynomial correlations. The TI as a percent of the emission limit value (TI%) is calculated at the appropriate PM CEMS response value specified in section 13.2(3).
3.26 “Upscale Check Value” means the expected response to a reference standard or procedure used to check the upscale response of your PM CEMS.
3.27 “Upscale Drift (UD) Check” means a check of the difference between your PM CEMS output reading and the upscale check value.
3.28 “Zero Check Value” means the expected response to a reference standard or procedure used to check the response of your PM CEMS to particulate-free or low-particulate concentration conditions.
3.29 “Zero Drift (ZD) Check” means a check of the difference between your PM CEMS output reading and the zero check value.
3.30 “Zero Point Correlation Value” means a value added to PM CEMS correlation data to represent low or near zero PM concentration data (see section 8.6 for rationale and procedures).
Yes, condensible water droplets or condensible acid gas aerosols (i.e., those with condensation temperatures above those specified by the reference method) at the measurement location can be interferences for your PM CEMS if the necessary precautions are not met.
4.1 Where are interferences likely to occur? Interferences may develop if your CEMS is installed downstream of a wet air pollution control system or any other conditions that produce flue gases, which, at your PM CEMS measurement point, normally or occasionally contain entrained water droplets or condensible salts before release to the atmosphere.
4.2 How do I deal with interferences? We recommend that you use a PM CEMS that extracts and heats representative samples of the flue gas for measurement to simulate results produced by the reference method for conditions such as those described in section 4.1. Independent of your PM CEMS measurement technology and extractive technique, you should have a configuration simulating the reference method to ensure that:
(1) No formation of new PM or deposition of PM occurs in sample delivery from the stack or duct; and
(2) No condensate accumulates in the sample flow measurement apparatus.
4.3 What PM CEMS measurement technologies should I use? You should use a PM CEMS measurement technology that is free of interferences from any condensible constituent in the flue gas.
People using the procedures required under PS-11 may be exposed to hazardous materials, operations, site conditions, and equipment. This performance specification does not purport to address all of the safety issues associated with its use. It is your responsibility to establish appropriate safety and health practices and determine the applicable regulatory limitations before performing these procedures. You must consult your CEMS user’s manual and other reference materials recommended by the reference method for specific precautions to be taken.
Different types of PM CEMS use different operating principles. You should select an appropriate PM CEMS based on your site-specific configurations, flue gas conditions, and PM characteristics.
(1) Your PM CEMS must sample the stack effluent continuously or, for batch sampling PM CEMS, intermittently.
(2) You must ensure that the averaging time, the number of measurements in an average, the minimum data availability, and the averaging procedure for your CEMS conform with those specified in the applicable emission regulation.
(3) Your PM CEMS must include, as a minimum, the equipment described in sections 6.1 through 6.7.
6.1 What equipment is needed for my PM CEMS’s sample interface? Your PM CEMS’s sample interface must be capable of delivering a representative sample of the flue gas to your PM CEMS. This subsystem may be required to heat the sample gas to avoid PM deposition or moisture condensation, provide dilution air, perform other gas conditioning to prepare the sample for analysis, or measure the sample volume or flow rate.
(1) If your PM CEMS is installed downstream of a wet air pollution control system such that the flue gases normally or occasionally contain entrained water droplets, we recommend that you select a sampling system that includes equipment to extract and heat a representative sample of the flue gas for measurement so that the pollutant monitor portion of your CEMS measures only dry PM. Heating should be sufficient to raise the temperature of the extracted flue gas above the water condensation temperature and should be maintained at all times and at all points in the sample line from where the flue gas is extracted, including the pollutant monitor and any sample flow measurement devices.
(2) You must consider the measured conditions of the sample gas stream to ensure that manual reference method test data are converted to units of PM concentration that are appropriate for the correlation calculations. Additionally, you must identify what, if any, additional auxiliary data from other monitoring and handling systems are necessary to convert your PM CEMS response into the units of the PM standard.
(3) If your PM CEMS is an extractive type and your source’s flue gas volumetric flow rate varies by more than 10 percent from nominal, your PM CEMS should maintain an isokinetic sampling rate (within 10 percent of true isokinetic). If your extractive-type PM CEMS does not maintain an isokinetic sampling rate, you must use actual site-specific data or data from a similar installation to prove to us, the State, and/or local enforcement agency that isokinetic sampling is not necessary.
6.2 What type of equipment is needed for my PM CEMS? Your PM CEMS must be capable of providing an electronic output that can be correlated to the PM concentration.
(1) Your PM CEMS must be able to perform zero and upscale drift checks. You may perform these checks manually, but performing these checks automatically is preferred.
(2) We recommend that you select a PM CEMS that is capable of performing automatic diagnostic checks and sending instrument status signals (flags) to the data recorder.
(3) If your PM CEMS is an extractive type that measures the sample volume and uses the measured sample volume as part of calculating the output value, your PM CEMS must be able to perform a check of the sample volume to verify the accuracy of the sample volume measuring equipment. The sample volume check must be conducted daily and at the normal sampling rate of your PM CEMS.
6.3 What is the appropriate measurement range for my PM CEMS? Initially, your PM CEMS must be set up to measure over the expected range of your source’s PM emission concentrations during routine operations. You may change the measurement range to a more appropriate range prior to correlation testing.
6.4 What if my PM CEMS does automatic range switching? Your PM CEMS may be equipped to perform automatic range switching so that it is operating in a range most sensitive to the detected concentrations. If your PM CEMS does automatic range switching, you must configure the data recorder to handle the recording of data values in multiple ranges during range-switching intervals.
6.5 What averaging time and sample intervals should be used? Your CEMS must sample the stack effluent such that the averaging time, the number of measurements in an average, the minimum sampling time, and the averaging procedure for reporting and determining compliance conform with those specified in the applicable regulation. Your PM CEMS must be designed to meet the specified response time and cycle time established in this performance specification (see section 13.3).
6.6 What type of equipment is needed for my data recorder? Your CEMS data recorder must be able to accept and record electronic signals from all the monitors associated with your PM CEMS.
(1) Your data recorder must record the signals from your PM CEMS that can be correlated to PM mass concentrations. If your PM CEMS uses multiple ranges, your data recorder must identify what range the measurement was made in and provide range-adjusted results.
(2) Your data recorder must accept and record monitor status signals (flagged data).
(3) Your data recorder must accept signals from auxiliary data monitors, as appropriate.
6.7 What other equipment and supplies might I need? You may need other supporting equipment as defined by the applicable reference method(s) (see section 7) or as specified by your CEMS manufacturer.
You will need reference standards or procedures to perform the zero drift check, the upscale drift check, and the sample volume check.
7.1 What is the reference standard value for the zero drift check? You must use a zero check value that is no greater than 20 percent of the PM CEMS’s response range. You must obtain documentation on the zero check value from your PM CEMS manufacturer.
7.2 What is the reference standard value for the upscale drift check? You must use an upscale check value that produces a response between 50 and 100 percent of the PM CEMS’s response range. For a PM CEMS that produces output over a range of 4 mA to 20 mA, the upscale check value must produce a response in the range of 12 mA to 20 mA. You must obtain documentation on the upscale check value from your PM CEMS manufacturer.
7.3 What is the reference standard value for the sample volume check? You must use a reference standard value or procedure that produces a sample volume value equivalent to the normal sampling rate. You must obtain documentation on the sample volume value from your PM CEMS manufacturer.
You must complete each of the activities in sections 8.1 through 8.8 for your performance specification test.
8.1 How should I select and set up my equipment? You should select a PM CEMS that is appropriate for your source, giving consideration to potential factors such as flue gas conditions, interferences, site-specific configuration, installation location, PM concentration range, and other PM characteristics. Your PM CEMS must meet the equipment specifications in sections 6.1 and 6.2.
(1) You should select a PM CEMS that is appropriate for the flue gas conditions at your source. If your source’s flue gas contains entrained water droplets, we recommend that your PM CEMS include a sample delivery and conditioning system that is capable of extracting and heating a representative sample.
(i) Your PM CEMS must maintain the sample at a temperature sufficient to prevent moisture condensation in the sample line before analysis of PM.
(ii) If condensible PM is an issue, we recommend that you operate your PM CEMS to maintain the sample gas temperature at the same temperature as the reference method filter.
(iii) Your PM CEMS must avoid condensation in the sample flow rate measurement lines.
(2) Some PM CEMS do not have a wide measurement range capability. Therefore, you must select a PM CEMS that is capable of measuring the full range of PM concentrations expected from your source from normal levels through the emission limit concentration.
(3) Some PM CEMS are sensitive to particle size changes, water droplets in the gas stream, particle charge, stack gas velocity changes, or other factors. Therefore, you should select a PM CEMS appropriate for the emission characteristics of your source.
(4) We recommend that you consult your PM CEMS vendor to obtain basic recommendations on the instrument capabilities and setup configuration. You are ultimately responsible for setup and operation of your PM CEMS.
8.2 Where do I install my PM CEMS? You must install your PM CEMS at an accessible location downstream of all pollution control equipment. You must perform your PM CEMS concentration measurements from a location considered representative or be able to provide data that can be corrected to be representative of the total PM emissions as determined by the manual reference method.
(1) You must select a measurement location that minimizes problems due to flow disturbances, cyclonic flow, and varying PM stratification (refer to Method 1 for guidance).
(2) If you plan to achieve higher emissions for correlation test purposes by adjusting the performance of the air pollution control device (per section 8.6(4)(i)), you must locate your PM CEMS and reference method sampling points well downstream of the control device (e.g., downstream of the induced draft fan), in order to minimize PM stratification that may be created in these cases.
8.3 How do I select the reference method measurement location and traverse points? You must follow EPA Method 1 for identifying manual reference method traverse points. Ideally, you should perform your manual reference method measurements at locations that satisfy the measurement site selection criteria specified in EPA Method 1 of at least eight duct diameters downstream and at least two duct diameters upstream of any flow disturbance. Where necessary, you may conduct testing at a location that is two diameters downstream and 0.5 diameters upstream of flow disturbances. If your location does not meet the minimum downstream and upstream requirements, you must obtain approval from us to test at your location.
8.4 What are my pretest preparation steps? You must install your CEMS and prepare the reference method test site according to the specifications in sections 8.2 and 8.3.
(1) After completing the initial field installation, we recommend that you operate your PM CEMS according to the manufacturer’s instructions to familiarize yourself with its operation before you begin correlation testing.
(i) During this initial period of operation, we recommend that you conduct daily checks (zero and upscale drift and sample volume, as appropriate), and, when any check exceeds the daily specification (see section 13.1), make adjustments and perform any necessary maintenance to ensure reliable operation.
(2) When you are confident that your PM CEMS is operating properly, we recommend that you operate your CEMS over a correlation test planning period of sufficient duration to identify the full range of operating conditions and PM emissions to be used in your PM CEMS correlation test.
(i) During the correlation test planning period, you should operate the process and air pollution control equipment over the normal range of operating conditions, except when you attempt to produce higher emissions.
(ii) Your data recorder should record PM CEMS response during the full range of routine process operating conditions.
(iii) You should try to establish the relationships between operating conditions and PM CEMS response, especially those conditions that produce the highest PM CEMS response over 15-minute averaging periods, and the lowest PM CEMS response as well. The objective is to be able to reproduce the conditions for purposes of the actual correlation testing discussed in section 8.6.
(3) You must set the response range of your PM CEMS such that the instrument measures the full range of responses that correspond to the range of source operating conditions that you will implement during correlation testing.
(4) We recommend that you perform preliminary reference method testing after the correlation test planning period. During this preliminary testing, you should measure the PM emission concentration corresponding to the highest PM CEMS response observed during the full range of normal operation, when perturbing the control equipment, or as the result of PM spiking.
(5) Before performing correlation testing, you must perform a 7-day zero and upscale drift test (see section 8.5).
(6) You must not change the response range of the monitor once the response range has been set and the drift test successfully completed.
8.5 How do I perform the 7-day drift test? You must check the zero (or low-level value between 0 and 20 percent of the response range of the instrument) and upscale (between 50 and 100 percent of the instrument’s response range) drift. You must perform this check at least once daily over 7 consecutive days. Your PM CEMS must quantify and record the zero and upscale measurements and the time of the measurements. If you make automatic or manual adjustments to your PM CEMS zero and upscale settings, you must conduct the drift test immediately before these adjustments, or conduct it in such a way that you can determine the amount of drift. You will find the calculation procedures for drift in section 12.1 and the acceptance criteria for allowable drift in section 13.1.
(1) What is the purpose of 7-day drift tests? The purpose of the 7-day drift test is to demonstrate that your system is capable of operating in a stable manner and maintaining its calibration for at least a 7-day period.
(2) How do I conduct the 7-day drift test? To conduct the 7-day drift test, you must determine the magnitude of the drift once each day, at 24-hour intervals, for 7 consecutive days while your source is operating normally.
(i) You must conduct the 7-day drift test at the two points specified in section 8.5. You may perform the 7-day drift tests automatically or manually by introducing to your PM CEMS suitable reference standards (these need not be certified) or by using other appropriate procedures.
(ii) You must record your PM CEMS zero and upscale response and evaluate them against the zero check value and upscale check value.
(3) When must I conduct the 7-day drift test? You must complete a valid 7-day drift test before attempting the correlation test.
8.6 How do I conduct my PM CEMS correlation test? You must conduct the correlation test according to the procedure given in paragraphs (1) through (5) of this section. If you need multiple correlations, you must conduct testing and collect at least 15 sets of reference method and PM CEMS data for calculating each separate correlation.
(1) You must use the reference method for PM (usually EPA Methods 5, 5I, or 17) that is prescribed by the applicable regulations. You may need to perform other reference methods or performance specifications (e.g., Method 3 for oxygen, Method 4 for moisture, etc.) depending on the units in which your PM CEMS reports PM concentration.
(i) We recommend that you use paired reference method trains when collecting manual PM data to identify and screen the reference method data for imprecision and bias. Procedures for checking reference method data for bias and precision can be found in the PM CEMS Knowledge Document (see section 16.5).
(ii) You may use test runs that are shorter than 60 minutes in duration (e.g., 20 or 30 minutes). You may perform your PM CEMS correlation tests during new source performance standards performance tests or other compliance tests subject to the Clean Air Act or other statutes, such as the Resource Conservation and Recovery Act. In these cases, your reference method results obtained during the PM CEMS correlation test may be used to determine compliance so long as your source and the test conditions and procedures (e.g., reference method sample run durations) are consistent with the applicable regulations and the reference method.
(iii) You must convert the reference method results to units consistent with the conditions of your PM CEMS measurements. For example, if your PM CEMS measures and reports PM emissions in the units of mass per actual volume of stack gas, you must convert your reference method results to those units (e.g., mg/acm). If your PM CEMS extracts and heats the sample gas to eliminate water droplets, then measures and reports PM emissions under those actual conditions, you must convert your reference method results to those same conditions (e.g., mg/acm at 160 °C).
(2) During each test run, you must coordinate process operations, reference method sampling, and PM CEMS operations. For example, you must ensure that the process is operating at the targeted conditions, both reference method trains are sampling simultaneously (if paired sampling trains are being used), and your PM CEMS and data logger are operating properly.
(i) You must coordinate the start and stop times of each run between the reference method sampling and PM CEMS operation. For a batch sampling PM CEMS, you must start the reference method at the same time as your PM CEMS sampling.
(ii) You must note the times for port changes (and other periods when the reference method sampling may be suspended) on the data sheets so that you can adjust your PM CEMS data accordingly, if necessary.
(iii) You must properly align the time periods for your PM CEMS and your reference method measurements to account for your PM CEMS response time.
(3) You must conduct a minimum of 15 valid runs each consisting of simultaneous PM CEMS and reference method measurement sets.
(i) You may conduct more than 15 sets of CEMS and reference method measurements. If you choose this option, you may reject certain test results so long as the total number of valid test results you use to determine the correlation is greater than or equal to 15.
(ii) You must report all data, including the rejected data.
(iii) You may reject the results of up to five test runs without explanation.
(iv) If you reject the results of more than five test runs, the basis for rejecting the results of the additional test runs must be explicitly stated in the reference method, this performance specification, Procedure 2 of appendix F, or your quality assurance plan.
(4) Simultaneous PM CEMS and reference method measurements must be performed in a manner to ensure that the range of data that will be used to establish the correlation for your PM CEMS is maximized. You must first attempt to maximize your correlation range by following the procedures described in paragraphs (4)(i) through (iv) of this section. If you cannot obtain the three levels as described in paragraphs (i) through (iv), then you must use the procedure described in section 8.6(5).
(i) You must attempt to obtain the three different levels of PM mass concentration by varying process operating conditions, varying PM control device conditions, or by means of PM spiking.
(ii) The three PM concentration levels you use in the correlation tests must be distributed over the complete operating range experienced by your source.
(iii) At least 20 percent of the minimum 15 measured data points you use should be contained in each of the following levels:
• Level 1: From no PM (zero concentration) emissions to 50 percent of the maximum PM concentration;
• Level 2: 25 to 75 percent of the maximum PM concentration; and
• Level 3: 50 to 100 percent of the maximum PM concentration.
(iv) Although the above levels overlap, you may only apply individual run data to one level.
(5) If you cannot obtain three distinct levels of PM concentration as described, you must perform correlation testing over the maximum range of PM concentrations that is practical for your PM CEMS. To ensure that the range of data used to establish the correlation for your PM CEMS is maximized, you must follow one or more of the steps in paragraphs (5)(i) through (iv) of this section.
(i) Zero point data for in-situ instruments should be obtained, to the extent possible, by removing the instrument from the stack and monitoring ambient air on a test bench.
(ii) Zero point data for extractive instruments should be obtained by removing the extractive probe from the stack and drawing in clean ambient air.
(iii) Zero point data also can be obtained by performing manual reference method measurements when the flue gas is free of PM emissions or contains very low PM concentrations (e.g., when your process is not operating, but the fans are operating or your source is combusting only natural gas).
(iv) If none of the steps in paragraphs (5)(i) through (iii) of this section are possible, you must estimate the monitor response when no PM is in the flue gas (e.g., 4 mA = 0 mg/acm).
8.7 What do I do with the initial correlation test data for my PM CEMS? You must calculate and report the results of the correlation testing, including the correlation coefficient, confidence interval, and tolerance interval for the PM CEMS response and reference method correlation data that are use to establish the correlation, as specified in section 12. You must include all data sheets, calculations, charts (records of PM CEMS responses), process data records including PM control equipment operating parameters, and reference media certifications necessary to confirm that your PM CEMS met the requirements of this performance specification. In addition, you must:
(1) Determine the integrated (arithmetic average) PM CEMS output over each reference method test period;
(2) Adjust your PM CEMS outputs and reference method test data to the same clock time (considering response time of your PM CEMS);
(3) Confirm that the reference method results are consistent with your PM CEMS response in terms of, where applicable, moisture, temperature, pressure, and diluent concentrations; and
(4) Determine whether any of the reference method test results do not meet the test method criteria.
8.8 What is the limitation on the range of my PM CEMS correlation? Although the data you collect during the correlation testing should be representative of the full range of normal operating conditions at your source, you must conduct additional correlation testing if either of the conditions specified in paragraphs (1) and (2) of this section occurs.
(1) If your source is a low-emitting source, as defined in section 3.16 of this specification, you must conduct additional correlation testing if either of the events specified in paragraphs (1)(i) or (ii) of this section occurs while your source is operating under normal conditions.
(i) Your source generates 24 consecutive hourly average PM CEMS responses that are greater than 125 percent of the highest PM CEMS response (e.g., mA reading) used for the correlation curve or are greater than the PM CEMS response that corresponds to 50 percent of the emission limit, whichever is greater, or
(ii) The cumulative hourly average PM CEMS responses generated by your source are greater than 125 percent of the highest PM CEMS response used for the correlation curve or are greater than the PM CEMS response that corresponds to 50 percent of the emission limit, whichever is greater, for more than 5 percent of your PM CEMS operating hours for the previous 30-day period.
(2) If your source is not a low-emitting source, as defined in section 3.16 of this specification, you must conduct additional correlation testing if either of the events specified in paragraph (i) or (ii) of this section occurs while your source is operating under normal conditions.
(i) Your source generates 24 consecutive hourly average PM CEMS responses that are greater than 125 percent of the highest PM CEMS response (e.g., mA reading) used for the correlation curve, or
(ii) The cumulative hourly average PM CEMS responses generated by your source are greater than 125 percent of the highest PM CEMS response used for the correlation curve for more than 5 percent of your PM CEMS operating hours for the previous 30-day period.
(3) If additional correlation testing is required, you must conduct at least three additional test runs under the conditions that caused the higher PM CEMS response.
(i) You must complete the additional testing and use the resulting new data along with the previous data to calculate a revised correlation equation within 60 days after the occurrence of the event that requires additional testing, as specified in paragraphs 8.8(1) and (2).
(4) If your source generates consecutive PM CEMS hourly responses that are greater than 125 percent of the highest PM CEMS response used to develop the correlation curve for 24 hours or for a cumulative period that amounts to more than 5 percent of the PM CEMS operating hours for the previous 30-day period, you must report the reason for the higher PM CEMS responses.
Quality control measures for PM CEMS are specified in 40 CFR 60, Appendix F, Procedure 2.
Specific analytical procedures are outlined in the applicable reference method(s).
You must determine the primary relationship for correlating the output from your PM CEMS to a PM concentration, typically in units of mg/acm or mg/dscm of flue gas, using the calculations and data analysis process in sections 12.2 and 12.3. You develop the correlation by performing an appropriate regression analysis between your PM CEMS response and your reference method data.
12.1 How do I calculate upscale drift and zero drift? You must determine the difference in your PM CEMS output readings from the established reference values (zero and upscale check values) after a stated period of operation during which you performed no unscheduled maintenance, repair or adjustment.
(1) Calculate the upscale drift (UD) using Equation 11-1:
(2) Calculate the zero drift (ZD) using Equation 11-2:
(3) Summarize the results on a data sheet similar to that shown in Table 2 (see section 17).
12.2 How do I perform the regression analysis? You must couple each reference method PM concentration measurement, y, in the appropriate units, with an average PM CEMS response, x, over corresponding time periods. You must complete your PM CEMS correlation calculations using data deemed acceptable by quality control procedures identified in 40 CFR 60, Appendix F, Procedure 2.
(1) You must evaluate all flagged or suspect data produced during measurement periods and determine whether they should be excluded from your PM CEMS’s average.
(2) You must assure that the reference method and PM CEMS results are on a consistent moisture, temperature, and diluent basis. You must convert the reference method PM concentration measurements (dry standard conditions) to the units of your PM CEMS measurement conditions. The conditions of your PM CEMS measurement are monitor-specific. You must obtain from your PM CEMS vendor or instrument manufacturer the conditions and units of measurement for your PM CEMS.
(i) If your sample gas contains entrained water droplets and your PM CEMS is an extractive system that measures at actual conditions (i.e., wet basis), you must use the measured moisture content determined from the impinger analysis when converting your reference method PM data to PM CEMS conditions; do not use the moisture content calculated from a psychrometric chart based on saturated conditions.
12.3 How do I determine my PM CEMS correlation? To predict PM concentrations from PM CEMS responses, you must use the calculation method of least squares presented in paragraphs (1) through (5) of this section. When performing the calculations, each reference method PM concentration measurement must be treated as a discrete data point; if using paired sampling trains, do not average reference method data pairs for any test run.
This performance specification describes procedures for evaluating five types of correlation models: linear, polynomial, logarithmic, exponential, and power. Procedures for selecting the most appropriate correlation model are presented in section 12.4 of this specification.
(1) How do I evaluate a linear correlation for my correlation test data? To evaluate a linear correlation, follow the procedures described in paragraphs (1)(i) through (iv) of this section.
(i) Calculate the linear correlation equation, which gives the predicted PM concentration () as a function of the PM CEMS response (x), as indicated by Equation 11-3:
Calculate the y intercept (b
Calculate the slope (b
(ii) Calculate the half range of the 95 percent confidence interval (CI) for the predicted PM concentration () at the mean value of x, using Equation 11-8:
(iii) Calculate the half range of the tolerance interval (TI) for the predicted PM concentration () at the mean x value using Equation 11-11:
Calculate the half range of the tolerance interval for the predicted PM concentration () at the mean x value as a percentage of the emission limit (TI%) using Equation 11-13:
(iv) Calculate the linear correlation coefficient (r) using Equation 11-14:
(2) How do I evaluate a polynomial correlation for my correlation test data? To evaluate a polynomial correlation, follow the procedures described in paragraphs (2)(i) through (iv) of this section.
(i) Calculate the polynomial correlation equation, which is indicated by Equation 11-16, using Equations 11-17 through 11-22:
Calculate the polynomial correlation curve coefficients (b
(ii) Calculate the 95 percent confidence interval half range (CI) by first calculating the C coefficients (C
(iii) Calculate the tolerance interval half range (TI) for the predicted PM concentration at the x value that corresponds to Δ
(iv) Calculate the polynomial correlation coefficient (r) using Equation 11-33:
(3) How do I evaluate a logarithmic correlation for my correlation test data? To evaluate a logarithmic correlation, which has the form indicated by Equation 11-34, follow the procedures described in paragraphs (3)(i) through (iii) of this section.
(i) Perform a logarithmic transformation of each PM CEMS response value (x values) using Equation 11-35:
(ii) Using the values for x
(iii) Using the values for x
(4) How do I evaluate an exponential correlation for my correlation test data? To evaluate an exponential correlation, which has the form indicated by Equation 11-37, follow the procedures described in paragraphs (4)(i) through (v) of this section:
(i) Perform a logarithmic transformation of each PM concentration measurement (y values) using Equation 11-38:
(ii) Using the values for y′
(iii) Using the values for y″
(iv) Using the values for y′
(v) Using the values for y″
(5) How do I evaluate a power correlation for my correlation test data? To evaluate a power correlation, which has the form indicated by Equation 11-46, follow the procedures described in paragraphs (5)(i) through (v) of this section.
(i) Perform logarithmic transformations of each PM CEMS response (x values) and each PM concentration measurement (y values) using Equations 11-35 and 11-38, respectively.
(ii) Using the values for x″
(iii) Using the same procedure described for exponential models in paragraph (4)(iii) of this section, calculate the half range of the 95 percent confidence interval for the predicted PM concentration corresponding to the mean value of x′ as a percentage of the emission limit.
(iv) Using the same procedure described for exponential models in paragraph (4)(iv) of this section, calculate the tolerance interval half range for the predicted PM concentration corresponding to the mean value of x′ as a percentage of the emission limit.
(v) Using the values for y′
Note: PS-11 does not address the application of correlation equations to calculate PM emission concentrations using PM CEMS response data during normal operations of a PM CEMS. However, we will provide guidance on the use of specific correlation models (i.e., logarithmic, exponential, and power models) to calculate PM concentrations in an operating PM CEMS in situations when the PM CEMS response values are equal to or less than zero, and the correlation model is undefined.
12.4 Which correlation model should I use? Follow the procedures described in paragraphs (1) through (4) of this section to determine which correlation model you should use.
(1) For each correlation model that you develop using the procedures described in section 12.3 of this specification, compare the confidence interval half range percentage, tolerance interval half range percentage, and correlation coefficient to the performance criteria specified in section 13.2 of this specification. You can use the linear, logarithmic, exponential, or power correlation model if the model satisfies all of the performance criteria specified in section 13.2 of this specification. However, to use the polynomial model you first must check that the polynomial correlation curve satisfies the criteria for minimum and maximum values specified in paragraph (3) of this section.
(2) If you develop more than one correlation curve that satisfy the performance criteria specified in section 13.2 of this specification, you should use the correlation curve with the greatest correlation coefficient. If the polynomial model has the greatest correlation coefficient, you first must check that the polynomial correlation curve satisfies the criteria for minimum and maximum values specified in paragraph (3) of this section.
(3) You can use the polynomial model that you develop using the procedures described in section 12.3(2) if the model satisfies the performance criteria specified in section 13.2 of this specification, and the minimum or maximum value of the polynomial correlation curve does not occur within the expanded data range. The minimum or maximum value of the polynomial correlation curve is the point where the slope of the curve equals zero. To determine if the minimum or maximum value occurs within the expanded data range, follow the procedure described in paragraphs (3)(i) through (iv) of this section.
(i) Determine if your polynomial correlation curve has a minimum or maximum point by comparing the polynomial coefficient b
(ii) Calculate the minimum value using Equation 11-48.
(iii) If your polynomial correlation curve has a minimum point, you must compare the minimum value to the minimum PM CEMS response used to develop the correlation curve. If the correlation curve minimum value is less than or equal to the minimum PM CEMS response value, you can use the polynomial correlation curve, provided the correlation curve also satisfies all of the performance criteria specified in section 13.2 of this specification. If the correlation curve minimum value is greater than the minimum PM CEMS response value, you cannot use the polynomial correlation curve to predict PM concentrations.
(iv) If your polynomial correlation curve has a maximum, the maximum value must be greater than the allowable extrapolation limit. If your source is not a low-emitting source, as defined in section 3.16 of this specification, the allowable extrapolation limit is 125 percent of the highest PM CEMS response used to develop the correlation curve. If your source is a low-emitting source, the allowable extrapolation limit is 125 percent of the highest PM CEMS response used to develop the correlation curve or the PM CEMS response that corresponds to 50 percent of the emission limit, whichever is greater. If the polynomial correlation curve maximum value is greater than the extrapolation limit, and the correlation curve satisfies all of the performance criteria specified in section 13.2 of this specification, you can use the polynomial correlation curve to predict PM concentrations. If the correlation curve maximum value is less than the extrapolation limit, you cannot use the polynomial correlation curve to predict PM concentrations.
(4) You may petition the Administrator for alternative solutions or sampling recommendations if the correlation models described in section 12.3 of this specification do not satisfy the performance criteria specified in section 13.2 of this specification.
You must evaluate your PM CEMS based on the 7-day drift check, the accuracy of the correlation, and the sampling periods and cycle/response time.
13.1 What is the 7-day drift check performance specification? Your daily PM CEMS internal drift checks must demonstrate that the daily drift of your PM CEMS does not deviate from the value of the reference light, optical filter, Beta attenuation signal, or other technology-suitable reference standard by more than 2 percent of the response range. If your CEMS includes diluent and/or auxiliary monitors (for temperature, pressure, and/or moisture) that are employed as a necessary part of this performance specification, you must determine the calibration drift separately for each ancillary monitor in terms of its respective output (see the appropriate performance specification for the diluent CEMS specification). None of the calibration drifts may exceed their individual specification.
13.2 What performance criteria must my PM CEMS correlation satisfy? Your PM CEMS correlation must meet each of the minimum specifications in paragraphs (1), (2), and (3) of this section. Before confidence and tolerance interval half range percentage calculations are made, you must convert the emission limit to the appropriate units of your PM CEMS measurement conditions using the average of emissions gas property values (e.g., diluent concentration, temperature, pressure, and moisture) measured during the correlation test.
(1) The correlation coefficient must satisfy the criterion specified in paragraph (1)(i) or (ii), whichever applies.
(i) If your source is not a low-emitting source, as defined in section 3.16 of this specification, the correlation coefficient (r) must be greater than or equal to 0.85.
(ii) If your source is a low-emitting source, as defined in section 3.16 of this specification, the correlation coefficient (r) must be greater than or equal to 0.75.
(2) The confidence interval half range must satisfy the applicable criterion specified in paragraph (2)(i), (ii), or (iii) of this section, based on the type of correlation model.
(i) For linear or logarithmic correlations, the 95 percent confidence interval half range at the mean PM CEMS response value from the correlation test must be within 10 percent of the PM emission limit value specified in the applicable regulation. Therefore, the CI% calculated using Equation 11-10 must be less than or equal to 10 percent.
(ii) For polynomial correlations, the 95 percent confidence interval half range at the PM CEMS response value from the correlation test that corresponds to the minimum value for Δ must be within 10 percent of the PM emission limit value specified in the applicable regulation. Therefore, the CI% calculated using Equation 11-28 must be less than or equal to 10 percent.
(iii) For exponential or power correlations, the 95 percent confidence interval half range at the mean of the logarithm of the PM CEMS response values from the correlation test must be within 10 percent of the PM emission limit value specified in the applicable regulation. Therefore, the CI% calculated using Equation 11-10 must be less than or equal to 10 percent.
(3) The tolerance interval half range must satisfy the applicable criterion specified in paragraph (3)(i), (ii), or (iii) of this section, based on the type of correlation model.
(i) For linear or logarithmic correlations, the half range tolerance interval with 95 percent confidence and 75 percent coverage at the mean PM CEMS response value from the correlation test must be within 25 percent of the PM emission limit value specified in the applicable regulation. Therefore, the TI% calculated using Equation 11-13 must be less than or equal to 25 percent.
(ii) For polynomial correlations, the half range tolerance interval with 95 percent confidence and 75 percent coverage at the PM CEMS response value from the correlation test that corresponds to the minimum value for Δ must be within 25 percent of the PM emission limit value specified in the applicable regulation. Therefore, the TI% calculated using Equation 11-32 must be less than or equal to 25 percent.
(iii) For exponential or power correlations, the half range tolerance interval with 95 percent confidence and 75 percent coverage at the mean of the logarithm of the PM CEMS response values from the correlation test must be within 25 percent of the PM emission limit value specified in the applicable regulation. Therefore, the TI% calculated using Equation 11-13 must be less than or equal to 25 percent.
13.3 What are the sampling periods and cycle/response time? You must document and maintain the response time and any changes in the response time following installation.
(1) If you have a batch sampling PM CEMS, you must evaluate the limits presented in paragraphs (1)(i) and (ii) of this section.
(i) The response time of your PM CEMS, which is equivalent to the cycle time, must be no longer than 15 minutes. In addition, the delay between the end of the sampling time and reporting of the sample analysis must be no greater than 3 minutes. You must document any changes in the response time following installation.
(ii) The sampling time of your PM CEMS must be no less than 30 percent of the cycle time. If you have a batch sampling PM CEMS, sampling must be continuous except during pauses when the collected pollutant on the capture media is being analyzed and the next capture medium starts collecting a new sample.
13.4 What PM compliance monitoring must I do? You must report your CEMS measurements in the units of the standard expressed in the regulations (e.g., mg/dscm @ 7 percent oxygen, pounds per million Btu (lb/mmBtu), etc.). You may need to install auxiliary data monitoring equipment to convert the units reported by your PM CEMS into units of the PM emission standard.
16.1 Technical Guidance Document: Compliance Assurance Monitoring. U.S. Environmental Protection Agency Office of Air Quality Planning and Standards Emission Measurement Center. August 1998.
16.2 40 CFR 60, Appendix B, “Performance Specification 2 – Specifications and Test Procedures for SO
16.3 40 CFR 60, Appendix B, “Performance Specification 1 – Specification and Test Procedures for Opacity Continuous Emission Monitoring Systems in Stationary Sources.”
16.4 40 CFR 60, Appendix A, “Method 1 – Sample and Velocity Traverses for Stationary Sources.”
16.5 “Current Knowledge of Particulate Matter (PM) Continuous Emission Monitoring.” EPA-454/R-00-039. U.S. Environmental Protection Agency, Research Triangle Park, NC. September 2000.
16.6 40 CFR 266, Appendix IX, section 2, “Performance Specifications for Continuous Emission Monitoring Systems.”
16.7 ISO 10155, “Stationary Source Emissions – Automated Monitoring of Mass Concentrations of Particles: Performance Characteristics, Test Procedures, and Specifications.” American National Standards Institute, New York City. 1995.
16.8 Snedecor, George W. and Cochran, William G. (1989), Statistical Methods, Eighth Edition, Iowa State University Press.
16.9 Wallis, W. A. (1951) “Tolerance Intervals for Linear Regression,” in Second Berkeley Symposium on Mathematical Statistics and Probability, ed. J. Neyman, Berkeley: University of California Press, pp. 43-51.
Use the information in Table 1 for determining the confidence and tolerance interval half ranges. Use Table 2 to record your 7-day drift test data.
Table 1 – Factors for Calculation of Confidence and Tolerance Interval Half Ranges
| df | Student’s t, t | Tolerance interval with 75% coverage and 95% confidence level | ||
|---|---|---|---|---|
| v | u | k | ||
| 3 | 3.182 | 2.920 | 1.266 | 3.697 |
| 4 | 2.776 | 2.372 | 1.247 | 2.958 |
| 5 | 2.571 | 2.089 | 1.233 | 2.576 |
| 6 | 2.447 | 1.915 | 1.223 | 2.342 |
| 7 | 2.365 | 1.797 | 1.214 | 2.183 |
| 8 | 2.306 | 1.711 | 1.208 | 2.067 |
| 9 | 2.262 | 1.645 | 1.203 | 1.979 |
| 10 | 2.228 | 1.593 | 1.198 | 1.909 |
| 11 | 2.201 | 1.551 | 1.195 | 1.853 |
| 12 | 2.179 | 1.515 | 1.192 | 1.806 |
| 13 | 2.160 | 1.485 | 1.189 | 1.766 |
| 14 | 2.145 | 1.460 | 1.186 | 1.732 |
| 15 | 2.131 | 1.437 | 1.184 | 1.702 |
| 16 | 2.120 | 1.418 | 1.182 | 1.676 |
| 17 | 2.110 | 1.400 | 1.181 | 1.653 |
| 18 | 2.101 | 1.384 | 1.179 | 1.633 |
| 19 | 2.093 | 1.370 | 1.178 | 1.614 |
| 20 | 2.086 | 1.358 | 1.177 | 1.597 |
| 21 | 2.080 | 1.346 | 1.175 | 1.582 |
| 22 | 2.074 | 1.335 | 1.174 | 1.568 |
| 23 | 2.069 | 1.326 | 1.173 | 1.555 |
| 24 | 2.064 | 1.316 | 1.172 | 1.544 |
| 25 | 2.060 | 1.308 | 1.172 | 1.533 |
| 26 | 2.056 | 1.300 | 1.171 | 1.522 |
| 27 | 2.052 | 1.293 | 1.170 | 1.513 |
| 28 | 2.048 | 1.286 | 1.170 | 1.504 |
| 29 | 2.045 | 1.280 | 1.169 | 1.496 |
| 30 | 2.042 | 1.274 | 1.168 | 1.488 |
| 31 | 2.040 | 1.268 | 1.168 | 1.481 |
| 32 | 2.037 | 1.263 | 1.167 | 1.474 |
| 33 | 2.035 | 1.258 | 1.167 | 1.467 |
| 34 | 2.032 | 1.253 | 1.166 | 1.461 |
| 35 | 2.030 | 1.248 | 1.166 | 1.455 |
| 36 | 2.028 | 1.244 | 1.165 | 1.450 |
| 37 | 2.026 | 1.240 | 1.165 | 1.444 |
| 38 | 2.024 | 1.236 | 1.165 | 1.439 |
| 39 | 2.023 | 1.232 | 1.164 | 1.435 |
| 40 | 2.021 | 1.228 | 1.164 | 1.430 |
| 41 | 2.020 | 1.225 | 1.164 | 1.425 |
| 42 | 2.018 | 1.222 | 1.163 | 1.421 |
| 43 | 2.017 | 1.218 | 1.163 | 1.417 |
| 44 | 2.015 | 1.215 | 1.163 | 1.413 |
| 45 | 2.014 | 1.212 | 1.163 | 1.410 |
| 46 | 2.013 | 1.210 | 1.162 | 1.406 |
| 47 | 2.012 | 1.207 | 1.162 | 1.403 |
| 48 | 2.011 | 1.204 | 1.162 | 1.399 |
| 49 | 2.010 | 1.202 | 1.162 | 1.396 |
| 50 | 2.009 | 1.199 | 1.161 | 1.393 |
| 51 | 2.008 | 1.197 | 1.161 | 1.390 |
| 52 | 2.007 | 1.195 | 1.161 | 1.387 |
| 53 | 2.006 | 1.192 | 1.161 | 1.384 |
| 54 | 2.005 | 1.190 | 1.161 | 1.381 |
| 55 | 2.004 | 1.188 | 1.160 | 1.379 |
| 56 | 2.003 | 1.186 | 1.160 | 1.376 |
| 57 | 2.002 | 1.184 | 1.160 | 1.374 |
| 58 | 2.002 | 1.182 | 1.160 | 1.371 |
| 59 | 2.001 | 1.180 | 1.160 | 1.369 |
| 60 | 2.000 | 1.179 | 1.160 | 1.367 |
References 16.8 (t values) and 16.9 (v
Table 2 – 7-Day Drift Test Data
| Zero drift day # | Date and time | Zero check value (R | PM CEMS response (R | Difference (R | Zero drift ((R |
|---|---|---|---|---|---|
| 1 | |||||
| 2 | |||||
| 3 | |||||
| 4 | |||||
| 5 | |||||
| 6 | |||||
| 7 |
| Upscale drift day # | Date and time | Upscale check value (R | PM CEMS response (R | Difference (R | Upscale drift ((R |
|---|---|---|---|---|---|
| 1 | |||||
| 2 | |||||
| 3 | |||||
| 4 | |||||
| 5 | |||||
| 6 | |||||
| 7 |
1.1 Analyte. The analyte measured by these procedures and specifications is total vapor phase mercury (Hg) in the flue gas, which represents the sum of elemental Hg (Hg°, CAS Number 7439-97-6) and oxidized forms of gaseous Hg (Hg
1.2 Applicability.
1.2.1 This specification is for evaluating the acceptability of total vapor phase Hg continuous emission monitoring systems (CEMS) installed at stationary sources at the time of or soon after installation and whenever specified in the regulations. The Hg CEMS must be capable of measuring the total concentration in µg/m
1.2.2 This specification is not designed to evaluate an installed CEMS’s performance over an extended period of time nor does it identify specific calibration techniques and auxiliary procedures to assess the CEMS’s performance. The source owner or operator, however, is responsible to calibrate, maintain, and operate the CEMS properly. The Administrator may require, under section 114 of the Clean Air Act, the operator to conduct CEMS performance evaluations at other times besides the initial performance evaluation test. See §§ 60.13(c) and 63.8(e)(1).
1.2.3 Mercury monitoring approaches not entirely suited to these specifications may be approvable under the alternative monitoring or alternative test method provisions of § 60.13(i) and § 63.8(f) or § 60.8(b)(3) and § 63.7(f), respectively.
Procedures for determining CEMS relative accuracy, linearity, and calibration drift are outlined. CEMS installation and measurement location specifications, data reduction procedures, and performance criteria are included.
3.1 Continuous Emission Monitoring System (CEMS) means the total equipment required to measure a pollutant concentration. The system generally consists of the following three major subsystems:
3.2 Sample Interface means that portion of the CEMS used for one or more of the following: sample acquisition, sample transport, sample conditioning, and protection of the monitor from the effects of the stack effluent.
3.3 Hg Analyzer means that portion of the Hg CEMS that measures the total vapor phase Hg mass concentration and generates a proportional output.
3.4 Data Recorder means that portion of the CEMS that provides a permanent electronic record of the analyzer output. The data recorder may provide automatic data reduction and CEMS control capabilities.
3.5 Span Value means the measurement range as specified in the applicable regulation or other requirement. If the span is not specified in the applicable regulation or other requirement, then it must be a value approximately equivalent to two times the emission standard. Unless otherwise specified, the span value may be rounded up to the nearest multiple of 10.
3.6 Measurement Error Test means a test procedure in which the accuracy of the concentrations measured by a CEMS at three or more points over its measurement range is evaluated using reference gases. For Hg CEMS, elemental and oxidized Hg (Hg
3.7 Measurement Error (ME) means the absolute value of the difference between the concentration indicated by the CEMS and the known concentration of a reference gas, expressed as a percentage of the span value, when the entire CEMS, including the sampling interface, is challenged.
3.8 Calibration Drift (CD) means the absolute value of the difference between the CEMS output response and either an upscale Hg reference gas or a zero-level Hg reference gas, expressed as a percentage of the span value, when the entire CEMS, including the sampling interface, is challenged after a stated period of operation during which no unscheduled maintenance or repair took place.
3.9 Relative Accuracy Test Procedure means a test procedure consisting of at least nine test runs, in which the accuracy of the concentrations measured by a CEMS is evaluated by comparison against concurrent measurements made with a reference method (RM). Relative accuracy tests repeated on a regular, on-going basis are referred to as relative accuracy test audits or RATAs.
3.10 Relative Accuracy (RA) means the absolute mean difference between the pollutant concentrations determined by the CEMS and the values determined by the RM plus the 2.5 percent error confidence coefficient of a series of tests divided by the mean of the RM tests. Alternatively, for sources with an average RM concentration less than 5.0 micrograms per standard cubic meter (µg/scm), the RA may be expressed as the absolute value of the difference between the mean CEMS and RM values.
The procedures required under this performance specification may involve hazardous materials, operations, and equipment. This performance specification may not address all of the safety problems associated with these procedures. It is the responsibility of the user to establish appropriate safety and health practices and determine the applicable regulatory limitations prior to performing these procedures. The CEMS user’s manual and materials recommended by the RM should be consulted for specific precautions to be taken.
6.1 CEMS Equipment Specifications.
6.1.1 Data Recorder Scale. The Hg CEMS data recorder output range must include the full range of expected Hg concentration values in the gas stream to be sampled including zero and the span value.
6.1.2 The Hg CEMS design should also provide for the determination of CD and ME at a zero value (zero to 20 percent of the span value) and at upscale values (between 50 and 100 percent of the span value). The Hg CEMS must be constructed to permit the introduction of known concentrations of Hg and HgCl
6.2 Reference Gas Delivery System. The reference gas delivery system must be designed so that the flowrate exceeds the sampling system flow requirements of the CEMS and that the gas is delivered to the CEMS at atmospheric pressure.
6.3 Other equipment and supplies, as needed by the reference method used for the Relative Accuracy Test Procedure. See section 8.6.2.
7.1 Reference Gases. Reference gas standards are required for both elemental and oxidized Hg (Hg and mercuric chloride, HgCl
7.1.1 Zero-level. 0 to 20 percent of the span value.
7.1.2 Mid-level. 50 to 60 percent of the span value.
7.1.3 High-level. 80 to 100 percent of the span value.
7.2 Reference gas standards may also be required for the reference methods. See section 8.6.2.
8.1 Installation and Measurement Location Specifications.
8.1.1 CEMS Installation. Install the CEMS at an accessible location downstream of all pollution control equipment. Place the probe outlet or other sampling interface at a point or location in the stack (or vent) representative of the stack gas concentration of Hg. Since the Hg CEMS sample system normally extracts gas from a single point in the stack, a location that has been shown to be free of stratification for Hg or, alternatively, SO
8.1.2 Measurement Location. The measurement location should be (1) at least two equivalent diameters downstream of the nearest control device, point of pollutant generation or other point at which a change of pollutant concentration may occur, and (2) at least half an equivalent diameter upstream from the effluent exhaust. The equivalent duct diameter is calculated according to Method 1 in appendix A-1 to this part.
8.1.3 Hg CEMS Sample Extraction Point. Use a sample extraction point either (1) no less than 1.0 meter from the stack or duct wall, or (2) within the centroidal velocity traverse area of the stack or duct cross section. This does not apply to cross-stack, in-situ measurement systems.
8.2 Measurement Error (ME) Test Procedure. Sequentially inject each of at least three elemental Hg reference gases (zero, mid-level, and high level, as defined in section 7.1), three times each for a total of nine injections. Inject the gases in such a manner that the entire CEMS is challenged. Do not inject the same gas concentration twice in succession. At each reference gas concentration, determine the average of the three CEMS responses and subtract the average response from the reference gas value. Calculate the measurement error (ME) using Equation 12-1 by expressing the absolute value of the difference between the average CEMS response (A) and the reference gas value (R) as a percentage of the span (see example data sheet in Figure 12A-1). For each elemental Hg reference gas, the absolute value of the difference between the CEMS response and the reference value must not exceed 5 percent of the span value. If this specification is not met, identify and correct the problem before proceeding. Repeat the measurement error test procedure using oxidized Hg reference gases. For each oxidized Hg reference gas, the absolute value of the difference between the CEMS response and the reference value shall not exceed 10 percent of the span value. If this specification is not met, identify and correct the problem before proceeding.
8.3 Seven-Day Calibration Drift (CD) Test Procedure.
8.3.1 CD Test Period. While the affected facility is operating normally, or as specified in an applicable regulation, determine the magnitude of the CD once each day (at 24-hour intervals, to the extent practicable) for 7 consecutive unit operating days according to the procedures in sections 8.3.2 and 8.3.3. The 7 consecutive unit operating days need not be 7 consecutive calendar days. Use either Hg° or HgCl
8.3.2 The purpose of the CD measurement is to verify the ability of the CEMS to conform to the established CEMS response used for determining emission concentrations or emission rates. Therefore, if periodic automatic or manual adjustments are made to the CEMS zero and upscale response settings, conduct the CD test immediately before these adjustments, or conduct it in such a way that the CD can be determined.
8.3.3 Conduct the CD test using the zero gas specified and either the mid-level or high-level gas as specified in section 7.1. Sequentially introduce the reference gases to the CEMS at the sampling system of the CEMS immediately preceding the sample extraction filtration system. Record the CEMS response (A) for each reference gas and, using Equation 12A-2, subtract the corresponding reference value (R) from the CEMS value, and express the absolute value of the difference as a percentage of the span value (see also example data sheet in Figure 12A-2). For each reference gas, the absolute value of the difference between the CEMS response and the reference value must not exceed 5 percent of the span value. If these specifications are not met, identify and correct the problem before proceeding.
8.4 Relative Accuracy (RA) Test Procedure.
8.4.1 RA Test Period. Conduct the RA test according to the procedure given in sections 8.4.2 through 8.4.6 while the affected facility is operating normally, or as specified in an applicable subpart. The RA test may be conducted during the CD test period.
8.4.2 Reference Methods (RM). Unless otherwise specified in an applicable subpart of the regulations, use Method 29, Method 30A, or Method 30B in appendix A-8 to this part or American Society of Testing and Materials (ASTM) Method D6784-02 (incorporated by reference, see § 60.17) as the RM for Hg concentration. For Method 29 and ASTM Method D6784-02 only, the filterable portion of the sample need not be included when making comparisons to the CEMS results. When Method 29, Method 30B, or ASTM D6784-02 is used, conduct the RM test runs with paired or duplicate sampling systems and use the average of the vapor phase Hg concentrations measured by the two trains. When Method 30A is used, paired sampling systems are not required. If the RM and CEMS measure on a different moisture basis, data derived with Method 4 in appendix A-3 to this part must also be obtained during the RA test.
8.4.3 Sampling Strategy for RM Tests. Conduct the RM tests in such a way that they will yield results representative of the emissions from the source and can be compared to the CEMS data. The RM and CEMS locations need not be immediately adjacent. Locate the RM measurement points in accordance with section 8.1.3 of Performance Specification 2 (PS 2) in this appendix. It is preferable to conduct moisture measurements (if needed) and Hg measurements simultaneously, although moisture measurements that are taken within an hour of the Hg measurements may be used to adjust the Hg concentrations to a consistent moisture basis. In order to correlate the CEMS and RM data properly, note the beginning and end of each RM test period for each paired RM run (including the exact time of day) on the CEMS chart recordings or other permanent record of output.
8.4.4 Number and Length of RM Test Runs. Conduct a minimum of nine RM test runs. When Method 29, Method 30B, or ASTM D6784-02 is used, only test runs for which the paired RM trains meet the relative deviation criteria (RD) of this PS must be used in the RA calculations. In addition, for Method 29 and ASTM D6784-02, use a minimum sample time of 2 hours and for Methods 30A and 30B use a minimum sample time of 30 minutes.
More than nine sets of RM test runs may be performed. If this option is chosen, RM test run results may be excluded so long as the total number of RM test run results used to determine the CEMS RA is greater than or equal to nine. However, all data must be reported including the excluded test run data.
8.4.5 Correlation of RM and CEMS Data. Correlate the CEMS and the RM test data as to the time and duration by first determining from the CEMS final output (the one used for reporting) the integrated average pollutant concentration for each RM test period. Consider system response time, if important, and confirm that the results are on a consistent moisture basis with the RM test. Then, compare each integrated CEMS value against the corresponding RM value. When Method 29, Method 30B, or ASTM D6784-02 is used, compare each CEMS value against the corresponding average of the paired RM values.
8.4.6 Paired RM Outliers.
8.4.6.1 When Method 29, Method 30B, or ASTM D6784-02 is used, outliers are identified through the determination of relative deviation (RD) of the paired RM tests. Data that do not meet the RD criteria must be flagged as a data quality problem and may not be used in the calculation of RA. The primary reason for performing paired RM sampling is to ensure the quality of the RM data. The percent RD of paired data is the parameter used to quantify data quality. Determine RD for paired data points as follows:
8.4.6.2 The minimum performance criteria for RM Hg data is that RD for any data pair must be ≤10 percent as long as the mean Hg concentration is greater than 1.0 µg/m
8.4.7 Calculate the mean difference between the RM and CEMS values in the units of micrograms per cubic meter (µg/m
8.5 Reporting. At a minimum (check with the appropriate EPA Regional Office, State or local Agency for additional requirements, if any), summarize in tabular form the results of the CD tests, the linearity tests, and the RA test or alternative RA procedure, as appropriate. Include all data sheets, calculations, charts (records of CEMS responses), reference gas concentration certifications, and any other information necessary to confirm that the CEMS meets the performance criteria.
For Method 30A, sample collection and analysis are concurrent. For the other RM, post-run sample analyses are performed. Refer to the RM employed for specific analytical procedures.
Calculate and summarize the RA test results on a data sheet similar to Figure 12A-3.
12.1 Consistent Basis. All data from the RM and CEMS must be compared in units of micrograms per standard cubic meter (µg/scm), on a consistent and identified moisture basis. The values must be standardized to 20 °C, 760 mm Hg.
12.1.1 Moisture Correction (as applicable). If the RM and CEMS measure Hg on a different moisture basis, they will need to be corrected to a consistent basis. Use Equation 12A-4a to correct data from a wet basis to a dry basis.
Use Equation 12A-4b to correct data from a dry basis to a wet basis.
12.2 Arithmetic Mean. Calculate d
12.3 Standard Deviation. Calculate the standard deviation, S
12.3 Confidence Coefficient (CC). Calculate the 2.5 percent error confidence coefficient (one-tailed), CC, as follows:
12.4 Relative Accuracy. Calculate the RA of a set of data as follows:
13.1 Measurement Error (ME). For Hg
13.2 Calibration Drift (CD). The CD must not exceed 5 percent of the span value on any of the 7 days of the CD test.
13.3 Relative Accuracy (RA). The RA of the CEMS must be no greater than 20 percent of the mean value of the RM test data in terms of units of µg/scm. Alternatively, if the mean RM is less than 5.0 µg/scm, the results are acceptable if the absolute value of the difference between the mean RM and CEMS values does not exceed 1.0 µg/scm.
17.1 40 CFR part 60, appendix B, “Performance Specification 2 – Specifications and Test Procedures for SO
17.2 40 CFR part 60, appendix A, “Method 29 – Determination of Metals Emissions from Stationary Sources.”
17.3 40 CFR part 60, appendix A, “Method 30A – Determination of Total Vapor Phase Mercury Emissions From Stationary Sources (Instrumental Analyzer Procedure).
17.4 40 CFR part 60, appendix A, “Method 30B – Determination of Total Vapor Phase Mercury Emissions From Coal-Fired Combustion Sources Using Carbon Sorbent Traps.”
17.5 ASTM Method D6784-02, “Standard Test Method for Elemental, Oxidized, Particle-Bound and Total Mercury in Flue Gas Generated from Coal-Fired Stationary Sources (Ontario Hydro Method).”
Table 12A-1 – T-Values
| n a | t | n a | t | n a | t |
|---|---|---|---|---|---|
| 2 | 12.706 | 7 | 2.447 | 12 | 2.201 |
| 3 | 4.303 | 8 | 2.365 | 13 | 2.179 |
| 4 | 3.182 | 9 | 2.306 | 14 | 2.160 |
| 5 | 2.776 | 10 | 2.262 | 15 | 2.145 |
| 6 | 2.571 | 11 | 2.228 | 16 | 2.131 |
a The values in this table are already corrected for n-1 degrees of freedom. Use n equal to the number of individual values.
Figure 12A-1 – ME Determination
| Date | Time | Reference gas value (µg/m 3) | CEMS measured value (µg/m 3) | Absolute difference (µg/m 3) | ME (% of span value) | |
|---|---|---|---|---|---|---|
| Zero level | ||||||
| Average | ||||||
| Mid level | ||||||
| Average | ||||||
| High level | ||||||
| Average | ||||||
Figure 12A-2 – 7-Day Calibration Drift Determination
| Date | Time | Reference gas value (µg/m 3) | CEMS measured value (µg/m 3) | Absolute difference (µg/m 3) | CD (% of span value) | |
|---|---|---|---|---|---|---|
| Zero level | ||||||
| Upscale (Mid or High) | ||||||
Figure 12A-3 – Relative Accuracy Test Data
| Run No. | Date | Begin time | End time | RM value (µg/m 3) | CEMS value (µg/m 3) | Difference (µg/m 3) | Run used? (Yes/No) | RD 1 |
|---|---|---|---|---|---|---|---|---|
| 1 | ||||||||
| 2 | ||||||||
| 3 | ||||||||
| 4 | ||||||||
| 5 | ||||||||
| 6 | ||||||||
| 7 | ||||||||
| 8 | ||||||||
| 9 | ||||||||
| 10 | ||||||||
| 11 | ||||||||
| 12 | ||||||||
| Average Values | ||||||||
| Arithmetic Mean Difference: | ||||||||
| Standard Deviation: | ||||||||
| Confidence Coefficient: | ||||||||
| T-Value: | ||||||||
| % Relative Accuracy: | ||||||||
| | (RM) | ||||||||
1 Calculate the RD only if paired samples are taken using RM 30B, RM 29, or ASTM 6784-08. Express RD as a percentage or, for very low RM concentrations (≤1.0 µg/m
3), as the absolute difference between C
The purpose of Performance Specification 12B (PS 12B) is to establish performance benchmarks for, and to evaluate the acceptability of, sorbent trap monitoring systems used to monitor total vapor-phase mercury (Hg) emissions in stationary source flue gas streams. These monitoring systems involve continuous repetitive in-stack sampling using paired sorbent media traps with periodic analysis of the time-integrated samples. Persons using PS 12B should have a thorough working knowledge of Methods 1, 2, 3, 4, 5 and 30B in appendices A-1 through A-3 and A-8 to this part.
1.1 Analyte. The analyte measured by these procedures and specifications is total vapor phase Hg in the flue gas, which represents the sum of elemental Hg (Hg
1.2.1 These procedures are only intended for use under relatively low particulate conditions (e.g., monitoring after all pollution control devices). This specification is for evaluating the acceptability of total vapor phase Hg sorbent trap monitoring systems installed at stationary sources at the time of, or soon after, installation and whenever specified in the regulations. The Hg monitoring system must be capable of measuring the total concentration of vapor phase Hg (regardless of speciation), in units of µg/dscm.
1.2.2 This specification contains routine procedures and specifications designed to evaluate an installed sorbent trap monitoring system’s performance over time; Procedure 5 of appendix F to this part contains additional procedures and specifications which may be required for long term operation. In addition, the source owner or operator is responsible to calibrate, maintain, and operate the monitoring system properly. The Administrator may require the owner or operator, under section 114 of the Clean Air Act, to conduct performance evaluations at other times besides the initial test to evaluate the CEMS performance. See § 60.13(c) and 63.8(e)(1).
Known volumes of flue gas are continuously extracted from a stack or duct through paired, in-stack, pre-spiked sorbent media traps at appropriate nominal flow rates. The sorbent traps in the sampling system are periodically exchanged with new ones, prepared for analysis as needed, and analyzed by any technique that can meet the performance criteria. For quality-assurance purposes, a section of each sorbent trap is spiked with Hg
3.1 Sorbent Trap Monitoring System means the total equipment required for the collection of gaseous Hg samples using paired three-partition sorbent traps.
3.2 Relative Accuracy Test Procedure means a test procedure consisting of at least nine runs, in which the accuracy of the total vapor phase Hg concentrations measured by the sorbent trap monitoring system is evaluated by comparison against concurrent measurements made with a reference method (RM). Relative accuracy tests repeated on a regular, on-going basis are referred to as relative accuracy test audits or RATAs.
3.3 Relative Accuracy (RA) means the absolute mean difference between the pollutant (Hg) concentrations determined by the sorbent trap monitoring system and the values determined by the reference method (RM) plus the 2.5 percent error confidence coefficient of a series of tests divided by the mean of the RM tests. Alternatively, for low concentration sources, the RA may be expressed as the absolute value of the difference between the mean sorbent trap monitoring system and RM values.
3.4 Relative Deviation (RD) means the absolute difference of the Hg concentration values obtained with a pair of sorbent traps divided by the sum of those concentrations, expressed as a percentage. RD is used to assess the precision of the sorbent trap monitoring system.
3.5 Spike Recovery means the mass of Hg recovered from the spiked trap section, expressed as a percentage of the amount spiked. Spike recovery is used to assess sample matrix interference.
The procedures required under this performance specification may involve hazardous materials, operations, and equipment. This performance specification may not address all of the safety problems associated with these procedures. It is the responsibility of the user to establish appropriate safety and health practices and determine the applicable regulatory limitations prior to performing these procedures.
6.1 Sorbent Trap Monitoring System Equipment Specifications.
6.1.1 Monitoring System. The equipment described in Method 30B in appendix A-8 to this part must be used to continuously sample for Hg emissions, with the substitution of three-section traps in place of two-section traps, as described below. A typical sorbent trap monitoring system is shown in Figure 12B-1.
6.1.2 Three-Section Sorbent Traps. The sorbent media used to collect Hg must be configured in traps with three distinct and identical segments or sections, connected in series, to be separately analyzed. section 1 is designated for primary capture of gaseous Hg. section 2 is designated as a backup section for determination of vapor-phase Hg breakthrough. section 3 is designated for quality assurance/quality control (QA/QC) purposes. section 3 must be spiked with a known amount of gaseous Hg
6.1.3 Gaseous Hg
6.1.4 Sample Analysis Equipment. Any analytical system capable of quantitatively recovering and quantifying total gaseous Hg from sorbent media is acceptable provided that the analysis can meet the performance criteria in Table 12B-1 in section 9 of this performance specification. Candidate recovery techniques include leaching, digestion, and thermal desorption. Candidate analytical techniques include ultraviolet atomic fluorescence (UV AF); ultraviolet atomic absorption (UV AA), with and without gold trapping; and in-situ X-ray fluorescence (XRF).
Only NIST-certified or NIST-traceable calibration gas standards and reagents must be used for the tests and procedures required under this performance specification. The sorbent media may be any collection material (e.g., carbon, chemically treated filter, etc.) capable of quantitatively capturing and recovering for subsequent analysis, all gaseous forms of Hg in the emissions from the intended application. Selection of the sorbent media must be based on the material’s ability to achieve the performance criteria contained in this method as well as the sorbent’s vapor phase Hg capture efficiency for the emissions matrix and the expected sampling duration at the test site.
8.1 Installation and Measurement Location Specifications.
8.1.1 Selection of Monitoring Site. Sampling site information should be obtained in accordance with Method 1 in appendix A-1 to this part. Place the probe inlet at a point or location in the stack (or vent) downstream of all pollution control equipment and representative of the stack gas concentration of Hg. A location that has been shown to be free of stratification for Hg or, alternatively, SO
8.1.2 Pre-sampling Spiking of Sorbent Traps. Based on the estimated Hg concentration in the stack, the target sample rate and the target sampling duration, calculate the expected mass loading for section 1 of each sorbent trap (see section 12.1 of this performance specification). The pre-sampling spike to be added to section 3 of each sorbent trap must be within ±50 percent of the expected section 1 mass loading. Spike section 3 of each sorbent trap at this level, as described in section 6.1.3 of this performance specification. For each sorbent trap, keep a record of the mass of Hg
8.1.3 Pre-monitoring Leak Check. Perform a leak check with the sorbent traps in place in the sampling system. Draw a vacuum in each sample train. Adjust the vacuum in each sample train to ∼15″ Hg. Use the gas flow meter to determine leak rate. The leakage rate must not exceed 4 percent of the target sampling rate. Once the leak check passes this criterion, carefully release the vacuum in the sample train, then seal the sorbent trap inlet until the probe is ready for insertion into the stack or duct.
8.1.4 Determination of Flue Gas Characteristics. Determine or measure the flue gas measurement environment characteristics (gas temperature, static pressure, gas velocity, stack moisture, etc.) in order to determine ancillary requirements such as probe heating requirements (if any), sampling rate, proportional sampling conditions, moisture management, etc.
8.2 Monitoring.
8.2.1 System Preparation and Initial Data Recording. Remove the plug from the end of each sorbent trap and store each plug in a clean sorbent trap storage container. Remove the stack or duct port cap and insert the probe(s) with the inlet(s) aligned perpendicular to the stack gas flow. Secure the probe(s) and ensure that no leakage occurs between the duct and environment. Record initial data including the sorbent trap ID, start time, starting gas flow meter readings, initial temperatures, set points, and any other appropriate information.
8.2.2 Flow Rate Control. Set the initial sample flow rate at the target value from section 8.1.1 of this performance specification. Then, for every operating hour during the sampling period, record the date and time, the sample flow rate, the gas flow meter reading, the stack temperature (if needed), the flow meter temperatures (if needed), temperatures of heated equipment such as the vacuum lines and the probes (if heated), and the sampling system vacuum readings. Also, record the stack gas flow rate and the ratio of the stack gas flow rate to the sample flow rate. Adjust the sampling flow rate to maintain proportional sampling, i.e., keep the ratio of the stack gas flow rate to sample flow rate within ±25 percent of the reference ratio from the first hour of the data collection period (see section 12.2 of this performance specification). The sample flow rate through a sorbent trap monitoring system during any hour (or portion of an hour) that the unit is not operating must be zero.
8.2.3 Stack Gas Moisture Determination. If data from the sorbent trap monitoring system will be used to calculate Hg mass emissions, determine the stack gas moisture content using a continuous moisture monitoring system or other means acceptable to the Administrator, such as the ones described in § 75.11(b) of this chapter. Alternatively, for combustion of coal, wood, or natural gas in boilers only, a default moisture percentage from § 75.11(b) of this chapter may be used.
8.2.4 Essential Operating Data. Obtain and record any essential operating data for the facility during the test period, e.g., the barometric pressure for correcting the sample volume measured by a dry gas meter to standard conditions. At the end of the data collection period, record the final gas flow meter reading and the final values of all other essential parameters.
8.2.5 Post-monitoring Leak Check. When the monitoring period is completed, turn off the sample pump, remove the probe/sorbent trap from the port and carefully re-plug the end of each sorbent trap. Perform a leak check with the sorbent traps in place, at the maximum vacuum reached during the monitoring period. Use the same general approach described in section 8.1.3 of this performance specification. Record the leakage rate and vacuum. The leakage rate must not exceed 4 percent of the average sampling rate for the monitoring period. Following the leak check, carefully release the vacuum in the sample train.
8.2.6 Sample Recovery. Recover each sampled sorbent trap by removing it from the probe and seal both ends. Wipe any deposited material from the outside of the sorbent trap. Place the sorbent trap into an appropriate sample storage container and store/preserve it in an appropriate manner.
8.2.7 Sample Preservation, Storage, and Transport. While the performance criteria of this approach provide for verification of appropriate sample handling, it is still important that the user consider, determine, and plan for suitable sample preservation, storage, transport, and holding times for these measurements. Therefore, procedures in recognized voluntary consensus standards such as those in ASTM D6911-03 “Standard Guide for Packaging and Shipping Environmental Samples for Laboratory Analysis” should be followed for all samples.
8.2.8 Sample Custody. Proper procedures and documentation for sample chain of custody are critical to ensuring data integrity. Chain of custody procedures in recognized voluntary consensus standards such as those in ASTM D4840-99 “Standard Guide for Sample Chain-of-Custody Procedures” should be followed for all samples (including field samples and blanks).
8.3 Relative Accuracy (RA) Test Procedure
8.3.1 For the initial certification of a sorbent trap monitoring system, a RA Test is required. Follow the basic RA test procedures and calculation methodology described in sections 8.4.1 through 8.4.7 and 12.4 of PS 12A in this appendix, replacing the term “CEMS” with “sorbent trap monitoring system”.
8.3.2 Special Considerations. The type of sorbent material used in the traps must be the same as that used for daily operation of the monitoring system; however, the size of the traps used for the RA test may be smaller than the traps used for daily operation of the system. Spike the third section of each sorbent trap with elemental Hg, as described in section 8.1.2 of this performance specification. Install a new pair of sorbent traps prior to each test run. For each run, the sorbent trap data must be validated according to the quality assurance criteria in Table 12B-1 in section 9.0, below.
8.3.3 Acceptance Criteria. The RA of the sorbent trap monitoring system must be no greater than 20 percent of the mean value of the RM test data in terms of units of µg/scm. Alternatively, if the RM concentration is less than or equal to 5.0 µg/scm, then the RA results are acceptable if the absolute difference between the means of the RM and sorbent trap monitoring system values does not exceed 1.0 µg/scm.
Table 12B-1 summarizes the QA/QC performance criteria that are used to validate the Hg emissions data from a sorbent trap monitoring system. Failure to achieve these performance criteria will result in invalidation of Hg emissions data, except where otherwise noted.
Table 12B-1 – QA/QC Criteria for Sorbent Trap Monitoring Systems
| QA/QC test or specification | Acceptance criteria | Frequency | Consequences if not met |
|---|---|---|---|
| Pre-test leak check | ≤4% of target sampling rate | Prior to monitoring | Monitoring must not commence until the leak check is passed. |
| Post-test leak check | ≤4% of average sampling rate | After monitoring | Invalidate the data from the paired traps or, if certain conditions are met, report adjusted data from a single trap (see Section 12.8.3). |
| Ratio of stack gas flow rate to sample flow rate | No more than 5% of the hourly ratios or 5 hourly ratios (whichever is less restrictive) may deviate from the reference ratio by more than ±25% | Every hour throughout monitoring period | Invalidate the data from the paired traps or, if certain conditions are met, report adjusted data from a single trap (see Section 12.8.3). |
| Sorbent trap section 2 breakthrough | ≤5% of Section 1 Hg mass ≤10% of Section 1 Hg mass if average Hg concentration is ≤0.5 µg/scm | Every sample | Invalidate the data from the paired traps or, if certain conditions are met, report adjusted data from a single trap (see Section 12.8.3). |
| No criterion when Hg concentration for trap less than 10% of the applicable emission limit (must meet all other QA/QC specifications) | |||
| Paired sorbent trap agreement | ≤10% Relative Deviation (RD) if the average concentration is > 1.0 µg/m 3 ≤20% RD if the average concentration is ≤1.0 µg/m 3 | Every sample | Either invalidate the data from the paired traps or report the results from the trap with the higher Hg concentration. |
| Results also acceptable if absolute difference between concentrations from paired traps is ≤ 0.03 µg/m 3 | |||
| Spike Recovery Study | Average recovery between 85% and 115% for each of the 3 spike concentration levels | Prior to analyzing field samples and prior to use of new sorbent media | Field samples must not be analyzed until the percent recovery criteria have been met. |
| Multipoint analyzer calibration | Each analyzer reading within ±10% of true value and r 2 ≥ 0.99 | On the day of analysis, before analyzing any samples | Recalibrate until successful. |
| Analysis of independent calibration standard | Within ±10% of true value | Following daily calibration, prior to analyzing field samples | Recalibrate and repeat independent standard analysis until successful. |
| Spike recovery from section 3 of both sorbent traps | 75-125% of spike amount | Every sample | Invalidate the data from the paired traps or, if certain conditions are met, report adjusted data from a single trap (see Section 12.8.3). |
| Relative Accuracy | RA ≤ 20.0% of RM mean value; or if RM mean value ≤5.0 µg/scm, absolute difference between RM and sorbent trap monitoring system mean values ≤1.0 µg/scm | RA specification must be met for initial certification | Data from the system are invalid until a RA test is passed. |
| Gas flow meter calibration | An initial calibration factor (Y) has been determined at 3 settings; for mass flow meters, initial calibration with stack gas has been performed. For subsequent calibrations, Y within ±5% of average value from the most recent 3-point calibration | At 3 settings prior to initial use and at least quarterly at one setting thereafter | Recalibrate meter at 3 settings to determine a new value of Y. |
| Temperature sensor calibration | Absolute temperature measured by sensor within ±1.5% of a reference sensor | Prior to initial use and at least quarterly thereafter | Recalibrate; sensor may not be used until specification is met. |
| Barometer calibration | Absolute pressure measured by instrument within ±10 mm Hg of reading with a NIST-traceable barometer | Prior to initial use and at least quarterly thereafter | Recalibrate; instrument may not be used until specification is met. |
10.1 Gaseous and Liquid Standards. Only NIST certified or NIST-traceable calibration standards (i.e., calibration gases, solutions, etc.) must be used for the spiking and analytical procedures in this performance specification.
10.2 Gas Flow Meter Calibration. The manufacturer or supplier of the gas flow meter should perform all necessary set-up, testing, programming, etc., and should provide the end user with any necessary instructions, to ensure that the meter will give an accurate readout of dry gas volume in standard cubic meters for the particular field application.
10.2.1 Initial Calibration. Prior to its initial use, a calibration of the flow meter must be performed. The initial calibration may be done by the manufacturer, by the equipment supplier, or by the end user. If the flow meter is volumetric in nature (e.g., a dry gas meter), the manufacturer, equipment supplier, or end user may perform a direct volumetric calibration using any gas. For a mass flow meter, the manufacturer, equipment supplier, or end user may calibrate the meter using a bottled gas mixture containing 12 ±0.5% CO
10.2.1.1 Initial Calibration Procedures. Determine an average calibration factor (Y) for the gas flow meter, by calibrating it at three sample flow rate settings covering the range of sample flow rates at which the sorbent trap monitoring system typically operates. Either the procedures in section 10.3.1 of Method 5 in appendix A-3 to this part or the procedures in section 16 of Method 5 in appendix A-3 to this part may be followed. If a dry gas meter is being calibrated, use at least five revolutions of the meter at each flow rate.
10.2.1.2 Alternative Initial Calibration Procedures. Alternatively, the initial calibration of the gas flow meter may be performed using a reference gas flow meter (RGFM). The RGFM may be either: (1) A wet test meter calibrated according to section 10.3.1 of Method 5 in appendix A-3 to this part; (2) A gas flow metering device calibrated at multiple flow rates using the procedures in section 16 of Method 5 in appendix A-3 to this part; or (3) A NIST-traceable calibration device capable of measuring volumetric flow to an accuracy of 1 percent. To calibrate the gas flow meter using the RGFM, proceed as follows: While the sorbent trap monitoring system is sampling the actual stack gas or a compressed gas mixture that simulates the stack gas composition (as applicable), connect the RGFM to the discharge of the system. Care should be taken to minimize the dead volume between the sample flow meter being tested and the RGFM. Concurrently measure dry gas volume with the RGFM and the flow meter being calibrated for a minimum of 10 minutes at each of three flow rates covering the typical range of operation of the sorbent trap monitoring system. For each 10-minute (or longer) data collection period, record the total sample volume, in units of dry standard cubic meters (dscm), measured by the RGFM and the gas flow meter being tested.
10.2.1.3 Initial Calibration Factor. Calculate an individual calibration factor Yi at each tested flow rate from section 10.2.1.1 or 10.2.1.2 of this performance specification (as applicable), by taking the ratio of the reference sample volume to the sample volume recorded by the gas flow meter. Average the three Yi values, to determine Y, the calibration factor for the flow meter. Each of the three individual values of Yi must be within ±0.02 of Y. Except as otherwise provided in sections 10.2.1.4 and 10.2.1.5 of this performance specification, use the average Y value from the three level calibration to adjust all subsequent gas volume measurements made with the gas flow meter.
10.2.2 Initial On-Site Calibration Check. For a mass flow meter that was initially calibrated using a compressed gas mixture, an on-site calibration check must be performed before using the flow meter to provide data. While sampling stack gas, check the calibration of the flow meter at one intermediate flow rate typical of normal operation of the monitoring system. Follow the basic procedures in section 10.2.1.1 or 10.2.1.2 of this performance specification. If the onsite calibration check shows that the value of Yi, the calibration factor at the tested flow rate, differs by more than 5 percent from the value of Y obtained in the initial calibration of the meter, repeat the full 3-level calibration of the meter using stack gas to determine a new value of Y, and apply the new Y value to all subsequent gas volume measurements made with the gas flow meter.
10.2.3 Ongoing Quality Control. Recalibrate the gas flow meter quarterly at one intermediate flow rate setting representative of normal operation of the monitoring system. Follow the basic procedures in section 10.2.1.1 or 10.2.1.2 of this performance specification. If a quarterly recalibration shows that the value of Yi, the calibration factor at the tested flow rate, differs from the current value of Y by more than 5 percent, repeat the full 3-level calibration of the meter to determine a new value of Y, and apply the new Y value to all subsequent gas volume measurements made with the gas flow meter.
10.3 Calibration of Thermocouples and Other Temperature Sensors. Use the procedures and criteria in section 10.3 of Method 2 in appendix A-1 to this part to calibrate in-stack temperature sensors and thermocouples. Calibrations must be performed prior to initial use and at least quarterly thereafter. At each calibration point, the absolute temperature measured by the temperature sensor must agree to within ±1.5 percent of the temperature measured with the reference sensor, otherwise the sensor may not continue to be used.
10.4 Barometer Calibration. Calibrate the barometer against another barometer that has a NIST-traceable calibration. This calibration must be performed prior to initial use and at least quarterly thereafter. At each calibration point, the absolute pressure measured by the barometer must agree to within ±10 mm Hg of the pressure measured by the NIST-traceable barometer, otherwise the barometer may not continue to be used.
10.5 Calibration of Other Sensors and Gauges. Calibrate all other sensors and gauges according to the procedures specified by the instrument manufacturer(s).
10.6 Analytical System Calibration. See section 11.1 of this performance specification.
The analysis of the Hg samples may be conducted using any instrument or technology capable of quantifying total Hg from the sorbent media and meeting the performance criteria in section 9 of this performance specification.
11.1 Analyzer System Calibration. Perform a multipoint calibration of the analyzer at three or more upscale points over the desired quantitative range (multiple calibration ranges must be calibrated, if necessary). The field samples analyzed must fall within a calibrated, quantitative range and meet the necessary performance criteria. For samples that are suitable for aliquotting, a series of dilutions may be needed to ensure that the samples fall within a calibrated range. However, for sorbent media samples that are consumed during analysis (e.g., thermal desorption techniques), extra care must be taken to ensure that the analytical system is appropriately calibrated prior to sample analysis. The calibration curve range(s) should be determined based on the anticipated level of Hg mass on the sorbent media. Knowledge of estimated stack Hg concentrations and total sample volume may be required prior to analysis. The calibration curve for use with the various analytical techniques (e.g., UV AA, UV AF, and XRF) can be generated by directly introducing standard solutions into the analyzer or by spiking the standards onto the sorbent media and then introducing into the analyzer after preparing the sorbent/standard according to the particular analytical technique. For each calibration curve, the value of the square of the linear correlation coefficient, i.e., r
11.2 Sample Preparation. Carefully separate the three sections of each sorbent trap. Combine for analysis all materials associated with each section, i.e., any supporting substrate that the sample gas passes through prior to entering a media section (e.g., glass wool, polyurethane foam, etc.) must be analyzed with that segment.
11.3 Spike Recovery Study. Before analyzing any field samples, the laboratory must demonstrate the ability to recover and quantify Hg from the sorbent media by performing the following spike recovery study for sorbent media traps spiked with elemental mercury. Using the procedures described in sections 6.2 and 12.1 of this performance specification, spike the third section of nine sorbent traps with gaseous Hg
11.4 Field Sample Analyses. Analyze the sorbent trap samples following the same procedures that were used for conducting the spike recovery study. The three sections of each sorbent trap must be analyzed separately (i.e., section 1, then section 2, then section 3). Quantify the total mass of Hg for each section based on analytical system response and the calibration curve from section 11.1 of this performance specification. Determine the spike recovery from sorbent trap section 3. The spike recovery must be no less than 75 percent and no greater than 125 percent. To report the final Hg mass for each trap, add together the Hg masses collected in trap sections 1 and 2.
12.1 Calculation of Pre-Sampling Spiking Level. Determine sorbent trap section 3 spiking level using estimates of the stack Hg concentration, the target sample flow rate, and the expected monitoring period. Calculate M
A pre-sampling spike of 10.8 µg ±50 percent is, therefore, appropriate.
12.2 Calculations for Flow-Proportional Sampling. For the first hour of the data collection period, determine the reference ratio of the stack gas volumetric flow rate to the sample flow rate, as follows:
Then, for each subsequent hour of the data collection period, calculate ratio of the stack gas flow rate to the sample flow rate using Equation 12B-3:
Maintain the value of R
12.3 Calculation of Spike Recovery. Calculate the percent recovery of each section 3 spike, as follows:
12.4 Calculation of Breakthrough. Calculate the percent breakthrough to the second section of the sorbent trap, as follows:
12.5 Calculation of Hg Concentration. Calculate the Hg concentration for each sorbent trap, using the following equation:
12.6 Calculation of Paired Trap Agreement. Calculate the relative deviation (RD) between the Hg concentrations measured with the paired sorbent traps:
12.7 Calculation of Relative Accuracy. Calculate the relative accuracy as described in section 12.4 of PS 12A in this appendix.
12.8 Data Reduction. Typical monitoring periods for normal, day-to-day operation of a sorbent trap monitoring system range from about 24 hours to 168 hours. For the required RA tests of the system, smaller sorbent traps are often used, and the “monitoring period” or time per run is considerably shorter (e.g., 1 hour or less). Generally speaking, to validate sorbent trap monitoring system data, the acceptance criteria for the following five QC specifications in Table 12B-1 above must be met for both traps: (a) the post-monitoring leak check; (b) the ratio of stack gas flow rate to sample flow rate; (c) section 2 breakthrough; (d) paired trap agreement; and (e) section 3 spike recovery.
12.8.1 For routine day-to-day operation of a sorbent trap monitoring system, when both traps meet the acceptance criteria for all five QC specifications, the two measured Hg concentrations must be averaged arithmetically and the average value must be applied to each hour of the data collection period.
12.8.2 To validate a RA test run, both traps must meet the acceptance criteria for all five QC specifications. However, as specified in section 12.8.3 below, for routine day-to-day operation of the monitoring system, a monitoring period may, in certain instances, be validated based on the results from one trap.
12.8.3 For the routine, day-to-day operation of the monitoring system, when one of the two sorbent trap samples or sampling systems either: (a) Fails the post-monitoring leak check; or (b) has excessive section 2 breakthrough; or (c) fails to maintain the proper stack flow-to-sample flow ratio; or (d) fails to achieve the required section 3 spike recovery; or (e) is lost, broken, or damaged, provided that the other trap meets the acceptance criteria for all four of these QC specifications, the Hg concentration measured by the valid trap may be multiplied by a factor of 1.111 and then used for reporting purposes. Further, if both traps meet the acceptance criteria for all four of these QC specifications, but the acceptance criterion for paired trap agreement is not met, the owner or operator may report the higher of the two Hg concentrations measured by the traps, in lieu of invalidating the data from the paired traps.
12.8.4 Whenever the data from a pair of sorbent traps must be invalidated and no quality-assured data from a certified backup Hg monitoring system or Hg reference method are available to cover the hours in the data collection period, treat those hours in the manner specified in the applicable regulation (i.e., use missing data substitution procedures or count the hours as monitoring system down time, as appropriate).
These monitoring criteria and procedures have been successfully applied to coal-fired utility boilers (including units with post-combustion emission controls), having vapor-phase Hg concentrations ranging from 0.03 µg/dscm to approximately 100 µg/dscm.
17.1 40 CFR Part 60, Appendix B, “Performance Specification 2 – Specifications and Test Procedures for SO
17.2 40 CFR Part 60, Appendix B, “Performance Specification 12A – Specifications and Test Procedures for Total Vapor Phase Mercury Continuous Emission Monitoring Systems in Stationary Sources.”
1.1 Analytes. This performance specification is applicable for measuring all hazardous air pollutants (HAPs) which absorb in the infrared region and can be quantified using Fourier Transform Infrared Spectroscopy (FTIR), as long as the performance criteria of this performance specification are met. This specification is to be used for evaluating FTIR continuous emission monitoring systems for measuring HAPs regulated under Title III of the 1990 Clean Air Act Amendments. This specification also applies to the use of FTIR CEMs for measuring other volatile organic or inorganic species.
1.2 Applicability. A source which can demonstrate that the extractive FTIR system meets the criteria of this performance specification for each regulated pollutant may use the FTIR system to continuously monitor for the regulated pollutants.
For compound-specific sampling requirements refer to FTIR sampling methods (e.g., reference 1). For data reduction procedures and requirements refer to the EPA FTIR Protocol (reference 2), hereafter referred to as the “FTIR Protocol.” This specification describes sampling and analytical procedures for quality assurance. The infrared spectrum of any absorbing compound provides a distinct signature. The infrared spectrum of a mixture contains the superimposed spectra of each mixture component. Thus, an FTIR CEM provides the capability to continuously measure multiple components in a sample using a single analyzer. The number of compounds that can be speciated in a single spectrum depends, in practice, on the specific compounds present and the test conditions.
For a list of definitions related to FTIR spectroscopy refer to Appendix A of the FTIR Protocol. Unless otherwise specified, spectroscopic terms, symbols and equations in this performance specification are taken from the FTIR Protocol or from documents cited in the Protocol. Additional definitions are given below.
3.1 FTIR Continuous Emission Monitoring System (FTIR CEM).
3.1.1 FTIR System. Instrument to measure spectra in the mid-infrared spectral region (500 to 4000 cm
3.1.2 Gas Cell. A gas containment cell that can be evacuated. It contains the sample as the infrared beam passes from the interferometer, through the sample, and to the detector. The gas cell may have multi-pass mirrors depending on the required detection limit(s) for the application.
3.1.3 Sampling System. Equipment used to extract sample from the test location and transport the gas to the FTIR analyzer. Sampling system components include probe, heated line, heated non-reactive pump, gas distribution manifold and valves, flow measurement devices and any sample conditioning systems.
3.2 Reference CEM. An FTIR CEM, with sampling system, that can be used for comparison measurements.
3.3 Infrared Band (also Absorbance Band or Band). Collection of lines arising from rotational transitions superimposed on a vibrational transition. An infrared absorbance band is analyzed to determine the analyte concentration.
3.4 Sample Analysis. Interpreting infrared band shapes, frequencies, and intensities to obtain sample component concentrations. This is usually performed by a software routine using a classical least squares (cls), partial least squares (pls), or K- or P- matrix method.
3.5 (Target) Analyte. A compound whose measurement is required, usually to some established limit of detection and analytical uncertainty.
3.6 Interferant. A compound in the sample matrix whose infrared spectrum overlaps at least part of an analyte spectrum complicating the analyte measurement. The interferant may not prevent the analyte measurement, but could increase the analytical uncertainty in the measured concentration. Reference spectra of interferants are used to distinguish the interferant bands from the analyte bands. An interferant for one analyte may not be an interferant for other analytes.
3.7 Reference Spectrum. Infrared spectra of an analyte, or interferant, prepared under controlled, documented, and reproducible laboratory conditions (see section 4.6 of the FTIR Protocol). A suitable library of reference spectra can be used to measure target analytes in gas samples.
3.8 Calibration Spectrum. Infrared spectrum of a compound suitable for characterizing the FTIR instrument configuration (Section 4.5 in the FTIR Protocol).
3.9 One hundred percent line. A double beam transmittance spectrum obtained by combining two successive background single beam spectra. Ideally, this line is equal to 100 percent transmittance (or zero absorbance) at every point in the spectrum. The zero absorbance line is used to measure the RMS noise of the system.
3.10 Background Deviation. Any deviation (from 100 percent) in the one hundred percent line (or from zero absorbance). Deviations greater than ±5 percent in any analytical region are unacceptable. Such deviations indicate a change in the instrument throughput relative to the single-beam background.
3.11 Batch Sampling. A gas cell is alternately filled and evacuated. A Spectrum of each filled cell (one discreet sample) is collected and saved.
3.12 Continuous Sampling. Sample is continuously flowing through a gas cell. Spectra of the flowing sample are collected at regular intervals.
3.13 Continuous Operation. In continuous operation an FTIR CEM system, without user intervention, samples flue gas, records spectra of samples, saves the spectra to a disk, analyzes the spectra for the target analytes, and prints concentrations of target analytes to a computer file. User intervention is permitted for initial set-up of sampling system, initial calibrations, and periodic maintenance.
3.14 Sampling Time. In batch sampling – the time required to fill the cell with flue gas. In continuous sampling – the time required to collect the infrared spectrum of the sample gas.
3.15 PPM-Meters. Sample concentration expressed as the concentration-path length product, ppm (molar) concentration multiplied by the path length of the FTIR gas cell. Expressing concentration in these units provides a way to directly compare measurements made using systems with different optical configurations. Another useful expression is (ppm-meters)/K, where K is the absolute temperature of the sample in the gas cell.
3.16 CEM Measurement Time Constant. The Time Constant (TC, minutes for one cell volume to flow through the cell) determines the minimum interval for complete removal of an analyte from the FTIR cell. It depends on the sampling rate (R
3.17 Independent Measurement. Two independent measurements are spectra of two independent samples. Two independent samples are separated by, at least 5 cell volumes. The interval between independent measurements depends on the cell volume and the sample flow rate (through the cell). There is no mixing of gas between two independent samples. Alternatively, estimate the analyte residence time empirically: (1) Fill cell to ambient pressure with a (known analyte concentration) gas standard, (2) measure the spectrum of the gas standard, (3) purge the cell with zero gas at the sampling rate and collect a spectrum every minute until the analyte standard is no longer detected spectroscopically. If the measured time corresponds to less than 5 cell volumes, use 5 * TC as the minimum interval between independent measurements. If the measured time is greater than 5 * TC, then use this time as the minimum interval between independent measurements.
3.18 Test Condition. A period of sampling where all process, and sampling conditions, and emissions remain constant and during which a single sampling technique and a single analytical program are used. One Run may include results for more than one test condition. Constant emissions means that the composition of the emissions remains approximately stable so that a single analytical program is suitable for analyzing all of the sample spectra. A greater than two-fold change in analyte or interferant concentrations or the appearance of additional compounds in the emissions, may constitute a new test condition and may require modification of the analytical program.
3.19 Run. A single Run consists of spectra (one spectrum each) of at least 10 independent samples over a minimum of one hour. The concentration results from the spectra can be averaged together to give a run average for each analyte measured in the test run.
Several compounds, including water, carbon monoxide, and carbon dioxide, are known interferences in the infrared region in which the FTIR instrument operates. Follow the procedures in the FTIR protocol for subtracting or otherwise dealing with these and other interferences.
The procedures required under this performance specification may involve hazardous materials, operations, and equipment. This performance specification may not address all of the safety problems associated with these procedures. It is the responsibility of the user to establish appropriate safety and health practices and determine the applicable regulatory limitations prior to performing these procedures. The CEMS users manual and materials recommended by this performance specification should be consulted for specific precautions to be taken.
6.1 Installation of sampling equipment should follow requirements of FTIR test Methods such as references 1 and 3 and the EPA FTIR Protocol (reference 2). Select test points where the gas stream composition is representative of the process emissions. If comparing to a reference method, the probe tips for the FTIR CEM and the RM should be positioned close together using the same sample port if possible.
6.2 FTIR Specifications. The FTIR CEM must be equipped with reference spectra bracketing the range of path length-concentrations (absorbance intensities) to be measured for each analyte. The effective concentration range of the analyzer can be adjusted by changing the path length of the gas cell or by diluting the sample. The optical configuration of the FTIR system must be such that maximum absorbance of any target analyte is no greater than 1.0 and the minimum absorbance of any target analyte is at least 10 times the RMSD noise in the analytical region. For example, if the measured RMSD in an analytical region is equal to 10
6.3 Data Storage Requirements. The system must have sufficient capacity to store all data collected in one week of routine sampling. Data must be stored to a write-protected medium, such as write-once-read-many (WORM) optical storage medium or to a password protected remote storage location. A back-up copy of all data can be temporarily saved to the computer hard drive. The following items must be stored during testing.
• At least one sample interferogram per sampling Run or one interferogram per hour, whichever is greater. This assumes that no sampling or analytical conditions have changed during the run.
• All sample absorbance spectra (about 12 per hr, 288 per day).
• All background spectra and interferograms (variable, but about 5 per day).
• All CTS spectra and interferograms (at least 2 each 24 hour period).
• Documentation showing a record of resolution, path length, apodization, sampling time, sampling conditions, and test conditions for all sample, CTS, calibration, and background spectra.
Using a resolution of 0.5 cm
These procedures shall be used for periodic quarterly or semiannual QA/QC checks on the operation of the FTIR CEM. Some procedures test only the analytical program and are not intended as a test of the sampling system.
9.1 Audit Sample. This can serve as a check on both the sampling system and the analytical program.
9.1.1 Sample Requirements. The audit sample can be a mixture or a single component. It must contain target analyte(s) at approximately the expected flue gas concentration(s). If possible, each mixture component concentration should be NIST traceable (±2 percent accuracy). If a cylinder mixture standard(s) cannot be obtained, then, alternatively, a gas phase standard can be generated from a condensed phase analyte sample. Audit sample contents and concentrations are not revealed to the FTIR CEM operator until after successful completion of procedures in 5.3.2.
9.1.2 Test Procedure. Spike the audit sample using the analyte spike procedure in section 11. The audit sample is measured directly by the FTIR system (undiluted) and then spiked into the effluent at a known dilution ratio. Measure a series of spiked and unspiked samples using the same procedures as those used to analyze the stack gas. Analyze the results using sections 12.1 and 12.2. The measured concentration of each analyte must be within ±5 percent of the expected concentration (plus the uncertainty), i.e., the calculated correction factor must be within 0.93 and 1.07 for an audit with an analyte uncertainty of ±2 percent.
9.2 Audit Spectra. Audit spectra can be used to test the analytical program of the FTIR CEM, but provide no test of the sampling system.
9.2.1 Definition and Requirements. Audit spectra are absorbance spectra that; (1) have been well characterized, and (2) contain absorbance bands of target analyte(s) and potential interferants at intensities equivalent to what is expected in the source effluent. Audit spectra are provided by the administrator without identifying information. Methods of preparing Audit spectra include; (1) mathematically adding sample spectra or adding reference and interferant spectra, (2) obtaining sample spectra of mixtures prepared in the laboratory, or (3) they may be sample spectra collected previously at a similar source. In the last case it must be demonstrated that the analytical results are correct and reproducible. A record associated with each Audit spectrum documents its method of preparation. The documentation must be sufficient to enable an independent analyst to reproduce the Audit spectra.
9.2.2 Test Procedure. Audit spectra concentrations are measured using the FTIR CEM analytical program. Analytical results must be within ±5 percent of the certified audit concentration for each analyte (plus the uncertainty in the audit concentration). If the condition is not met, demonstrate how the audit spectra are unrepresentative of the sample spectra. If the audit spectra are representative, modify the FTIR CEM analytical program until the test requirement is met. Use the new analytical program in subsequent FTIR CEM analyses of effluent samples.
9.3 Submit Spectra For Independent Analysis. This procedure tests only the analytical program and not the FTIR CEM sampling system. The analyst can submit FTIR CEM spectra for independent analysis by EPA. Requirements for submission include; (1) three representative absorbance spectra (and stored interferograms) for each test period to be reviewed, (2) corresponding CTS spectra, (3) corresponding background spectra and interferograms, (4) spectra of associated spiked samples if applicable, and (5) analytical results for these sample spectra. The analyst will also submit documentation of process times and conditions, sampling conditions associated with each spectrum, file names and sampling times, method of analysis and reference spectra used, optical configuration of FTIR CEM including cell path length and temperature, spectral resolution and apodization used for every spectrum. Independent analysis can also be performed on site in conjunction with the FTIR CEM sampling and analysis. Sample spectra are stored on the independent analytical system as they are collected by the FTIR CEM system. The FTIR CEM and the independent analyses are then performed separately. The two analyses will agree to within ±120 percent for each analyte using the procedure in section 12.3. This assumes both analytical routines have properly accounted for differences in optical path length, resolution, and temperature between the sample spectra and the reference spectra.
10.1 Calibration Transfer Standards. For CTS requirements see section 4.5 of the FTIR Protocol. A well characterized absorbance band in the CTS gas is used to measure the path length and line resolution of the instrument. The CTS measurements made at the beginning of every 24 hour period must agree to within ±5 percent after correction for differences in pressure.
Verify that the frequency response of the instrument and CTS absorbance intensity are correct by comparing to other CTS spectra or by referring to the literature.
10.2 Analyte Calibration. If EPA library reference spectra are not available, use calibration standards to prepare reference spectra according to section 6 of the FTIR Protocol. A suitable set of analyte reference data includes spectra of at least 2 independent samples at each of at least 2 different concentrations. The concentrations bracket a range that includes the expected analyte absorbance intensities. The linear fit of the reference analyte band areas must have a fractional calibration uncertainty (FCU in Appendix F of the FTIR Protocol) of no greater than 10 percent. For requirements of analyte standards refer to section 4.6 of the FTIR Protocol.
10.3 System Calibration. The calibration standard is introduced at a point on the sampling probe. The sampling system is purged with the calibration standard to verify that the absorbance measured in this way is equal to the absorbance in the analyte calibration. Note that the system calibration gives no indication of the ability of the sampling system to transport the target analyte(s) under the test conditions.
10.4 Analyte Spike. The target analyte(s) is spiked at the outlet of the sampling probe, upstream of the particulate filter, and combined with effluent at a ratio of about 1 part spike to 9 parts effluent. The measured absorbance of the spike is compared to the expected absorbance of the spike plus the analyte concentration already in the effluent. This measures sampling system bias, if any, as distinguished from analyzer bias. It is important that spiked sample pass through all of the sampling system components before analysis.
10.5 Signal-to-Noise Ratio (S/N). The measure of S/N in this performance specification is the root-mean-square (RMS) noise level as given in Appendix C of the FTIR Protocol. The RMS noise level of a contiguous segment of a spectrum is defined as the RMS difference (RMSD) between the n contiguous absorbance values (A
10.6 Background Deviation. The 100 percent baseline must be between 95 and 105 percent transmittance (absorbance of 0.02 to −0.02) in every analytical region. When background deviation exceeds this range, a new background spectrum must be collected using nitrogen or other zero gas.
10.7 Detector Linearity. Measure the background and CTS at three instrument aperture settings; one at the aperture setting to be used in the testing, and one each at settings one half and twice the test aperture setting. Compare the three CTS spectra. CTS band areas should agree to within the uncertainty of the cylinder standard. If test aperture is the maximum aperture, collect CTS spectrum at maximum aperture, then close the aperture to reduce the IR through-put by half. Collect a second background and CTS at the smaller aperture setting and compare the spectra as above. Instead of changing the aperture neutral density filters can be used to attenuate the infrared beam. Set up the FTIR system as it will be used in the test measurements. Collect a CTS spectrum. Use a neutral density filter to attenuate the infrared beam (either immediately after the source or the interferometer) to approximately
11.1 Initial Certification. First, perform the evaluation procedures in section 6.0 of the FTIR Protocol. The performance of an FTIR CEM can be certified upon installation using EPA Method 301 type validation (40 CFR, Part 63, Appendix A), or by comparison to a reference Method if one exists for the target analyte(s). Details of each procedure are given below. Validation testing is used for initial certification upon installation of a new system. Subsequent performance checks can be performed with more limited analyte spiking. Performance of the analytical program is checked initially, and periodically as required by EPA, by analyzing audit spectra or audit gases.
11.1.1 Validation. Use EPA Method 301 type sampling (reference 4, section 5.3 of Method 301) to validate the FTIR CEM for measuring the target analytes. The analyte spike procedure is as follows: (1) a known concentration of analyte is mixed with a known concentration of a non-reactive tracer gas, (2) the undiluted spike gas is sent directly to the FTIR cell and a spectrum of this sample is collected, (3) pre-heat the spiked gas to at least the sample line temperature, (4) introduce spike gas at the back of the sample probe upstream of the particulate filter, (5) spiked effluent is carried through all sampling components downstream of the probe, (6) spike at a ratio of roughly 1 part spike to 9 parts flue gas (or more dilute), (7) the spike-to-flue gas ratio is estimated by comparing the spike flow to the total sample flow, and (8) the spike ratio is verified by comparing the tracer concentration in spiked flue gas to the tracer concentration in undiluted spike gas. The analyte flue gas concentration is unimportant as long as the spiked component can be measured and the sample matrix (including interferences) is similar to its composition under test conditions. Validation can be performed using a single FTIR CEM analyzing sample spectra collected sequentially. Since flue gas analyte (unspiked) concentrations can vary, it is recommended that two separate sampling lines (and pumps) are used; one line to carry unspiked flue gas and the other line to carry spiked flue gas. Even with two sampling lines the variation in unspiked concentration may be fast compared to the interval between consecutive measurements. Alternatively, two FTIR CEMs can be operated side-by-side, one measuring spiked sample, the other unspiked sample. In this arrangement spiked and unspiked measurements can be synchronized to minimize the affect of temporal variation in the unspiked analyte concentration. In either sampling arrangement, the interval between measured concentrations used in the statistical analysis should be, at least, 5 cell volumes (5 * TC in equation 1). A validation run consists of, at least, 24 independent analytical results, 12 spiked and 12 unspiked samples. See section 3.17 for definition of an “independent” analytical result. The results are analyzed using sections 12.1 and 12.2 to determine if the measurements passed the validation requirements. Several analytes can be spiked and measured in the same sampling run, but a separate statistical analysis is performed for each analyte. In lieu of 24 independent measurements, averaged results can be used in the statistical analysis. In this procedure, a series of consecutive spiked measurements are combined over a sampling period to give a single average result. The related unspiked measurements are averaged in the same way. The minimum 12 spiked and 12 unspiked result averages are obtained by averaging measurements over subsequent sampling periods of equal duration. The averaged results are grouped together and statistically analyzed using section 12.2.
11.1.1.1 Validation with a Single Analyzer and Sampling Line. If one sampling line is used, connect the sampling system components and purge the entire sampling system and cell with at least 10 cell volumes of sample gas. Begin sampling by collecting spectra of 2 independent unspiked samples. Introduce the spike gas into the back of the probe, upstream of the particulate filter. Allow 10 cell volumes of spiked flue gas to purge the cell and sampling system. Collect spectra of 2 independent spiked samples. Turn off the spike flow and allow 10 cell volumes of unspiked flue gas to purge the FTIR cell and sampling system. Repeat this procedure 6 times until the 24 samples are collected. Spiked and unspiked samples can also be measured in groups of 4 instead of in pairs. Analyze the results using sections 12.1 and 12.2. If the statistical analysis passes the validation criteria, then the validation is completed. If the results do not pass the validation, the cause may be that temporal variations in the analyte sample gas concentration are fast relative to the interval between measurements. The difficulty may be avoided by: (1) Averaging the measurements over long sampling periods and using the averaged results in the statistical analysis, (2) modifying the sampling system to reduce TC by, for example, using a smaller volume cell or increasing the sample flow rate, (3) using two sample lines (4) use two analyzers to perform synchronized measurements. This performance specification permits modifications in the sampling system to minimize TC if the other requirements of the validation sampling procedure are met.
11.1.1.2 Validation With a Single Analyzer and Two Sampling Lines. An alternative sampling procedure uses two separate sample lines, one carrying spiked flue gas, the other carrying unspiked gas. A valve in the gas distribution manifold allows the operator to choose either sample. A short heated line connects the FTIR cell to the 3-way valve in the manifold. Both sampling lines are continuously purged. Each sample line has a rotameter and a bypass vent line after the rotameter, immediately upstream of the valve, so that the spike and unspiked sample flows can each be continuously monitored. Begin sampling by collecting spectra of 2 independent unspiked samples. Turn the sampling valve to close off the unspiked gas flow and allow the spiked flue gas to enter the FTIR cell. Isolate and evacuate the cell and fill with the spiked sample to ambient pressure. (While the evacuated cell is filling, prevent air leaks into the cell by making sure that the spike sample rotameter always indicates that a portion of the flow is directed out the by-pass vent.) Open the cell outlet valve to allow spiked sample to continuously flow through the cell. Measure spectra of 2 independent spiked samples. Repeat this procedure until at least 24 samples are collected.
11.1.1.3 Synchronized Measurements With Two Analyzers. Use two FTIR analyzers, each with its own cell, to perform synchronized spiked and unspiked measurements. If possible, use a similar optical configuration for both systems. The optical configurations are compared by measuring the same CTS gas with both analyzers. Each FTIR system uses its own sampling system including a separate sampling probe and sampling line. A common gas distribution manifold can be used if the samples are never mixed. One sampling system and analyzer measures spiked effluent. The other sampling system and analyzer measures unspiked flue gas. The two systems are synchronized so that each measures spectra at approximately the same times. The sample flow rates are also synchronized so that both sampling rates are approximately the same (TC
11.1.1.4 Compare to a Reference Method (RM). Obtain EPA approval that the method qualifies as an RM for the analyte(s) and the source to be tested. Follow the published procedures for the RM in preparing and setting up equipment and sampling system, performing measurements, and reporting results. Since FTIR CEMS have multicomponent capability, it is possible to perform more than one RM simultaneously, one for each target analyte. Conduct at least 9 runs where the FTIR CEM and the RM are sampling simultaneously. Each Run is at least 30 minutes long and consists of spectra of at least 5 independent FTIR CEM samples and the corresponding RM measurements. If more than 9 runs are conducted, the analyst may eliminate up to 3 runs from the analysis if at least 9 runs are used.
11.1.1.4.1 RMs Using Integrated Sampling. Perform the RM and FTIR CEM sampling simultaneously. The FTIR CEM can measure spectra as frequently as the analyst chooses (and should obtain measurements as frequently as possible) provided that the measurements include spectra of at least 5 independent measurements every 30 minutes. Concentration results from all of the FTIR CEM spectra within a run may be averaged for use in the statistical comparison even if all of the measurements are not independent. When averaging the FTIR CEM concentrations within a run, it is permitted to exclude some measurements from the average provided the minimum of 5 independent measurements every 30 minutes are included: The Run average of the FTIR CEM measurements depends on both the sample flow rate and the measurement frequency (MF). The run average of the RM using the integrated sampling method depends primarily on its sampling rate. If the target analyte concentration fluctuates significantly, the contribution to the run average of a large fluctuation depends on the sampling rate and measurement frequency, and on the duration and magnitude of the fluctuation. It is, therefore, important to carefully select the sampling rate for both the FTIR CEM and the RM and the measurement frequency for the FTIR CEM. The minimum of 9 run averages can be compared according to the relative accuracy test procedure in Performance Specification 2 for SO
11.1.1.4.2 RMs Using a Grab Sampling Technique. Synchronize the RM and FTIR CEM measurements as closely as possible. For a grab sampling RM, record the volume collected and the exact sampling period for each sample. Synchronize the FTIR CEM so that the FTIR measures a spectrum of a similar cell volume at the same time as the RM grab sample was collected. Measure at least five independent samples with both the FTIR CEM and the RM for each of the minimum nine runs. Compare the run concentration averages by using the relative accuracy analysis procedure in Performance Specification 2 of appendix B of 40 CFR part 60.
11.1.1.4.3 Continuous Emission Monitors as RMs. If the RM is a CEM, synchronize the sampling flow rates of the RM and the FTIR CEM. Each run is at least 1 hour long and consists of at least 10 FTIR CEM measurements and the corresponding 10 RM measurements (or averages). For the statistical comparison, use the relative accuracy analysis procedure in Performance Specification 2 of appendix B of 40 CFR part 60. If the RM time constant is 1/2 the FTIR CEM time constant, brief fluctuations in analyte concentrations that are not adequately measured with the slower FTIR CEM time constant can be excluded from the run average along with the corresponding RM measurements. However, the FTIR CEM run average must still include at least 10 measurements over a 1-hour period.
12.1 Spike Dilution Ratio, Expected Concentration. The Method 301 bias is calculated as follows.
The CS is determined by comparing the SF
12.2 Statistical Analysis of Validation Measurements. Arrange the independent measurements (or measurement averages) as in Table 1. More than 12 pairs of measurements can be analyzed. The statistical analysis follows EPA Method 301, section 6.3. section 12.1 of this performance specification shows the calculations for the bias, expected spike concentration, and correction factor. This section shows the determination of the statistical significance of the bias. Determine the statistical significance of the bias at the 95 percent confidence level by calculating the t-value for the set of measurements. First, calculate the differences, d
1. Method 318, 40 CFR, Part 63, Appendix A (Draft), “Measurement of Gaseous Formaldehyde, Phenol and Methanol Emissions by FTIR Spectroscopy,” EPA Contract No. 68D20163, Work Assignment 2-18, February, 1995.
2. “EPA Protocol for the Use of Extractive Fourier Transform Infrared (FTIR) Spectrometry in Analyses of Gaseous Emissions from Stationary Industrial Sources,” February, 1995.
3. “Measurement of Gaseous Organic and Inorganic Emissions by Extractive FTIR Spectroscopy,” EPA Contract No. 68-D2-0165, Work Assignment 3-08.
4. “Method 301 – Field Validation of Pollutant Measurement Methods from Various Waste Media,” 40 CFR 63, App A.
Table 1 – Arrangement of Validation Measurements for Statistical Analysis
| Measurement (or average) | Time | Spiked (ppm) | d | Unspiked (ppm) | d |
|---|---|---|---|---|---|
| 1 | S | U | |||
| 2 | S | S | U | U | |
| 3 | S | U | |||
| 4 | S | S | U | U | |
| 5 | S | U | |||
| 6 | S | S | U | U | |
| 7 | S | U | |||
| 8 | S | S | U | U | |
| 9 | S | U | |||
| 10 | S | S | U | U | |
| 11 | S | U | |||
| 12 | S | S | U | U | |
| Average −> | S | M |
Table 2 – t = Values
| n−1 a | t−value | n−1 a | t−value | n−1 a | t−value | n−1 a | t−value |
|---|---|---|---|---|---|---|---|
| 11 | 2.201 | 17 | 2.110 | 23 | 2.069 | 29 | 2.045 |
| 12 | 2.179 | 18 | 2.101 | 24 | 2.064 | 30 | 2.042 |
| 13 | 2.160 | 19 | 2.093 | 25 | 2.060 | 40 | 2.021 |
| 14 | 2.145 | 20 | 2.086 | 26 | 2.056 | 60 | 2.000 |
| 15 | 2.131 | 21 | 2.080 | 27 | 2.052 | 120 | 1.980 |
| 16 | 2.120 | 22 | 2.074 | 28 | 2.048 | 8 | 1.960 |
a n is the number of independent pairs of measurements (a pair consists of one spiked and its corresponding unspiked measurement). Either discreet (independent) measurements in a single run, or run averages can be used.
1.1 Does this performance specification apply to me? If you, the source owner or operator, intend to use (with any necessary approvals) a predictive emission monitoring system (PEMS) to show compliance with your emission limitation under 40 CFR 60, 61, or 63, you must use the procedures in this performance specification (PS) to determine whether your PEMS is acceptable for use in demonstrating compliance with applicable requirements. Use these procedures to certify your PEMS after initial installation and periodically thereafter to ensure the PEMS is operating properly. If your PEMS contains a diluent (O
1.1.1 How do I certify my PEMS after it is installed? PEMS must pass a relative accuracy (RA) test and accompanying statistical tests in the initial certification test to be acceptable for use in demonstrating compliance with applicable requirements. Ongoing quality assurance tests also must be conducted to ensure the PEMS is operating properly. An ongoing sensor evaluation procedure must be in place before the PEMS certification is complete. The amount of testing and data validation that is required depends upon the regulatory needs, i.e., whether precise quantification of emissions will be needed or whether indication of exceedances of some regulatory threshold will suffice. Performance criteria are more rigorous for PEMS used in determining continual compliance with an emission limit than those used to measure excess emissions. You must perform the initial certification test on your PEMS before reporting any PEMS data as quality-assured.
1.1.2 Is other testing required after certification? After you initially certify your PEMS, you must pass additional periodic performance checks to ensure the long-term quality of data. These periodic checks are listed in the table in section 9. You are always responsible for properly maintaining and operating your PEMS.
The following performance tests are required in addition to other equipment and measurement location requirements.
2.1 Initial PEMS Certification.
2.1.1 Excess Emissions PEMS. For a PEMS that is used for excess emission reporting, the owner or operator must perform a minimum 9-run, 3-level (3 runs at each level) RA test (see section 8.2).
2.1.2 Compliance PEMS. For a PEMS that is used for continual compliance standards, the owner or operator must perform a minimum 27-run, 3-level (9 runs at each level) RA test (see section 8.2). Additionally, the data must be evaluated for bias and by F-test and correlation analysis.
2.2 Periodic Quality Assurance (QA) Assessments. Owners and operators of all PEMS are required to conduct quarterly relative accuracy audits (RAA) and yearly relative accuracy test audits (RATA) to assess ongoing PEMS operation. The frequency of these periodic assessments may be shortened by successful operation during a prior year.
The following definitions apply:
3.1 Centroidal Area means that area in the center of the stack (or duct) comprising no more than 1 percent of the stack cross-sectional area and having the same geometric shape as the stack.
3.2 Data Recorder means the equipment that provides a permanent record of the PEMS output. The data recorder may include automatic data reduction capabilities and may include electronic data records, paper records, or a combination of electronic data and paper records.
3.3 Defective sensor means a sensor that is responsible for PEMS malfunction or that operates outside the approved operating envelope. A defective sensor may be functioning properly, but because it is operating outside the approved operating envelope, the resulting predicted emission is not validated.
3.4 Diluent PEMS means the total equipment required to predict a diluent gas concentration or emission rate.
3.5 Operating envelope means the defined range of a parameter input that is established during PEMS development. Emission data generated from parameter inputs that are beyond the operating envelope are not considered quality assured and are therefore unacceptable.
3.6 PEMS means all of the equipment required to predict an emission concentration or emission rate. The system may consist of any of the following major subsystems: sensors and sensor interfaces, emission model, algorithm, or equation that uses process data to generate an output that is proportional to the emission concentration or emission rate, diluent emission model, data recorder, and sensor evaluation system. Systems that use fewer than 3 variables do not qualify as PEMS unless the system has been specifically approved by the Administrator for use as a PEMS. A PEMS may predict emissions data that are corrected for diluent if the relative accuracy and relevant QA tests are passed in the emission units corrected for diluent. Parametric monitoring systems that serve as indicators of compliance and have parametric limits but do not predict emissions to comply with an emissions limit are not included in this definition.
3.7 PEMS training means the process of developing or confirming the operation of the PEMS against a reference method under specified conditions.
3.8 Quarter means a quarter of a calendar year in which there are at least 168 unit operating hours.
3.9 Reconciled Process Data means substitute data that are generated by a sensor evaluation system to replace that of a failed sensor. Reconciled process data may not be used without approval from the Administrator.
3.10 Relative Accuracy means the accuracy of the PEMS when compared to a reference method (RM) at the source. The RA is the average difference between the pollutant PEMS and RM data for a specified number of comparison runs plus a 2.5 percent confidence coefficient, divided by the average of the RM tests. For a diluent PEMS, the RA may be expressed as a percentage of absolute difference between the PEMS and RM. Alternative specifications are given for units that have very low emissions.
3.11 Relative Accuracy Audit means a quarterly audit of the PEMS against a portable analyzer meeting the requirements of ASTM D6522-00 or a RM for a specified number of runs. A RM may be used in place of the portable analyzer for the RAA.
3.12 Relative Accuracy Test Audit means a RA test that is performed at least once every four calendar quarters after the initial certification test while the PEMS is operating at the normal operating level.
3.13 Reference Value means a PEMS baseline value that may be established by RM testing under conditions when all sensors are functioning properly. This reference value may then be used in the sensor evaluation system or in adjusting new sensors.
3.14 Sensor Evaluation System means the equipment or procedure used to periodically assess the quality of sensor input data. This system may be a sub-model that periodically cross-checks sensor inputs among themselves or any other procedure that checks sensor integrity at least daily (when operated for more than one hour in any calendar day).
3.15 Sensors and Sensor Interface means the equipment that measures the process input signals and transports them to the emission prediction system.
6.1 PEMS Design. You must detail the design of your PEMS and make this available in reports and for on-site inspection. You must also establish the following, as applicable:
6.1.1 Number of Input Parameters. An acceptable PEMS will normally use three or more input parameters. You must obtain the Administrator’s permission on a case-by-case basis if you desire to use a PEMS having fewer than three input parameters.
6.1.2 Parameter Operating Envelopes. Before you evaluate your PEMS through the certification test, you must specify the input parameters your PEMS uses, define their range of minimum and maximum values (operating envelope), and demonstrate the integrity of the parameter operating envelope using graphs and data from the PEMS development process, vendor information, or engineering calculations, as appropriate. If you operate the PEMS beyond these envelopes at any time after the certification test, the data generated during this condition will not be acceptable for use in demonstrating compliance with applicable requirements. If these parameter operating envelopes are not clearly defined and supported by development data, the PEMS operation will be limited to the range of parameter inputs encountered during the certification test until the PEMS has a new operating envelope established.
6.1.3 Source-Specific Operating Conditions. Identify any source-specific operating conditions, such as fuel type, that affect the output of your PEMS. You may only use the PEMS under the source-specific operating conditions it was certified for.
6.1.4 Ambient Conditions. You must explain whether and how ambient conditions and seasonal changes affect your PEMS. Some parameters such as absolute ambient humidity cannot be manipulated during a test. The effect of ambient conditions such as humidity on the pollutant concentration must be determined and this effect extrapolated to include future anticipated conditions. Seasonal changes and their effects on the PEMS must be evaluated unless you can show that such effects are negligible.
6.1.5 PEMS Principle of Operation. If your PEMS is developed on the basis of known physical principles, you must identify the specific physical assumptions or mathematical manipulations that support its operation. If your PEMS is developed on the basis of linear or nonlinear regression analysis, you must make available the paired data (preferably in graphic form) used to develop or train the model.
6.1.6 Data Recorder Scale. If you are not using a digital recorder, you must choose a recorder scale that accurately captures the desired range of potential emissions. The lower limit of your data recorder’s range must be no greater than 20 percent of the applicable emission standard (if subject to an emission standard). The upper limit of your data recorder’s range must be determined using the following table. If you obtain approval first, you may use other lower and upper recorder limits.
| If PEMS is measuring. . . | And if. . . | Then your upper limit. . . |
|---|---|---|
| Uncontrolled emissions, such as NO | No other regulation sets an upper limit for the data recorder’s range | Must be 1.25 to 2 times the average potential emission level |
| Uncontrolled emissions, such as NO | Another regulation sets an upper limit for the data recorder’s range | Must follow the other regulation |
| Controlled emissions | Must be 1.5 to 2.0 times concentration of the emission standard that applies to your emission unit | |
| Continual compliance emissions for an applicable regulation | Must be 1.1 to 1.5 times the concentration of the emission standard that applies to your emission unit |
6.1.7 Sensor Location and Repair. We recommend you install sensors in an accessible location in order to perform repairs and replacements. Permanently-installed platforms or ladders may not be needed. If you install sensors in an area that is not accessible, you may be required to shut down the emissions unit to repair or replace a sensor. Conduct a new RATA after replacing a sensor that supplies a critical PEMS parameter if the new sensor provides a different output or scaling or changes the historical training dataset of the PEMS. Replacement of a non-critical sensor that does not cause an impact in the accuracy of the PEMS does not trigger a RATA. All sensors must be calibrated as often as needed but at least as often as recommended by the manufacturers.
6.1.8 Sensor Evaluation System. Your PEMS must be designed to perform automatic or manual determination of defective sensors on at least a daily basis. This sensor evaluation system may consist of a sensor validation sub-model, a comparison of redundant sensors, a spot check of sensor input readings at a reference value, operation, or emission level, or other procedure that detects faulty or failed sensors. Some sensor evaluation systems generate substitute values (reconciled data) that are used when a sensor is perceived to have failed. You must obtain prior approval before using reconciled data.
6.1.9 Parameter Envelope Exceedances. Your PEMS must include a plan to detect and notify the operator of parameter envelope exceedances. Emission data collected outside the ranges of the sensor envelopes will not be considered quality assured.
6.2 Recordkeeping. All valid data recorded by the PEMS must be used to calculate the emission value.
8.1 Initial Certification. Use the following procedure to certify your PEMS. Complete all PEMS training before the certification begins.
8.2 Relative Accuracy Test.
8.2.1 Reference Methods. Unless otherwise specified in the applicable regulations, you must use the test methods in appendix A of this part for the RM test. Conduct the RM tests at three operating levels. The RM tests shall be performed at a low-load (or production) level between the minimum safe, stable load and 50 percent of the maximum level load, at the mid-load level (an intermediary level between the low and high levels), and at a high-load level between 80 percent and the maximum load. Alternatively, if practicable, you may test at three levels of the key operating parameter (e.g. selected based on a covariance analysis between each parameter and the PEMS output) equally spaced within the normal range of the parameter.
8.2.2 Number of RM Tests for Excess Emission PEMS. For PEMS used for excess emission reporting, conduct at least the following number of RM tests at the following key parameter operating levels:
(1) Three at a low level.
(2) Three at a mid level.
(3) Three at a high level.
You may choose to perform more than nine total RM tests. If you perform more than nine tests, you may reject a maximum of three tests as long as the total number of test results used to determine the RA is nine or greater and each operating level has at least three tests. You must report all data, including the rejected data.
8.2.3 Number of RM Tests for Continual Compliance PEMS. For PEMS used to determine compliance, conduct at least the following number of RM tests at the following key parameter operating levels:
(1) Nine at a low level.
(2) Nine at a mid level.
(3) Nine at a high level.
You may choose to perform more than 9 RM runs at each operating level. If you perform more than 9 runs, you may reject a maximum of three runs per level as long as the total number of runs used to determine the RA at each operating level is 9 or greater.
8.2.4 Reference Method Measurement Location. Select an accessible measurement point for the RM that will ensure you measure emissions representatively. Ensure the location is at least two equivalent stack diameters downstream and half an equivalent diameter upstream from the nearest flow disturbance such as the control device, point of pollutant generation, or other place where the pollutant concentration or emission rate can change. You may use a half diameter downstream instead of the two diameters if you meet both of the following conditions:
(1) Changes in the pollutant concentration are caused solely by diluent leakage, such as leaks from air heaters.
(2) You measure pollutants and diluents simultaneously at the same locations.
8.2.5 Traverse Points. Select traverse points that ensure representative samples. Conduct all RM tests within 3 cm of each selected traverse point but no closer than 3 cm to the stack or duct wall. The minimum requirement for traverse points are as follows:
(1) Establish a measurement line across the stack that passes through the center and in the direction of any expected stratification.
(2) Locate a minimum of three traverse points on the line at 16.7, 50.0, and 83.3 percent of the stack inside diameter.
(3) Alternatively, if the stack inside diameter is greater than 2.4 meters, you may locate the three traverse points on the line at 0.4, 1.2, and 2.0 meters from the stack or duct wall. You may not use this alternative option after wet scrubbers or at points where two streams with different pollutant concentrations are combined. You may select different traverse points if you demonstrate and provide verification that it provides a representative sample. You may also use the traverse point specifications given the RM.
8.2.6 Relative Accuracy Procedure. Perform the number of RA tests at the levels required in sections 8.2.2 and 8.2.3. For integrated samples (e.g., Method 3A or 7E), make a sample traverse of at least 21 minutes, sampling for 7 minutes at each traverse point. For grab samples (e.g., Method 3 or 7), take one sample at each traverse point, scheduling the grab samples so that they are taken simultaneously (within a 3-minute period) or at an equal interval of time apart over a 21-minute period. A test run for grab samples must be made up of at least three separate measurements. Where multiple fuels are used in the monitored unit and the fuel type affects the predicted emissions, determine a RA for each fuel unless the effects of the alternative fuel on predicted emissions or diluent were addressed in the model training process. The unit may only use fuels that have been evaluated this way.
8.2.7 Correlation of RM and PEMS Data. Mark the beginning and end of each RM test run (including the exact time of day) on the permanent record of PEMS output. Correlate the PEMS and the RM test data by the time and duration using the following steps:
A. Determine the integrated pollutant concentration for the PEMS for each corresponding RM test period.
B. Consider system response time, if important, and confirm that the pair of results is on a consistent moisture, temperature, and diluent concentration basis.
C. Compare each average PEMS value to the corresponding average RM value. Use the following guidelines to make these comparisons.
| If . . . | Then . . . | And then . . . |
|---|---|---|
| The RM has an instrumental or integrated non-instrumental sampling technique | Directly compare RM and PEMS results | |
| The RM has a grab sampling technique | Average the results from all grab samples taken during the test run. The test run must include ≥3 separate grab measurements | Compare this average RM result with the PEMS result obtained during the run. |
Use the paired PEMS and RM data and the equations in section 12.2 to calculate the RA in the units of the applicable emission standard. For this 3-level RA test, calculate the RA at each operation level.
8.3 Statistical Tests for PEMS that are Used for Continual Compliance. In addition to the RA determination, evaluate the paired RA and PEMS data using the following statistical tests.
8.3.1 Bias Test. From the RA data taken at the mid-level, determine if a bias exists between the RM and PEMS. Use the equations in section 12.3.1.
8.3.2 F-test. Perform a separate F-test for the RA paired data from each operating level to determine if the RM and PEMS variances differ by more than might be expected from chance. Use the equations in section 12.3.2.
8.3.3 Correlation Analysis. Perform a correlation analysis using the RA paired data from all operating levels combined to determine how well the RM and PEMS correlate. Use the equations in section 12.3.3. The correlation is waived if the process cannot be varied to produce a concentration change sufficient for a successful correlation test because of its technical design. In such cases, should a subsequent RATA identify a variation in the RM measured values by more than 30 percent, the waiver will not apply, and a correlation analysis test must be performed at the next RATA.
8.4 Reporting. Summarize in tabular form the results of the RA and statistical tests. Include all data sheets, calculations, and charts (records of PEMS responses) necessary to verify that your PEMS meets the performance specifications. Include in the report the documentation used to establish your PEMS parameter envelopes.
8.5 Reevaluating Your PEMS After a Failed Test, Change in Operations, or Change in Critical PEMS Parameter. After initial certification, if your PEMS fails to pass a quarterly RAA or yearly RATA, or if changes occur or are made that could result in a significant change in the emission rate (e.g., turbine aging, process modification, new process operating modes, or changes to emission controls), your PEMS must be recertified using the tests and procedures in section 8.1. For example, if you initially developed your PEMS for the emissions unit operating at 80-100 percent of its range, you would have performed the initial test under these conditions. Later, if you wanted to operate the emission unit at 50-100 percent of its range, you must conduct another RA test and statistical tests, as applicable, to verify that the new conditions of 50-100 percent of range are functional. These tests must demonstrate that your PEMS provides acceptable data when operating in the new range or with the new critical PEMS parameter(s). The requirements of section 8.1 must be completed by the earlier of 60 unit operating days or 180 calendar days after the failed RATA or after the change that caused a significant change in emission rate.
You must incorporate a QA plan beyond the initial PEMS certification test to verify that your system is generating quality-assured data. The QA plan must include the components of this section.
9.1 QA/QC Summary. Conduct the applicable ongoing tests listed below.
Ongoing Quality Assurance Tests
| Test | PEMS regulatory purpose | Acceptability | Frequency |
|---|---|---|---|
| Sensor Evaluation | All | Daily. | |
| RAA | Compliance | 3-test avg ≤10% of simultaneous analyzer or RM average | Each quarter except quarter when RATA performed. |
| RATA | All | Same as for RA in Sec. 13.1 | Yearly in quarter when RAA not performed. |
| Bias Correction | All | If d | Bias test passed (no correction factor needed). |
| PEMS Training | All | If F r ≥0.8 | Optional after initial and subsequent RATAs. |
| Sensor Evaluation Alert Test (optional) | All | See Section 6.1.8 | After each PEMS training. |
9.2 Daily Sensor Evaluation Check. Your sensor evaluation system must check the integrity of each PEMS input at least daily.
9.3 Quarterly Relative Accuracy Audits. In the first year of operation after the initial certification, perform a RAA consisting of at least three 30-minute portable analyzer or RM determinations each quarter a RATA is not performed. To conduct a RAA, follow the procedures in Section 8.2 for the relative accuracy test, except that only three sets of measurement data are required, and the statistical tests are not required. The average of the three or more portable analyzer or RM determinations must not exceed the limits given in Section 13.5. Report the data from all sets of measurement data. If a PEMS passes all quarterly RAAs in the first year and also passes the subsequent yearly RATA in the second year, you may elect to perform a single mid-year RAA in the second year in place of the quarterly RAAs. This option may be repeated, but only until the PEMS fails either a mid-year RAA or a yearly RATA. When such a failure occurs, you must resume quarterly RAAs in the quarter following the failure and continue conducting quarterly RAAs until the PEMS successfully passes both a year of quarterly RAAs and a subsequent RATA.
9.4 Yearly Relative Accuracy Test. Perform a minimum 9-run RATA at the normal operating level on a yearly basis in the quarter that the RAA is not performed. The statistical tests in Section 8.3 are not required for the yearly RATA.
12.2 Relative Accuracy Calculations. Calculate the mean of the RM values. Calculate the differences between the pairs of observations for the RM and the PEMS output sets. Finally, calculate the mean of the differences, standard deviation, confidence coefficient, and PEMS RA, using Equations 16-1, 16-2, 16-3, and 16-4, respectively. For compliance PEMS, calculate the RA at each test level. The PEMS must pass the RA criterion at each test level.
12.2.1 Arithmetic Mean. Calculate the arithmetic mean of the differences between paired RM and PEMS observations using Equation 16-1.
12.2.2 Standard Deviation. Calculate the standard deviation of the differences using Equation 16-2 (positive square root).
12.2.3 Confidence Coefficient. Calculate the confidence coefficient using Equation 16-3 and Table 16-1 for n−1 degrees of freedom.
12.2.4 Relative Accuracy. Calculate the RA of your data using Equation 16-4.
12.3 Compliance PEMS Statistical Tests. If your PEMS will be used for continual compliance purposes, conduct the following tests using the information obtained during the RA tests. For the pollutant measurements at any one test level, if the mean value of the RM is less than either 10 ppm or 5 percent of the emission standard, all statistical tests are waived at that specific test level. For diluent measurements at any one test level, if the mean value of the RM is less than 3 percent of span, all statistical tests are waived for that specific test level.
12.3.1 Bias Test. Conduct a bias test to determine if your PEMS is biased relative to the RM. Determine the PEMS bias by comparing the confidence coefficient obtained from Equation 16-3 to the arithmetic mean of the differences determined in Equation 16-1. If the arithmetic mean of the differences (d
12.3.2 F-test. Conduct an F-test for each of the three RA data sets collected at different test levels. Calculate the variances of the PEMS and the RM using Equation 16-6.
12.3.3 Correlation Analysis. Calculate the correlation coefficient either manually using Eq. 16-8, on a graph, or by computer using all of the paired data points from all operating levels. Your PEMS correlation must be 0.8 or greater to be acceptable. If during the initial certification test, your PEMS data are determined to be auto-correlated according to the procedures in 40 CFR 75.41(b)(2), or if the signal-to-noise ratio of the data is less than 4, then the correlation analysis is permanently waived.
12.4 Relative Accuracy Audit. Calculate the quarterly RAA using Equation 16-9.
13.1 PEMS Relative Accuracy. The RA must not exceed 10 percent if the PEMS measurements are greater than 100 ppm or 0.2 lbs/mm Btu. The RA must not exceed 20 percent if the PEMS measurements are between 100 ppm (or 0.2 lb/mm Btu) and 10 ppm (or 0.05 lb/mm Btu). For measurements below 10 ppm, the absolute mean difference between the PEMS measurements and the RM measurements must not exceed 2 pppm. For diluent PEMS, an alternative criterion of ±1 percent absolute difference between the PEMS and RM may be used if less stringent.
13.2 PEMS Bias. Your PEMS data is considered biased and must be adjusted if the arithmetic mean (d) is greater than the absolute value of the confidence coefficient (cc) in Equations 16.1 and 16.3. In such cases, a bias factor must be used to correct your PEMS data.
13.3 PEMS Variance. Your calculated F-value must not be greater than the critical F-value at the 95-percent confidence level for your PEMS to be acceptable.
13.4 PEMS Correlation. Your calculated r-value must be greater than or equal to 0.8 for your PEMS to be acceptable.
13.5 Relative Accuracy Audits. The average of the three portable analyzer or RM determinations must not differ from the simultaneous PEMS average value by more than 10 percent of the analyzer or RM for concentrations greater than 100 ppm or 20 percent for concentrations between 100 and 20 ppm, or the test is failed. For measurements at 20 ppm or less, this difference must not exceed 2 ppm for a pollutant PEMS and 1 percent absolute for a diluents PEMS.
Table 16-1 –
| n−1 * | t-value | n−1 | t-value |
|---|---|---|---|
| 1 | 12.706 | 15 | 2.131 |
| 2 | 4.303 | 16 | 2.120 |
| 3 | 3.182 | 17 | 2.110 |
| 4 | 2.776 | 18 | 2.101 |
| 5 | 2.571 | 19 | 2.093 |
| 6 | 2.447 | 20 | 2.086 |
| 7 | 2.365 | 21 | 2.080 |
| 8 | 2.306 | 22 | 2.074 |
| 9 | 2.262 | 23 | 2.069 |
| 10 | 2.228 | 24 | 2.064 |
| 11 | 2.201 | 25 | 2.060 |
| 12 | 2.179 | 26 | 2.056 |
| 13 | 2.160 | 27 | 2.052 |
| 14 | 2.145 | >28 | t-Table |
* The value n is the number of RM runs; n−1 equals the degrees of freedom.
1.1 Analyte. This performance specification (PS) is applicable for measuring gaseous concentrations of hydrogen chloride (HCl), CAS: 7647-01-0, on a continuous basis in the units of the applicable standard or in units that can be converted to units of the applicable standard(s).
1.2 Applicability.
1.2.1 This specification is used to evaluate the acceptability of HCl continuous emission monitoring systems (CEMS) at the time of installation or soon after and whenever specified in the regulations. The specification includes requirements for initial acceptance including instrument accuracy and stability assessments and use of audit samples if they are available.
1.2.2 The Administrator may require the operator, under section 114 of the Clean Air Act, to conduct CEMS performance evaluations at other times besides the initial test to evaluate the CEMS performance. See 40 CFR part 60, §§ 60.13(c) and 63.8(e)(1).
1.2.3 A source that demonstrates their CEMS meets the criteria of this PS may use the system to continuously monitor gaseous HCl under any regulation or permit that requires compliance with this PS. If your CEMS is capable of reporting the HCl concentration in the units of the applicable standard, no additional CEMS components are necessary. If your CEMS does not report concentrations in the units of the existing standard, then other CEMS components (e.g., oxygen (O
1.2.4 These specification test results are intended to be valid for the life of the system. As a result, the HCl measurement system must be tested and operated in a configuration consistent with the configuration that will be used for ongoing continuous emissions monitoring.
1.2.5 Substantive changes to the system configuration require retesting according to this PS. Examples of such conditions include, but are not limited to: major changes in dilution ratio (for dilution based systems); changes in sample conditioning and transport, if used, such as filtering device design or materials; changes in probe design or configuration and changes in materials of construction. Changes consistent with instrument manufacturer upgrade that fall under manufacturer’s certification do not require additional field verification. Manufacturer’s upgrades require recertification by the manufacturer for those requirements allowed by this PS, including interference, level of detection (LOD), and light intensity qualification.
1.2.6 This specification is not designed to evaluate the ongoing CEMS performance nor does it identify specific calibration techniques and auxiliary procedures to assess CEMS performance over an extended period of time. The requirements in appendix F, Procedure 6 are designed to provide a way to assess CEMS performance over an extended period of time. The source owner or operator is responsible to calibrate, maintain, and operate the CEMS properly.
2.1 This specification covers the procedures that each CEMS must meet during the performance evaluation test. Installation and measurement location specifications, data reduction procedures, and performance criteria are included.
2.2 The technology used to measure gaseous HCl must provide a distinct response and address any appropriate interference correction(s). It must accurately measure gaseous HCl in a representative sample (path or point sampling) of stack effluent.
2.3 The relative accuracy (RA) must be established against a reference method (RM) (e.g., Method 26A, Method 320, ASTM International (ASTM) D6348-12, including mandatory annexes, or Method 321 for Portland cement plants as specified by the applicable regulation or, if not specified, as appropriate for the source concentration and category). Method 26 may be approved as a RM by the Administrator on a case-by-case basis if not otherwise allowed or denied in an applicable regulation.
2.4 A standard addition (SA) procedure using a reference standard is included in appendix A to this performance specification for use in verifying LOD. For extractive CEMS, where the SA is done by dynamic spiking (DS), the appendix A procedure is allowed as an option for assessing calibration drift and is also referenced by Procedure 6 of appendix F to this part for ongoing quality control tests.
3.1 Beam attenuation is the reduction in electromagnetic radiation (light) throughput from the maximum beam intensity experienced during site specific CEMS operation.
3.2 Beam intensity is the electromagnetic radiation (light) throughput for an IP-CEMS instrument measured following manufacturers specifications.
3.3 Calibration cell means a gas containment cell used with cross stack or integrated path (IP) CEMS for calibration and to perform many of the test procedures required by this performance specification. The cell may be a removable sealed cell or an evacuated and/or purged cell capable of exchanging reference and other calibration gases as well as zero gas standards. When charged, it contains a known concentration of HCl and/or interference gases. The calibration cell is filled with zero gas or removed from the optical path during stack gas measurement.
3.4 Calibration drift (CD) means the absolute value of the difference between the CEMS output response and an upscale reference gas or a zero-level gas, expressed as a percentage of the span value, when the CEMS is challenged after a stated period of operation during which no unscheduled adjustments, maintenance or repairs took place.
3.5 Centroidal area means a central area that is geometrically similar to the stack or duct cross section and is no greater than 10 percent of the stack or duct cross-sectional area.
3.6 Continuous Emission Monitoring System (CEMS) means the total equipment required to measure the pollutant concentration or emission rate continuously. The system generally consists of the following three major subsystems:
3.6.1 Sample interface means that portion of the CEMS used for one or more of the following: Sample acquisition, sample transport, sample conditioning, defining the optical measurement path, and protection of the monitor from the effects of the stack effluent.
3.6.2 HCl analyzer means that portion of the HCl CEMS that measures the total vapor phase HCl concentration and generates a proportional output.
3.6.3 Data recorder means that portion of the CEMS that provides a permanent electronic record of the analyzer output. The data recorder may record other pertinent data such as effluent flow rates, various instrument temperatures or abnormal CEMS operation. The data recorder may also include automatic data reduction capabilities and CEMS control capabilities.
3.7 Diluent gas means a major gaseous constituent in a gaseous pollutant mixture. For combustion sources, either carbon dioxide (CO
3.8 Dynamic spiking (DS) means the procedure where a known concentration of HCl gas is injected into the probe sample gas stream for extractive CEMS at a known flow rate to assess the performance of the measurement system in the presence of potential interference from the flue gas sample matrix.
3.9 Independent measurement(s) means the series of CEMS data values taken during sample gas analysis separated by two times the procedure specific response time (RT) of the CEMS.
3.10 Integrated path CEMS (IP-CEMS) means an in-situ CEMS that measures the gas concentration along an optical path in the stack or duct cross section.
3.11 Interference means a compound or material in the sample matrix other than HCl whose characteristics may bias the CEMS measurement (positively or negatively). The interference may not prevent the sample measurement, but could increase the analytical uncertainty in the measured HCl concentration through reaction with HCl or by changing the electronic signal generated during HCl measurement.
3.12 Interference test means the test to detect CEMS responses to interferences that are not adequately accounted for in the calibration procedure and may cause measurement bias.
3.13 Level of detection (LOD) means the lowest level of pollutant that the CEMS can detect in the presence of the source gas matrix interferents with 99 percent confidence.
3.14 Liquid evaporative standard means a reference gas produced by vaporizing National Institute of Standards and Technology (NIST) traceable liquid standards of known HCl concentration and quantitatively diluting the resultant vapor with a carrier gas.
3.15 Measurement error (ME) is the mean difference between the concentration measured by the CEMS and the known concentration of a reference gas standard, divided by the span, when the entire CEMS, including the sampling interface, is challenged.
3.16 Optical path means the route light travels from the light source to the receiver used to make sample measurements.
3.17 Path length means, for an extractive optical CEMS, the distance in meters of the optical path within a gas measurement cell. For an IP-CEMS, path length means the distance in meters of the optical path that passes through the source gas in the stack or duct.
3.18 Point CEMS means a CEMS that measures the source gas concentration, either at a single point at the sampling probe tip or over a path length for IP-CEMS less than 10 percent of the equivalent diameter of the stack or duct cross section.
3.19 Stack pressure measurement device means a NIST-traceable gauge or monitor that measures absolute pressure and conforms to the design requirements of ASME B40.100-2010, “Pressure Gauges and Gauge Attachments” (incorporated by reference – see § 60.17).
3.20 Reference gas standard means a NIST-traceable gas standard containing a known concentration of HCl certified in accordance with an EPA traceability protocol in section 7.1 of this PS.
3.21 Relative accuracy (RA) means the absolute mean difference between the gas concentration or the emission rate determined by the CEMS and the value determined by the RM, plus the confidence coefficient of a series of nine test runs, divided by the average of the RM or the applicable emission standard.
3.22 Response time (RT) means the time it takes for the measurement system, while operating normally at its target sample flow rate, dilution ratio, or data collection rate to respond to a known step change in gas concentration, either from a low- or zero-level to a high-level gas concentration or from a high-level to a low or zero-level gas concentration, and to read 95 percent of the change to the stable instrument response. There may be several RTs for an instrument related to different functions or procedures (e.g., DS, LOD, and ME).
3.23 Span value means an HCl concentration approximately equal to two times the concentration equivalent to the emission standard unless otherwise specified in the applicable regulation, permit or other requirement. Unless otherwise specified, the span may be rounded up to the nearest multiple of 5.
3.24 Standard addition means the addition of known amounts of HCl gas (either statically or dynamically) to the actual measurement path or measured sample gas stream.
3.25 Zero gas means a gas or liquid with an HCl concentration that is below the LOD of the measurement system.
Sample gas interferences will vary depending on the instrument or technology used to make the measurement. Interferences must be evaluated through the interference test in this PS. Several compounds including carbon dioxide (CO
The procedures required under this PS may involve hazardous materials, operations, and equipment. This PS may not address all of the safety issues associated with these procedures. It is the responsibility of the user to establish appropriate safety and health practices and determine the applicable regulatory limitations prior to performing these procedures. The CEMS user’s manual and materials recommended by the RM should be consulted for specific precautions to be taken.
Equipment and supplies for CEMS will vary depending on the measurement technology and equipment vendors. This section provides a description of the equipment and supplies typically found in one or more types of CEMS.
6.1 Sample Extraction System. The portion of an extractive CEMS that collects and transports the sample to the pressure regulation and sample conditioning module. The extraction system must deliver a representative sample to the measurement instrument. The sample extraction system typically consists of a sample probe and a heated umbilical line.
6.2 Sample Conditioning Module. The portion of an extractive CEMS that removes particulate matter and moisture from the gas stream and provides a sample gas stream to the CEMS analysis module or analyzer. You must keep the particle-free gas sample above the dew point temperature of its components.
6.3 HClAnalyzer. The portion of the CEMS that detects, quantifies and generates an output proportional to the sample gas HCl concentration.
6.4 System Controller. The portion of the CEMS that provides control of the analyzer and other sub-systems (e.g., sample extraction, sample conditioning, reference gas) as necessary for continuous operation and periodic maintenance/QC activities.
6.5 Data Recorder. The portion of the CEMS that provides a record of analyzer output. The data recorder may record other pertinent data such as effluent flow rates, various instrument temperatures or abnormal CEMS operation. The data recorder output range must include the full range of expected HCl concentration values in the gas stream to be sampled including zero and span value.
6.6 Reference Gas System(s). Gas handling system(s) needed to introduce reference and other gases into the measurement system. For extractive CEMS, the system must be able to introduce gas flow sufficient to flood the sampling probe and prevent entry of gas from the effluent stream. For IP-CEMS, the system must be able to introduce a known concentration of HCl, at known cell length, pressure and temperature, into the optical path used to measure HCl gas concentration.
6.7 Moisture Measurement System. If correction of the measured HCl emissions for moisture is required, you must install, operate, maintain, and quality assure a continuous moisture monitoring system for measuring and recording the moisture content of the flue gases. The following continuous moisture monitoring systems are acceptable: An FTIR system validated according to Method 301 or section 13.0 of Method 320 in appendix A to part 63 of this chapter; a continuous moisture sensor; an oxygen analyzer (or analyzers) capable of measuring O
7.1 Reference Gases. Reference gases (e.g., cylinder gases or liquid evaporative standards) used to meet the requirements of this PS must be NIST certified or NIST-traceable and vendor certified to ±5.0 percent accuracy. HCl cylinder gases must be certified according to Reference 5 in section 16 of this PS through a documented unbroken chain of comparisons each contributing to the reported uncertainty. Liquid evaporative standards must be certified using the gravimetrically-based procedures of the latest version of the EPA Traceability Protocol for Qualification and Certification of Evaporative HCl Gas Standards and Humidification of HCl Gas Standards from Cylinders (see EPA-HQ-OAR-2013-0696-0026.pdf).
7.2 Cylinder gas and/or liquid evaporative standards must be used within their certification periods.
7.3 High concentration cylinder gas or liquid evaporative HCl standards may be diluted for use in this specification. You must document the quantitative introduction of HCl standards into the system using Method 205, found in 40 CFR part 51, appendix M, or other procedure approved by the Administrator.
8.1 Prior to the start of your initial PS tests, you must ensure that the CEMS is installed according to the manufacturer’s specifications and the requirements in this section. You may use either point or IP sampling technology.
8.2 CEMS Installation. Install the CEMS at an accessible location where the pollutant concentration or emission rate measurements are directly representative of the HCl emissions or can be corrected so as to be representative of the total emissions from the affected facility. The CEMS need not be installed at the same location as the relative accuracy test location. If you fail the RA requirements in this specification due to the CEMS measurement location and a satisfactory correction technique cannot be established, the Administrator may require the CEMS to be relocated.
8.2.1 Single point sample gas extraction should be (1) no less than 1.0 m (3.3 ft.) from the stack or duct wall or (2) within the centroidal area of the stack or duct cross section.
8.2.2 IP-CEMS measurements should (1) be conducted totally within the inner area bounded by a line 1.0 m (3.3 ft.) from the stack or duct wall, (2) have at least 70 percent of the path within the inner 50 percent of the stack or duct cross-sectional area, or (3) be located over any part of the centroidal area.
8.2.2.1 You must measure the IP-CEMS path length from the inner flange of the sampling ports or the inner end of the instrument insertion into the stack cavity using a laser tape measure, mechanical measurement tape, or similar device accurate to ±1.5 mm (0.059 in).
8.2.2.2 You must ensure that any purge flow used to protect IP-CEMS instrument windows from stack gas does not alter the measurement path length. Purge flow of less than or equal to 10 percent of the gas velocity in the duct meets this requirement.
8.2.3 CEMS and Data Recorder Scale Check. After CEMS installation, record and document the measurement range of the HCl CEMS. The CEMS operating range and the range of the data recording device must encompass all potential and expected HCl concentrations, including the concentration equivalent to the applicable emission limit and the span value.
After completing the CEMS installation, setup and calibration, you must complete the PS test procedures in this section. You must perform the following procedures and meet the performance requirements for the initial demonstration of your CEMS:
a. Interference Test;
b. Beam Intensity Test (IP-CEMS only);
c. Temperature Verification Procedure (IP-CEMS only);
d. Pressure Verification Procedure (IP-CEMS only);
e. Level of Detection Determination;
f. Response Time Test;
g. Measurement Error Test;
h. Calibration Drift Test; and
i. Relative Accuracy Test.
11.1.1 Prior to its initial use in the field, you must demonstrate that your monitoring system meets the performance requirements of the interference test in section 13.5 to verify that the candidate system measures HCl accurately in the presence of common interferences in emission matrices.
11.1.2 Your interference test must be conducted in a controlled environment. The equipment you test for interference must include the combination of the analyzer, related analysis software, and any sample conditioning equipment (e.g., dilution module, moisture removal equipment or other interferent scrubber) used to control interferents.
11.1.3 If you own multiple measurement systems with components of the same make and model numbers, you need only perform this interference test on one analyzer and associated interference conditioning equipment combination. You may also rely on an interference test conducted by the manufacturer or a continuous measurement system integrator on a system having components of the same make and model(s) of the system that you use.
11.1.4 Perform the interference check using an HCl reference gas concentration of approximately five times the LOD.
11.1.5 Introduce the interference test gases listed in Table 1 in section 17.0 of this PS to the analyzer/conditioning system separately or in any combination. The interference test gases need not be of reference gas quality.
11.1.5.1 For extractive CEMS, the interference test gases may be introduced directly into the inlet to the analyzer/conditioning system after the probe extension coupling.
11.1.5.2 For IP-CEMS, the interference test gases may be added with the HCl in a calibration cell or separately in a temperature-controlled cell. The effective concentration of the gas in the cell must meet the requirements in Table 1 corrected for absolute pressure, temperature and the nominal stack sampling path length of the CEMS.
11.1.6 The interference test must be performed by combining an HCl reference gas with each interference test gas (or gas mixture). You must measure the baseline HCl response, followed by the response after adding the interference test gas(es) while maintaining a constant HCl concentration. You must perform each interference gas injection and evaluation in triplicate.
The baseline HCl gas may include interference gases at concentrations typical of ambient air (e.g., 21 percent O
11.1.7 You should document the gas volume/rate, temperature, and pressure used to conduct the interference test. A gas blending system or manifold may be used.
11.1.8 Ensure the duration of each interference test is sufficient to condition the HCl measurement system surfaces before a stable measurement is obtained.
11.1.9 Measure the HCl response of the analyzer/sample conditioning system combination to the test gases in ppmv. Record the responses and determine the overall interference response using Table 2 in section 17.0.
11.1.10 For each interference gas (or mixture), calculate the mean difference (ΔMC
11.1.11 Calculate the percent interference (I) for the gas runs using Equation 2 in section 12.2.
11.1.12 The total interference response (i.e., the sum of the interference responses of all tested gaseous components) must not exceed the criteria set forth in section 13.5 of this PS.
11.2.1 For IP-CEMS, you must establish the tolerance of your system to beam intensity attenuation.
11.2.1.1 Your beam intensity test may be conducted in either a controlled environment or on-site during initial setup and demonstration of your CEMS.
11.2.1.2 If you have multiple measurement systems with components of the same make and model numbers, you need only perform this attenuation check on one system and you may also rely on an attenuation test conducted by the manufacturer on a system having components of the same make and model(s) of the system that you use.
11.2.2 Insert one or more neutral density filter(s) or otherwise attenuate the beam intensity by a known percentage (e.g., 90 percent of the beam intensity).
11.2.3 Perform a high-level HCl reference gas measurement.
11.2.4 Record and report the attenuated beam intensity, the measured HCl calibration gas concentration at full beam intensity, the measured HCl gas concentration with attenuated beam intensity, and the percent difference between the two HCl measurements with and without attenuation of the beam intensity. The percent difference must not exceed the criteria set forth in section 13.6 of this PS.
11.2.5 In the future, you may not operate your IP-CEMS at a beam intensity lower than that established based on the attenuation used during this test. However, you may repeat the test to establish a lower beam intensity limit or level.
11.3.1 Any measurement instrument or device that is used as a reference in verification of temperature measurement must have an accuracy that is traceable to NIST.
11.3.2 You must verify the temperature sensor used in IP-CEMS measurements on-site as part of the initial installation and verification procedures.
11.3.3 Comparison to Calibrated Temperature Measurement Device.
11.3.3.1 Place the sensor of a calibrated temperature reference device adjacent to the sensor used to measure stack temperature for your IP-CEMS. The calibrated temperature reference device must satisfy the accuracy requirements specified in Table 3 of this PS. The calibrated temperature reference device must also have a range equal to or greater than the range of your IP-CEMS temperature sensor.
11.3.3.2 Allow sufficient time for the response of the calibrated temperature reference device to reach equilibrium. With the process and control device operating under normal conditions, concurrently record the temperatures measured by your IP-CEMS system (M
11.3.3.3 If your IP-CEMS temperature sensor does not satisfy the accuracy requirement of this PS, check all system components and take any corrective action that is necessary to achieve the required minimum accuracy. Repeat this verification procedure until the accuracy requirement of this specification is satisfied.
11.4.1 For stack pressure measurement verification, you must select a NIST-traceable gauge or monitor that conforms to the design requirements of ASME B40.100-2010, “Pressure Gauges and Gauge Attachments,” (incorporated by reference – see § 60.17) as a reference device.
11.4.2 As an alternative for a calibrated pressure reference device with NIST-traceable accuracy, you may use a water-in-glass U-tube manometer to verify your IP-CEMS pressure measurement equipment, provided there is also an accurate measurement of absolute atmospheric pressure at the manometer location.
11.4.3 Allow sufficient time for the response of the reference pressure measurement device to reach equilibrium. With the process and control device operating under normal conditions, concurrently record the pressures measured by your IP-CEMS system (M
11.4.4 If your IP-CEMS pressure sensor does not satisfy the accuracy requirement of this PS, check all system components and take any corrective action that is necessary to achieve the required minimum accuracy. Repeat this verification procedure until the accuracy requirement of this specification is satisfied.
11.5.1 You must determine the minimum amount of HCl that can be detected above the background in a representative gas matrix.
11.5.2 You must perform the LOD determination in a controlled environment such as a laboratory or manufacturer’s facility.
11.5.3 You must add interference gases listed in Table 1 of this PS to a constant concentration of HCl reference gas.
11.5.3.1 You may not use an effective reference HCl gas concentration greater than five times the estimated instrument LOD.
11.5.3.2 For extractive CEMS, inject the HCl and interferents described in section 11.1.5 directly into the inlet to the analyzer.
11.5.3.3 For IP-CEMS, the HCl and interference test gases may be added to a calibration cell or separately in a temperature-controlled cell that is part of the measurement path. The effective concentration of the gas in the cell must meet the requirements in Table 1 corrected for absolute pressure, temperature and the nominal stack sampling path length of the CEMS.
11.5.4 Collect seven or more consecutive measurements separated by twice the RT (described in section 11.6) to determine the LOD.
11.5.5 Calculate the standard deviation of the measured values and define the LOD as three times the standard deviation of these measurements.
11.5.5.1 The LOD for extractive units must be determined and reported in ppmv.
11.5.5.2 The LOD for IP units must be determined and reported on a ppm-meter basis and the site- or installation-specific LOD must be calculated based on the actual measurement path length and gas density of the emissions at the specific site installation in ppmv.
11.5.6 You must verify the controlled environment LOD of section 11.5.2 of this PS for your CEMS during initial setup and field certification testing. You must use the SA procedure in appendix A of this PS with the following exceptions:
11.5.6.1 For the LOD verification in the field, you must make three independent SA measurements spiking the native source concentration by no more than three times the controlled environment LOD concentration determined in section 11.5.5.
11.5.6.2 For extractive CEMS, you must perform the SA as a dynamic spike by passing the spiked source gas sample through all filters, scrubbers, conditioners and other monitoring system components used during normal sampling, and as much of the sampling probe as practical. For IP-CEMS, you must perform the SA procedure by adding or passing a known concentration reference gas into a calibration cell in the optical path of the CEMS; you must also include the source measurement optical path while performing the SA measurement.
11.5.6.3 The amount detected, or standard addition response (SAR), is based on the average difference of the native HCl concentration in the stack or duct relative to the native stack concentration plus the SA. You must be able to detect the effective spike addition (ESA) above the native HCl present in the stack gas matrix. For extractive CEMS, the ESA is calculated using Equation A7 in appendix A of this PS. For IP-CEMS, the ESA is calculated as C
11.5.6.4 For extractive CEMS, calculate the SAR using Equation A4 in appendix A of this PS. For IP-CEMS, calculate the SAR using Equation A8.
11.5.6.5 If your system LOD field verification does not demonstrate a SAR greater than or equal to your initial controlled environment LOD, you must increase the SA concentration incrementally and repeat the field verification procedure until the SAR is equal to or greater than LOD. The site-specific standard addition detection level (SADL) is equal to the standard addition needed to achieve the acceptable SAR, and SADL replaces the controlled environment LOD. For extractive CEMS, the SADL is calculated as the ESA using Equation A7 in appendix A of this PS. For IP-CEMS, the SADL is the SA calculated using Equation A8 in appendix A of this PS. As described in section 13.1 of this PS, the LOD or the SADL that replaces an LOD must be less than 20 percent of the applicable emission limit.
11.6.1 For ME- or LOD-RT, start the upscale RT determination by injecting zero gas into the measurement system as required by the procedures in section 11.7 or 11.5, respectively. You may use humidified zero gas. For standard addition RT, start the upscale RT determination by measuring the native stack gas concentration of HCl.
11.6.1.1 For extractive CEMS measuring ME- or LOD-RT, the output has stabilized when there is no change greater than 1.0 percent of full scale for 30 seconds.
11.6.1.2 For standard addition RT that includes the stack gas matrix the final stable response may continue to vary by more than 1 percent, but may be considered stable if the variability is random and not continuously rising or falling.
11.6.2 When the CEMS output has stabilized, record the response in ppmv and introduce an upscale (high level) or spike reference gas as required by the relevant procedure.
11.6.3 Record the time (upscale RT) required to reach 95 percent of the change to the final stable value.
11.6.4 Next, for ME or LOD RT, reintroduce the zero gas and record the time required to reach 95 percent of the change to the stable instrument response at the zero gas reading. For SA RT, introduce zero gas to the IP-CEMS cell or stop the spike gas flow to the extractive CEMS as required by the specified procedure and record the time required to reach 95 percent of the change to the stable instrument response of the native gas reading. This time is the downscale RT.
(
11.6.5 Repeat the entire procedure until you have three sets of data, then determine the mean upscale and mean downscale RTs for each relevant procedure. Report the greater of the average upscale or average downscale RTs as the RT for the system.
11.7.1 On the same day and as close in time as practicable to when the ME test is conducted, perform and meet requirements for a calibration drift (CD) test using a zero gas as used in the Seven-Day Drift Test (see section 11.8) and document and report the results. To meet this requirement, the ME test may be conducted during the Seven-Day CD Test.
11.7.2 Extractive CEMS ME Test.
11.7.2.1 Introduce reference gases to the CEMS probe, prior to the sample conditioning and filtration system.
11.7.2.2 Measure three upscale HCl reference gas concentrations in the range shown in Table 4 of this PS.
11.7.2.3 Introduce the gases into the sampling probe with sufficient flow rate to replace the entire source gas sample.
11.7.2.4 Continue to add the reference gas until the response is stable as evidenced when the difference between two consecutive measurements is less than the LOD or within five percent of each other.
11.7.2.5 Make triplicate measurements for each reference gas for a total of nine measurements. Introduce different reference gas concentrations in any order but do not introduce the same gas concentration twice in succession.
11.7.2.6 At each reference gas concentration, determine the average of the three CEMS responses (
11.7.2.7 If you desire to determine the system RT during this test, you must inject zero gas immediately before and after each injection of the high-level gas standard.
11.7.2.8 For non-dilution systems, you may adjust the system to maintain the correct flow rate at the analyzer during the test, but you may not make adjustments for any other purpose. For dilution systems, you must operate the measurement system at the appropriate dilution ratio during all system ME checks, and you may make only the adjustments necessary to maintain the proper ratio.
11.7.3 IP-CEMS ME Test.
11.7.3.1 Conduct a 3-level system ME test by individually adding the known concentrations of HCl reference gases into a calibration cell of known volume, temperature, pressure and path length.
Note: The optical path used for IP-CEMS ME checks must include the native HCl measurement path. You must also collect native stack concentration HCl measurements before and after each HCl standard measurement. Bracketing HCl reference gas measurements with native stack HCl measurements must be used in the calculations in Equation 5 in section 12.4.2 to correct the upscale measurements for stack gas HCl concentration changes.
11.7.3.2 Introduce HCl reference gas into your calibration cell in a range of concentrations that produce responses equivalent to the source concentrations shown in Table 4 of this PS for your path length.
11.7.3.3 Make triplicate measurements for each reference gas standard for a total of nine measurements. Introduce different calibration concentrations in any order but do not introduce the same reference gas concentration twice in succession.
11.7.3.4 You must calculate the effective concentration (C
11.7.3.5 You may use the LSF provided by your instrument manufacturer or determine an instrument-specific LSF as a function of temperature using a heated gas cell and equivalent concentrations (C
11.7.3.6 At each reference gas concentration, average the three independent CEMS measurement responses corrected for native HCl stack concentration. Calculate the ME using Equation 6A in section 12.4.3.
11.7.4 You may use Figure 1 in section 17.0 to record and report your ME test results.
11.7.5 If the ME specification in section 13.3 is not met for all three reference gas concentrations, take corrective action and repeat the test until an acceptable 3-level ME test is achieved.
11.8.1 The CD Test Period. Prior to the start of the RA tests, you must perform a seven-day CD test. The purpose of the seven-day CD test is to verify the ability of the CEMS to maintain calibration for each of seven consecutive unit operating days as specified in section 11.8.5 of this PS.
11.8.2 The CD tests must be performed using the zero gas and mid-level reference gas standards as defined in Table 4 of this PS.
11.8.3 Conduct the CD test on each day during continuous operation of the CEMS and normal facility operations following the procedures in section 11.7 of this PS, except that the zero gas and mid-level gas need only be introduced to the measurement system once each.
11.8.4 If periodic automatic or manual adjustments are made to the CEMS zero and upscale response factor settings, conduct the CD test immediately before these adjustments.
Automatic signal or mathematical processing of all measurement data to determine emission results may be performed throughout the entire CD process.
11.8.5 Determine the magnitude of the CD at approximately 24-hour intervals, for 7 consecutive unit operating days. The 7 consecutive unit operating days need not be 7 consecutive calendar days.
11.8.6 Record the CEMS response for single measurements of zero gas and mid-level reference gas. You may use Figure 2 in section 17 of this PS to record and report the results of your 7-day CD test.
11.8.6.1 For extractive CEMS, calculate the CD using Equation 3B in section 12.3. Report the absolute value of the differences as a percentage of the span value.
11.8.6.2 For IP-CEMS, you must include the source measurement optical path while performing the upscale CD measurement; you may exclude the source measurement optical path when determining the zero gas concentration. Calculate the CD for IP CEMS using equations 4, 5, 6B, and 7 in section 12.4.
11.8.7 The zero-level and mid-level CD for each day must be less than 5.0 percent of the span value as specified in section 13.2 of this PS. You must meet this criterion for 7 consecutive operating days.
11.8.8 Dynamic Spiking Option for Seven-Day CD Test. For extractive CEMS, you have the option to conduct a mid-level dynamic spiking procedure for each of the 7 days in lieu of the mid-level reference gas injection described in sections 11.8.2 and 11.8.3. If this option is selected, the daily zero CD check is still required.
11.8.8.1 To conduct each of the seven daily mid-level dynamic spikes, you must use the DS procedure described in appendix A of this PS using a single spike of the mid-level reference gas (see Table 4).
11.8.8.2 You must perform the dynamic spike procedure by passing the spiked source gas sample through all filters, scrubbers, conditioners and other monitoring system components used during normal sampling, and as much of the sampling probe as practical.
11.8.8.3 Calculate the mid-level CD as a percent of span using Equation A6 of appendix A to this PS and calculate the zero drift using Equation 3B in section 12.3. Record and report the results as described in sections 11.8.6 and 11.8.7.
11.9.1 Unless otherwise specified in an applicable regulation, use Method 26A in 40 CFR part 60, appendix A-8, Method 320 in 40 CFR part 63, appendix A, or ASTM D6348-12 including all annexes, as applicable, as the RMs for HCl measurement. Obtain and analyze RM audit samples, if they are available, concurrently with RM test samples according to the same procedure specified for performance tests in the general provisions of the applicable part. If Method 26 is not specified in an applicable subpart of the regulations, you may request approval to use Method 26 in appendix A-8 to this part as the RM on a site-specific basis under §§ 63.7(f) or 60.8(b). Other RMs for moisture, O
11.9.1.1 When Method 26A is used as the RM, you must sample sufficient gas to reach three times your method detection limit for Method 26A in 40 CFR part 60, appendix A-8, or for a minimum of one hour, whichever is greater.
11.9.1.2 When Method 320 or Method 321, both found in 40 CFR part 63, appendix A, or ASTM D6348-12, are used as the RM, you must collect gas samples that are at stack conditions (hot and wet) and you must traverse as required in section 11.9.3.
11.9.2 Conduct the diluent (if applicable), moisture (if needed), and pollutant measurements simultaneously. However, diluent and moisture measurements that are taken within an hour of the pollutant measurements may be used to calculate dry pollutant concentration and emission rates.
11.9.3 Reference Method Measurement Location and Traverse Point(s) Selection.
11.9.3.1 Measurement Location. Select, as appropriate, an accessible RM measurement location at least two equivalent diameters downstream from the nearest control device, point of pollutant generation, or other point at which a change in the pollutant concentration or emission rate may occur, and at least one half equivalent diameter upstream from the effluent exhaust or a control device. When pollutant concentration changes are due solely to diluent leakage (e.g., air heater leakages) and pollutants and diluents are simultaneously measured at the same location, a half diameter may be used in lieu of two equivalent diameters. The equivalent duct diameter is calculated according to Method 1 in appendix A-1 to this part. The CEMS and RM sampling locations need not be the same.
11.9.3.2 Traverse Point Selection. Select traverse points that assure acquisition of representative RM samples over the stack or duct cross section according to one of the following options: (a) sample at twelve traverse points located according to section 11.3 of Method 1 in appendix A-1 to this part, (b) sample at 6 Method 1 traverse points according to section 6.5.6(b)(1) of appendix A to part 75 of this chapter, or (c) sample at three points on a measurement line (“3-point long line”) that passes through the centroidal area of the duct in the direction of any potential stratification. If this line interferes with the CEMS measurements, you may displace the line up to 20 cm (12 in.) or 5.0 percent of the equivalent diameter of the cross section, whichever is less, from the centroidal area. Locate the three traverse points at 16.7, 50.0, and 83.3 percent of the measurement line. Alternatively, you may conduct a stratification test following the procedures in sections 11.9.3.2.1 through 11.9.3.2.4 to justify sampling at a single point or three points located on the measurement line at 0.4, 1.2, and 2.0 m from the stack wall (“3-point short line”). Stratification testing must be conducted at the sampling location to be used for the RM measurements during the RA test and must be made during normal facility operating conditions. You must evaluate the stratification by measuring the gas on the same moisture basis as the HCl CEMS (wet or dry). Stratification testing must be repeated for each RA test program to justify single point or “3-point short line” sampling.
11.9.3.2.1 Use a probe of appropriate length to measure the HCl concentration or an alternative analyte, as described in this section, using 12 traverse points located according to section 11.3 of Method 1 in appendix A-1 to 40 CFR part 60 for a circular stack or nine points at the centroids of similarly-shaped, equal area divisions of the cross section of a rectangular stack.
11.9.3.2.2 You may substitute a stratification test for SO
11.9.3.2.3 Calculate the mean measured concentration for all sampling points (MN
11.9.3.2.4 Calculate the percent stratification (S
11.9.3.2.5 The gas stream is considered to be unstratified and you may perform the RA testing at a single point that most closely matches the mean if the concentration at each traverse point differs from the mean concentration for all traverse points by: (a) No more than 5.0 percent of the mean concentration; or (b) 0.2 ppm (for HCl) or 3 ppm (for SO
11.9.3.2.6 If the criterion for single point sampling (5.0 percent, 0.2 ppm for HCl or 3 ppm for SO
11.9.3.2.7 If the concentration at any traverse point differs from the mean concentration by more than 10 percent, the gas stream is considered stratified and you must sample using one of the options in section 11.9.3.2 above.
11.9.3.3 Conduct all necessary RM tests within 3 cm (1.2 in.) of the traverse points, but no closer than 3 cm (1.2 in.) to the stack or duct wall.
11.9.4 In order to correlate the CEMS and RM data properly, record the beginning and end of each RM run (including the time of day in hours, minutes, and seconds) using a clock synchronized with the CEM clock used to create a permanent time record with the CEMS output.
11.9.5 You must conduct the RATA during representative process and control operating conditions or as specified in an applicable regulation, permit or subpart.
11.9.6 Conduct a minimum of nine RM test runs. NOTE: More than nine RM test runs may be performed. If this option is chosen, up to three test run results may be excluded so long as the total number of test run results used to determine the CEMS RA is greater than or equal to nine. However, all data must be reported including the excluded test runs.
11.9.7 Analyze the results from the RM test runs using Equations 9-14 in section 12.6. Calculate the RA between the CEMS results and the RM.
11.10.1 For systems that use a liquid evaporative standard generator to deliver HCl reference gas standards, record supporting data for these devices, including liquid feed calibrations, liquid standard concentration(s) and NIST-traceability, feed rate and gas flow calibrations for all diluent and HCl gas flows. All calibrations must include a stated uncertainty, and the combined uncertainty of the delivered HCl reference gas concentration must be calculated and reported.
11.10.2 Record the results of the CD test, the RT test, the ME test, the RA test, and for IP-CEMS, the results of the beam intensity, temperature and pressure verification procedures. Also keep records of the RM and CEMS field data, calculations, and reference gas certifications necessary to confirm that the performance of the CEMS met the performance specifications.
11.10.3 For systems that use Method 205 to prepare HCl reference gas standards, record results of Method 205 performance test field evaluation, reference gas certifications, and gas dilution system calibration.
11.10.4 Record the LOD for the CEMS. For extractive CEMS, record the LOD in ppmv. For IP-CEMS, record the LOD on a ppm-meter basis along with a calculation of the installation specific LOD in ppmv. For both CEMS types, you must also record the field verified SADL.
11.10.5 Record the results of the interference test.
11.10.6 Report the results of all certification tests to the appropriate regulatory agency (or agencies), in hardcopy and/or electronic format, as required by the applicable regulation or permit.
12.2 Calculate the difference between the measured HCl concentration with and without interferents for each interference gas (or mixture) for your CEMS as:
Calculate the total percent interference as:
12.2.1 Calculate the equivalent concentration C
12.4.1 Calculate the equivalent concentration C
12.4.2 Calculate the average native concentration before and after each calibration check measurement as:
12.4.3 Calculate the ME or CD at concentration i for an IP-CEM as:
12.4.4 Calculate the zero CD as a percent of span for an IP-CEMS as:
12.6.1 Determine the CEMS final integrated minute average pollutant concentration or emission rate for each RM test period. Consider system RT, if important, and confirm that the results have been corrected to the same moisture, temperature and diluent concentration basis.
12.6.2 When Method 26A (or if approved for use, Method 26), found in 40 CFR part 60, appendix A-8 of this part, is used as the RM, compare each CEMS integrated average value against the corresponding RM value for identical test periods. Make these comparisons on the same basis (e.g., wet, dry, ppmv, or units of the standard). To convert results generate by Method 26A or 26 in mg/DSCM to ppmv, use the conversion factor 0.662 ppm/(mg/DSCM).
12.6.3 If the RM is Method 320 or Method 321, found in 40 CFR part 63, appendix A, or ASTM D6348-12, make a direct comparison of the average RM results and CEMS average value for identical test periods.
12.6.4 For each test run, calculate the arithmetic difference of the RM and CEMS results using Equation 9.
12.6.5 Calculate the standard deviation of the differences (S
12.6.6 Calculate the confidence coefficient (CC) for the RATA using Equation 11.
12.6.7 Calculate the mean difference (d
12.6.8 Calculate the average RM value using Equation 13.
12.6.9 Calculate RA of the CEMS using Equation 14.
13.1 Level of Detection. You may not use a CEMS whose LOD or SADL is greater than 20 percent of the applicable regulatory limit or other action level for the intended use of the data.
13.2 Calibration Drift. The zero- and mid-level calibration drift for the CEMS must not exceed 5.0 percent of the span value for 7 consecutive operating days.
13.3 Measurement Error. The ME must be less than or equal to 5.0 percent of the span value at the low-, mid-, and high-level reference gas concentrations.
13.4 Relative Accuracy. Unless otherwise specified in an applicable regulation or permit, the RA of the CEMS, whether calculated in units of HCl concentration or in units of the emission standard, must be less than or equal to 20.0 percent of the RM when RM
13.4.1 In cases where the RA is calculated on a concentration (ppmv) basis, if the average RM emission level for the test is less than 75 percent of the HCl concentration equivalent to the emission standard, you may substitute the HCl concentration equivalent to the standard in the denominator of Equation 14 in place of RM
13.4.2 Similarly, if the RA is calculated in units of the emission standard and the HCl emission level measured by the RMs is less than 75 percent of the emission standard, you may substitute the emission standard in the denominator of Equation 14 in place of RM
13.4.3 The alternative calculated RA in paragraph 13.4.1 or 13.4.2 must be less than or equal to 15.0 percent.
13.5 Interference Test.
13.5.1 The sum of the interference response(s) from Equation 2 must not be greater than 2.5 percent of the calibration span or ±3.0 percent of the equivalent HCl concentration used for the interference test, whichever is less restrictive. The results are also acceptable if the sum of the interference response(s) does not exceed six times the LOD or 0.5 ppmv for a calibration span of 5 to 10 ppm, or 0.2 ppmv for a calibration span of less than 5 ppmv.
13.6 IP-CEMS Beam Intensity Test. For IP-CEMS, the percent difference between the measured concentration with and without attenuation of the light source must not exceed ±3.0 percent.
13.7 IP-CEMS Temperature Measurement Verification. Your temperature sensor satisfies the accuracy required if the absolute relative difference between measured value of stack temperature (M
13.8 IP-CEMS Pressure Sensor Measurement Verification. Your pressure sensor satisfies the accuracy required if the absolute relative difference between the measured value of stack pressure (M
1. Method 318 – Extractive FTIR Method for the Measurement of Emissions From the Mineral Wool and Wool Fiberglass Industries, 40 CFR, part 63, subpart HHHHHHH, appendix A.
2. “EPA Protocol for the Use of Extractive Fourier Transform Infrared (FTIR) Spectrometry in Analyses of Gaseous Emissions from Stationary Industrial Sources,” February, 1995.
3. “Measurement of Gaseous Organic and Inorganic Emissions by Extractive FTIR Spectroscopy,” EPA Contract No. 68-D2-0165, Work Assignment 3-08.
4. “Method 301 – Field Validation of Pollutant Measurement Methods from Various Waste Media,” 40 CFR part 63, appendix A.
5. EPA Traceability Protocol for Assay and Certification of Gaseous Calibration Standards, U.S. Environmental Protection Agency office of Research and Development, EPA/600/R-12/531, May 2012.
Table 1 – Interference Test Gas Concentrations
| Potential interferent gas 1 | Approximate concentration (balance N |
|---|---|
| CO | 15% ± 1% CO 2 |
| CO | 100 ± 20 ppm. |
| CH | 20 ± 5 ppm. |
| CH | 100 ± 20 ppm. |
| NH | 10 ± 5 ppm (extractive CEMS only). |
| NO | 250 ± 50 ppm. |
| SO | 200 ± 20 ppm. |
| O | 3% ± 1% O 2 |
| H | 10% ± 1% H 2 |
| N | Balance. 2 |
1 Any of these specific gases can be tested at a lower level if the manufacturer has provided reliable means for limiting or scrubbing that gas to a specified level in CEMS field installations.
2 Gases for short path IP cell interference tests cannot be added above 100 percent stack equivalent concentration. Add these gases at the indicated percentages to make up the remaining cell volume.
Table 3 – Design Standards for Temperature Sensors
| If the sensor is a . . . | You can use the following design standards as guidance in selecting a sensor for your IP-CEMS |
|---|---|
| 1. Thermocouple | a. ASTM E235-88 (1996), “Specification for Thermocouples, Sheathed, Type K, for Nuclear or Other High-Reliability Applications.” |
| b. ASTM E585/E585M-04, “Specification for Compacted Mineral-Insulated, Metal-Sheathed, Base Metal Thermocouple Cable.” | |
| c. ASTM E608/E608M-06, “Specification for Mineral-Insulated, Metal-Sheathed Base Metal Thermocouples.” | |
| d. ASTM E696-07, “Specification for Tungsten-Rhenium Alloy Thermocouple Wire.” | |
| e. ASTM E1129/E1129M-98 (2002), “Standard Specification for Thermocouple Connectors.” | |
| f. ASTM E1159-98 (2003), “Specification for Thermocouple Materials, Platinum-Rhodium Alloys, and Platinum.” | |
| g. ISA-MC96.1-1982, “Temperature Measurement Thermocouples.” | |
| 2. Resistance temperature detector | ASTM E1137/E1137M-04, “Standard Specification for Industrial Platinum Resistance Thermometers.” |
Table 4 – Performance Specification Test Zero and Reference Gas Ranges
| Test | Units | HCl Zero and Reference Gas Concentrations in Terms of Percent of Span a | Section | |||
|---|---|---|---|---|---|---|
| Zero | Low Level | Mid Level | High Level | |||
| Calibration Drift | % of Span | | NA | 50-60 | b NA | 11.8 | |
| Measurement Error | % of Span | NA | 20-30 | 50-60 | 80-100 | 11.7 |
a Reference gas concentration must be NIST traceable. (see section 7.1)
b Mid-level is required. For DS calibration drift option, choose a concentration that yields a value in this range at the analyzer.
Table 5 – Student’s t-Values
| n-1 a | t-value | n-1 a | t-value | n-1 a | t-value |
|---|---|---|---|---|---|
| 1 | 12.71 | 11 | 2.201 | 21 | 2.080 |
| 2 | 4.303 | 12 | 2.179 | 22 | 2.074 |
| 3 | 3.182 | 13 | 2.160 | 23 | 2.069 |
| 4 | 2.776 | 14 | 2.145 | 24 | 2.064 |
| 5 | 2.571 | 15 | 2.131 | 25 | 2.060 |
| 6 | 2.447 | 16 | 2.120 | 26 | 2.056 |
| 7 | 2.365 | 17 | 2.110 | 27 | 2.052 |
| 8 | 2.306 | 18 | 2.101 | 28 | 2.048 |
| 9 | 2.262 | 19 | 2.093 | 29 | 2.045 |
| 10 | 2.228 | 20 | 2.086 | 30 | 2.042 |
a The value n is the number of independent pairs of measurements. Either discrete (independent) measurements in a single run, or run averages can be used.
1.1 This appendix to Performance Specification (PS) 18 describes the procedure and performance requirements for standard addition (SA) as a quality check for hydrogen chloride (HCl) continuous emission monitoring systems (CEMS).
1.2 This appendix is applicable to quality checks of both extractive and integrated path (IP) technologies used to measure HCl emissions.
1.3 For extractive CEMS, this procedure must be used, as a level of detection (LOD) verification of all field-installed CEMS. Additionally, it is allowed by Procedure 6 in appendix F to this part as an alternative to upscale calibration drift (CD) tests, cylinder gas audits and relative accuracy audits (RAAs), and may be used for quality assurance purposes under other applicable regulations or permits that require HCl monitoring.
1.4 For IP-CEMS, this procedure must be used as a LOD verification of all field-installed CEMS.
As used here, SA is a gas phase method of standard additions (either static or dynamic) used to verify the accuracy of CEMS measurements in the presence of the sample matrix. For extractive CEMS, it consists of spiking a known quantity of HCl dynamically into the measurement system as an addition to the native HCl and the native source gas matrix. For IP-CEMS, this procedure consists of introducing a known quantity of HCl into the optical path that also includes the native source gas.
5.0 Safety. The procedures required under this appendix may involve hazardous materials, operations and equipment. This procedure may not address all of the safety problems associated with these procedures. You as the facility or operator must establish appropriate safety and health practices and determine the applicable regulatory limitations prior to performing these procedures. As the CEMS user, you should consult instrument operation manuals, material safety data sheets, compressed gas safety requirements, and other Occupational Safety and Health Administration regulations for specific precautions to be taken.
6.0 Equipment and Supplies. An example of equipment and supplies is described in section 6 of PS-18.
7.0 Reagents and Standards. SA materials must meet the requirements defined for reference gases in section 7 of PS-18 to perform this procedure with the following exception. You may use gases certified by the gas vendor to ±5 percent to perform the daily calibration drift assessment in section 4.1 of Procedure 6 in appendix F of this part.
For extractive CEMS the concentrations of reference gases required for SA are likely to be significantly higher than the concentration of reference gases associated with PS-18 requirements.
8.0 Standard Addition and Dynamic Spiking Procedure. The standard addition procedure consists of measuring the native source gas concentration, addition of reference gas, and measurement of the resulting SA elevated source gas concentration. For extractive CEMS, HCl is spiked dynamically and thus, one must account for the dilution of sample gas from the addition of the HCl reference gas. For IP-CEMS, standard addition of an HCl reference gas is made by either adding an HCl reference gas to a flow through cell or inserting a sealed reference gas cell into the measurement path of the CEMS. The enclosed cell or a fixed cell must contain an HCl concentration that accounts for the difference in path length of the cell used for SA relative to the measurement path.
8.1 SA Concentration and Measurement Replicates.
8.1.1 You must inject HCl gas to create a measured concentration based on the requirements of the particular performance test (e.g., LOD verification, CD, DSA).
8.1.2 Each dynamic spike (DS) or standard addition (SA) replicate consists of a measurement of the source emissions concentration of HCl (native stack concentration) with and without the addition of HCl. With a single CEMS, you must alternate the measurement of the native and SA-elevated source gas so that each measurement of SA-elevated source gas is immediately preceded and followed by a measurement of native stack gas. Introduce the SA gases in such a manner that the entire CEMS is challenged. Alternatively, you may use an independent continuous HCl monitor to measure the native source concentration before and after each standard addition as described in section 8.1.4.
8.1.3 Unless specified otherwise by an applicable rule, your SA-elevated concentration may not exceed 100 percent of span when the SA and native HCl concentration are combined.
8.1.4 As an alternative to making background measurements pre- and post-SA, you may use an independent continuous HCl monitor as a temporary unit to measure native stack HCl concentration while simultaneously using the CEMS to measure the SA-elevated source concentration. If you use an independent continuous HCl monitor you must make one concurrent background or native HCl measurement using both the installed CEMS and the independent continuous HCl monitor, immediately before the SA procedure in section 8.2 or 8.3 begins, to confirm that the independent monitoring system measures the same background concentration as the CEMS being qualified with this PS.
8.2 SA Procedure for Extractive CEMS (Dynamic Spiking)
8.2.1 Your HCl spike addition must not alter the total volumetric sample system flow rate or basic dilution ratio of your CEMS (if applicable).
8.2.2 Your spike gas flow rate must not contribute more than 10 percent of the total volumetric flow rate through the CEMS.
8.2.3 You must determine a dilution factor (DF) or relative concentration of HCl for each dynamic spike. Calibrated, NIST-traceable flow meters accurate to within 2.0 percent or highly accurate tracer gas measurements are required to make the necessary DF determinations at the accuracy required for this PS. Calibrated, NIST-traceable flow meters (e.g., venturi, orifice) accurate to within 2.0 percent should be recertified against an NIST-traceable flow meter annually.
8.2.4 You must monitor and record the total sampling system flow rate and sample dilution factor (DF) for the spiking and stack gas sampling systems to ensure they are known and do not change during the spiking procedure. Record all data on a data sheet similar to Table A1 in section 13 of this appendix.
8.2.4.1 You may either measure the spike gas flow and the total flow with calibrated flow meters capable of NIST traceable accuracy to ±2.0 percent or calculate the flow using a stable tracer gas included in your spike gas standard.
8.2.4.2 If you use flow measurements to determine the spike dilution, then use Equation A1 in section 11.2.1 of this appendix to calculate the DF. Determination of the spike dilution requires measurement of HCl spike flow (Q
8.2.4.3 If your CEMS is capable of measuring an independent stable tracer gas, you may use a spike gas that includes the tracer to determine the DF using Equation A2 or A3 (sections 11.2.2 and 11.2.3 of this appendix) depending on whether the tracer gas is also present in the native source emissions.
8.2.4.4 For extractive CEMS, you must correct the background measurements of HCl for the dilution caused by the addition of the spike gas standard. For spiking systems that alternate between addition of HCl and zero gas at a constant DF, the background measurements between spikes will not be equal to the native source concentration.
8.2.5 Begin by collecting unspiked sample measurements of HCl. You must use the average of two unspiked sample measurements as your pre-spike background.
Measurements should agree within 5.0 percent or three times the level of detection to avoid biasing the spike results.
8.2.5.1 Introduce the HCl gas spike into the permanent CEMS probe, upstream of the particulate filter or sample conditioning system and as close to the sampling inlet as practical.
8.2.5.2 Maintain the HCl gas spike for at least twice the DS response time of your CEMS or until the consecutive measurements agree within 5.0 percent. Collect two independent measurements of the native plus spiked HCl concentration.
8.2.5.3 Stop the flow of spike gas for at least twice the DS response time of your CEMS or until the consecutive measurements agree within 5.0 percent. Collect two independent measurements of the native HCl concentration.
8.2.6 Repeat the collection of sample measurements in section 8.2.5 until you have data for each spike concentration including a final set of unspiked sample measurements according to section 8.2.5.3.
8.2.7 Verify that the CEMS responded as expected for each spike gas injection, and that the data quality is not impacted by large shifts in the native source concentration. Discard and repeat any spike injections as necessary to generate a complete set of the required replicate spike measurements.
8.2.8 Calculate the standard addition response (SAR) for extractive CEMS, using Equation A4 in section 11.2, of this appendix.
8.2.9 If the DS results do not meet the specifications for the appropriate performance test in PS-18 or Procedure 6 of appendix F of this part, you must take corrective action and repeat the DS procedure.
8.3 SA Procedure for IP-CEMS (Static Spiking).
8.3.1 For IP-CEMS, you must make measurements of native source gas HCl concentration and an HCl standard addition using a calibration cell added to the optical measurement path.
8.3.2 Introduce zero gas into a calibration cell located in the optical measurement path of the instrument. Continue to flush the zero gas into the cell for at least the SA response time of your CEMS or until two consecutive measurements taken are within 5.0 percent, then collect two independent measurements. Alternatively you may measure native concentrations without the calibration cell in the optical path.
8.3.3 Introduce the HCl spike gas into the calibration cell. Continue to flush the spike gas into the cell for at least the SA response time of your CEMS or until two consecutive measurements taken are within 5.0 percent of one another. Then collect two independent measurements of the SA addition to the native concentration. Alternatively you may insert a sealed calibration cell, containing HCl at the appropriate concentration, into the optical path to measure the SA addition to the native concentration.
8.3.4 Repeat the collection of SA-elevated and native HCl measurements in sections 8.3.2 and 8.3.3 until you have data for each SA concentration. Then, make a final native HCl measurement. The measured concentrations must be corrected for calibration cell and stack temperature, pressure and stack measurement path length.
8.3.5 Calculate the standard addition response (SAR) for an IP-CEMS, using Equation A8 in section 11.3 of this appendix.
8.3.6 If the SA results do not meet the specifications for the appropriate performance test in PS-18 or Procedure 6 of appendix F of this part, you must take corrective action and repeat the SA procedure.
11.0 Calculations and Data Analysis. Calculate the SA response for each measurement and its associated native HCl measurement(s), using equations in this section. (
11.1 Nomenclature.
11.2 Calculating Dynamic Spike Response and Error for Extractive CEMS.
11.2.1 If you determine your spike DF using spike gas and stack sample flow measurements, calculate the DF using equation A1:
11.2.2 If you determine your spike DF using an independent stable tracer gas that is not present in the native source emissions, calculate the DF for DS using equation A2:
11.2.3 If you determine your spike dilution factor using an independent stable tracer that is present in the native source emissions, calculate the dilution factor for dynamic spiking using equation A3:
11.2.4 Calculate the SA response using Equation A4:
11.2.5 Calculate the DS error using Equation A5.
11.2.6 Calculating CD using DS. When using the DS option for determining mid-level CD, calculate the CD as a percent of span using equation A6:
11.2.7 The effective spike addition (ESA) is the expected increase in the measured concentration as a result of injecting a spike. Calculate ESA using Equation A7:
11.3 Standard Addition Response for IP-CEMS. If you use an IP-CEMS and a calibration cell, calculate the SA response using Equation A8.
Appendix C to Part 60 – Determination of Emission Rate Change
1.1 The following method shall be used to determine whether a physical or operational change to an existing facility resulted in an increase in the emission rate to the atmosphere. The method used is the Student’s t test, commonly used to make inferences from small samples.
2.1 Each emission test shall consist of n runs (usually three) which produce n emission rates. Thus two sets of emission rates are generated, one before and one after the change, the two sets being of equal size.
2.2 When using manual emission tests, except as provided in § 60.8(b) of this part, the reference methods of appendix A to this part shall be used in accordance with the procedures specified in the applicable subpart both before and after the change to obtain the data.
2.3 When using continuous monitors, the facility shall be operated as if a manual emission test were being performed. Valid data using the averaging time which would be required if a manual emission test were being conducted shall be used.
3.1 Subscripts a and b denote prechange and postchange respectively.
3.2 Calculate the arithmetic mean emission rate, E, for each set of data using Equation 1.
3.3 Calculate the sample variance, S
3.4 Calculate the pooled estimate, S
3.5 Calculate the test statistic, t, using Equation 4.
4.1 If E
Table 1
| Degrees of freedom ( | |
|---|---|
| 2 | 2.920 |
| 3 | 2.353 |
| 4 | 2.132 |
| 5 | 2.015 |
| 6 | 1.943 |
| 7 | 1.895 |
| 8 | 1.860 |
5.1 Assume the two performance tests produced the following set of data:
| Test a | Test b |
|---|---|
| Run 1. 100 | 115 |
| Run 2. 95 | 120 |
| Run 3. 110 | 125 |
5.2 Using Equation 1 –
5.3 Using Equation 2 –
5.4 Using Equation 3 –
5.5 Using Equation 4 –
5.6 Since (n
6.1 Hourly averages from continuous monitoring devices, where available, should be used as data points and the above procedure followed.
Appendix D to Part 60 – Required Emission Inventory Information
(a) Completed NEDS point source form(s) for the entire plant containing the designated facility, including information on the applicable criteria pollutants. If data concerning the plant are already in NEDS, only that information must be submitted which is necessary to update the existing NEDS record for that plant. Plant and point identification codes for NEDS records shall correspond to those previously assigned in NEDS; for plants not in NEDS, these codes shall be obtained from the appropriate Regional Office.
(b) Accompanying the basic NEDS information shall be the following information on each designated facility:
(1) The state and county identification codes, as well as the complete plant and point identification codes of the designated facility in NEDS. (The codes are needed to match these data with the NEDS data.)
(2) A description of the designated facility including, where appropriate:
(i) Process name.
(ii) Description and quantity of each product (maximum per hour and average per year).
(iii) Description and quantity of raw materials handled for each product (maximum per hour and average per year).
(iv) Types of fuels burned, quantities and characteristics (maximum and average quantities per hour, average per year).
(v) Description and quantity of solid wastes generated (per year) and method of disposal.
(3) A description of the air pollution control equipment in use or proposed to control the designated pollutant, including:
(i) Verbal description of equipment.
(ii) Optimum control efficiency, in percent. This shall be a combined efficiency when more than one device operates in series. The method of control efficiency determination shall be indicated (e.g., design efficiency, measured efficiency, estimated efficiency).
(iii) Annual average control efficiency, in percent, taking into account control equipment down time. This shall be a combined efficiency when more than one device operates in series.
(4) An estimate of the designated pollutant emissions from the designated facility (maximum per hour and average per year). The method of emission determination shall also be specified (e.g., stack test, material balance, emission factor).
Appendix E to Part 60 [Reserved]
Appendix F to Part 60 – Quality Assurance Procedures
1.1 Applicability. Procedure 1 is used to evaluate the effectiveness of quality control (QC) and quality assurance (QA) procedures and the quality of data produced by any continuous emission monitoring system (CEMS) that is used for determining compliance with the emission standards on a continuous basis as specified in the applicable regulation. The CEMS may include pollutant (e.g., S0
This procedure specifies the minimum QA requirements necessary for the control and assessment of the quality of CEMS data submitted to the Environmental Protection Agency (EPA). Source owners and operators responsible for one or more CEMS’s used for compliance monitoring must meet these minimum requirements and are encouraged to develop and implement a more extensive QA program or to continue such programs where they already exist.
Data collected as a result of QA and QC measures required in this procedure are to be submitted to the Agency. These data are to be used by both the Agency and the CEMS operator in assessing the effectiveness of the CEMS QC and QA procedures in the maintenance of acceptable CEMS operation and valid emission data.
Appendix F, Procedure 1 is applicable December 4, 1987. The first CEMS accuracy assessment shall be a relative accuracy test audit (RATA) (see section 5) and shall be completed by March 4, 1988 or the date of the initial performance test required by the applicable regulation, whichever is later.
1.2 Principle. The QA procedures consist of two distinct and equally important functions. One function is the assessment of the quality of the CEMS data by estimating accuracy. The other function is the control and improvement of the quality of the CEMS data by implementing QC policies and corrective actions. These two functions form a control loop: When the assessment function indicates that the data quality is inadequate, the control effort must be increased until the data quality is acceptable. In order to provide uniformity in the assessment and reporting of data quality, this procedure explicitly specifies the assessment methods for response drift and accuracy. The methods are based on procedures included in the applicable performance specifications (PS’s) in appendix B of 40 CFR part 60. Procedure 1 also requires the analysis of the EPA audit samples concurrent with certain reference method (RM) analyses as specified in the applicable RM’s.
Because the control and corrective action function encompasses a variety of policies, specifications, standards, and corrective measures, this procedure treats QC requirements in general terms to allow each source owner or operator to develop a QC system that is most effective and efficient for the circumstances.
2.1 Continuous Emission Monitoring System. The total equipment required for the determination of a gas concentration or emission rate.
2.2 Diluent Gas. A major gaseous constituent in a gaseous pollutant mixture. For combustion sources, CO
2.3 Span Value. The upper limit of a gas concentration measurement range that is specified for affected source categories in the applicable subpart of the regulation.
2.4 Zero, Low-Level, and High-Level Values. The CEMS response values related to the source specific span value. Determination of zero, low-level, and high-level values is defined in the appropriate PS in appendix B of this part.
2.5 Calibration Drift (CD). The difference in the CEMS output reading from a reference value after a period of operation during which no unscheduled maintenance, repair or adjustment took place. The reference value may be supplied by a cylinder gas, gas cell, or optical filter and need not be certified.
2.6 Relative Accuracy (RA). The absolute mean difference between the gas concentration or emission rate determined by the CEMS and the value determined by the RM’s plus the 2.5 percent error confidence coefficient of a series of tests divided by the mean of the RM tests or the applicable emission limit.
Each source owner or operator must develop and implement a QC program. As a minimum, each QC program must include written procedures which should describe in detail, complete, step-by-step procedures and operations for each of the following activities:
1. Calibration of CEMS.
2. CD determination and adjustment of CEMS.
3. Preventive maintenance of CEMS (including spare parts inventory).
4. Data recording, calculations, and reporting.
5. Accuracy audit procedures including sampling and analysis methods.
6. Program of corrective action for malfunctioning CEMS.
As described in section 5.2, whenever excessive inaccuracies occur for two consecutive quarters, the source owner or operator must revise the current written procedures or modify or replace the CEMS to correct the deficiency causing the excessive inaccuracies.
These written procedures must be kept on record and available for inspection by the enforcement agency.
4.1 CD Requirement. As described in 40 CFR 60.13(d), source owners and operators of CEMS must check, record, and quantify the CD at two concentration values at least once daily (approximately 24 hours) in accordance with the method prescribed by the manufacturer. The CEMS calibration must, as minimum, be adjusted whenever the daily zero (or low-level) CD or the daily high-level CD exceeds two times the limits of the applicable PS’s in appendix B of this regulation.
4.2 Recording Requirement for Automatic CD Adjusting Monitors. Monitors that automatically adjust the data to the corrected calibration values (e.g., microprocessor control) must be programmed to record the unadjusted concentration measured in the CD prior to resetting the calibration, if performed, or record the amount of adjustment.
4.3 Criteria for Excessive CD. If either the zero (or low-level) or high-level CD result exceeds twice the applicable drift specification in appendix B for five, consecutive, daily periods, the CEMS is out-of-control. If either the zero (or low-level) or high-level CD result exceeds four times the applicable drift specification in appendix B during any CD check, the CEMS is out-of-control. If the CEMS is out-of-control, take necessary corrective action. Following corrective action, repeat the CD checks.
4.3.1 Out-Of-Control Period Definition. The beginning of the out-of-control period is the time corresponding to the completion of the fifth, consecutive, daily CD check with a CD in excess of two times the allowable limit, or the time corresponding to the completion of the daily CD check preceding the daily CD check that results in a CD in excess of four times the allowable limit. The end of the out-of-control period is the time corresponding to the completion of the CD check following corrective action that results in the CD’s at both the zero (or low-level) and high-level measurement points being within the corresponding allowable CD limit (i.e., either two times or four times the allowable limit in appendix B).
4.3.2 CEMS Data Status During Out-of-Control Period. During the period the CEMS is out-of-control, the CEMS data may not be used in calculating emission compliance nor be counted towards meeting minimum data availability as required and described in the applicable subpart [e.g., § 60.47a(f)].
4.4 Data Recording and Reporting. As required in § 60.7(d) of this regulation (40 CFR part 60), all measurements from the CEMS must be retained on file by the source owner for at least 2 years. However, emission data obtained on each successive day while the CEMS is out-of-control may not be included as part of the minimum daily data requirement of the applicable subpart [e.g., § 60.47a(f)] nor be used in the calculation of reported emissions for that period.
5.1 Auditing Requirements. Each CEMS must be audited at least once each calendar quarter. Successive quarterly audits shall occur no closer than 2 months. The audits shall be conducted as follows:
5.1.1 Relative Accuracy Test Audit (RATA). The RATA must be conducted at least once every four calendar quarters, except as otherwise noted in section 5.1.4 of this appendix. Conduct the RATA as described for the RA test procedure in the applicable PS in appendix B (e.g., PS 2 for SO
5.1.2 Cylinder Gas Audit (CGA). If applicable, a CGA may be conducted in three of four calendar quarters, but in no more than three quarters in succession.
To conduct a CGA: (1) Challenge the CEMS (both pollutant and diluent portions of the CEMS, if applicable) with an audit gas of known concentration at two points within the following ranges:
| Audit point | Audit range | ||
|---|---|---|---|
| Pollutant monitors | Diluent monitors for – | ||
| CO | O | ||
| 1 | 20 to 30% of span value | 5 to 8% by volume | 4 to 6% by volume. |
| 2 | 50 to 60% of span value | 10 to 14% by volume | 8 to 12% by volume. |
Introduce each of the audit gases, three times each for a total of six challenges. Introduce the gases in such a manner that the entire CEMS is challenged. Do not introduce the same gas concentration twice in succession.
Use of separate audit gas cylinder for audit points 1 and 2. Do not dilute gas from audit cylinder when challenging the CEMS.
The monitor should be challenged at each audit point for a sufficient period of time to assure adsorption-desorption of the CEMS sample transport surfaces has stabilized.
(2) Operate each monitor in its normal sampling mode, i.e., pass the audit gas through all filters, scrubbers, conditioners, and other monitor components used during normal sampling, and as much of the sampling probe as is practical. At a minimum, the audit gas should be introduced at the connection between the probe and the sample line.
(3) Use Certified Reference Materials (CRM’s) (See Citation 1) audit gases that have been certified by comparison to National Institute of Standards and Technology (NIST) Standard Reference Materials (SRM’s) or EPA Protocol Gases following the most recent edition of the EPA Traceability Protocol for Assay and Certification of Gaseous Calibration Standards (See Citation 2). Procedures for preparation of CRM’s are described in Citation 1. Procedures for preparation of EPA Protocol Gases are described in Citation 2. In the case that a suitable audit gas level is not commercially available, Method 205 (See Citation 3) may be used to dilute CRM’s or EPA Protocol Gases to the needed level. The difference between the actual concentration of the audit gas and the concentration indicated by the monitor is used to assess the accuracy of the CEMS.
5.1.3 Relative Accuracy Audit (RAA). The RAA may be conducted three of four calendar quarters, but in no more than three quarters in succession. To conduct a RAA, follow the procedure described in the applicable PS in appendix B for the relative accuracy test, except that only three sets of measurement data are required. Analyses of EPA performance audit samples are also required.
The relative difference between the mean of the RM values and the mean of the CEMS responses will be used to assess the accuracy of the CEMS.
5.1.4 Other Alternative Audits. Other alternative audit procedures may be used as approved by the Administrator for three of four calendar quarters. One RATA is required at least every four calendar quarters, except in the case where the affected facility is off-line (does not operate) in the fourth calendar quarter since the quarter of the previous RATA. In that case, the RATA shall be performed in the quarter in which the unit recommences operation. Also, cylinder gas audits are not be required for calendar quarters in which the affected facility does not operate.
5.2 Excessive Audit Inaccuracy. If the RA, using the RATA, CGA, or RAA exceeds the criteria in section 5.2.3, the CEMS is out-of-control. If the CEMS is out-of-control, take necessary corrective action to eliminate the problem. Following corrective action, the source owner or operator must audit the CEMS with a RATA, CGA, or RAA to determine if the CEMS is operating within the specifications. A RATA must always be used following an out-of-control period resulting from a RATA. The audit following corrective action does not require analysis of EPA performance audit samples. If audit results show the CEMS to be out-of-control, the CEMS operator shall report both the audit showing the CEMS to be out-of-control and the results of the audit following corrective action showing the CEMS to be operating within specifications.
5.2.1 Out-Of-Control Period Definition. The beginning of the out-of-control period is the time corresponding to the completion of the sampling for the RATA, RAA, or CGA. The end of the out-of-control period is the time corresponding to the completion of the sampling of the subsequent successful audit.
5.2.2 CEMS Data Status During Out-Of-Control Period. During the period the monitor is out-of-control, the CEMS data may not be used in calculating emission compliance nor be counted towards meeting minimum data availabilty as required and described in the applicable subpart [e.g., § 60.47a(f)].
5.2.3 Criteria for Excessive Audit Inaccuracy. Unless specified otherwise in the applicable subpart, the criteria for excessive inaccuracy are:
(1) For the RATA, the allowable RA in the applicable PS in appendix B.
(2) For the CGA, ±15 percent of the average audit value or ±5 ppm, whichever is greater; for diluent monitors, ±15 percent of the average audit value.
(3) For the RAA, ±15 percent of the three run average or ±7.5 percent of the applicable standard, whichever is greater.
5.3 Criteria for Acceptable QC Procedure. Repeated excessive inaccuracies (i.e., out-of-control conditions resulting from the quarterly audits) indicates the QC procedures are inadequate or that the CEMS is incapable of providing quality data. Therefore, whenever excessive inaccuracies occur for two consective quarters, the source owner or operator must revise the QC procedures (see section 3) or modify or replace the CEMS.
6.1 RATA RA Calculation. Follow the equations described in section 8 of appendix B, PS 2 to calculate the RA for the RATA. The RATA must be calculated in units of the applicable emission standard (e.g., ng/J).
6.2 RAA Accuracy Calculation. Use the calculation procedure in the relevant performance specification to calculate the accuracy for the RAA. The RAA must be calculated in the units of the applicable emission standard.
6.3 CGA Accuracy Calculation. Use Equation 1-1 to calculate the accuracy for the CGA, which is calculated in units of the appropriate concentration (e.g., ppm SO
A = Accuracy of the CEMS, percent.
C
C
6.4 Example Accuracy Calculations. Example calculations for the RATA, RAA, and CGA are available in Citation 3.
At the reporting interval specified in the applicable regulation, report for each CEMS the accuracy results from section 6 and the CD assessment results from section 4. Report the drift and accuracy information as a Data Assessment Report (DAR), and include one copy of this DAR for each quarterly audit with the report of emissions required under the applicable subparts of this part.
As a minimum, the DAR must contain the following information:
1. Source owner or operator name and address.
2. Identification and location of monitors in the CEMS.
3. Manufacturer and model number of each monitor in the CEMS.
4. Assessment of CEMS data accuracy and date of assessment as determined by a RATA, RAA, or CGA described in section 5 including the RA for the RATA, the A for the RAA or CGA, the RM results, the cylinder gases certified values, the CEMS responses, and the calculations results as defined in section 6. If the accuracy audit results show the CEMS to be out-of-control, the CEMS operator shall report both the audit results showing the CEMS to be out-of-control and the results of the audit following corrective action showing the CEMS to be operating within specifications.
5. Results from EPA performance audit samples described in section 5 and the applicable RM’s.
6. Summary of all corrective actions taken when CEMS was determined out-of-control, as described in sections 4 and 5.
An example of a DAR format is shown in Figure 1.
1. “A Procedure for Establishing Traceability of Gas Mixtures to Certain National Bureau of Standards Standard Reference Materials.” Joint publication by NBS and EPA-600/7-81-010, Revised 1989. Available from the U.S. Environmental Protection Agency. Quality Assurance Division (MD-77). Research Triangle Park, NC 27711.
2. “EPA Traceability Protocol For Assay And Certification Of Gaseous Calibration Standards.” EPA-600/R-97/121, September 1997. Available from EPA’s Emission Measurement Center at http://www.epa.gov/ttn/emc.
3. Method 205, “Verification of Gas Dilution Systems for Field Instrument Calibrations,” 40 CFR 51, appendix M.
I. Accuracy assessment results (Complete A, B, or C below for each CEMS or for each pollutant and diluent analyzer, as applicable.) If the quarterly audit results show the CEMS to be out-of-control, report the results of both the quarterly audit and the audit following corrective action showing the CEMS to be operating properly.
A. Relative accuracy test audit (RATA) for ________ (e.g., SO
1. Date of audit ________.
2. Reference methods (RM’s) used ________ (e.g., Methods 3 and 6).
3. Average RM value ________ (e.g., ng/J, mg/dsm
4. Average CEMS value ________.
5. Absolute value of mean difference [d] ________.
6. Confidence coefficient [CC] ________.
7. Percent relative accuracy (RA) ________ percent.
8. EPA performance audit results:
a. Audit lot number (1) ________ (2) ________
b. Audit sample number (1) ________ (2) ________
c. Results (mg/dsm
d. Actual value (mg/dsm
e. Relative error* (1) ________ (2) ________
B. Cylinder gas audit (CGA) for ________ (e.g., SO
| Audit point 1 | Audit point 2 | ||
|---|---|---|---|
| 1. Date of audit | |||
| 2. Cylinder ID number | |||
| 3. Date of certification | |||
| 4. Type of certification | (e.g., EPA Protocol 1 or CRM). | ||
| 5. Certified audit value | (e.g., ppm). | ||
| 6. CEMS response value | (e.g., ppm). | ||
| 7. Accuracy | percent. |
C. Relative accuracy audit (RAA) for ________ (e.g., SO
1. Date of audit ________.
2. Reference methods (RM’s) used ________ (e.g., Methods 3 and 6).
3. Average RM value ________ (e.g., ng/J).
4. Average CEMS value ________.
5. Accuracy ________ percent.
6. EPA performance audit results:
a. Audit lot number (1) ________ (2) ________
b. Audit sample number (1) ________ (2) ________
c. Results (mg/dsm
d. Actual value (mg/dsm
e. Relative error*
* To be completed by the Agency.
D. Corrective action for excessive inaccuracy.
1. Out-of-control periods.
a. Date(s) ________.
b. Number of days ________.
3. Results of audit following corrective action. (Use format of A, B, or C above, as applicable.)
II. Calibration drift assessment.
A. Out-of-control periods.
1. Date(s) ________.
2. Number of days ________.
The purpose of Procedure 2 is to establish the minimum requirements for evaluating the effectiveness of quality control (QC) and quality assurance (QA) procedures and the quality of data produced by your particulate matter (PM) continuous emission monitoring system (CEMS). Procedure 2 applies to PM CEMS used for continuously determining compliance with emission standards or operating permit limits as specified in an applicable regulation or permit. Other QC procedures may apply to diluent (e.g., O
1.1 What measurement parameter does Procedure 2 address? Procedure 2 covers the instrumental measurement of PM as defined by your source’s applicable reference method (no Chemical Abstract Service number assigned).
1.2 For what types of devices must I comply with Procedure 2? You must comply with Procedure 2 for the total equipment that:
(1) We require you to install and operate on a continuous basis under the applicable regulation, and
(2) You use to monitor the PM mass concentration associated with the operation of a process or emission control device.
1.3 What are the data quality objectives (DQOs) of Procedure 2? The overall DQO of Procedure 2 is the generation of valid, representative data that can be transferred into useful information for determining PM CEMS concentrations averaged over a prescribed interval. Procedure 2 is also closely associated with Performance Specification 11 (PS-11).
(1) Procedure 2 specifies the minimum requirements for controlling and assessing the quality of PM CEMS data submitted to us or the delegated permitting authority.
(2) You must meet these minimum requirements if you are responsible for one or more PM CEMS used for compliance monitoring. We encourage you to develop and implement a more extensive QA program or to continue such programs where they already exist.
1.4 What is the intent of the QA/QC procedures specified in Procedure 2? Procedure 2 is intended to establish the minimum QA/QC requirements for PM CEMS and is presented in general terms to allow you to develop a program that is most effective for your circumstances. You may adopt QA/QC procedures that go beyond these minimum requirements to ensure compliance with applicable regulations.
1.5 When must I comply with Procedure 2? You must comply with the basic requirements of Procedure 2 immediately following successful completion of the initial correlation test of PS-11.
Procedure 2 requires you to perform periodic evaluations of PM CEMS performance and to develop and implement QA/QC programs to ensure that PM CEMS data quality is maintained.
2.1 What are the basic functions of Procedure 2?
(1) Assessment of the quality of your PM CEMS data by estimating measurement accuracy;
(2) Control and improvement of the quality of your PM CEMS data by implementing QC requirements and corrective actions until the data quality is acceptable; and
(3) Specification of requirements for daily instrument zero and upscale drift checks and daily sample volume checks, as well as routine response correlation audits, absolute correlation audits, sample volume audits, and relative response audits.
The definitions in Procedure 2 include those provided in PS-11 of Appendix B, with the following additions:
3.1 “Absolute Correlation Audit (ACA)” means an evaluation of your PM CEMS response to a series of reference standards covering the full measurement range of the instrument (e.g., 4 mA to 20 mA).
3.2 “Correlation Range” means the range of PM CEMS responses used in the complete set of correlation test data.
3.3 “PM CEMS Correlation” means the site-specific relationship (i.e., a regression equation) between the output from your PM CEMS (e.g., mA) and the particulate concentration, as determined by the reference method. The PM CEMS correlation is expressed in the same units as the PM concentration measured by your PM CEMS (e.g., mg/acm). You must derive this relation from PM CEMS response data and manual reference method data that were gathered simultaneously. These data must be representative of the full range of source and control device operating conditions that you expect to occur. You must develop the correlation by performing the steps presented in sections 12.2 and 12.3 of PS-11.
3.4 “Reference Method Sampling Location” means the location in your source’s exhaust duct from which you collect manual reference method data for developing your PM CEMS correlation and for performing relative response audits (RRAs) and response correlation audits (RCAs).
3.5 “Response Correlation Audit (RCA)” means the series of tests specified in section 10.3(8) of this procedure that you conduct to ensure the continued validity of your PM CEMS correlation.
3.6 “Relative Response Audit (RRA)” means the brief series of tests specified in section 10.3(6) of this procedure that you conduct between consecutive RCAs to ensure the continued validity of your PM CEMS correlation.
3.7 “Sample Volume Audit (SVA)” means an evaluation of your PM CEMS measurement of sample volume if your PM CEMS determines PM concentration based on a measure of PM mass in an extracted sample volume and an independent determination of sample volume.
People using Procedure 2 may be exposed to hazardous materials, operations, and equipment. Procedure 2 does not purport to address all of the safety issues associated with its use. It is your responsibility to establish appropriate safety and health practices and determine the applicable regulatory limitations before performing this procedure. You must consult your CEMS user’s manual for specific precautions to be taken with regard to your PM CEMS procedures.
You will need reference standards or procedures to perform the zero drift check, the upscale drift check, and the sample volume check.
7.1 What is the reference standard value for the zero drift check? You must use a zero check value that is no greater than 20 percent of the PM CEMS’s response range. You must obtain documentation on the zero check value from your PM CEMS manufacturer.
7.2 What is the reference standard value for the upscale drift check? You must use an upscale check value that produces a response between 50 and 100 percent of the PM CEMS’s response range. For a PM CEMS that produces output over a range of 4 mA to 20 mA, the upscale check value must produce a response in the range of 12 mA to 20 mA. You must obtain documentation on the upscale check value from your PM CEMS manufacturer.
7.3 What is the reference standard value for the sample volume check? You must use a reference standard value or procedure that produces a sample volume value equivalent to the normal sampling rate. You must obtain documentation on the sample volume value from your PM CEMS manufacturer.
You must develop and implement a QC program for your PM CEMS. Your QC program must, at a minimum, include written procedures that describe, in detail, complete step-by-step procedures and operations for the activities in paragraphs (1) through (8) of this section.
(1) Procedures for performing drift checks, including both zero drift and upscale drift and the sample volume check (see sections 10.2(1), (2), and (5)).
(2) Methods for adjustment of PM CEMS based on the results of drift checks, sample volume checks (if applicable), and the periodic audits specified in this procedure.
(3) Preventative maintenance of PM CEMS (including spare parts inventory and sampling probe integrity).
(4) Data recording, calculations, and reporting.
(5) RCA and RRA procedures, including sampling and analysis methods, sampling strategy, and structuring test conditions over the prescribed range of PM concentrations.
(6) Procedures for performing ACAs and SVAs and methods for adjusting your PM CEMS response based on ACA and SVA results.
(7) Program of corrective action for malfunctioning PM CEMS, including flagged data periods.
(8) For extractive PM CEMS, procedures for checking extractive system ducts for material accumulation.
9.1 What QA/QC documentation must I have? You are required to keep the written QA/QC procedures on record and available for inspection by us, the State, and/or local enforcement agency for the life of your CEMS or until you are no longer subject to the requirements of this procedure.
9.2 How do I know if I have acceptable QC procedures for my PM CEMS? Your QC procedures are inadequate or your PM CEMS is incapable of providing quality data if you fail two consecutive QC audits (i.e., out-of-control conditions resulting from the annual audits, quarterly audits, or daily checks). Therefore, if you fail the same two consecutive audits, you must revise your QC procedures or modify or replace your PM CEMS to correct the deficiencies causing the excessive inaccuracies (see section 10.4 for limits for excessive audit inaccuracy).
You must generate a site-specific correlation for each of your PM CEMS installation(s) relating response from your PM CEMS to results from simultaneous PM reference method testing. The PS-11 defines procedures for developing the correlation and defines a series of statistical parameters for assessing acceptability of the correlation. However, a critical component of your PM CEMS correlation process is ensuring the accuracy and precision of reference method data. The activities listed in sections 10.1 through 10.10 assure the quality of the correlation.
10.1 When should I use paired trains for reference method testing? Although not required, we recommend that you should use paired-train reference method testing to generate data used to develop your PM CEMS correlation and for RCA testing. Guidance on the use of paired sampling trains can be found in the PM CEMS Knowledge Document (see section 16.5 of PS-11).
10.2 What routine system checks must I perform on my PM CEMS? You must perform routine checks to ensure proper operation of system electronics and optics, light and radiation sources and detectors, and electric or electro-mechanical systems. Necessary components of the routine system checks will depend on design details of your PM CEMS. As a minimum, you must verify the system operating parameters listed in paragraphs (1) through (5) of this section on a daily basis. Some PM CEMS may perform one or more of these functions automatically or as an integral portion of unit operations; for other PM CEMS, you must initiate or perform one or more of these functions manually.
(1) You must check the zero drift to ensure stability of your PM CEMS response to the zero check value. You must determine system output on the most sensitive measurement range when the PM CEMS is challenged with a zero reference standard or procedure. You must, at a minimum, adjust your PM CEMS whenever the daily zero drift exceeds 4 percent.
(2) You must check the upscale drift to ensure stability of your PM CEMS response to the upscale check value. You must determine system output when the PM CEMS is challenged with a reference standard or procedure corresponding to the upscale check value. You must, at a minimum, adjust your PM CEMS whenever the daily upscale drift check exceeds 4 percent.
(3) For light-scattering and extinction-type PM CEMS, you must check the system optics to ensure that system response has not been altered by the condition of optical components, such as fogging of lens and performance of light monitoring devices.
(4) You must record data from your automatic drift-adjusting PM CEMS before any adjustment is made. If your PM CEMS automatically adjusts its response to the corrected calibration values (e.g., microprocessor control), you must program your PM CEMS to record the unadjusted concentration measured in the drift check before resetting the calibration. Alternately, you may program your PM CEMS to record the amount of adjustment.
(5) For extractive PM CEMS that measure the sample volume and use the measured sample volume as part of calculating the output value, you must check the sample volume on a daily basis to verify the accuracy of the sample volume measuring equipment. This sample volume check must be done at the normal sampling rate of your PM CEMS. You must adjust your PM CEMS sample volume measurement whenever the daily sample volume check error exceeds 10 percent.
10.3 What are the auditing requirements for my PM CEMS? You must subject your PM CEMS to an ACA and an SVA, as applicable, at least once each calendar quarter. Successive quarterly audits must occur no closer than 2 months apart. You must conduct an RCA and an RRA at the frequencies specified in the applicable regulation or facility operating permit. An RRA or RCA conducted during any calendar quarter can take the place of the ACA required for that calendar quarter. An RCA conducted during the period in which an RRA is required can take the place of the RRA for that period.
(1) When must I perform an ACA? You must perform an ACA each quarter unless you conduct an RRA or RCA during that same quarter.
(2) How do I perform an ACA? You perform an ACA according to the procedure specified in paragraphs (2)(i) through (v) of this section.
(i) You must challenge your PM CEMS with an audit standard or an equivalent audit reference to reproduce the PM CEMS’s measurement at three points within the following ranges:
| Audit point | Audit range |
|---|---|
| 1 | 0 to 20 percent of measurement range |
| 2 | 40 to 60 percent of measurement range |
| 3 | 70 to 100 percent of measurement range |
(ii) You must then challenge your PM CEMS three times at each audit point and use the average of the three responses in determining accuracy at each audit point. Use a separate audit standard for audit points 1, 2, and 3. Challenge the PM CEMS at each audit point for a sufficient period of time to ensure that your PM CEMS response has stabilized.
(iii) Operate your PM CEMS in the mode, manner, and range specified by the manufacturer.
(iv) Store, maintain, and use audit standards as recommended by the manufacturer.
(v) Use the difference between the actual known value of the audit standard and the response of your PM CEMS to assess the accuracy of your PM CEMS.
(3) When must I perform an SVA? You must perform an audit of the measured sample volume (e.g., the sampling flow rate for a known time) once per quarter for applicable PM CEMS with an extractive sampling system. Also, you must perform and pass an SVA prior to initiation of any of the reference method data collection runs for an RCA or RRA.
(4) How do I perform an SVA? You perform an SVA according to the procedure specified in paragraphs (4)(i) through (iii) of this section.
(i) You perform an SVA by independently measuring the volume of sample gas extracted from the stack or duct over each batch cycle or time period with a calibrated device. You may make this measurement either at the inlet or outlet of your PM CEMS, so long as it measures the sample gas volume without including any dilution or recycle air. Compare the measured volume with the volume reported by your PM CEMS for the same cycle or time period to calculate sample volume accuracy.
(ii) You must make measurements during three sampling cycles for batch extractive monitors (e.g., Beta-gauge) or during three periods of at least 20 minutes for continuous extractive PM CEMS.
(iii) You may need to condense, collect, and measure moisture from the sample gas prior to the calibrated measurement device (e.g., dry gas meter) and correct the results for moisture content. In any case, the volumes measured by the calibrated device and your PM CEMS must be on a consistent temperature, pressure, and moisture basis.
(5) How often must I perform an RRA? You must perform an RRA at the frequency specified in the applicable regulation or facility operating permit. You may conduct an RCA instead of an RRA during the period when the RRA is required.
(6) How do I perform an RRA? You must perform the RRA according to the procedure specified in paragraphs (6)(i) and (ii) of this section.
(i) You perform an RRA by collecting three simultaneous reference method PM concentration measurements and PM CEMS measurements at the as-found source operating conditions and PM concentration.
(ii) We recommend that you use paired trains for reference method sampling. Guidance on the use of paired sampling trains can be found in the PM CEMS Knowledge Document (see section 16.5 of PS-11).
(7) How often must I perform an RCA? You must perform an RCA at the frequency specified in the applicable regulation or facility operating permit.
(8) How do I perform an RCA? You must perform the RCA according to the procedures for the PM CEMS correlation test described in PS-11, section 8.6, except that the minimum number of runs required is 12 in the RCA instead of 15 as specified in PS-11.
(9) What other alternative audits can I use? You can use other alternative audit procedures as approved by us, the State, or local agency for the quarters when you would conduct ACAs.
10.4 What are my limits for excessive audit inaccuracy? Unless specified otherwise in the applicable subpart, the criteria for excessive audit inaccuracy are listed in paragraphs (1) through (6) of this section.
(1) What are the criteria for excessive zero or upscale drift? Your PM CEMS is out of control if the zero drift check or upscale drift check either exceeds 4 percent for five consecutive daily periods or exceeds 8 percent for any one day.
(2) What are the criteria for excessive sample volume measurement error? Your PM CEMS is out of control if sample volume check error exceeds 10 percent for five consecutive daily periods or exceeds 20 percent for any one day.
(3) What are the criteria for excessive ACA error? Your PM CEMS is out of control if the results of any ACA exceed ±10 percent of the average audit value, as calculated using Equation 2-1a, or 7.5 percent of the applicable standard, as calculated using Equation 2-1b, whichever is greater.
(4) What is the criterion for excessive SVA error? Your PM CEMS is out of control if results exceed ±5 percent of the average sample volume audit value.
(5) What are the criteria for passing a RCA? To pass a RCA, you must meet the criteria specified in paragraphs (5)(i) and (ii) of this section. If your PM CEMS fails to meet these RCA criteria, it is out of control.
(i) For all 12 data points, the PM CEMS response value can be no greater than the greatest PM CEMS response value used to develop your correlation curve.
(ii) At least 75 percent of a minimum number of 12 sets of PM CEMS and reference method measurements must fall within a specified area on a graph of the correlation regression line. The specified area on the graph of the correlation regression line is defined by two lines parallel to the correlation regression line, offset at a distance of ±25 percent of the numerical emission limit value from the correlation regression line. If any of the PM CEMS response values resulting from your RCA are lower than the lowest PM CEMS response value of your existing correlation curve, you may extend your correlation regression line to the point corresponding to the lowest PM CEMS response value obtained during the RCA. This extended correlation regression line must then be used to determine if the RCA data meets this criterion.
(6) What are the criteria to pass a RRA? To pass a RRA, you must meet the criteria specified in paragraphs (6)(i) and (ii) of this section. If your PM CEMS fails to meet these RRA criteria, it is out of control.
(i) For all three data points, the PM CEMS response value can be no greater than the greatest PM CEMS response value used to develop your correlation curve.
(ii) At least two of the three sets of PM CEMS and reference method measurements must fall within the same specified area on a graph of the correlation regression line as required for the RCA and described in paragraph (5)(ii) of this section.
10.5 What do I do if my PM CEMS is out of control? If your PM CEMS is out of control, you must take the actions listed in paragraphs (1) and (2) of this section.
(1) You must take necessary corrective action to eliminate the problem and perform tests, as appropriate, to ensure that the corrective action was successful.
(i) Following corrective action, you must repeat the previously failed audit to confirm that your PM CEMS is operating within the specifications.
(ii) If your PM CEMS failed an RRA, you must take corrective action until your PM CEMS passes the RRA criteria. If the RRA criteria cannot be achieved, you must perform an RCA.
(iii) If your PM CEMS failed an RCA, you must follow procedures specified in section 10.6 of this procedure.
(2) You must report both the audit showing your PM CEMS to be out of control and the results of the audit following corrective action showing your PM CEMS to be operating within specifications.
10.6 What do I do if my PM CEMS fails an RCA? After an RCA failure, you must take all applicable actions listed in paragraphs (1) through (3) of this section.
(1) Combine RCA data with data from the active PM CEMS correlation and perform the mathematical evaluations defined in PS-11 for development of a PM CEMS correlation, including examination of alternate correlation models (i.e., linear, polynomial, logarithmic, exponential, and power). If the expanded data base and revised correlation meet PS-11 statistical criteria, use the revised correlation.
(2) If the criteria specified in paragraph (1) of this section are not achieved, you must develop a new PM CEMS correlation based on revised data. The revised data set must consist of the test results from only the RCA. The new data must meet all requirements of PS-11 to develop a revised PM CEMS correlation, except that the minimum number of sets of PM CEMS and reference method measurements is 12 instead of the minimum of 15 sets required by PS-11. Your PM CEMS is considered to be back in controlled status when the revised correlation meets all of the performance criteria specified in section 13.2 of PS-11.
(3) If the actions in paragraphs (1) and (2) of this section do not result in an acceptable correlation, you must evaluate the cause(s) and comply with the actions listed in paragraphs (3)(i) through (iv) of this section within 90 days after the completion of the failed RCA.
(i) Completely inspect your PM CEMS for mechanical or operational problems. If you find a mechanical or operational problem, repair your PM CEMS and repeat the RCA.
(ii) You may need to relocate your PM CEMS to a more appropriate measurement location. If you relocate your PM CEMS, you must perform a new correlation test according to the procedures specified in PS-11.
(iii) The characteristics of the PM or gas in your source’s flue gas stream may have changed such that your PM CEMS measurement technology is no longer appropriate. If this is the case, you must install a PM CEMS with measurement technology that is appropriate for your source’s flue gas characteristics. You must perform a new correlation test according to the procedures specified in PS-11.
(iv) If the corrective actions in paragraphs (3)(i) through (iii) of this section were not successful, you must petition us, the State, or local agency for approval of alternative criteria or an alternative for continuous PM monitoring.
10.7 When does the out-of-control period begin and end? The out-of-control period begins immediately after the last test run or check of an unsuccessful RCA, RRA, ACA, SVA, drift check, or sample volume check. The out-of-control period ends immediately after the last test run or check of the subsequent successful audit or drift check.
10.8 Can I use the data recorded by my PM CEMS during out-of-control periods? During any period when your PM CEMS is out of control, you may not use your PM CEMS data to calculate emission compliance or to meet minimum data availability requirements described in the applicable regulation.
10.9 What are the QA/QC reporting requirements for my PM CEMS? You must report the accuracy results for your PM CEMS, specified in section 10.4 of this procedure, at the interval specified in the applicable regulation. Report the drift and accuracy information as a Data Assessment Report (DAR), and include one copy of this DAR for each quarterly audit with the report of emissions required under the applicable regulation. An example DAR is provided in Procedure 1, Appendix F of this part.
10.10 What minimum information must I include in my DAR? As a minimum, you must include the information listed in paragraphs (1) through (5) of this section in the DAR:
(1) Your name and address.
(2) Identification and location of monitors in your CEMS.
(3) Manufacturer and model number of each monitor in your CEMS.
(4) Assessment of PM CEMS data accuracy/acceptability, and date of assessment, as determined by an RCA, RRA, ACA, or SVA described in section 10, including the acceptability determination for the RCA or RRA, the accuracy for the ACA or SVA, the reference method results, the audit standards, your PM CEMS responses, and the calculation results as defined in section 12. If the accuracy audit results show your PM CEMS to be out of control, you must report both the audit results showing your PM CEMS to be out of control and the results of the audit following corrective action showing your PM CEMS to be operating within specifications.
(5) Summary of all corrective actions you took when you determined your PM CEMS to be out of control, as described in section 10.5, or after failing on RCA, as described in section 10.6.
10.7 Where and how long must I retain the QA data that this procedure requires me to record for my PM CEMS? You must keep the records required by this procedure for your PM CEMS onsite and available for inspection by us, the State, and/or local enforcement agency for a period of 5 years.
Sample collection and analysis are concurrent for this procedure. You must refer to the appropriate reference method for the specific analytical procedures.
(1) How do I determine RCA and RRA acceptability? You must plot each of your PM CEMS and reference method data sets from an RCA or RRA on a graph based on your PM CEMS correlation line to determine if the criteria in paragraphs 10.4(5) or (6), respectively, are met.
(2) How do I calculate ACA accuracy? You must use either Equation 2-1a or 2-1b to calculate ACA accuracy for each of the three audit points. However, when calculating ACA accuracy for the first audit point (0 to 20 percent of measurement range), you must use Equation 2-1b to calculate ACA accuracy if the reference standard value (R
(3) How do I calculate daily upscale and zero drift? You must calculate the upscale drift using Equation 2-2 and the zero drift using Equation 2-3:
(4) How do I calculate SVA accuracy? You must use Equation 2-4 to calculate the accuracy, in percent, for each of the three SVA tests or the daily sample volume check:
Before calculating SVA accuracy, you must correct the sample gas volumes measured by your PM CEMS and the independent calibrated reference device to the same basis of temperature, pressure, and moisture content. You must document all data and calculations.
The purpose of Procedure 3 is to establish quality assurance and quality control (QA/QC) procedures for continuous opacity monitoring systems (COMS). Procedure 3 applies to COMS used to demonstrate continuous compliance with opacity standards specified in new source performance standards (NSPS) promulgated by EPA pursuant to section 111(b) of the Clean Air Act, 42 U.S.C. 7411(b) – Standards of Performance for New Stationary Sources.
1.1 What are the data quality objectives of Procedure 3? The overall data quality objective (DQO) of Procedure 3 is the generation of valid and representative opacity data. Procedure 3 specifies the minimum requirements for controlling and assessing the quality of COMS data submitted to us or the delegated regulatory agency. Procedure 3 requires you to perform periodic evaluations of a COMS performance and to develop and implement QA/QC programs to ensure that COMS data quality is maintained.
1.2 What is the intent of the QA/QC procedures specified in Procedure 3? Procedure 3 is intended to establish the minimum QA/QC requirements to verify and maintain an acceptable level of quality of the data produced by COMS. It is presented in general terms to allow you to develop a program that is most effective for your circumstances.
1.3 When must I comply with Procedure 3? You must comply with Procedure 3 no later than November 12, 2014.
The basic functions of Procedure 3 are assessment of the quality of your COMS data and control and improvement of the quality of the data by implementing QC requirements and corrective actions. Procedure 3 provides requirements for:
(1) Daily instrument zero and upscale drift checks and status indicators checks;
(2) Quarterly performance audits which include the following assessments:
(i) Optical alignment,
(ii) Calibration error, and
(iii) Zero compensation.
(3) Annual zero alignment.
The definitions in Procedure 3 include those provided in Performance Specification 1 (PS-1) of Appendix B of this part and ASTM D6216-12 and the following additional definitions.
3.1 Out-of-control periods. Out-of-control periods mean that one or more COMS parameters falls outside of the acceptable limits established by this rule.
(1) Daily Assessments. Whenever the calibration drift (CD) exceeds twice the specification of PS-1, the COMS is out-of-control. The beginning of the out-of-control period is the time corresponding to the completion of the daily calibration drift check. The end of the out-of-control period is the time corresponding to the completion of appropriate adjustment and subsequent successful CD assessment.
(2) Quarterly and Annual Assessments. Whenever an annual zero alignment or quarterly performance audit fails to meet the criteria established in paragraphs (2) and (3) of section 10.4, the COMS is out-of-control. The beginning of the out-of-control period is the time corresponding to the completion of the performance audit indicating the failure to meet these established criteria. The end of the out-of-control period is the time corresponding to the completion of appropriate corrective actions and the subsequent successful audit (or, if applicable, partial audit).
Opacity cannot be measured accurately in the presence of condensed water vapor. Thus, COMS opacity compliance determinations cannot be made when condensed water vapor is present, such as downstream of a wet scrubber without a reheater or at other saturated flue gas locations. Therefore, COMS must be located where condensed water vapor is not present.
Those implementing Procedure 3 may be exposed to hazardous materials, operations and equipment. Procedure 3 does not purport to address all of the safety issues associated with its use. It is your responsibility to establish appropriate health and safety practices and determine the applicable regulatory limitations before performing this procedure. You should consult the COMS user’s manual for specific precautions to take.
The equipment and supplies that you need are specified in PS-1. You are not required to purchase a new COMS if your existing COMS meets the requirements specified in Procedure 3.
The reagents and standards that you need are specified in PS-1. You are not required to purchase a new COMS if your existing COMS meets the requirements specified in Procedure 3.
You must develop and implement a QC program for your COMS. Your QC program must, at a minimum, include written procedures which describe in detail complete step-by-step procedures and operations for the activities in paragraphs (1) through (4):
(1) Procedures for performing drift checks, including both zero and upscale drift and the status indicators check,
(2) Procedures for performing quarterly performance audits,
(3) A means of checking the zero alignment of the COMS, and
(4) A program of corrective action for a malfunctioning COMS. The corrective action must include, at a minimum, the requirements specified in section 10.5.
9.1 What QA/QC documentation must I have? You are required to keep the QA/QC written procedures required in section 9.0 on site and available for inspection by us, the state, and/or local enforcement agencies.
9.2 What actions must I take if I fail QC audits? If you fail two consecutive annual audits, two consecutive quarterly audits, or five consecutive daily checks, you must either revise your QC procedures or determine if your COMS is malfunctioning. If you determine that your COMS is malfunctioning, you must take the necessary corrective action as specified in section 10.5. If you determine that your COMS requires extensive repairs, you may use a substitute COMS provided the substitute meets the requirements in section 10.6.
(1) You must perform daily system checks to ensure proper operation of system electronics and optics, light and radiation sources and detectors, electric or electro-mechanical systems, and general stability of the system calibration. Daily is defined as any portion of a calendar day in which a unit operates.
(2) You must subject your COMS to a performance audit to include checks of the individual COMS components and factors affecting the accuracy of the monitoring data at least once per QA operating quarter. A QA operating quarter is a calendar quarter in which a unit operates at least 168 hours.
(3) At least annually, you must perform a zero alignment by comparing the COMS simulated zero to the actual clear path zero. Annually is defined as a period wherein the unit is operating at least 28 days in a calendar year. The simulated zero device produces a simulated clear path condition or low-level opacity condition, where the energy reaching the detector is between 90 and 110 percent of the energy reaching the detector under actual clear path conditions.
10.1 What daily system checks must I perform on my COMS? The specific components required to undergo daily system checks will depend on the design details of your COMS. At a minimum, you must verify the system operating parameters listed in paragraphs (1) through (3) of this section. Some COMS may perform one or more of these functions automatically or as an integral portion of unit operations; other COMS may perform one or more of these functions manually.
(1) You must check the zero drift to ensure stability of your COMS response to the simulated zero device. The simulated zero device, an automated mechanism within the transmissometer that produces a simulated clear path condition or low-level opacity condition, is used to check the zero drift. You must, at a minimum, take corrective action on your COMS whenever the daily zero drift exceeds twice the applicable drift specification in section 13.3(6) of PS-1.
(2) You must check the upscale drift to ensure stability of your COMS response to the upscale drift value. The upscale calibration device, an automated mechanism (employing an attenuator or reduced reflectance device) within the transmissometer that produces an upscale opacity value is used to check the upscale drift. You must, at a minimum, take corrective action on your COMS whenever the daily upscale drift check exceeds twice the applicable drift specification in section 13.3(6) of PS-1.
(3) You must, at a minimum, check the status indicators, data acquisition system error messages, and other system self-diagnostic indicators. You must take appropriate corrective action based on the manufacturer’s recommendations when the COMS is operating outside preset limits.
10.2 What are the quarterly auditing requirements for my COMS? At a minimum, the parameters listed in paragraphs (1) through (3) of this section must be included in the performance audit conducted on a quarterly basis as defined in section 10.0(2).
(1) For units with automatic zero compensation, you must determine the zero compensation for the COMS. The value of the zero compensation applied at the time of the audit must be calculated as equivalent opacity and corrected to stack exit conditions according to the procedures specified by the manufacturer. The compensation applied to the effluent by the monitor system must be recorded.
(2) You must conduct a three-point calibration error test of the COMS. Three calibration attenuators, either primary or secondary must meet the requirements of PS-1, with one exception. Instead of recalibrating the attenuators semi-annually, they must be recalibrated annually. If two annual calibrations agree within 0.5 percent opacity, the attenuators may then be calibrated once every five years. The three attenuators must be placed in the COMS light beam path for at least three nonconsecutive readings. All monitor responses must then be independently recorded from the COMS permanent data recorder. Additional guidance for conducting this test is included in section 8.1(3)(ii) of PS-1. The low-, mid-, and high-range calibration error results must be computed as the mean difference and 95 percent confidence interval for the difference between the expected and actual responses of the monitor as corrected to stack exit conditions. The equations necessary to perform the calculations are found in section 12.0 of PS-1. For the calibration error test method, you must use the external audit device. When the external audit device is installed, with no calibration attenuator inserted, the COMS measurement reading must be less than or equal to one percent opacity. You must also document procedures for properly handling and storing the external audit device and calibration attenuators within your written QC program.
(3) You must check the optical alignment of the COMS in accordance with the instrument manufacturer’s recommendations. If the optical alignment varies with stack temperature, perform the optical alignment test when the unit is operating.
10.3 What are the annual auditing requirements for my COMS?
(1) You must perform the primary zero alignment method under clear path conditions. The COMS must be removed from its installation and set up under clear path conditions. There must be no adjustments to the monitor other than the establishment of the proper monitor path length and correct optical alignment of the COMS components. You must record the COMS response to a clear condition and to the COMS’s simulated zero condition as percent opacity corrected to stack exit conditions. For a COMS with automatic zero compensation, you must disconnect or disable the zero compensation mechanism or record the amount of correction applied to the COMS’s simulated zero condition. The response difference in percent opacity to the clear path and simulated zero conditions must be recorded as the zero alignment error. You must adjust the COMS’s simulated zero device to provide the same response as the clear path condition as specified in paragraph (3) of section 10.0.
(2) As an alternative, monitors capable of allowing the installation of an external zero device may use the device for the zero alignment provided that: (1) The external zero device setting has been established for the monitor path length and recorded for the specific COMS by comparison of the COMS responses to the installed external zero device and to the clear path condition, and (2) the external zero device is demonstrated to be capable of producing a consistent zero response when it is repeatedly (i.e., three consecutive installations and removals prior to conducting the final zero alignment check) installed on the COMS. This can be demonstrated by either the manufacturer’s certificate of conformance (MCOC) or actual on-site performance. The external zero device setting must be permanently set at the time of initial zeroing to the clear path zero value and protected when not in use to ensure that the setting equivalent to zero opacity does not change. The external zero device response must be checked and recorded prior to initiating the zero alignment. If the external zero device setting has changed, you must remove the COMS from the stack in order to reset the external zero device. If you employ an external zero device, you must perform the zero alignment audits with the COMS off the stack at least every three years. If the external zero device is adjusted within the three-year period, you must perform the zero alignment with the COMS off the stack no later than three years from the date of adjustment.
(3) The procedure in section 6.8 of ASTM D6216-12 is allowed.
10.4 What are my limits for excessive audit inaccuracy? Unless specified otherwise in the applicable subpart, the criteria for excessive inaccuracy are listed in paragraphs (1) through (4).
(1) What is the criterion for excessive zero or upscale drift? Your COMS is out-of-control if either the zero drift check or upscale drift check exceeds twice the applicable drift specification in PS-1 for any one day.
(2) What is the criterion for excessive zero alignment? Your COMS is out-of-control if the zero alignment error exceeds 2 percent opacity.
(3) What is the criterion to pass the quarterly performance audit? Your COMS is out-of-control if the results of a quarterly performance audit indicate noncompliance with the following criteria:
(i) The optical alignment indicator does not show proper alignment (i.e., does not fall within a specific reference mark or condition).
(ii) The zero compensation exceeds 4 percent opacity, or
(iii) The calibration error exceeds 3 percent opacity.
(4) What is the criterion for data capture? You must adhere to the data capture criterion specified in the applicable subpart.
10.5 What corrective action must I take if my COMS is malfunctioning? You must have a corrective action program in place to address the repair and/or maintenance of your COMS. The corrective action program must address routine/preventative maintenance and various types of analyzer repairs. The corrective action program must establish what diagnostic testing must be performed after each type of activity to ensure that the COMS is collecting valid, quality-assured data. Recommended maintenance and repair procedures and diagnostic testing after repairs may be found in an associated guidance document.
10.6 What requirements must I meet if I use a temporary opacity monitor?
(1) In the event that your certified opacity monitor has to be removed for extended service, you may install a temporary replacement monitor to obtain required opacity emissions data provided that:
(i) The temporary monitor has been certified according to ASTM D6216-12 for which a MCOC has been provided;
(ii) The use of the temporary monitor does not exceed 1080 hours (45 days) of operation per year as a replacement for a fully certified opacity monitor. After that time, the analyzer must complete a full certification according to PS-1 prior to further use as a temporary replacement monitor. Once a temporary replacement monitor has been installed and required testing and adjustments have been successfully completed, it cannot be replaced by another temporary replacement monitor to avoid the full PS-1 certification testing required after 1080 hours (45 days) of use;
(iii) The temporary monitor has been installed and successfully completed an optical alignment assessment and status indicator assessment;
(iv) The temporary monitor has successfully completed an off-stack clear path zero assessment and zero calibration value adjustment procedure;
(v) The temporary monitor has successfully completed an abbreviated zero and upscale drift check consisting of seven zero and upscale calibration value drift checks which may be conducted within a 24-hour period with not more than one calibration drift check every three hours and not less than one calibration drift check every 25 hours. Calculated zero and upscale drift requirements are the same as specified for the normal PS-1 certification;
(vi) The temporary monitor has successfully completed a three-point calibration error test;
(vii) The upscale reference calibration check value of the new monitor has been updated in the associated data recording equipment;
(viii) The overall calibration of the monitor and data recording equipment has been verified; and
(ix) The user has documented all of the above in the maintenance log.
(2) Data generated by the temporary monitor is considered valid when paragraphs (i) through (ix) in this section have been met.
10.7 When do out-of-control periods begin and end? The out-of-control periods are as specified in section 3.1.
10.8 What are the limitations on the use of my COMS data collected during out-of-control periods? During the period your COMS is out-of-control, you may not use your COMS data to calculate emission compliance or to meet minimum data capture requirements in this procedure or the applicable regulation.
10.9 What are the QA/QC reporting requirements for my COMS? You must report in a Data Assessment Report (DAR) the information required by sections 10.0, 10.1, 10.2, and 10.3 for your COMS at the interval specified in the applicable regulation.
10.10 What minimum information must I include in my DAR? At a minimum, you must include the information listed in paragraphs (1) through (5) of this section in the DAR.
(1) Name of person completing the report and facility address,
(2) Identification and location of your COMS(s),
(3) Manufacturer, model, and serial number of your COMS(s),
(4) Assessment of COMS data accuracy/acceptability and date of assessment as determined by a performance audit described in section 10.0. If the accuracy audit results show your COMS to be out-of-control, you must report both the audit results showing your COMS to be out-of-control and the results of the audit following corrective action showing your COMS to be operating within specifications, and
(5) Summary of all corrective actions you took when you determined your COMS was out-of-control.
10.11 Where and how long must I retain the QA data that this procedure requires me to record for my COMS? You must keep the records required by this procedure for your COMS on site and available for inspection by us, the state, and/or the local enforcement agency for the period specified in the regulations requiring the use of COMS.
16.1 Performance Specification 1-Specifications and Test Procedures for Continuous Opacity Monitoring Systems in Stationary Sources, 40 CFR part 60, Appendix B.
16.2 ASTM D6216-12-Standard Practice for Opacity Monitor Manufacturers to Certify Conformance with Design and Performance Specifications, American Society for Testing and Materials (ASTM).
1.1 Applicability. The purpose of Procedure 5 is to establish the minimum requirements for evaluating the effectiveness of quality control (QC) and quality assurance (QA) procedures as well as the quality of data produced by vapor phase mercury (Hg) continuous emissions monitoring systems (CEMS) and sorbent trap monitoring systems. Procedure 5 applies to Hg CEMS and sorbent trap monitoring systems used for continuously determining compliance with emission standards or operating permit limits as specified in an applicable regulation or permit. Other QA/QC procedures may apply to other auxiliary monitoring equipment that may be needed to determine Hg emissions in the units of measure specified in an applicable permit or regulation.
Procedure 5 covers the measurement of Hg emissions as defined in Performance Specification 12A (PS 12A) and Performance Specification 12B (PS 12B) in appendix B to this part, i.e., total vapor phase Hg representing the sum of the elemental (Hg°, CAS Number 7439-97-6) and oxidized (Hg
Procedure 5 specifies the minimum requirements for controlling and assessing the quality of Hg CEMS and sorbent trap monitoring system data submitted to EPA or a delegated permitting authority. You must meet these minimum requirements if you are responsible for one or more Hg CEMS or sorbent trap monitoring systems used for compliance monitoring. We encourage you to develop and implement a more extensive QA program or to continue such programs where they already exist.
You must comply with the basic requirements of Procedure 5 immediately following successful completion of the initial performance test described in PS 12A or PS 12B in appendix B to this part (as applicable).
1.2 Principle. The QA procedures consist of two distinct and equally important functions. One function is the assessment of the quality of the Hg CEMS or sorbent trap monitoring system data by estimating accuracy. The other function is the control and improvement of the quality of the CEMS or sorbent trap monitoring system data by implementing QC policies and corrective actions. These two functions form a control loop: When the assessment function indicates that the data quality is inadequate, the quality control effort must be increased until the data quality is acceptable. In order to provide uniformity in the assessment and reporting of data quality, this procedure explicitly specifies assessment methods for calibration drift, system integrity, and accuracy. Several of the procedures are based on those of PS 12A and PS 12B in appendix B to this part. Because the control and corrective action function encompasses a variety of policies, specifications, standards, and corrective measures, this procedure treats QC requirements in general terms to allow each source owner or operator to develop a QC system that is most effective and efficient for the circumstances.
2.1 Mercury Continuous Emission Monitoring System (Hg CEMS) means the equipment required for the determination of the total vapor phase Hg concentration in the stack effluent. The Hg CEMS consists of the following major subsystems:
2.1.1 Sample Interface means that portion of the CEMS used for one or more of the following: sample acquisition, sample transport, sample conditioning, and protection of the monitor from the effects of the stack effluent.
2.1.2 Hg Analyzer means that portion of the Hg CEMS that measures the total vapor phase Hg concentration and generates a proportional output.
2.1.3 Data Recorder means that portion of the CEMS that provides a permanent electronic record of the analyzer output. The data recorder may provide automatic data reduction and CEMS control capabilities.
2.2 Sorbent Trap Monitoring System means the total equipment required for the collection of gaseous Hg samples using paired three-partition sorbent traps as described in PS 12B in appendix B to this part.
2.3 Span Value means the measurement range as specified for the affected source category in the applicable regulation and/or monitoring performance specification.
2.4 Zero, Mid-Level, and High Level Values means the reference gas concentrations used for calibration drift assessments and system integrity checks on a Hg CEMS, expressed as percentages of the span value (see section 7.1 of PS 12A in appendix B to this part).
2.5 Calibration Drift (CD) means the absolute value of the difference between the CEMS output response and either the upscale Hg reference gas or the zero-level Hg reference gas, expressed as a percentage of the span value, when the entire CEMS, including the sampling interface, is challenged after a stated period of operation during which no unscheduled maintenance, repair, or adjustment took place.
2.6 System Integrity (SI) Check means a test procedure assessing transport and measurement of oxidized Hg by a Hg CEMS. In particular, system integrity is expressed as the absolute value of the difference between the CEMS output response and the reference value of either a mid- or high-level mercuric chloride (HgCl
2.7 Relative Accuracy (RA) means the absolute mean difference between the pollutant concentrations determined by a continuous monitoring system (e.g., Hg CEMS or sorbent trap monitoring system) and the values determined by a reference method (RM) plus the 2.5 percent error confidence coefficient of a series of tests divided by the mean of the RM tests. Alternatively, for sources with an average RM concentration less than 5.0 micrograms per standard cubic meter (µg/scm), the RA may be expressed as the absolute value of the difference between the mean CEMS and RM values.
2.8 Relative Accuracy Test Audit (RATA) means an audit test procedure consisting of at least nine runs, in which the accuracy of the total vapor phase Hg concentrations measured by a CEMS or sorbent trap monitoring system is evaluated by comparison against concurrent measurements made with a reference test method.
2.9 Quarterly Gas Audit (QGA) means an audit procedure in which the accuracy of the total vapor phase Hg concentrations measured by a CEMS is evaluated by challenging the CEMS with a zero and two upscale reference gases.
3.1 Each source owner or operator must develop and implement a QC program. At a minimum, each QC program must include written procedures which should describe in detail, complete, step-by-step procedures and operations for each of the following activities (as applicable):
(a) Calibration drift (CD) checks of Hg CEMS.
(b) CD determination and adjustment of Hg CEMS.
(c) Weekly system integrity check procedures for Hg CEMS.
(d) Routine operation, maintenance, and QA/QC procedures for sorbent trap monitoring systems.
(e) Routine and preventive maintenance procedures for Hg CEMS (including spare parts inventory).
(f) Data recording, calculations, and reporting.
(g) Accuracy audit procedures for Hg CEMS and sorbent trap monitoring systems including sampling and analysis methods.
(h) Program of corrective action for malfunctioning Hg CEMS and sorbent trap monitoring systems.
These written procedures must be kept on record and available for inspection by the responsible enforcement agency. Also, as noted in section 5.2.4, below, whenever excessive inaccuracies of a Hg CEMS occur for two consecutive quarters, the source owner or operator must revise the current written procedures or modify or replace the CEMS or sorbent trap monitoring system to correct the deficiency causing the excessive inaccuracies.
4.1 CD Requirement. As described in 40 CFR 60.13(d) and 63.8(c), source owners and operators of Hg CEMS must check, record, and quantify the CD at two concentration values at least once daily (approximately 24 hours) in accordance with the method prescribed by the manufacturer. The Hg CEMS calibration must, as minimum, be adjusted whenever the daily zero (or low-level) CD or the daily high-level CD exceeds two times the limits of the applicable PS in appendix B of this part.
4.2 Recording Requirement for Automatic CD Adjusting CEMS. CEMS that automatically adjust the data to the corrected calibration values (e.g., microprocessor control) must either be programmed to record the unadjusted concentration measured in the CD prior to resetting the calibration, if performed, or to record the amount of adjustment.
4.3 Criteria for Excessive CD. If either the zero (or low-level) or high-level CD result exceeds twice the applicable drift specification in section 13.2 of PS 12A in appendix B to this part for five, consecutive, daily periods, the CEMS is out-of-control. If either the zero (or low-level) or high-level CD result exceeds four times the applicable drift specification in PS 12A during any CD check, the CEMS is out-of-control. If the CEMS is out-of-control, take necessary corrective action. Following corrective action, repeat the CD checks.
4.3.1 Out-Of-Control Period Definition. The beginning of the out-of-control period is the time corresponding to the completion of the fifth, consecutive, daily CD check with a CD in excess of two times the allowable limit, or the time corresponding to the completion of the daily CD check preceding the daily CD check that results in a CD in excess of four times the allowable limit. The end of the out-of-control period is the time corresponding to the completion of the CD check following corrective action that results in the CD’s at both the zero (or low-level) and high-level measurement points being within the corresponding allowable CD limit (i.e., either two times or four times the allowable limit in the applicable PS in appendix B).
4.3.2 CEMS Data Status During Out-of-Control Period. During the period the CEMS is out-of-control, the CEMS data may not be used either to determine compliance with an emission limit or to meet a minimum data availability requirement specified in an applicable regulation or permit.
5.1 Hg CEMS Audit Requirements. For each Hg CEMS, an accuracy audit must be performed at least once each calendar quarter. Successive quarterly audits must, to the extent practicable, be performed no less than 2 months apart. The audits must be conducted as follows:
5.1.1 Relative Accuracy Test Audit (RATA). A RATA of the Hg CEMS must be conducted at least once every four calendar quarters, except as otherwise noted in section 5.1.4 of this appendix. Perform the RATA as described in section 8.5 of PS 12A in appendix B to this part. Calculate the results according to section 12.4 of PS 12A.
5.1.2 Quarterly Gas Audit. A quarterly gas audit (QGA) may be conducted in three of four calendar quarters, but in no more than three quarters in succession. To perform a QGA, challenge the CEMS with a zero-level and two upscale level audit gases of known concentrations, first of elemental Hg and then of oxidized Hg, within the following ranges:
| Audit point | Audit range |
|---|---|
| 1 | 20 to 30% of span value. |
| 2 | 50 to 60% of span value. |
Sequentially inject each of the three audit gases (zero and two upscale), three times each for a total of nine injections. Inject the gases in such a manner that the entire CEMS is challenged. Do not inject the same gas concentration twice in succession.
Use elemental Hg and oxidized Hg (mercuric chloride, HgCl
5.1.3 Relative Accuracy Audit (RAA). As an alternative to the QGA, a RAA may be conducted in three of four calendar quarters, but in no more than three quarters in succession. To conduct a RAA, follow the RATA test procedures in section 8.5 of PS 12A in appendix B to this part, except that only three test runs are required.
5.1.4 Alternative Quarterly Audits. Alternative quarterly audit procedures may be used as approved by the Administrator for three of four calendar quarters. One RATA is required at least every four calendar quarters, except in the case where the affected facility is off-line (does not operate) in the fourth calendar quarter since the quarter of the previous RATA. In that case, the RATA must be performed in the quarter in which the unit recommences operation. Also, quarterly gas audits (or RAAs, if applicable) are not required for calendar quarters in which the affected facility does not operate.
5.2 Sorbent Trap Monitoring System Audit Requirements. For each sorbent trap monitoring system, a RATA must be conducted at least once every four calendar quarters, except as otherwise noted in section 5.1.4 of this appendix. Perform the RATA as described in section 8.3 of PS 12B in appendix B to this part. Calculate the results according to section 12.4 of PS 12A.
5.3 Excessive Audit Inaccuracy. If the results of a RATA, QGA, or RAA exceed the applicable criteria in section 5.3.3, the Hg CEMS or sorbent trap monitoring system is out-of-control. If the Hg CEMS or sorbent trap monitoring system is out-of-control, take necessary corrective action to eliminate the problem. Following corrective action, the source owner or operator must audit the CEMS or sorbent trap monitoring system using the same type of test that failed to meet the accuracy criterion. For instance, a RATA must always be performed following an out-of-control period resulting from a failed RATA. Whenever audit results show the Hg CEMS or sorbent trap monitoring system to be out-of-control, the owner or operator must report both the results of the failed test and the results of the retest following corrective action showing the CEMS to be operating within specifications.
5.3.1 Out-Of-Control Period Definition. The beginning of the out-of-control period is the hour immediately following the completion of a RATA, RAA, QGA or system integrity check that fails to meet the applicable performance criteria in section 5.3.3, below. The end of the out-of-control period is the time corresponding to the completion of a subsequent successful test of the same type.
5.3.2 Monitoring Data Status During Out-Of-Control Period. During the period the monitor is out-of-control, the monitoring data may not be used to determine compliance with an applicable emission limit or to meet a minimum data availability requirement in an applicable regulation or permit.
5.3.3 Criteria for Excessive Audit Inaccuracy. Unless specified otherwise in an applicable regulation or permit, the criteria for excessive inaccuracy are:
(a) For the RATA, the allowable RA in the applicable PS in appendix B (e.g., PS 12A or PS 12B).
(b) For the QGA, ±15 percent of the average audit value or ±0.5 µg/m
(c) For the RAA, ±20 percent of the three run average or ±10 percent of the applicable standard, whichever is greater.
5.3.4 Criteria for Acceptable QC Procedures. Repeated excessive inaccuracies (i.e., out-of-control conditions resulting from the quarterly audits) indicates the QC procedures are inadequate or that the CEMS or sorbent trap monitoring system is incapable of providing quality data. Therefore, whenever excessive inaccuracies occur for two consecutive quarters, the source owner or operator must revise the QC procedures (see section 3) or modify, repair, or replace the CEMS or sorbent trap monitoring system.
6.1 Data Assessment Report. At the reporting interval specified in the applicable regulation or permit, report for each Hg CEMS and/or sorbent trap monitoring system the accuracy assessment results from section 5, above. For Hg CEMS, also report the CD assessment results from section 4, above. Report this information as a Data Assessment Report (DAR), and include the appropriate DAR(s) with the emissions report required under the applicable regulation or permit.
6.2 Contents of the DAR. At a minimum, the DAR must contain the following information:
6.2.1 Facility name and address including identification of source owner/operator.
6.2.2 Identification and location of each Hg CEMS and/or sorbent trap monitoring system.
6.2.3 Manufacturer, model, and serial number of each Hg CEMS and/or sorbent trap monitoring system.
6.2.4 CD Assessment for each Hg CEMS, including the identification of out-of-control periods.
6.2.5 System integrity check data for each Hg CEMS.
6.2.6 Accuracy assessment for each Hg CEMS and/or sorbent trap monitoring system, including the identification of out-of-control periods. The results of all required RATAs, QGAs, RAAs, and audits of auxiliary equipment must be reported. If an accuracy audit shows a CEMS or sorbent trap monitoring system to be out-of-control, report both the audit results that caused the out-of-control period and the results of the retest following corrective action, showing the monitoring system to be operating within specifications.
6.2.7 Summary of all corrective actions taken when the Hg CEMS and/or sorbent trap monitoring system was determined to be out-of-control.
6.3 Data Retention. As required in 40 CFR 60.7(d) and 63.10(b), all measurements from CEMS and sorbent trap monitoring systems, including the quality assurance data required by this procedure, must be retained by the source owner for at least 5 years.
7.1 Calculation and Interpretation of Accuracy for Continuous Emission Monitoring Systems (CEMS). section 3.0.7 of the Quality Assurance Handbook for Air Pollution Measurement Systems, Volume III, Stationary Source Specific Methods. EPA-600/4-77-027b. August 1977. U.S. Environmental Protection Agency. Office of Research and Development Publications, 26 West St. Clair Street, Cincinnati, OH 45268.
1.1 Applicability. Procedure 6 is used to evaluate the effectiveness of quality control (QC) and quality assurance (QA) procedures and evaluate the quality of data produced by any hydrogen chloride (HCl) gas, CAS: 7647-01-0, continuous emission monitoring system (CEMS) that is used for determining compliance with emission standards for HCl on a continuous basis as specified in an applicable permit or regulation.
1.1.1 This procedure specifies the minimum QA requirements necessary for the control and assessment of the quality of CEMS data submitted to the Environmental Protection Agency (EPA) or a delegated authority. If you are responsible for one or more CEMS used for HCl compliance monitoring you must meet these minimum requirements and you are encouraged to develop and implement a more extensive QA program or to continue such programs where they already exist.
1.1.2 Data collected as a result of QA and QC measures required in this procedure are to be submitted to the EPA or the delegated authority in accordance with the applicable regulation or permit. These data are to be used by both the delegated authority and you, as the CEMS operator, in assessing the effectiveness of the CEMS QC and QA procedures in the maintenance of acceptable CEMS operation and valid emission data.
1.2.1 The QA procedures consist of two distinct and equally important functions. One function is the assessment of the quality of the CEMS data by estimating accuracy. The other function is the control and improvement of the quality of the CEMS data by implementing QC policies and corrective actions. These two functions form an iterative control loop. When the assessment function indicates that the data quality is inadequate, the control effort must be increased until the data quality is acceptable. In order to provide uniformity in the assessment and reporting of data quality, this procedure specifies the assessment procedures to evaluate response drift and accuracy. The procedures specified are based on Performance Specification 18 (PS-18) in appendix B to this part.
(
See PS-18 of this subpart for the primary definitions used in this Procedure.
3.1 You, as a source owner or operator, must develop and implement a QC program. At a minimum, each QC program must include written procedures and/or manufacturer’s information which should describe in detail, complete, step-by-step procedures and operations for each of the following activities:
(a) Calibration Drift (CD) checks of CEMS;
(b) CD determination and adjustment of CEMS;
(c) Integrated Path (IP) CEMS temperature and pressure sensor accuracy checks;
(d) IP CEMS beam intensity checks;
(e) Routine and preventative maintenance of CEMS (including spare parts inventory);
(f) Data recording, calculations, and reporting;
(g) Accuracy audit procedures for CEMS including reference method(s); and
(h) Program of corrective action for malfunctioning CEMS.
3.2 These written procedures must be kept on site and available for inspection by the delegated authority. As described in section 5.4, whenever excessive inaccuracies occur for two consecutive quarters, you must revise the current written procedures, or modify or replace the CEMS to correct the deficiency causing the excessive inaccuracies.
4.1 CD Assessment. An upscale gas, used to meet a requirement in this section must be either a NIST-traceable reference gas or a gas certified by the gas vendor to ±5.0 percent accuracy.
4.1.1 CD Requirement. Consistent with 40 CFR 60.13(d) and 63.8(c), you, as source owners or operators of CEMS must check, record, and quantify the CD at two levels, using a zero gas and mid-level gas at least once daily (approximately every 24 hours). Perform the CD check in accordance with the procedure in applicable performance specification (e.g., section 11.8 of PS-18 in appendix B of this part). The daily zero- and mid-level CD must not exceed two times the drift limits specified in the applicable performance specification (e.g., section 13.2 of PS-18 in appendix B to this part.)
4.1.2 Recording Requirement for CD Corrective action. Corrective actions taken to bring a CEMS back in control after exceeding a CD limit must be recorded and reported with the associated CEMS data. Reporting corrective action must include the unadjusted concentration measured prior to resetting the calibration and the adjusted value after resetting the calibration to bring the CEMS back into control.
4.1.3 Dynamic Spiking Option for Mid-level CD. For extractive CEMS, you have the option to conduct a daily dynamic spiking procedure found in section 11.8.8 of PS-18 of appendix B of this part in lieu of the daily mid-level CD check. If this option is selected, the daily zero CD check is still required.
4.1.4 Out of Control Criteria for Excessive CD. As specified in § 63.8(c)(7)(i)(A), a CEMS is out of control if the zero or mid-level CD exceeds two times the applicable CD specification in the applicable PS or in the relevant standard. When a CEMS is out of control, you as owner or operator of the affected source must take the necessary corrective actions and repeat the tests that caused the system to go out of control (in this case, the failed CD check) until the applicable performance requirements are met.
4.1.5 Additional Quality Assurance for Data above Span. This procedure must be used when required by an applicable regulation and may be used when significant data above span are being collected. Furthermore, the terms of this procedure do not apply to the extent that alternate terms are otherwise specified in an applicable rule or permit.
4.1.5.1 Any time the average measured concentration of HCl exceeds 150 percent of the span value for two consecutive one-hour averages, conduct the following ‘above span’ CEMS response check.
4.1.5.1.1 Within a period of 24 hours (before or after) of the ‘above span’ period, introduce a higher, ‘above span’ HCl reference gas standard to the CEMS. Use ‘above span’ reference gas that meets the requirements of section 7.0 of PS-18 and target a concentration level between 75 and 125 percent of the highest hourly concentration measured during the period of measurements above span.
4.1.5.1.2 Introduce the reference gas at the probe for extractive CEMS or for IP-CEMS as an equivalent path length corrected concentration in the instrument calibration cell.
4.1.5.1.3 At no time may the ‘above span’ concentration exceed the analyzer full-scale range.
4.1.5.2 Record and report the results of this procedure as you would for a daily calibration. The ‘above span’ response check is successful if the value measured by the CEMS is within 20 percent of the certified value of the reference gas.
4.1.5.3 If the ‘above span’ response check is conducted during the period when measured emissions are above span and there is a failure to collect at least one data point in an hour due to the response check duration, then determine the emissions average for that missed hour as the average of hourly averages for the hour preceding the missed hour and the hour following the missed hour.
4.1.5.4 In the event that the ‘above span’ response check is not successful (i.e., the CEMS measured value is not within 20 percent of the certified value of the reference gas), then you must normalize the one-hour average stack gas values measured above the span during the 24-hour period preceding or following the ‘above span’ response check for reporting based on the CEMS response to the reference gas as shown in Eq. 6-1:
4.2.1 Beam Intensity Measurement. If you use a HCl IP-CEMS, you must quantify and record the beam intensity of the IP-CEMS in appropriate units at least once daily (approximately 24 hours apart) according to manufacturer’s specifications and procedures.
4.2.2 Out of Control Criteria for Excessive Beam Intensity Loss. If the beam intensity falls below the level established for the operation range determined following the procedures in section 11.2 of PS-18 of this part, then your CEMS is out-of-control. This quality check is independent of whether the CEMS daily CD is acceptable. If your CEMS is out-of-control, take necessary corrective action. You have the option to repeat the beam intensity test procedures in section 11.2 of PS-18 to expand the acceptable range of acceptable beam intensity. Following corrective action, repeat the beam intensity check.
4.3 Out Of Control Period Duration for Daily Assessments. The beginning of the out-of-control period is the hour in which the owner or operator conducts a daily performance check (e.g., calibration drift or beam intensity check) that indicates an exceedance of the performance requirements established under this procedure. The end of the out-of-control period is the completion of daily assessment of the same type following corrective actions, which shows that the applicable performance requirements have been met.
4.4 CEMS Data Status During Out-of-Control Period. During the period the CEMS is out-of-control, the CEMS data may not be used in calculating compliance with an emissions limit nor be counted towards meeting minimum data availability as required and described in the applicable regulation or permit.
You must audit your CEMS for the accuracy of HCl measurement on a regular basis at the frequency described in this section, unless otherwise specified in an applicable regulation or permit. Quarterly audits are performed at least once each calendar quarter. Successive quarterly audits, to the extent practicable, shall occur no closer than 2 months apart. Annual audits are performed at least once every four consecutive calendar quarters.
5.1.1 Stack or source gas temperature measurement audits for HCl IP-CEMS must be conducted and recorded at least annually in accordance with the procedure described in section 11.3 of PS-18 in appendix B to this part. As an alternative, temperature measurement devices may be replaced with certified instruments on an annual basis. Units removed from service may be bench tested against an NIST traceable sensor and reused during subsequent years. Any measurement instrument or device that is used to conduct ongoing verification of temperature measurement must have an accuracy that is traceable to NIST.
5.1.2 Stack or source gas pressure measurement audits for HCl IP-CEMS must be conducted and recorded at least annually in accordance with the procedure described in section 11.4 of PS-18 in appendix B of this part. As an alternative, pressure measurement devices may be replaced with certified instruments on an annual basis. Units removed from service may be bench tested against an NIST traceable sensor and reused during subsequent years. Any measurement instrument or device that is used to conduct ongoing verification of pressure measurement must have an accuracy that is traceable to NIST.
5.1.3 Out of Control Criteria for Excessive Parameter Verification Inaccuracy. If the temperature or pressure verification audit exceeds the criteria in sections 5.3.4.5 and 5.3.4.6, respectively, the CEMS is out-of-control. If the CEMS is out-of-control, take necessary corrective action to eliminate the problem. Following corrective action, you must repeat the failed verification audit until the temperature or pressure measurement device is operating within the applicable specifications, at which point the out-of-control period ends.
5.2 Concentration Accuracy Auditing Requirements. Unless otherwise specified in an applicable rule or permit, you must audit the HCl measurement accuracy of each CEMS at least once each calendar quarter, except in the case where the affected facility is off-line (does not operate). In that case, the audit must be performed as soon as is practicable in the quarter in which the unit recommences operation. Successive quarterly audits must, to the extent practicable, be performed no less than 2 months apart. The accuracy audits shall be conducted as follows:
5.2.1 Relative Accuracy Test Audit. A RATA must be conducted at least once every four calendar quarters, except as otherwise noted in sections 5.2.5 or 5.5 of this procedure. Perform the RATA as described in section 11.9 of PS-18 in appendix B to this part. If the HCl concentration measured by the RM during a RATA (in ppmv) is less than or equal to 20 percent of the concentration equivalent to the applicable emission standard, you must perform a Cylinder Gas Audit (CGA) or a Dynamic Spike Audit (DSA) for at least one subsequent (one of the following three) quarterly accuracy audits.
5.2.2 Quarterly Relative Accuracy Audit (RAA). A quarterly RAA may be conducted as an option to conducting a RATA in three of four calendar quarters, but in no more than three quarters in succession. To conduct an RAA, follow the test procedures in section 11.9 of PS-18 in appendix B to this part, except that only three test runs are required. The difference between the mean of the RM values and the mean of the CEMS responses relative to the mean of the RM values (or alternatively the emission standard) is used to assess the accuracy of the CEMS. Calculate the RAA results as described in section 6.2. As an alternative to an RAA, a cylinder gas audit or a dynamic spiking audit may be conducted.
5.2.3 Cylinder Gas Audit. A quarterly CGA may be conducted as an option to conducting a RATA in three of four calendar quarters, but in no more than three consecutive quarters. To perform a CGA, challenge the CEMS with a zero-level and two upscale level audit gases of known concentrations within the following ranges:
| Audit point | Audit range |
|---|---|
| 1 (Mid-Level) | 50 to 60% of span value. |
| 2 (High-Level) | 80 to 100% of span value. |
5.2.3.1 Inject each of the three audit gases (zero and two upscale) three times each for a total of nine injections. Inject the gases in such a manner that the entire CEMS is challenged. Do not inject the same gas concentration twice in succession.
5.2.3.2 Use HCl audit gases that meet the requirements of section 7 of PS-18 in appendix B to this part.
5.2.3.3 Calculate results as described in section 6.3.
5.2.4 Dynamic Spiking Audit. For extractive CEMS, a quarterly DSA may be conducted as an option to conducting a RATA in three of four calendar quarters, but in no more than three quarters in succession.
5.2.4.1 To conduct a DSA, you must challenge the entire HCl CEMS with a zero gas in accordance with the procedure in section 11.8 of PS-18 in appendix B of this part. You must also conduct the DS procedure as described in appendix A to PS-18 of appendix B to this part. You must conduct three spike injections with each of two upscale level audit gases. The upscale level gases must meet the requirements of section 7 of PS-18 in appendix B to this part and must be chosen to yield concentrations at the analyzer of 50 to 60 percent of span and 80 to 100 percent of span. Do not inject the same gas concentration twice in succession.
5.2.4.2 Calculate results as described in section 6.4. To determine CEMS accuracy, you must calculate the dynamic spiking error (DSE) for each of the two upscale audit gases using Equation A5 in appendix A to PS-18 and Equation 6-3 in section 6.4 of Procedure 6 in appendix B to this part.
5.2.5 Other Alternative Quarterly Audits. Other alternative audit procedures, as approved by the Administrator, may be used for three of four calendar quarters.
5.3 Out of Control Criteria for Excessive Audit Inaccuracy. If the results of the RATA, RAA, CGA, or DSA do not meet the applicable performance criteria in section 5.3.4, the CEMS is out-of-control. If the CEMS is out-of-control, take necessary corrective action to eliminate the problem. Following corrective action, the CEMS must pass a test of the same type that resulted in the out-of-control period to determine if the CEMS is operating within the specifications (e.g., a RATA must always follow an out-of-control period resulting from a RATA).
5.3.1 If the audit results show the CEMS to be out-of-control, you must report both the results of the audit showing the CEMS to be out-of-control and the results of the audit following corrective action showing the CEMS to be operating within specifications.
5.3.2 Out-Of-Control Period Duration for Excessive Audit Inaccuracy. The beginning of the out-of-control period is the time corresponding to the completion of the sampling for the failed RATA, RAA, CGA or DSA. The end of the out-of-control period is the time corresponding to the completion of the sampling of the subsequent successful audit.
5.3.3 CEMS Data Status During Out-Of-Control Period. During the period the CEMS is out-of-control, the CEMS data may not be used in calculating emission compliance nor be counted towards meeting minimum data availability as required and described in the applicable regulation or permit.
5.3.4 Criteria for Excessive Quarterly and Yearly Audit Inaccuracy. Unless specified otherwise in the applicable regulation or permit, the criteria for excessive inaccuracy are:
5.3.4.1 For the RATA, the CEMS must meet the RA specifications in section 13.4 of PS-18 in appendix B to this part.
5.3.4.2 For the CGA, the accuracy must not exceed 5.0 percent of the span value at the zero gas and the mid- and high-level reference gas concentrations.
5.3.4.3 For the RAA, the RA must not exceed 20.0 percent of the RM
5.3.4.4 For DSA, the accuracy must not exceed 5.0 percent of the span value at the zero gas and the mid- and high-level reference gas concentrations or 20.0 percent of the applicable emission standard, whichever is greater.
5.3.4.5 For the gas temperature measurement audit, the CEMS must satisfy the requirements in section 13.7 in PS-18 of appendix B to this part.
5.3.4.6 For the gas pressure measurement audit, the CEMS must satisfy the requirements in section 13.8 in PS-18 of appendix B to this part.
5.4 Criteria for Acceptable QC Procedures. Repeated excessive inaccuracies (i.e., out-of-control conditions resulting from the quarterly or yearly audits) indicate that the QC procedures are inadequate or that the CEMS is incapable of providing quality data. Therefore, whenever excessive inaccuracies occur for two consecutive quarters, you must revise the QC procedures (see section 3.0) or modify or replace the CEMS.
5.5 Criteria for Optional QA Test Frequency. If all the quality criteria are met in sections 4 and 5 of this procedure, the CEMS is in-control.
5.5.1 Unless otherwise specified in an applicable rule or permit, if the CEMS is in-control and if your source emits ≤75 percent of the HCl emission limit for each averaging period as specified in the relevant standard for eight consecutive quarters that include a minimum of two RATAs, you may revise your auditing procedures to use CGA, RAA or DSA each quarter for seven subsequent quarters following a RATA.
5.5.2 You must perform at least one RATA that meets the acceptance criteria every 2 years.
5.5.3 If you fail a RATA, RAA, CGA, or DSA, then the audit schedule in section 5.2 must be followed until the audit results meet the criteria in section 5.3.4 to start requalifying for the optional QA test frequency in section 5.5.
6.1 RATA RA Calculation. Follow Equations 9 through 14 in section 12 of PS-18 in appendix B to this part to calculate the RA for the RATA. The RATA must be calculated either in units of the applicable emission standard or in concentration units (ppmv).
6.2 RAA Accuracy Calculation. Use Equation 6-2 to calculate the accuracy for the RAA. The RA may be calculated in concentration units (ppmv) or in the units of the applicable emission standard.
6.3 CGA Accuracy Calculation. For each gas concentration, determine the average of the three CEMS responses and subtract the average response from the audit gas value. For extractive CEMS, calculate the ME at each gas level using Equation 3A in section 12.3 of PS-18 in appendix B to this part. For IP-CEMS, calculate the ME at each gas level using Equation 6A in section 12.4.3 of PS-18 in appendix B to this part.
6.4 DSA Accuracy Calculation. DSA accuracy is calculated as a percent of span. To calculate the DSA accuracy for each upscale spike concentration, first calculate the DSE using Equation A5 in appendix A of PS-18 in appendix B to this part. Then use Equation 6-3 to calculate the average DSA accuracy for each upscale spike concentration. To calculate DSA accuracy at the zero level, use equation 3A in section 12.3 of PS-18 in appendix B to this part.
At the reporting interval specified in the applicable regulation or permit, report for each CEMS the quarterly and annual accuracy audit results from section 6 and the daily assessment results from section 4. Unless otherwise specified in the applicable regulation or permit, include all data sheets, calculations, CEMS data records (i.e., charts, records of CEMS responses), reference gas certifications and reference method results necessary to confirm that the performance of the CEMS met the performance specifications.
7.1 Unless otherwise specified in the applicable regulations or permit, report the daily assessments (CD and beam intensity) and accuracy audit information at the interval for emissions reporting required under the applicable regulations or permits.
7.1.1 At a minimum, the daily assessments and accuracy audit information reporting must contain the following information:
a. Company name and address.
b. Identification and location of monitors in the CEMS.
c. Manufacturer and model number of each monitor in the CEMS.
d. Assessment of CEMS data accuracy and date of assessment as determined by a RATA, RAA, CGA or DSA described in section 5 including:
i. The RA for the RATA;
ii. The accuracy for the CGA, RAA, or DSA;
iiii. Temperature and pressure sensor audit results for IP-CEMS;
iv. The RM results, the reference gas certified values;
v. The CEMS responses;
vi. The calculation results as defined in section 6; and
vii. Results from the performance audit samples described in section 5 and the applicable RMs.
e. Summary of all out-of-control periods including corrective actions taken when CEMS was determined out-of-control, as described in sections 4 and 5.
7.1.2 If the accuracy audit results show the CEMS to be out-of-control, you must report both the audit results showing the CEMS to be out-of-control and the results of the audit following corrective action showing the CEMS to be operating within specifications.
1. EPA Traceability Protocol for Assay and Certification of Gaseous Calibration Standards, U.S. Environmental Protection Agency office of Research and Development, EPA/600/R-12/531, May 2012.
2. Method 205, “Verification of Gas Dilution Systems for Field Instrument Calibrations,” 40 CFR part 51, appendix M.
Appendix G to Part 60 – Provisions for an Alternative Method of Demonstrating Compliance With 40 CFR 60.43 for the Newton Power Station of Central Illinois Public Service Company
1. Designation of Affected Facilities
1.1 The affected facilities to which this alternative compliance method applies are the Unit 1 and 2 coal-fired steam generating units located at the Central Illinois Public Service Company’s (CIPS) Newton Power Station in Jasper County, Illinois. Each of these units is subject to the Standards of Performance for Fossil-Fuel-Fired Steam Generators for Which Construction Commenced After August 17, 1971 (subpart D).
2. Definitions
2.1 All definitions in subparts D and Da of part 60 apply to this provision except that:
24-hour period means the period of time between 12:00 midnight and the following midnight.
Boiler operating day means a 24-hour period during which any fossil is combusted in either the Unit 1 or Unit 2 steam generating unit and during which the provisions of § 60.43(e) are applicable.
CEMs means continuous emission monitoring system.
Coal bunker means a single or group of coal trailers, hoppers, silos or other containers that:
(1) are physically attached to the affected facility; and
(2) provide coal to the coal pulverizers.
DAFGDS means the dual alkali flue gas desulfurization system for the Newton Unit 1 steam generating unit.
3. Compliance Provisions
3.1 If the owner or operator of the affected facility elects to comply with the 470 ng/J (1.1 lbs/MMBTU) of combined heat input emission limit under § 60.43(e), he shall notify the Regional Administrator, of the United States Environmental Protection Agency (USEPA), Region 5 and the Director, of the Illinois Environmental Protection Agency (IEPA) at least 30 days in advance of the date such election is to take effect, stating the date such operation is to commence. When the owner or operator elects to comply with this limit after one or more periods of reverting to the 520 ng/J heat input (1.2 lbs/MMBTU) limit of § 60.43(a)(2), as provided under 3.4, he shall notify the Regional Administrator of the USEPA, Region 5 and the Director of the (IEPA) in writing at least ten (10) days in advance of the date such election is to take effect.
3.2 Compliance with the sulfur dioxide emission limit under § 60.43(e) is determined on a continuous basis by performance testing using CEMs. Within 60 days after the initial operation of Units 1 and 2 subject to the combined emission limit in § 60.43(e), the owner or operator shall conduct an initial performance test, as required by § 60.8, to determine compliance with the combined emission limit. This initial performance test is to be scheduled so that the thirtieth boiler operating day of the 30 successive boiler operating days is completed within 60 days after initial operation subject to the 470 ng/J (1.1 lbs/MMBTU) combined emission limit. Following the initial performance test, a separate performance test is completed at the end of each boiler operating day Unit 1 and Unit 2 are subject to § 60.43(e), and a new 30 day average emission rate calculated.
3.2.1 Following the initial performance test, a new 30 day average emission rate is calculated for each boiler operating day the affected facility is subject to § 60.43(e). If the owner or operator of the affected facility elects to comply with § 60.43(e) after one or more periods of reverting to the 520 ng/J heat input (1.2 lbs/MMBTU) limit under § 60.43(a)(2), as provided under 3.4, the 30 day average emission rate under § 60.43(e) is calculated using emissions data of the current boiler operating day and data for the previous 29 boiler operating days when the affected facility was subject to § 60.43(e). Periods of operation of the affected facility under § 60.43(a)(2) are not considered boiler operating days. Emissions data collected during operation under § 60.43(a)(2) are not considered relative to 4.6 and emissions data are not included in calculations of emission under § 60.43(e).
3.2.2 When the affected facility is operated under the provisions of § 60.43(e), the Unit 1 DAFGDS bypass damper must be fully closed. The DAFGDS bypass may be opened only during periods of DAFGDS startup, shutdown, malfunction or testing as described under sections 3.5.1, 3.5.2, 3.5.3, 3.5.4, and 4.8.2.
3.3 Compliance with the sulfur dioxide emission limit set forth in § 60.43(e) is based on the average combined hourly emission rate from Units 1 and 2 for 30 successive boiler operating days determined as follows:
3.3.1 The average hourly combined emission rate for Units 1 and 2for each hour of operation of either Unit 1 or 2, or both, is determined as follows:
3.3.2 If data for any of the four hourly parameters (E1, E2, H1and H2, under 3.3.1 are unavailable during an hourly period, the combined emission rate (EC) is not calculated and the period is counted as missing data under 4.6.1., except as provided under 3.5. and 4.4.2.
3.4 After the date of initial operation subject to the combined emission limit, Units 1 and 2 shall remain subject to the combined emission limit and the owner or operator shall remain subject to the requirements of this Appendix until the initial performance test as required by 3.2 is completed and the owner or operator of the affected facility elects and provides notice to revert on a certain date to the 520 ng/J heat input (1.2 lbs/MMBTU) limit of § 60.43(a)(2) applicable separately at each unit. The Regional Administrator of the USEPA, Region 5 and the Director, of the IEPA shall be given written notification from CIPS as soon as possible of CIPs’ decision to revert to the 520 ng/J heat input (1.2 lbs/MMBTU) limit of § 60.43(a)(2) separately at each unit, but no later than 10 days in advance of the date such election is to take effect.
3.5 Emission monitoring data for Unit 1 may be excluded from calculations of the 30 day rolling average only during the following times:
3.5.1 Periods of DAFGDS startup.
3.5.2 Periods of DAFGDS shutdown.
3.5.3 Periods of DAFGDS malfunction during system emergencies as defined in § 60.41a.
3.5.4 The first 250 hours per calendar year of DAFGDS malfunctions of Unit 1 DAFGDS provided that efforts are made to minimize emissions from Unit 1 in accordance with § 60.11(d), and if, after 16 hours but not more than 24 hours of DAFGDS malfunction, the owner or operator of the affected facility begins (following the customary loading procedures) loading into the Unit 1 coal bunker, coal with a potential SO
3.5.4.1 The malfunction exemption in 3.5.4 is limited to the first 250 hours per calendar year of DAFGDS malfunction.
3.5.4.2 For malfunctions of the DAFGDS after the 250 hours per calendar year limit (cumulative), other than those defined in 3.5.3, the owner or operator of the affected facility shall combust lower sulfur coal or use any other method to comply with the 470 ng/J (1.1 lbs/MMBTU) combined emission limit.
3.5.4.3 During the first 250 hours of DAFGDS malfunction per year or during periods of DAFGDS startup, or DAFGDS shutdown, CEMs emissions data from Unit 2 shall continue to be included in the daily calculation of the combined 30 day rolling average emission rate; that is, the load on Unit 1 is assumed to be zero (H1 and E1 = O; EC = E2/H2).
3.5.5-3.5.7 [Reserved]
3.6 The provision for excluding CEMs data from Unit 1 during the first 250 hours of DAFGDS malfunctions from combined hourly emissions calculations supersedes the provisions of § 60.11(d). However, the general purpose contained in § 60.11(d) (i.e., following good control practices to minimize air pollution emission during malfunctions) has not been superseded.
4.1 The CEMs required under section 3.2 are operated and data are recorded for all periods of operation of the affected facility including periods of the DAFGDS startup, shutdown and malfunction except for CEMs breakdowns, repairs, calibration checks, and zero and span adjustment. All provisions of § 60.45 apply except as follows:
4.2 The owner or operator shall install, calibrate, maintain, and operate CEMs and monitoring devices for measuring the following:
4.2.1 For Unit 1:
4.2.1.1 Sulfur dioxide, oxygen or carbon dioxide, and volumetric flow rate for the Unit 1 DAFGDS stack.
4.2.1.2 Sulfur dioxide, oxygen or carbon dioxide, and volumetric flow rate for the Unit 1 DAFGDS bypass stack.
4.2.1.3 Moisture content of the flue gas must be determined continuously for the Unit 1 DAFGDS stack and the Unit 1 DAFGDS bypass stack, if the sulfur dioxide concentration in each stack is measured on a dry basis.
4.2.2 For Unit 2, sulfur dioxide, oxygen or carbon dioxide, and volumetric flow rate.
4.2.2.1 Moisture content of the flue gas must be determined continuously for the Unit 2 stack, if the sulfur dioxide concentration in the stack is measured on a dry basis.
4.2.3 For Units 1 and 2, the hourly heat input, the hourly steam production rate, or the hourly gross electrical power output from each unit.
4.3 For the Unit 1 bypass stack and the Unit 2 stack, the span value of the sulfur dioxide analyzer shall be equivalent to 200 percent of the maximum estimated hourly potential sulfur dioxide emissions of the fuel fired in parts per million sulfur dioxide. For the Unit 1 DAFGDS stack, the span value of the sulfur dioxide analyzer shall be equivalent to 100 percent of the maximum estimated hourly potential emissions of the fuel fired in parts per million sulfur dioxide. The span value for volumetric flow monitors shall be equivalent to 125 percent of the maximum estimated hourly flow in standard cubic meters/minute (standard cubic feet per minute). The span value of the continuous moisture monitors, if required by 4.2.1.3 and 4.2.2.1, shall be equivalent to 100 percent by volume. The span value of the oxygen or carbon dioxide analyzers shall be equivalent to 25 percent by volume.
4.3.1-4.3.2 [Reserved]
4.4 The monitoring devices required in 4.2 shall be installed, calibrated, and maintained as follows:
4.4.1 Each volumetric flow rate monitoring device specified in 4.2 shall be installed at approximately the same location as the sulfur dioxide emission monitoring sample location.
4.4.2 Hourly steam production rate and hourly electrical power output monitoring devices for Unit 1 and Unit 2 shall be calibrated and maintained according to manufacturer’s specifications. The data from either of these devices may be used in the calculation of the combined emission rate in section 3.3.1, only when the hourly heat input for Unit 1 (H1) or the hourly heat input for Unit 2 (H2) cannot be determined from CEM data, and the hourly heat input to steam production or hourly heat input to electrical power output efficiency over a given segment of each boiler or generator operating range, respectively, varies by less than 5 percent within the specified operating range, or the efficiencies of the boiler/generator units differ by less than 5 percent. The hourly heat input for Unit 1 (H1) or the hourly heat input for Unit 2 (H2) in section 3.3.1 may also be calculated based on the fuel firing rates and fuel analysis.
4.4.3-4.4.5 [Reserved]
4.5 The hourly mass emissions from Unit 1 (E1) and Unit 2 (E2) and the hourly heat inputs from Unit 1 (H1) and Unit 2 (H2) used to determine the hourly combined emission rate for Units 1 and 2 (EC) in section 3.3.1 are calculated using CEM data for each respective stack as follows:
4.5.1 The hourly SO
4.5.2 The hourly heat input from each respective stack is determined as follows:
4.5.3 The hourly SO
4.5.4 The hourly heat input for Unit 1 in MMBTU per hour (H1) is calculated as follows, when leakage or diversion of any DAFGDS inlet gas to the bypass stack occurs:
4.6 For the CEMs required for Unit 1 and Unit 2, the owner or operator of the affected facility shall maintain and operate the CEMs and obtain combined emission data values (EC) for at least 75 percent of the boiler operting hours per day for at least 26 out of each 30 successive boiler operating days.
4.6.1 When hourly SO
4.6.2 Independent of complying with the minimum data requirements of 4.6, all valid emissions data collected are used to calculate combined hourly emission rates (EC) and 30-day rolling average emission rates (E30) are calculated and used to judge compliance with 60.43(e).
4.7 For each continuous emission monitoring system, a quality control plan shall be prepared by CIPS and submitted to the Regional Administrator of the USEPA, Region 5 and the Director, of the IEPA. The plan is to be submitted to the Regional Administrator of the USEPA, Region 5 and the Director, of the IEPA 45 days before initiation of the initial performance test. At a minimum, the plan shall contain the following quality control elements:
4.7.1 Calibration of continuous emission monitoring systems (CEMs) and volumetric flow measurement devices.
4.7.2 Calibration drift determination and adjustment of CEMs and volumetric flow measurement devices.
4.7.3 Periodic CEMs, volumetric flow measurement devices and relative accuracy determinations.
4.7.4 Preventive maintenance of CEMs and volumetric flow measurement devices (including spare parts inventory).
4.7.5 Data recording and reporting.
4.7.6 Program of corrective action for malfunctioning CEMs and volumetric flow measurement devices.
4.7.7 Criteria for determining when the CEMs and volumetric flow measurement devices are not producing valid data.
4.7.8 Calibration and periodic checks of monitoring devices identified in 4.4.2.
4.8 For the purpose of conducting the continuous emission monitoring system performance specification tests as required by § 60.13 and appendix B, the following conditions apply:
4.8.1 The calibration drift specification of Performance Specification 2, appendix B shall be determined separately for each of the Unit 1 SO
4.8.2 The relative accuracy of the combined SO
4.8.3-4.8.3.4 [Reserved]
4.9 The total monitoring system required by 4.2 shall be subject only to an annual relative accuracy test audit (RATA) in accordance with the quality assurance requirements of section 5.1.1 of 40 CFR part 60, appendix F. Each SO
5.1 The plant owner or operator shall keep a record of each hourly emission rate, each hourly SO
5.2 The plant owner or operator shall keep a record of each hourly gas flow rate through the DAFGDS stack, each hourly stack gas flow rate through the bypass stack during any periods that the DAFGDS bypass damper is opened or flow is indicated, and reason for bypass operation.
6.1 The owner or operator of any affected facility shall submit the written reports required under 6.2 of this section and subpart A to the Regional Administrator of the USEPA, Region 5 and the Director, of the IEPA for every calendar quarter. All quarterly reports shall be submitted by the 30th day following the end of each calendar quarter.
6.2 For sulfur dioxide, the following data resubmitted to the Regional Administrator of the USEPA, Region 5 and the Director, of the IEPA for each 24-hour period:
6.2.1 Calendar date
6.2.2 The combined average sulfur dioxide emission rate (ng/J or lb/million Btu) for the past 30 successive boiler operating days (ending with the last 30-day period in the quarter); and, for any noncompliance periods, reasons for noncompliance with the emission standards and description of corrective action taken.
6.2.3 Identification of the boiler operating days for which valid sulfur dioxide emissions data required by 4.6 have not been obtained for 75 percent of the boiler operating hours; reasons for not obtaining sufficient data; and description of corrective actions taken to prevent recurrence.
6.2.4 Identification of the time periods (hours) when Unit 1 or Unit 2 were operated but combined hourly emission rates (EC) were not calculated because of the unavailability of parameters E1, E2, H1, or H2 as described in 3.2.
6.2.5 Identification of the time periods (hours) when Unit 1 and Unit 2 were operated and where the combined hourly emission rate (EC) equalled Unit 2 (E2/H2) emissions because of the Unit 1 malfunction provisions under 3.5.3, and 3.5.4.
6.2.6 Identification of the time periods (hours) when emissions from the Unit 1 DAFGDS have been excluded from the calculation of average sulfur dioxide emission rates because of Unit 1 DAFGDS startup, shutdown, malfunction, or other reasons; and justification for excluding data for reasons other than startup or shutdown. Reporting of hourly emission rate of Unit 1 (E1/H2) during each hour of the DAFGDS startup, malfunction under 3.5.1, 3.5.2, 3.5.3, and 3.5.4 (see 4.5).
6.2.7 Identification of the number of days in the calendar quarter that the affected facility was operated (any fuel fired).
6.2.8 Identify any periods where Unit 1 DAFGDS malfunctions occurred and the cumulative hours of Unit 1 DAFGDS malfunction for the quarter.
6.2.9 Identify any periods of time that any exhaust gases were discharged to the DAFGDS bypass stack and the hourly gas flow rate through the DAFGDS stack and through the DAFGDS bypass stack during such periods and reason for bypass operation.
6.2.10 [Reserved]
Appendix H to Part 60 [Reserved]
Appendix I to Part 60 – Owner’s Manuals and Temporary Labels for Wood Heaters Subject to Subparts AAA and QQQQ of Part 60
The purpose of this appendix is to provide specific instructions and examples to manufacturers for compliance with the owner’s manual provisions of subparts AAA and QQQQ of this part.
2.1 Introduction
Although the owner’s manuals do not require premarket approval, EPA will monitor the contents to ensure that sufficient information is included to provide heater proper operation and maintenance information affecting emissions to consumers. The manufacturer must make current and historical owner’s manuals available on the company Web site and upon request to the EPA. The purpose of this section is to provide instructions to manufacturers for compliance with the owner’s manual provisions of § 60.536(g) of subpart AAA that applies to wood heaters and § 60.5478(f) of subpart QQQQ that applies to hydronic heaters and forced-air furnaces. A checklist of topics and illustrative language is provided as instructions. Owner’s manuals should be tailored to specific wood heater models, as appropriate.
(a) Wood heater description and compliance status;
(b) Tamper warnings;
(c) Overall heater warranty information and catalyst information and warranty (if catalyst-equipped);
(d) Fuel selection;
(e) Achieving and maintaining catalyst light-off (if catalyst-equipped);
(f) Catalyst monitoring (if catalyst-equipped);
(g) Troubleshooting catalytic-equipped heaters (if catalyst-equipped);
(h) Catalyst replacement (if catalyst-equipped);
(i) Wood heater proper operation and maintenance, including minimizing visible emissions;
(j) Wood heater proper installation, including location, stack height and achieving proper draft;
(k) Use of smoke detectors and carbon monoxide monitors; and
(l) Efficiency.
(a) The following are example texts and/or further descriptions illustrating the topics identified above. Although the regulation requires manufacturers to address (where applicable) the 10 topics identified above, the exact language is not specified. Manuals should be written specific to the model and design of the wood heater. The following instructions are composed of generic descriptions and texts.
(b) If manufacturers choose to use the language provided in the example, the portion in italics should be revised as appropriate. Any manufacturer electing to use the EPA example language will be considered to be in compliance with owner’s manual requirements provided that the particular language is printed in full with only such changes as are necessary to ensure accuracy.
Example language is not provided for certain topics, since these areas are generally heater specific. For these topics, manufacturers should develop text that is specific to the proper operation and maintenance of their particular products.
Owner’s manuals must include:
(a) Manufacturer and model;
(b) Compliance status (2015 standard, 2016 standard, 2017 standard, 2020 standard, crib wood standard or cord wood alternative standard, last allowable sell date, etc.); and
(c) Heat output range.
Exhibit 1 – Example Text covering 2.3.1(a), (b), and (c) of this appendix:
“This manual describes the installation and operation of the Brand X, Model 0 catalytic equipped wood heater. This heater meets the 2015 U.S. Environmental Protection Agency’s crib wood emission limits for wood heaters sold after May 15, 2015. Under specific test conditions this heater has been shown to deliver heat at rates ranging from 8,000 to 35,000 Btu/hr.”
(a) The following statement must be included in the owner’s manual for all units:
“This wood heater has a manufacturer-set minimum low burn rate that must not be altered. It is against federal regulations to alter this setting or otherwise operate this wood heater in a manner inconsistent with operating instructions in this manual.”
(b) The following statement must be included in the owner’s manual for catalyst-equipped units:
“This wood heater contains a catalytic combustor, which needs periodic inspection and replacement for proper operation. It is against federal regulations to operate this wood heater in a manner inconsistent with operating instructions in this manual, or if the catalytic element is deactivated or removed.”
The following information must be included with or supplied in the owner’s and warranty manuals:
(a) Manufacturer and model, including catalyst if catalyst-equipped;
(b) Warranty details, including catalyst if catalyst-equipped; and
(c) Instructions for warranty claims.
Exhibit 2 – Example Text covering 2.3.3(a), (b), and (c) of this appendix for catalysts:
“The combustor supplied with this heater is a Brand Z, Long Life Combustor. Consult the catalytic combustor warranty also supplied with this wood heater. Warranty claims should be addressed to:
2.3.3.1 This section should also provide clear instructions on how to exercise the warranty (how to package parts for return shipment, etc.).
2.3.4 Fuel Selection
Owner’s manuals must include:
(a) Instructions on acceptable fuels;
(b) Warning against inappropriate fuels; and
(c) How to determine seasoned wood compared to unseasoned wood, how to use moisture meters and other techniques and the importance of seasoned wood.
Exhibit 3 – Example Text covering 2.3.4(a) and (b) of this appendix:
“This heater is designed to burn natural wood only. Higher efficiencies and lower emissions generally result when burning air dried seasoned hardwoods, as compared to softwoods or to green or freshly cut hardwoods. DO NOT BURN:
(1) Garbage;
(2) Lawn clippings or yard waste;
(3) Materials containing rubber, including tires;
(4) Materials containing plastic;
(5) Waste petroleum products, paints or paint thinners, or asphalt products;
(6) Materials containing asbestos;
(7) Construction or demolition debris;
(8) Railroad ties or pressure-treated wood;
(9) Manure or animal remains;
(10) Salt water driftwood or other previously salt water saturated materials;
(11) Unseasoned wood; or
(12) Paper products, cardboard, plywood, or particleboard. The prohibition against burning these materials does not prohibit the use of fire starters made from paper, cardboard, saw dust, wax and similar substances for the purpose of starting a fire in an affected wood heater.
Burning these materials may result in release of toxic fumes or render the heater ineffective and cause smoke.”
Owner’s manuals must describe in detail proper procedures for:
(a) Operation of catalyst bypass (stove specific);
(b) Achieving catalyst light-off from a cold start; and
(c) Achieving catalyst light-off when refueling.
2.3.5.1 No example text is supplied for describing operation of catalyst bypass mechanisms (Item 2.3.5(a) of this appendix) since these are typically stove-specific. Manufacturers must provide instructions specific to their model describing:
(1) Bypass position during startup;
(2) Bypass position during normal operation; and
(3) Bypass position during reloading.
Exhibit 4 – Example Text for Item 2.3.5(b) of this appendix:
“The temperature in the stove and the gases entering the combustor must be raised to between 500° to 700 °F for catalytic activity to be initiated. During the startup of a cold stove, a medium to high firing rate must be maintained for about 20 minutes. This ensures that the stove, catalyst, and fuel are all stabilized at proper operating temperatures. Even though it is possible to have gas temperatures reach 600 °F within 2 to 3 minutes after a fire is started, if the fire is allowed to die down immediately, it may go out or the combustor may stop working. Once the combustor starts working, heat generated in it by burning the smoke will keep it working.”
Exhibit 5 – Example Text for Item 2.3.5(c) of this appendix:
“REFUELING: During the refueling and rekindling of a cool fire, or a fire that has burned down to the charcoal phase, operate the stove at a medium to high firing rate for about 10 minutes to ensure that the catalyst reaches approximately 600 °F.”
Owner’s manuals must include:
(a) Recommendation to visually inspect combustor at least three times during the heating season;
(b) Discussion on expected combustor temperatures for monitor-equipped units; and
(c) Suggested monitoring and inspection techniques and importance of ensuring catalyst is operating properly.
Exhibit 6 – Example Text covering 2.3.6(a), (b) and (c) of this appendix:
“It is important to periodically monitor the operation of the catalytic combustor to ensure that it is functioning properly and to determine when it needs to be replaced. A non-functioning combustor will result in a loss of heating efficiency, and an increase in creosote and emissions. Following is a list of items that should be checked on a periodic basis:
• Combustors should be visually inspected at least three times during the heating season to determine if physical degradation has occurred. Actual removal of the combustor is not recommended unless more detailed inspection is warranted because of decreased performance. If any of these conditions exists, refer to Catalyst Troubleshooting section of this owner’s manual.
• This catalytic (or hybrid) heater is equipped with a temperature probe to monitor catalyst operation. Properly functioning combustors typically maintain temperatures in excess of 500 °F, and often reach temperatures in excess of 1,000 °F. If catalyst temperatures are not in excess of 500 °F, refer to Catalyst Troubleshooting section of this owner’s manual.
• You can get an indication of whether the catalyst is working by comparing the amount of smoke leaving the chimney when the smoke is going through the combustor and catalyst light-off has been achieved, to the amount of smoke leaving the chimney when the smoke is not routed through the combustor (bypass mode).
Step 1 – Light stove in accordance with instructions in section 3.3.5.
Step 2 – With smoke routed through the catalyst, go outside and observe the emissions leaving the chimney.
Step 3 – Engage the bypass mechanism and again observe the emissions leaving the chimney.
Significantly more smoke will be seen when the exhaust is not routed through the combustor (bypass mode).”
The owner’s manual must provide clear descriptions of symptoms and remedies to common combustor problems and importance. It is recommended that photographs of catalyst peeling, plugging, thermal cracking, mechanical cracking, and masking be included in the manual to aid the consumer in identifying problems and to provide direction for corrective action.
The owner’s manual must provide clear step-by-step instructions on how to remove and replace the catalytic combustor. The section should include diagrams and/or photographs.
The owner’s manual must provide clear descriptions of symptoms and remedies to common heater problems and importance. The owner’s manual information must be adequate to enable consumers to achieve optimal emissions performance. Such information must be consistent with the operating instructions provided by the manufacturer to the approved test laboratory for operating the wood heater during certification testing, except for details of the certification test that would not be relevant to the user.
Owner’s manual must include:
(a) Recommendations about building and maintaining a fire, especially for cold starts and the effectiveness of the top-down approach for starting fires;
(b) Instruction on proper use of air controls, including how to establish good combustion and how to ensure good combustion at the lowest burn rate for which the heater is warranted;
(c) Ash removal and disposal;
(d) Instruction replacement of gaskets, air tubes and other parts that are critical to the emissions performance of the unit, and other maintenance and repair instructions;
(e) Warning against overfiring; and
(f) Suggested monitoring and inspection techniques and importance of ensuring heater is operating properly, including ensuring visible emissions are minimized.
2.3.9.1 No example text is supplied for 2.3.9(a), (b), (d) and (f) of this appendix since these items are model specific. Manufacturers should provide detailed instructions on building and maintaining a fire including selection of fuel pieces, fuel quantity and stacking arrangement. Manufacturers should also provide instruction on proper air settings (both primary and secondary) for attaining minimum and maximum heat outputs and any special instructions for operating thermostatic controls. Step-by-step instructions on inspection and replacement of gaskets should also be included. Manufacturers should provide diagrams and/or photographs to assist the consumer. Gasket type and size should be specified.
Exhibit 7 – Example Text for Item 2.3.9(c) of this appendix:
“Whenever ashes get 3 to 4 inches deep in your firebox or ash pan, and when the fire has burned down and cooled, remove excess ashes. Leave an ash bed approximately 1 inch deep on the firebox bottom to help maintain a hot charcoal bed.”
“Ashes should be placed in a metal container with a tight-fitting lid. The closed container of ashes should be placed on a noncombustible floor or on the ground, away from all combustible materials, pending final disposal. The ashes should be retained in the closed container until all cinders have thoroughly cooled.”
Exhibit 8 – Example Text covering Item 2.3.9(e) of this appendix:
“Attempts to achieve heat output rates that exceed heater design specifications can result in permanent damage to the heater and to the catalytic combustor if so equipped.”
Owner’s manual must include:
(a) Importance of proper draft;
(b) Conditions indicating inadequate draft;
(c) Conditions indicating excessive draft; and
(d) Guidance on proper stack height and proper heater locations, i.e., not too close to neighbors or in valleys that would cause unhealthy air quality or nuisance conditions.
2.3.10.1 No example text is supplied for (d) because state, local and tribal requirements are model and location specific.
Exhibit 9 – Example Text for Item (a):
“Draft is the force which moves air from the appliance up through the chimney. The amount of draft in your chimney depends on the length of the chimney, local geography, nearby obstructions and other factors. Too much draft may cause excessive temperatures in the appliance and may damage the catalytic combustor. Inadequate draft may cause backpuffing into the room and ‘plugging’ of the chimney or the catalyst.”
Exhibit 10 – Example Text for Item (b):
“Inadequate draft will cause the appliance to leak smoke into the room through appliance and chimney connector joints.”
Exhibit 11 – Example Text for Item (c):
“An uncontrollable burn or excessive temperature indicates excessive draft.”
Owner’s manual must include:
(a) Description of how the efficiency was determined, e.g., use higher heating value of the fuel instead of lower heating value of the fuel, discuss sweet spot versus annual average versus annual fuel usage efficiency (AFUE);
(b) How operation and fuels affect efficiency, e.g., seasoned wood versus high moisture fuel; operation at sweet spot versus low-burn rates; and
(c) How location affects the efficiency, e.g., in main living area versus basement versus outdoors in sub-freezing temperatures.
Owner’s manual must include:
(a) Discussion of smoke and carbon monoxide (CO) emissions, including the CO data submitted in the certification application and expected variations for different operating conditions;
(b) Recommendation to have smoke monitors; and
(c) Recommendation to have monitors for areas that are expected to generate CO, e.g., heater fueling areas, pellet fuel bulk storage areas, sheds containing hydronic heaters.
3.1 Temporary labels that show the values for emissions, efficiency, recommended heating area and the compliance status may (voluntarily) be affixed by the manufacturer to wood heaters that meet the 2020 particulate matter emission standards early or that meet the cord wood alternative compliance options in subparts AAA and QQQQ of this part.
3.2 The seller of each heater covered by section 3.1 may ensure that the temporary label remains affixed until each heater is purchased by the end user.
3.3 The temporary label option for the 2020 particulate matter emission standards end as of May 15, 2020.
3.4 The template for the temporary labels will be supplied by the Administrator upon request.