53.22—Generation of test atmospheres.

(a) Table B-2 specifies preferred methods for generating test atmospheres and suggested methods of verifying the concentrations. Only one means of establishing the concentration of a test atmosphere is normally required. If the method of generation can produce reproducible concentrations, verification is optional. If the method of generation is not reproducible, then establishment of the concentration by some verification method is required. However, when a method of generation other than that given in table B-2 is used, the test concentration shall be verified.

(b) The test atmosphere delivery system shall be designed and constructed so as not to significantly alter the test atmosphere composition or concentration during the period of the test. The delivery system shall be fabricated from borosilicate glass or FEP Teflon.

(c) The output of the test atmosphere generation system shall be sufficiently stable to obtain stable response during the required tests. If a permeation device is used for generation of a test atmosphere, the device, as well as the air passing over it, shall be controlled to ±0.1 °C.

(d) All diluent air shall be zero air free of contaminants likely to cause a detectable response on the test analyzer.

Table B-2—Test Atmospheres

Test gas	Generation	Verification
Ammonia	Permeation device. Similar to system described in references 1 and 2	Indophenol method, reference 3.
Carbon dioxide	Cylinder of zero air or nitrogen containing CO2 as required to obtain the concentration specified in Table B-3	Use NIST-certified standards whenever possible. If NIST standards are not available, obtain 2 standards from independent sources which agree within 2 percent, or obtain one standard and submit it to an independent laboratory for analysis, which must agree within 2 percent of the supplier's nominal analysis.
Carbon monoxide	Cylinder of zero air or nitrogen containing CO as required to obtain the concentration specified in Table B-3	Use a FRM CO analyzer as described in reference 8.
Ethane	Cylinder of zero air or nitrogen containing ethane as required to obtain the concentration specified in Table B-3	Gas chromatography, ASTM D2820, reference 10. Use NIST-traceable gaseous methane or propane standards for calibration.
Ethylene	Cylinder of pre-purified nitrogen containing ethylene as required to obtain the concentration specified in Table B-3	Do.
Hydrogen chloride	Cylinder1 of pre-purified nitrogen containing approximately 100 ppm of gaseous HCL. Dilute with zero air to concentration specified in Table B-3	Collect samples in bubbler containing distilled water and analyze by the mercuric thiocyante method, ASTM (D612), p. 29, reference 4.
Hydrogen sulfide	Permeation device system described in references 1 and 2	Tentative method of analysis for H2S content of the atmosphere, p. 426, reference 5.
Methane	Cylinder of zero air containing methane as required to obtain the concentration specified in Table B-3	Gas chromatography ASTM D2820, reference 10. Use NIST-traceable methane standards for calibration.
Naphthalene	1. Permeation device as described in references 1 and 22. Cylinder of pre-purified nitrogen containing 100 ppm naphthalene. Dilute with zero air to concentration specified in Table B-3.	Use NIST-certified standards whenever possible. If NIST standards are not available, obtain 2 standards from independent sources which agree within 2 percent, or obtain one standard and submit it to an independent laboratory for analysis, which must agree within 2 percent of the supplier's nominal analysis.
Nitric oxide	Cylinder1 of pre-purified nitrogen containing approximately 100 ppm NO. Dilute with zero air to required concentration	Use NIST-certified standards whenever possible. If NIST standards are not available, obtain 2 standards from independent sources which agree within 2 percent, or obtain one standard and submit it to an independent laboratory for analysis, which must agree within 2 percent of the supplier's nominal analysis.
Code of Federal Regulations 25
Nitrogen dioxide	1. Gas phase titration as described in reference 62. Permeation device, similar to system described in reference 6.	1. Use an FRM NO2 analyzer calibrated with a gravimetrically calibrated permeation device.2. Use an FRM NO2 analyzer calibrated by gas-phase titration as described in reference 6.
Ozone	Calibrated ozone generator as described in reference 9	Use an FEM ozone analyzer calibrated as described in reference 9.
Sulfur dioxide	1. Permeation device as described in references 1 and 22. Dynamic dilution of a cylinder containing approximately 100 ppm SO2 as described in Reference 7.	Use an SO2 FRM or FEM analyzer as described in reference 7.
Water	Pass zero air through distilled water at a fixed known temperature between 20° and 30 °C such that the air stream becomes saturated. Dilute with zero air to concentration specified in Table B-3	Measure relative humidity by means of a dew-point indicator, calibrated electrolytic or piezo electric hygrometer, or wet/dry bulb thermometer.
Xylene	Cylinder of pre-purified nitrogen containing 100 ppm xylene. Dilute with zero air to concentration specified in Table B-3	Use NIST-certified standards whenever possible. If NIST standards are not available, obtain 2 standards from independent sources which agree within 2 percent, or obtain one standard and submit it to an independent laboratory for analysis, which must agree within 2 percent of the supplier's nominal analysis.
Zero air	1. Ambient air purified by appropriate scrubbers or other devices such that it is free of contaminants likely to cause a detectable response on the analyzer.
	2. Cylinder of compressed zero air certified by the supplier or an independent laboratory to be free of contaminants likely to cause a detectable response on the analyzer.
1 Use stainless steel pressure regulator dedicated to the pollutant measured.
Reference 1. O'Keefe, A. E., and Ortaman, G. C. “Primary Standards for Trace Gas Analysis,” Anal. Chem. 38, 760 (1966).
Reference 2. Scaringelli, F. P., A. E. Rosenberg, E., and Bell, J. P., “Primary Standards for Trace Gas Analysis.” Anal. Chem. 42, 871 (1970).
Reference 3. “Tentative Method of Analysis for Ammonia in the Atmosphere (Indophenol Method)”, Health Lab Sciences, vol. 10, No. 2, 115-118, April 1973.
Reference 4. 1973 Annual Book of ASTM Standards, American Society for Testing and Materials, 1916 Race St., Philadelphia, PA.
Reference 5. Methods for Air Sampling and Analysis, Intersociety Committee, 1972, American Public Health Association, 1015.
Reference 6. 40 CFR 50 Appendix F, “Measurement Principle and Calibration Principle for the Measurement of Nitrogen Dioxide in the Atmosphere (Gas Phase Chemiluminescence).”
Reference 7. 40 CFR 50 Appendix A-1, “Measurement Principle and Calibration Procedure for the Measurement of Sulfur Dioxide in the Atmosphere (Ultraviolet FIuorscence).”
Reference 8. 40 CFR 50 Appendix C, “Measurement Principle and Calibration Procedure for the Measurement of Carbon Monoxide in the Atmosphere” (Non-Dispersive Infrared Photometry)”.
Reference 9. 40 CFR 50 Appendix D, “Measurement Principle and Calibration Procedure for the Measurement of Ozone in the Atmosphere”.
Reference 10. “Standard Test Method for C, through C5 Hydrocarbons in the Atmosphere by Gas Chromatography”, D 2820, 1987 Annual Book of Aston Standards, vol 11.03, American Society for Testing and Materials, 1916 Race St., Philadelphia, PA 19103.

(e) The concentration of each test atmosphere shall be established and/or verified before or during each series of tests. Samples for verifying test concentrations shall be collected from the test atmosphere delivery system as close as possible to the sample intake port of the test analyzer.

(f) The accuracy of all flow measurements used to calculate test atmosphere concentrations shall be documented and referenced to a primary standard (such as a spirometer, bubble meter, etc.). Any corrections shall be clearly shown. All flow measurements given in volume units shall be standardized to 25 °C. and 760 mm Hg.

(g) Schematic drawings and other information showing complete procedural details of the test atmosphere generation, verification, and delivery system shall be provided. All pertinent calculations shall be clearly indicated.

Code of Federal Regulations

[40 FR 7049, Feb. 18, 1975, as amended at 40 FR 18168, Apr. 25, 1975; 75 FR 35599, June 22, 2010]

CFR

53.22—Generation of test atmospheres.

Code of Federal Regulations