Current as of: July 2009
(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 [deg]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
Indophenol method, reference 3.
system described in references 1
and 2.Carbon dioxide........................
Cylinder of zero air or nitrogen
Use NBS-certified standards whenever
containing CO2 as required to
possible. If NBS standards are not
obtain the concentration
available, obtain 2 standards from
specified in table B-3.
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
Do.
containing CO as required to
obtain the concentration
specified in table B-3.Ethane................................
Cylinder of zero air or nitrogen
Do.
containing ethane as required to
obtain the concentration
specified in table B-3.Ethylene..............................
Cylinder of prepurified nitrogen
Do.
containing ethylene as required
to obtain the concentration
specified in table B-3.Hydrogen chloride.....................
Cylinder 1 of prepurified
Collect samples in bubbler containing
nitrogen containing
distilled water and analyze by the
approximately 100 p/m of gaseous
mercuric thiocyanate method, ASTM
HCl. Dilute with zero air to
(D512), p. 29, reference 4.
concentration specified in table
B-3.Hydrogen sulfide......................
Permeation device system
Tentative method of analysis for H2 S
described in references 1 and 2.
content of the atmosphere, p. 426,
reference 5.Methane...............................
Cylinder of zero air containing
Use NBS-certified standards whenever
methane as required to obtain
possible. If NBS standards are not
the concentration specified in
available, obtain 2 standards from
table B-3.
independent sources which agree
within 2 percent; or obtain one
standard and submit it to an
independent laboratory for an
analysis which must agree within 2
percent of the supplier's nominal
analysis.Nitric oxide..........................
Cylinder 1 of prepurified
Gas-phase titration as described in
nitrogen containing
reference 6, section 7.1.
approximately 100 p/m NO. Dilute
with zero air to required
concentration.Nitrogen dioxide......................
1. Gas phase titration as
1. Use an NO 2 analyzer calibrated
described in reference 6.
with a gravimetrically calibrated
2. Permeation device, similar to
permeation device.
system described in references 1
2. Use an NO 2 analyzer calibrated by
and 2.
gas-phase titration as described in
reference 6.Ozone.................................
Calibrated ozone generator as
Use an ozone analyzer calibrated by
described in reference 7,
gas-phase titration as described in
appendix D.
reference 6.Sulfur dioxide........................
Permeation device Similar to
P-rosaniline method. Reference 7,
system described in reference
appendix A.
method for SO2, reference 7,
appendix A.Water.................................
Pass zero air through distilled
Measure relative humidity by means of
water at a fixed known
a dew-point indicator, calibrated
temperature between 20[deg] and
electrolytic or piezo electric
30 [deg]C. such that the air
hygrometer, or wet/dry bulb
stream becomes saturated. Dilute
thermometer.
with zero air to concentration
specified in table B-3.Xylene................................
Cylinder of prepurified nitrogen
Use NBS-certified standards whenever
containing 100 p/m xylene.
possible. If NBS standards are not
Dilute with zero air to
available, obtain 2 standards from
concentration specified in table
independent sources which agree
B-3.
within 2 percent; or obtain one
standard and submit it to an
independent laboratory for an
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'Keeffe, 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. Federal Register, vol. 38, No. 110, Tentative Method for the Continuous Measurement of Nitrogen
Dioxide (Chemiluminescent) addenda C. (June 8, 1973).Reference 7. Federal Register, vol. 36, No. 228, National Primary and Secondary Ambient Air Quality Standards,
Nov. 25, 1971.
(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 [deg]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.
[40 FR 7049, Feb. 18, 1975, as amended at 40 FR 18168, Apr. 25, 1975]________________________________________________________________________
U.S. Code Provisions: Air PollutionState Laws: Air Pollution
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