Significance and Use
This test method provides a means to measure the total nitrogen oxides (NOx) content of gaseous emissions for purposes such as determining compliance with regulations, studying the effect of various abatement procedures on NOx emissions, and checking the validity of instrumental measurements.
1.1 This test method describes the phenol-disulfonic acid colorimetric procedure (1)2 for the determination of total oxides of nitrogen [nitrous oxide (N2O) excepted] in gaseous effluents from combustion and other nitrogen oxidation processes.
1.2 It is applicable to a concentration range of oxides of nitrogen as nitrogen dioxide (NO2) of 5 ppm to several thousand parts per million by volume (four to several thousand milligrams per dry standard cubic metre).
1.3 Since the grab sampling technique used takes a relatively small sample over a very short period of time, the result obtained will be an instantaneous measure of the nitrogen oxides and, therefore, will be representative of the emissions only if the gas stream is well mixed and the concentration constant with time. Multiple samples are recommended.
1.4 The values stated in SI units are to be regarded as standard. The SI equivalents are in parentheses and may be approximate.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. (For more specific safety precautionary information see 8.5 and Section 3.)
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
D1193 Specification for Reagent Water
D1356 Terminology Relating to Sampling and Analysis of Atmospheres
D1357 Practice for Planning the Sampling of the Ambient Atmosphere
D1605 Practices for Sampling Atmospheres for Analysis of Gases and Vapors
combustion sources; emissions; EPA Method 7; Method 7; oxides of nitrogen; phenol-disulfonic acid procedure; stack emissions; total oxides of nitrogen; Atmospheric analysis; Emission testing--stacks and flues; Gaseous environments; Nitrogen oxides; Phenol-disulfonic acid procedures; Spectrophotometry--absorption;
ICS Number Code 71.040.40 (Chemical analysis)
ASTM International is a member of CrossRef.
Citing ASTM Standards
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