ASTM_D_3162_-_21.pdf

Designation:D316221Standard Test Method forCarbon Monoxide in the Atmosphere(ContinuousMeasurement by Nondispersive Infrared Spectrometry)1This standard is issued under the fixed designation D3162;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 This test method is applicable to the determination ofthe carbon monoxide(CO)concentration of the atmospherebetween 0.6 mg/m3(0.5 ppm(v)and 115 mg/m3(100 ppm(v).The measuring principle is based on the absorption of infraredradiation by CO in the 4.7 m region(1).21.2 The test method has a limit of detection of about 0.6mg/m3(0.5 ppm(v)carbon monoxide in air.1.3 The values stated in SI units are to be regarded asstandard.The values and units in parentheses are provided forinformation only and are not considered standard.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.See Section 9 for additional precautions.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:3D1356 Terminology Relating to Sampling and Analysis ofAtmospheresD1357 Practice for Planning the Sampling of the AmbientAtmosphereD1914 Practice for Conversion Units and Factors Relating toSampling and Analysis of AtmospheresD3249 Practice for General Ambient Air Analyzer Proce-duresD3631 Test Methods for Measuring Surface AtmosphericPressureE1 Specification for ASTM Liquid-in-Glass ThermometersE180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals(Withdrawn 2009)43.Terminology3.1 Definitions:3.1.1 For definitions of terms used in this test method,referto Terminology D1356 and Practice D3249.3.2 Definitions of Terms Specific to This Standard:3.2.1 fall time,nthe time interval between initial responseand 90%of final response after a step decrease in inputconcentrations.4.Summary of Test Method4.1 An atmospheric sample is introduced into a sampleconditioning system and then into a nondispersive infraredspectrometer(NDIR).The spectrometer measures the absorp-tion by CO at 4.7 m using either a single path monitor capableof distinguishing between sample and reference gases,or twoparallel infrared beams through a sample and a reference celland a selective detector.The detector signal is conducted to anamplifier control section,and the analyzer output measured ona meter and recording system(2).4.1.1 Some instruments use gas filter correlation to comparethe IR absorption spectrum between the measured gas andother gases present in the gas being sampled,in a single samplecell.These instruments use a concentrated sample of CO as afilter for the IR transmitted through the sample cell to producea beam that cannot be further attenuated by the CO in the1This test method is under the jurisdiction of ASTM Committee D22 on AirQuality and is the direct responsibility of Subcommittee D22.03 on AmbientAtmospheres and Source Emissions.Current edition approved Nov.1,2021.Published May 2022.Originallyapproved in 1973.Last previous edition approved in 2020 as D3162 12(2020).DOI:10.1520/D3162-21.2The boldface numbers in parentheses refer to the list of references at the end ofthe standard.3For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.4The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1sample,and thus produces the reference beam.The broadbandradiation that passes through the sample cell and the CO filteris filtered again by a narrow-band-pass filter that allows onlythe CO-sensitive portion of the band to pass to the detector.Theremoval of wavelengths sensitive to