ASTM_D_3162_-_12.pdf

Designation:D316212Standard 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 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 and health practices and determine the applica-bility of regulatory limitations prior to use.See Section 9 foradditional precautions.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Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals(Withdrawn 2009)43.Terminology3.1 Definitions:3.1.1 For definitions of terms used in this test method,referto Terminology D1356 and Practice D3249.3.2 Definitions of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 timethe 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 two parallel infrared beams througha sample and a reference cell and a selective detector.Thedetector signal is conducted to an amplifier control section,andthe analyzer output measured on a 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 utilize a concentrated sample of CO asa filter for the IR transmitted through the sample cell toproduce a beam that cannot be further attenuated by the CO inthe sample,and thus produces the reference beam.Thebroadband radiation that passes through the sample cell and theCO filter is filtered again by a narrow-band-pass filter thatallows only the CO-sensitive portion of the band to pass to thedetector.The removal of wavelengths sensitive to other gasesreduces interferences.4.2 The concentration of CO in the sample is determinedfrom a calibration curve prepared using standard calibrationgases.1This 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 April 1,2012.Published May 2012.Originallyapproved in 1973.Last previous edition approved in 2005 as D3162 94(2005).DOI:10.1520/D3162-94R05.2The 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 States1 5.Significance and Use5.1 Determination of carbon monoxide is essential to evalu-ation of many air pollution complexes.This test methodderives significance from providing such determination.5.2 Carbon monoxide is formed in the process of incom-plete combustion of hydrocarbon fuels,and is a constituent ofthe exhaust of gasoline engines.The Environmental ProtectionAgency(EPA)has set primary and secondary air qualitystandards for CO that are designed to protect the public healthand welfare(3,4).5.3 This test method is suitable for measurements appropri-ate for the purposes noted in 5.1 and 5.2.6.Interferences6.1 Degree of interference varies among individual instru-ments.Consult manufacturers specifications for the particularanalyzer t