ASTM_D_3824_-_20.pdf

Designation:D382420Standard Test Methods forContinuous Measurement of Oxides of Nitrogen in theAmbient or Workplace Atmosphere by Chemiluminescence1This standard is issued under the fixed designation D3824;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.1.Scope1.1 These test methods cover procedures for the continuousdetermination of total nitrogen dioxide(NO2)and nitric oxide(NO)as NOx,or nitric oxide(NO)alone or nitrogen dioxide(NO2)alone,in the ranges shown in the following table:Approximate Range of Concentration(25C and 101.3 kPa(1 atm)GasAmbient AtmosphereWorkplace Atmosphereg/m3(ppm)mg/m3(ppm)NO10 to 600(0.01 to 0.5)0.6 to 30(0.5 to 25)(NO+NO2)=NOx20 to 1000(0.01 to 0.05)1 to 50(0.5 to 25)NO220 to 1000(0.01 to 0.5)1 to 50(0.5 to 25)1.2 The test methods are based on the chemiluminescentreaction between nitric oxide and ozone.1.3 The values stated in SI units are to be regarded asstandard.The values given in parentheses after SI units areprovided for information 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.For specific precautionary statements,see Section 9.1.5 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:2D1356 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 AtmospheresD3195/D3195M Practice for Rotameter CalibrationD3249 Practice for General Ambient Air Analyzer Proce-duresD3609 Practice for Calibration Techniques Using Perme-ation TubesD3631 Test Methods for Measuring Surface AtmosphericPressure2.2 Other Documents:29 CFR Part 1910,Occupational Safety and Health Stan-dards340 CFR Parts 50 and 53,Environmental Protection AgencyRegulations on Ambient Air Monitoring Reference andEquivalent Methods33.Terminology3.1 Definitions:3.1.1 Four definitions of terms used in these test methods,refer to Terminology D1356 and Practice D3249.4.Summary of Test Methods4.1 The principle of the methodology is based upon thechemiluminescence,or the emission of light,resulting from thehomogeneous gas phase reaction of nitric oxide and ozone(1).4The equation is as follows:NO1O35 NO2*1O2(1)NO2*5 NO21hvIn the presence of excess ozone,the intensity of the lightemission is directly proportional to the nitric oxide concentra-tion.1These test methods are under the jurisdiction of ASTM Committee D22 on AirQuality and are the direct responsibility of Subcommittee D22.03 on AmbientAtmospheres and Source Emissions.Current edition approved Dec.1,2020.Published January 2021.Originallyapproved in 1979.Last previous edition approved in 2012 as D3824 12.DOI:10.1520/D3824-20.2For 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.3Available from U.S.Government Printing Office,Superintendent ofDocuments,732 N.Capitol St.,NW,Washington,DC 20401-0001,http:/www.access.gpo.gov.4The boldface numbers in parentheses refer to a list of references at the end ofthis standard.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.14.2 To measure nitric oxide concentrations,the gas samplebeing analyzed is blended with ozone in a flow reactor.Theresulting light emissions are monitored by a photomultipliertube.4.3 To measure total oxides of nitrogen(NOx=NO+NO2),the gas sample is diverted through a NO2to NO converterbefore being admitted to the flow reactor.4.4 To measure nitrogen dioxide(NO2),the gas sample isintermittently diverted through the converter,and the NOsignal subtracted from the NOxsignal.Some instrumentsutilize a dual stream principle with two reaction chambers.5.Significance and Use5.1 Most oxides of nitrogen are formed