ASTM_D_3608_-_19.pdf

Designation:D360819Standard Test Method forNitrogen Oxides(Combined)Content in the Atmosphere bythe Griess-Saltzman Reaction1This standard is issued under the fixed designation D3608;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 This test method covers the manual determination of thecombined nitrogen dioxide(NO2)and nitric oxide(NO)content,total NOx;in the atmosphere in the range from 4 to10 000 g/m3(0.002 to 5 ppm(v).1.2 The maximum sampling period is 60 min at a flow rateof 0.4 L/min.1.3 The values stated in SI units are to be regarded asstandard.The values given in parentheses are for informationonly.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.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:2D1071 Test Methods for Volumetric Measurement of Gas-eous Fuel SamplesD1193 Specification for Reagent WaterD1356 Terminology Relating to Sampling and Analysis ofAtmospheresD1357 Practice for Planning the Sampling of the AmbientAtmosphereD3195 Practice for Rotameter CalibrationD3609 Practice for Calibration Techniques Using Perme-ation TubesD3631 Test Methods for Measuring Surface AtmosphericPressureE1 Specification for ASTM Liquid-in-Glass ThermometersE128 Test Method for Maximum Pore Diameter and Perme-ability of Rigid Porous Filters for Laboratory Use3.Terminology3.1 DefinitionsFor definitions of terms used in this testmethod,refer to Terminology D1356.4.Summary of Test Method4.1 The NO is quantitatively(1)3converted to NO2by achromic acid oxidizer.The resulting NO2,plus the NO2alreadypresent,are absorbed in an azo-dye-forming reagent(2).Ared-violet color is produced within 15 min,the intensity ofwhich is measured spectrophotometrically at 550 nm.5.Significance and Use5.1 Both NO2and NO play an important role inphotochemical-smog-forming reactions.In sufficient concen-trations NO2is deleterious to health,agriculture,materials,andvisibility.5.2 In combustion processes,significant amounts of NOmay be produced by combination of atmospheric nitrogen andoxygen;at ambient temperatures,NO can be converted to NO2by oxygen and other atmospheric oxidants.Nitrogen dioxidealso may be generated from processes involving nitric acid,nitrates,the use of explosives,and welding.6.Interferences6.1 Any significant interferences due to sulfur dioxide(SO2)should be negated by the oxidation step.The addition ofacetone to the reagent retards color-fading by forming atemporary addition product with SO2.This will protect thereagent from incidental exposure to SO2and will permitreading the color intensity within 4 to 5 h(instead of the 45 minrequired without acetone)without appreciable losses.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 March 1,2019.Published April 2019.Originallyapproved in 1977.Last previous edition approved in 2011 as D3608 95(2011).DOI:10.1520/D3608-19.2For 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.3The 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.1 6.2 A five-fold ratio of ozone to NO2will cause a smallinterference,the maximal effect occurring in 3 h.The reagentassumes a slightly orange tint.6.3 The interferences from nitrous oxide and nitrogenpentoxide,and other gases that might be found in polluted airare considered to be negligible.7.Apparatus7.1 Sampling ProbeA glass or TFE-fluorocarbon(pre-ferred)tube,6 to 10 mm in diameter,provided with adownward-facing intake(funnel or tip).The dead volume ofthe system should