1、Designation:D432315Standard Test Method forHydrogen Sulfide in the Atmosphere by Rate of Change ofReflectance1This standard is issued under the fixed designation D4323;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last
2、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 automatic continuous deter-mination of hydrogen sulfide(H2S)in the atmosphere or ingaseous samples i
3、n the range from one part per billion byvolume(1 ppb/v)to 3000 ppb/v.Information obtained may beused for air-pollution studies and to monitor for emissionsources.1.2 The range may be extended by appropriate dilutiontechniques or by equipment modification.1.3 The values stated in SI units are to be r
4、egarded asstandard.The values given in parentheses are mathematicalconversions to inch-pound units that are provided for informa-tion 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
5、 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 forspecific safety precautionary statements.)2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD1356 Te
6、rminology Relating to Sampling and Analysis ofAtmospheresD2420 Test Method for Hydrogen Sulfide in LiquefiedPetroleum(LP)Gases(Lead Acetate Method)D2725 Test Method for Hydrogen Sulfide in Natural Gas(Methylene Blue Method)(Withdrawn 1996)3D3609 Practice for Calibration Techniques Using Perme-ation
7、TubesD4084 Test Method for Analysis of Hydrogen Sulfide inGaseous Fuels(Lead Acetate Reaction Rate Method)D4323 Test Method for Hydrogen Sulfide in theAtmosphereby Rate of Change of ReflectanceD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate Analyt
8、icalMeasurement System PerformanceD6792 Practice for Quality System in Petroleum Productsand Lubricants Testing Laboratories3.Terminology3.1 DefinitionsFor definitions of terms used in this testmethod,refer to Terminology D1356.4.Summary of Test Method4.1 Hydrogen sulfide is determined by use of the
9、 reaction ofH2S with lead acetate-impregnated paper tape and by compar-ing a reading of an unknown sample with that of a knownstandard using a differential colorimetric detection.Detectionof the rate of change of reflectance provides measurement inppb/v ranges with an analysis time appropriate for t
10、he appli-cation.(See Fig.1.)Sample gas is passed through a flowmeterand a humidifier;then across lead acetate-treated paper tape.Aconstant humidity is required for a constant reaction rate ofH2S with lead acetate.H2S reacts with lead acetate to form abrown stain on the paper.The resultant change in
11、reflectance isdetected by a photon detection system.The rate of change ofreflectance is proportional to H2S concentration.The analyzeris composed of an optical system,a photon detection system,asignal differentiation system of first order,and a signal outputsystem.5.Significance and Use5.1 Hydrogen
12、sulfide is an odorous substance which isoffensive even at low concentrations in the atmosphere andtoxic at higher levels.It may be a product of biologicalprocesses in the absence of oxygen,as may occur in municipalgarbage landfills.It is emitted from geothermal sources,occursin oil and gas,and may b
13、e emitted from industrial processes.Measurement is required for air pollution studies,for pollutioncontrol,and for plume characterization.This test method isintended for hydrogen sulfide content up to 3000 ppbv.1This test method is under the jurisdiction of ASTM Committee D22 on AirQuality and is th
14、e direct responsibility of Subcommittee D22.03 on AmbientAtmospheres and Source Emissions.Current edition approved April 1,2015.Published April 2015.Originallyapproved in 1984.Last previous edition approved in 2009 as D4323 84(2009).DOI:10.1520/D4323-15.2For referenced ASTM standards,visit the ASTM
15、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 last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International
16、,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 Measurement of hydrogen sulfide above this concentration ingaseous fuels,carbon dioxide or other gaseous matrices isdescribed in Test Method D4084.Equipment described issuitable for fixed site or for mobile monitoring.6.Interferences6.1 In applications of this method,high levels of somecompounds can result in instrument response.Methylmercaptan,when 1000 times the H2S concentration can affectresponse equal to H2S r
