Designation:D8488−22StandardTestMethodforDeterminationofHydrogenSulfide(H2S)inNaturalGasbyTunableDiodeLaserSpectroscopy(TDLAS)1ThisstandardisissuedunderthefixeddesignationD8488;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodisfortheonlinedeterminationofhydrogensulfide(H2S)innaturalgasusingtunablediodelaserabsorptionspectroscopy(TDLAS)analyzersalsoknownasa“TDLanalyzers.”TheparticularwavelengthforH2Smeasure-mentvariesbymanufacturer,typicallybetween1000and10000nmwithanindividuallaserhavingatunablerangeoflessthan10nm.TheH2Sconcentrationrangescanbeany-wherefrom0-5ppm(v)to0-90%byvolume.1.2Units—ThevaluesstatedinSIunitsaretoberegardedasthestandard.Nootherunitsofmeasurementareincludedinthisstandard.TDLASanalyzersinherentlyoutputconcentra-tionsinunitlessmolarratiossuchasppm(v).NOTE1—Weight-per-volumeunitssuchasmilligramsorgrainsofH2Spercubicfootorcubicmetercanbederivedfromppm(v)at“standardconditions”orstandardtemperatureandpressure.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.1.4Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:2D1945TestMethodforAnalysisofNaturalGasbyGasChromatographyD4150TerminologyRelatingtoGaseousFuelsD5503PracticeforNaturalGasSample-HandlingandCon-ditioningSystemsforPipelineInstrumentation(With-drawn2017)3D5504TestMethodforDeterminationofSul...
