Designation:D5305−12StandardTestMethodforDeterminationofEthylMercaptaninLP-GasVapor1ThisstandardisissuedunderthefixeddesignationD5305;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1ThistestmethodcoversarapidandsimpleprocedureusinglengthofstaintubesforfieldmeasurementofethylmercaptaninthevaporphaseofLP-gassystems.Althoughlength-of-staintubesareavailabletodetectethylmercaptanconcentrationsintherangeof0.5to120partspermillionvolume(ppmv),thistestmethodisspecificallyapplicabletosystemscontaining5ppmvormoreofethylmercaptaninLP-gasvapors.NOTE1—Achromatographictechniquecanbeusedformoreprecise,quantitativedeterminationofethylmercaptaninLP-gas.1.2ThevaluesstatedinSI(metric)unitsaretoberegardedasthestandard.Thevaluesinparenthesesareforinformationonly.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1NFPAStandard:2NFPA58StandardfortheStorageandHandlingofLiquefiedPetroleumGases3.SummaryofTestMethod3.1Usingamanually-operatedvacuumpump,asampleofLP-gasfromthevaporspaceofanLP-gascylinder,storagetankorotherclosedcontainmentsystemisdrawnthroughadetectortubemadespecificallyfordetectionofmercaptans.Thelengthofstain(colorchange)producedinthedetectortubewhenexposedtoameasuredvolumeofsampleisdirectlyproportionaltotheamountofethylmercaptanpresentinthesamplebeingtested.Thelengthofstainproducedinthedetectortubeisconvertedtoconcentration,inpartspermillionvolume(ppmv),bycomparisonwithacalibrationscalepro-videdbythemanufacturerofthestaintube.4.SignificanceandUse4.1LP-gasiscolorlessandodorless,andnotdetectablebynormalhumansenses.Toprovideanolfactorywarningintheev...
