Designation:D7191−18StandardTestMethodforDeterminationofMoistureinPlasticsbyRelativeHumiditySensor1ThisstandardisissuedunderthefixeddesignationD7191;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthequantitativedeterminationofwaterdownto20ppminplasticsusingarelativehumiditysensor.1.2ValuesstatedinSIunitsaretoberegardedasstandard.1.3Specimenstestedinthistestmethodcanreachorexceed250°C,usecautionwhenhandlingthemaftertestinghascompleted.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.NOTE1—ThereisnoknownISOequivalenttothisstandard.1.5Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:2D1193SpecificationforReagentWaterD883TerminologyRelatingtoPlasticsD1600TerminologyforAbbreviatedTermsRelatingtoPlas-ticsD6869TestMethodforCoulometricandVolumetricDeter-minationofMoistureinPlasticsUsingtheKarlFischerReaction(theReactionofIodinewithWater)E177PracticeforUseoftheTermsPrecisionandBiasinASTMTestMethodsE691PracticeforConductinganInterlaboratoryStudytoDeterminethePrecisionofaTestMethod3.Terminology3.1Definitions—ThedefinitionsusedinthistestmethodareinaccordancewithTerminologyD883.4.SummaryofTestMethod4.1Asampleisloadedintoaseptum-cappedglassvialthatismovedintoaheatertoevolvethevolatilesfromthesampleintotheheadspace.Acoaxialneedle,ortwoneedleset,piercestheseptumofthevia...
