Designation:D3663−20StandardTestMethodforSurfaceAreaofCatalystsandCatalystCarriers1ThisstandardisissuedunderthefixeddesignationD3663;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1ThistestmethodcoversthedeterminationofsurfaceareasofcatalystandcatalystcarriersthathaveTypeIIorIVnitrogenadsorptionisotherms,andatleast1m2/gofarea.AvolumetricmeasuringsystemisusedtoobtainatleastfourdatapointswhichfitonthelinearBET2equationline.1.2Units—ThevaluesstatedinSIunitsaretoberegardedasstandard.ThevaluesgiveninparenthesesafterSIunitsareprovidedforinformationonlyandarenotconsideredstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.1.4Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:3D3766TerminologyRelatingtoCatalystsandCatalysisE177PracticeforUseoftheTermsPrecisionandBiasinASTMTestMethodsE456TerminologyRelatingtoQualityandStatisticsE691PracticeforConductinganInterlaboratoryStudytoDeterminethePrecisionofaTestMethod3.Terminology3.1ConsultTerminologyD3766fordefinitionsofothertermsused.3.2Definitions:3.2.1surfaceareaofacatalyst,n—thetotalprobeacces-siblesurfaceofthecatalyst;itisexpressedinsquaremetrespergram.3.3Symbols:PH1=initialheliumpressure,torrPH2=heliumpressureafterequilibration,torrTH1=temperatureofmanifoldatinitialheliumpressure,°CTH2=temperatureofmanifoldafterequilibration,°CP1...
