Designation:D1993−22StandardTestMethodforPrecipitatedSilica-SurfaceAreabyMultipointBETNitrogenAdsorption1ThisstandardisissuedunderthefixeddesignationD1993;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1ThistestmethodcoversaprocedurewhichisusedtomeasurethesurfaceareaofprecipitatedhydratedsilicasbytheconventionalBrunauer,Emmett,andTeller(BET)2theoryofmultilayergasadsorptionbehaviorusingmultipointdeterminations,similartothatusedforcarbonblackinTestMethodD6556.Thistestmethodspecifiesthesampleprepa-rationandtreatment,instrumentcalibrations,requiredaccuracyandprecisionofexperimentaldata,andcalculationsofthesurfacearearesultsfromtheobtaineddata.1.2Thistestmethodisusedtodeterminethenitrogensurfaceareaofprecipitatedsilicaswithspecificsurfaceareasintherangeof10to500m2/g.1.3ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.Theminimumsafetyequipmentshouldincludeprotectivegloves,sturdyeyeandfaceprotection,andmeanstodealsafelywithaccidentalmercuryspills.1.5Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:3D1799PracticeforCarbonBlack—SamplingPackagedShipmentsD1900PracticeforCarbonBlack—SamplingBulkShip-mentsD4483PracticeforEvaluatingPrecisionforTestMethodStandardsintheRubberandCarbonBlackMan...
