Designation:D374/D374M−16AnAmericanNationalStandardStandardTestMethodsforThicknessofSolidElectricalInsulation1ThisstandardisissuedunderthefixeddesignationD374/D374M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheU.S.DepartmentofDefense.1.Scope1.1Thesetestmethodscoverthedeterminationofthethicknessofseveraltypesofsolidelectricalinsulatingmateri-alsemployingrecommendedtechniques.Usethesetestmeth-odsexceptasotherwiserequiredbyamaterialspecification.1.2ThevaluesstatedineitherSIunitsorinch-poundunitsaretoberegardedseparatelyasstandard.Thevaluesstatedineachsystemmaynotbeexactequivalents;therefore,eachsystemshallbeusedindependentlyoftheother.Combiningvaluesfromthetwosystemsmayresultinnon-conformancewiththestandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D1711TerminologyRelatingtoElectricalInsulationD6054PracticeforConditioningElectricalInsulatingMate-rialsforTesting(Withdrawn2012)3E252TestMethodforThicknessofFoil,ThinSheet,andFilmbyMassMeasurement3.Terminology3.1RefertoTerminologyD1711fordefinitionspertinenttothisstandard.3.2DefinitionsofTermsSpecifictoThisStandard:3.2.11micron,µm,n—adimensionequivalentto0.03937mils.3.2.21mil,n—adimensionequivalentto0.0010in.3.2.3absoluteuncertainty(ofameasurement),n—thesmallestdivisionabletobereaddirectlyontheinstrumentusedformeasurement.3.2.4micrometer,n—aninstrumentformeasuringanydi-mensionwithabsoluteuncertaintyof1mil[25µm]orsmaller.4.SummaryofTestMethods4.1Thisstandardprovideseightdifferenttestmethodsforthemeasurementofthicknessofsolide...
