Designation:D3941−20StandardTestMethodforFlashPointbytheEquilibriumMethodWithaClosed-CupApparatus1ThisstandardisissuedunderthefixeddesignationD3941;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheU.S.DepartmentofDefense.INTRODUCTIONTestMethodsD56andD93describeproceduresusingtheTagClosedTesterandthePensky-MartensTester,respectively.Bothtestmethodsdependonadefiniterateoftemperatureincreasetocontroltheprecisionofthetestmethod.Therateofheatingmaynotinallcasesgivetheaccuracyexpectedbecauseoflowthermalconductivityofcertainmaterials.Toreducethiseffect,ISO/TC35,PaintsandVarnishes,andISO/TC28,PetroleumProductsandLubricants,haveissuedISO1523inwhichtheheatingrateisconsiderablyslower.ThistestmethodissimilartoISO1523,butusesstandardASTMcups,style,andformat.Duetotheslowerheatingrate,thetimerequiredtomakeadeterminationofaflashpointisconsiderablylongerthanforTestMethodsD56andD93buttheaccuracyisimproved.1.Scope1.1Thistestmethodcoversthedeterminationoftheflashpointofliquidsinwhichthespecimenandtheair/vapormixtureaboveitareapproximatelyintemperatureequilibrium.1.2Thistestmethodislimitedtoatemperaturerangefrom0to110°C(32to230°F).1.3ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesareforinformationonly.1.4Warning—Mercuryhasbeendesignatedbymanyregu-latoryagenciesasahazardoussubstancethatcancauseseriousmedicalissues.Mercury,oritsvapor,hasbeendemonstratedtobehazardoustohealthandcorrosivetomaterials.Usecautionwhenhandlingmercuryandmercury-containingproducts.SeetheapplicableproductSafetyDataSheet(SDS)foradditionalinformation.Thepotentialexiststhatsellingmercuryormercury-containingproducts,orboth,isprohibitedbylocalornationallaw.Usersmustdeterminelegalityofsalesintheirlocation.1.5Thisstandardisusedtomea...
