Designation:D6890−21StandardTestMethodforDeterminationofIgnitionDelayandDerivedCetaneNumber(DCN)ofDieselFuelOilsbyCombustioninaConstantVolumeChamber1,2ThisstandardisissuedunderthefixeddesignationD6890;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thisautomatedlaboratorytestmethodcoversthequan-titativedeterminationoftheignitioncharacteristicsofconven-tionaldieselfueloil,oil-sandsbasedfuels,hydrocarbonoils,blendsoffuelcontainingbiodieselmaterial,dieselfueloilscontainingcetanenumberimproveradditives,andisapplicabletoproductstypicalofASTMSpecificationD975gradesNo.1-DS15,No.1-DS500,andNo.1-DS5000,andgradesNo.2-DS15,No.2-DS500,andNo.2-DS5000dieselfueloils,EuropeanstandardEN590,andCanadianstandardsCAN/CGSB-3.517and3.520.Thetestmethodmayalsobeappliedtothequantitativedeterminationoftheignitioncharacteristicsofdieselfuelblendingcomponents.1.2Thistestmethodmeasurestheignitiondelayofadieselfuelinjecteddirectlyintoaconstantvolumecombustionchambercontainingheated,compressedair.Anequationcor-relatesanignitiondelaydeterminationtocetanenumberbyTestMethodD613,resultinginaderivedcetanenumber(DCN).1.3Thistestmethodcoverstheignitiondelayrangefrom2.64msto6.90ms(75.1DCNto31.5DCN).Thecombustionanalyzercanmeasureshorterandlongerignitiondelays,butprecisionmaybeaffected.FortheseshorterorlongerignitiondelaysthecorrelationequationforDCNisgiveninAppendixX2.1.4Forpurposesofdeterminingconformancewiththeparametersofthistestmethod,anobservedvalueoracalculatedvalueshallberounded“tothenearestunit”inthelastright-handdigitusedinexpressingtheparameter,inaccordancewiththeroundingmethodofPracticeE29.1.5ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.6Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithi...
