Designation:D189−06(Reapproved2019)BritishStandard4380StandardTestMethodforConradsonCarbonResidueofPetroleumProducts1ThisstandardisissuedunderthefixeddesignationD189;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheU.S.DepartmentofDefense.1.Scope1.1Thistestmethodcoversthedeterminationoftheamountofcarbonresidue(Note1)leftafterevaporationandpyrolysisofanoil,andisintendedtoprovidesomeindicationofrelativecoke-formingpropensities.Thistestmethodisgenerallyap-plicabletorelativelynonvolatilepetroleumproductswhichpartiallydecomposeondistillationatatmosphericpressure.Petroleumproductscontainingash-formingconstituentsasdeterminedbyTestMethodD482orIPMethod4willhaveanerroneouslyhighcarbonresidue,dependingupontheamountofashformed(Note2andNote4).NOTE1—Thetermcarbonresidueisusedthroughoutthistestmethodtodesignatethecarbonaceousresidueformedafterevaporationandpyrolysisofapetroleumproductundertheconditionsspecifiedinthistestmethod.Theresidueisnotcomposedentirelyofcarbon,butisacokewhichcanbefurtherchangedbypyrolysis.Thetermcarbonresidueiscontinuedinthistestmethodonlyindeferencetoitswidecommonusage.NOTE2—ValuesobtainedbythistestmethodarenotnumericallythesameasthoseobtainedbyTestMethodD524.Approximatecorrelationshavebeenderived(seeFig.X1.1),butneednotapplytoallmaterialswhichcanbetestedbecausethecarbonresiduetestisappliedtoawidevarietyofpetroleumproducts.NOTE3—ThetestresultsareequivalenttoTestMethodD4530,(seeFig.X1.2).NOTE4—Indieselfuel,thepresenceofalkylnitratessuchasamylnitrate,hexylnitrate,oroctylnitratecausesahigherresiduevaluethanobservedinuntreatedfuel,whichcanleadtoerroneousconclusionsastothecokeformingpropensityofthefuel.ThepresenceofalkylnitrateinthefuelcanbedetectedbyTestMethodD4046.1.2ThevaluesstatedinSIunitsaretobere...
