Designation:D6481−14StandardTestMethodforDeterminationofPhosphorus,Sulfur,Calcium,andZincinLubricationOilsbyEnergyDispersiveX-rayFluorescenceSpectroscopy1ThisstandardisissuedunderthefixeddesignationD6481;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thistestmethodcoversthequantitativedeterminationofadditiveelementsinunusedlubricatingoils,asshowninTable1.1.2ThistestmethodislimitedtotheuseofenergydispersiveX-rayfluorescence(EDXRF)spectrometersem-ployinganX-raytubeforexcitationinconjunctionwiththeabilitytoseparatethesignalsofadjacentelements.1.3Thistestmethodusesinterelementcorrectionfactorscalculatedfromempiricalcalibrationdata.1.4Thistestmethodisnotsuitableforthedeterminationofmagnesiumandcopperattheconcentrationspresentinlubri-catingoils.1.5Thistestmethodexcludeslubricatingoilsthatcontainchlorineorbariumasanadditiveelement.1.6ThistestmethodcanbeusedbypersonswhoarenotskilledinX-rayspectrometry.Itisintendedtobeusedasaroutinetestmethodforproductioncontrolanalysis.1.7Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationstouse.2.SummaryofTestMethod2.1AspecimenisplacedintheX-raybeam,andtheappropriateregionsofitsspectrumaremeasuredtogivethefluorescentintensitiesofphosphorus,sulfur,calcium,andzinc.Otherregionsofthespectrumaremeasuredtocompensateforvaryingbackground.Ifthedetectordoesnotcompletelyresolvealltheelementsinasinglemeasurement,thentoimproveselectivity,thereisacombinationofsequentialandsimultaneousmeasurementsemployingprimaryandsecondarybeamfilters.Therecanbecorrectionofmeasuredintensitiesforspectraloverlap.Concentrationsoftheelementsofinterestaredeterminedbycomparisonofthe...
