Designation:D7843−12StandardTestMethodforMeasurementofLubricantGeneratedInsolubleColorBodiesinIn-ServiceTurbineOilsusingMembranePatchColorimetry1ThisstandardisissuedunderthefixeddesignationD7843;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodextractsinsolublecontaminantsfromasampleofin-serviceturbineoilontoapatchandthecolorofthemembranepatchisanalyzedbyaspectrophotometer.Theresultsarereportedasa∆Evalue,withintheCIELABscale.1.2Thistestmethodisnotappropriateforturbineoilswithdyes.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D4057PracticeforManualSamplingofPetroleumandPetroleumProductsD4177PracticeforAutomaticSamplingofPetroleumandPetroleumProductsD4378PracticeforIn-ServiceMonitoringofMineralTur-bineOilsforSteamandGasTurbinesE177PracticeforUseoftheTermsPrecisionandBiasinASTMTestMethodsE284TerminologyofAppearanceE308PracticeforComputingtheColorsofObjectsbyUsingtheCIESystemE691PracticeforConductinganInterlaboratoryStudytoDeterminethePrecisionofaTestMethod3.Terminology3.1Definitions:3.1.1CIELABcolorscales,n—CIE1976L*,a*,b*opponent-colorscales,inwhicha*ispositiveinthereddirectionandnegativeinthegreendirection;b*ispositiveintheyellowdirectionandnegativeinthebluedirection;andL*ispositiveinthelightnessdirectionandnegativeinthedarknessdirection.E3083.1.2colorimetry,n—thescienceofcolormeasurement.E2843.1.3in-serviceoil,n—lubricatingoilthatispresentinamachinethathasbeenatoperatingtemperatureforatleastonehour(forexample,anengine,gearbox,transformer,orturbine).3.1.4membranecolor,n—avisualratingofparticulateonaf...
