Designation:D1698–03StandardTestMethodforSedimentsandSolubleSludgeinService-AgedInsulatingOils1ThisstandardisissuedunderthefixeddesignationD1698;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthedeterminationofsedimentandsolublesludgeinservice-agedinsulatingoilsofpetroleumorigin.Also,provisionismadefordeterminingorganicandinorganiccontentofthesediment.Themethodisintendedprimarilyforoilsofcomparativelylowviscosity;forexample5.7to13.0cSt(mm2/s)at40°C(104°F).Suitabilityforhighviscosityoilshavenotbeendetermined.1.2Thisstandardmayinvolvehazardousmaterials,opera-tions,andequipment.Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:D923PracticesforSamplingElectricalInsulatingLiquids2D2440TestMethodforOxidationStabilityofMineralInsulatingOil23.Terminology3.1DefinitionsofTermsSpecifictoThisStandard:3.1.1inorganicsediment—thatportionofthetotalsedimentwhichremainsafterignitionat500°C.3.1.2organicsediment—thatportionofthetotalsedimentwhichislostduringignitionat500°C.3.1.3sediment—anysolidsubstanceorsubstancesthatareinsolubleintheoilundertestatordinaryroomtemperatures,andthatcanbeseparatedbycentrifugingundercertainprescribedconditions.3.1.4solublesludge—oildeteriorationproductsorcontami-nants,orboth,whichbecomeinsolubleupondilutionwithn-pentaneunderprescribedconditions.4.SummaryofTestMethod4.1Asampleportioniscentrifugedtoseparatesedimentfromtheoil.Theupper,sediment-freeportionisdecantedandretainedfordeterminationofsolublesludge.Thesedimentisdislodgedandfilteredthroughafilteringcrucible.Afterdryingandweighingtoob...
