Designation:D2285–99StandardTestMethodforInterfacialTensionofElectricalInsulatingOilsofPetroleumOriginAgainstWaterbytheDrop-WeightMethod1ThisstandardisissuedunderthefixeddesignationD2285;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversacomparativelyrapidproce-dureparticularlyapplicableforfielduseformeasuring,undernonequilibriumconditions,theinterfacialtensionsofelectricalinsulatingoilsofpetroleumoriginagainstwater.Thistestmethodhasbeenshownbyexperiencetogiveareliableindicationofthepresenceofhydrophiliccompounds.Thistestmethodmaynotbeapplicableforhighlyviscousinsulatingfluids.1.2Thisstandarddoesnotpurporttoaddressthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:D971TestMethodforInterfacialTensionofOilAgainstWaterbytheRingMethod2D1298PracticeforDensity(SpecificGravity)orAPIGravityofCrudePetroleumandLiquidPetroleumProd-uctsbyHydrometerMethod33.SummaryofTestMethod3.1Interfacialtensionisdeterminedbymeasuringthevolumeofadropofwaterformedinoil.Alargerwaterdropmeansahigherinterfacialtension.Theinstrumentiscalibratedtoreadapproximatelyinmillinewtonspermetre(dynespercentimetre).Themeasurementiscompletedwithin1minaftertheformationofthewaterdropinoil.4.SignificanceandUse4.1Thistestmethodindicatesthepresenceofhydrophiliccompounds.Thesecompoundscanbeanindicatorofcontami-nantsinnewoilandinusedoil,oxidationordeteriorationoftheoilormaterialsofconstructionincontactwiththeoil.5.Apparatus5.1Tensiometer4thatprovidesasimplewayofinjectingameasuredquantityofwaterintooil.Thescaleattachedtothepistonforcingthewaterintotheoilisgraduatedinmillinew-tonspermetre(dynespercentim...
