Designation:D2603−20StandardTestMethodforSonicShearStabilityofPolymer-ContainingOils1ThisstandardisissuedunderthefixeddesignationD2603;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheU.S.DepartmentofDefense.1.Scope*1.1Thistestmethodcoverstheevaluationoftheshearstabilityofanoilcontainingpolymerintermsofthepermanentlossinviscositythatresultsfromirradiatingasampleoftheoilinasonicoscillator.Thistestmethodcanbeusefulinpredictingthecontinuityofthispropertyinanoilwherenochangeismadeinthebasestockorthepolymer.Itisnotintendedthatthistestmethodservetopredicttheperformanceofpolymer-containingoilsinservice.1.2Evidencehasbeenpresentedthatcorrelationbetweenthesheardegradationresultsobtainedbymeansofsonicoscillationandthoseobtainedinmechanicaldevicescanbepoor.Thisisespeciallytrueinthecaseofautomotiveengines.Furtherevidenceindicatesthatthesonictechniquemayratedifferentfamiliesofpolymersinadifferentorderthanme-chanicaldevices.2,31.3Becauseoftheselimitations,thecommitteeunderwhosejurisdictionthistestmethodfallshasdevelopedalter-nativesheartestmethodsusingadieselinjectornozzle,TestMethodsD5275,D6278,andD7109.Whilethosetestmethodshavefoundsomeutilityintheevaluationofcrankcaseoils,thestressimpartedtothesamplehasbeenfoundtobeinsufficienttoshearpolymersoftheshear-resistanttypefoundinaircrafthydraulicfluids.1.4Thistestmethodisusedforpolymericadditivespecifications,especiallyinthehydraulicfluidmarket.1.5ThevaluesstatedinSIunitsaretoberegardedasstandard.ThevaluesgiveninparenthesesafterSIunitsareprovidedforinformationonlyandarenotconsideredstandard.1.6Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracti...
