ASTID24289207595100515071972AnAmericanNationalStandardAMERICANSOCIETYMRTESTINGANDMATERIALS1916RaceStPhiladelphla,Pa19103ReprintedfromtheAnnualBookofACTMStandards.CopyrightAsTh4IfMtlistedinthecurrentcomblnedtndex,willappearinthenexteditlon.(@$Designation:D2428-92StandardTestMethodforSimulativeRecirculatingSystemTestingofAerospaceHydraulicFluids1ThisstandardisissuedunderthefixeddesignationD2428;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(6)indicatesaneditorialchangesincethelastrevisionorreapproval.1,Scope1.1Thistestmethodcoversaprocedureforsystemevaluationofaerospacehydraulicfluids.Thetestmethodrecommendscontroloftestvariables,atypicaltestsystemgeometry,datatobeobtained,andprocedureswhichwillassureauniformapproachtofluidscreeningandevaluation.Recommendationsconcerningspecifichardwareandrigidtechniqueshavebeenavoidedwherepossibletoallowthetestmethodtobeusedasthestate-of-the-artadvances.1.2Eachagencyusingthetestmethodcansimulateaspecificsystem,thusfluidscanbequalifiedforuseinapplicationshavinguniquehardwareanddesignconcepts.Thisapproachprovidesthetestflexibilityneededtomeettherapidchangesinfluidrequirementsandalsoprovidevalu-ablecomparativedataforbothusersanddevelopersofhydraulicfluids.1,3Sincethetestsystemwaspurposelygeneralized,itisimportantthatthespecifieddatabeobtainedinorderthatfluidflowdynamicscanbedefined.Suchfactorsasshearrate,massflowrate,temperaturegradients,etc.,mustbedefinedforvalidcomparisons.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyproblems,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesdetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.1.5Thevaluesstatedinmetricunitsaretoberegardedasthestandard,Thevaluesgiveninparenthesesareforinformationonly.2.ReferencedDocuments2.1ASTMStandards:D88TestMethodforSayboltViscosity2...
