Designation:F538−13StandardTerminologyRelatingtotheCharacteristicsandPerformanceofTires1ThisstandardisissuedunderthefixeddesignationF538;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thisterminologyprimarilycoversdefinitionsfortech-nicaltermsthatoccurinASTMCommitteeF09standardsonthecharacteristicsandperformanceoftires.1.2Definitionsfortermsthatmayalsobeusedinothertechnologies,suchasvehiclebehavior,arewordedtocoverbothareas.1.3Whenanydefinitioninthisterminology(thatdoesnothavethelimitingphrase)isquotedoutofcontext,editoriallyinsertthelimitingphraseinatireafterthedashfollowingtheterm.Thiswillproperlylimitthefieldofapplicationofthetermanddefinition.2.Terminology2.1Definitions:accelerometer,n—aninstrumentthatsensesinertialreactiontomeasurelinearorangularacceleration.F811accuracy,n—ameasurementconceptthatdescribesthedegreeofcorrespondencebetweenanaveragemeasuredvalueandanacceptedreferenceorstandardvaluefortheobject,materialorphenomenonundertest.F1082age,v—toapplyconditionssoastopromotechangeofmaterialproperties.F2838aging,acceleratedlaboratory(also:aging,laboratory),n—increasedrateoftirematerialpropertychangesunderspecifiedconditions,includingtemperature,inflationpressure,oxygenconcentrationinthefillinggas,andtime.F2838aging,in-service,n—materialpropertychangeswithintiresduetoconsumerusage.F2838aging,oven,n—acceleratedlaboratoryaginginanelevatedtemperatureenvironment.F2838aging,thermaloxidative,n—theprocesswherebychemicalandphysicalmaterialpropertiesofatirechangewithexposuretoheatandoxygen.F2838aligningstiffness[FL/γ],n—ofatire,therateofchangeoftirealigningtorquewithrespecttochangeintireslipangle,usuallyevaluatedatzeroslipangle.aligningstiffnesscoefficient,n—ofatire,theratiooftirealigningstiffnesstothetirenormalforce.aligningtorque[FL],n—o...
