Designation:D7917−14(Reapproved2018)StandardPracticeforInductiveWearDebrisSensorsinGearboxandDrivetrainApplications1ThisstandardisissuedunderthefixeddesignationD7917;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.INTRODUCTIONWeardebrissensors,employinginductivesensingtechnologies(1,2),2areabletoquantifyweardebristoclassifysizeandmaterialcomposition(ferrous/non-ferrous)ofmetallicdebrisfoundinlubricatingoilasaconsequenceofwear.Initialapplicationshavebeenlargelyconfinedtoindustrialaero-derivativeandaircraftgasturbineenginemonitoringinstallationswherethefailureofhighspeedballandrollerbearingsresultsinsignificantsecondarydamage(2,3).Withanalmostexponentialgrowthinthewindturbineindustry,oneengineeringissuestilltoberesolvedistheunacceptablegearboxfailurerate(4).Weardebrissensorscanplayanimportantroleinunderstandingthevariedbearingfailuremodesobserved.Therearethousandsofinductivesensorsoperatinginwindturbinesandothergearboxanddrivetrainapplicationsaccruingmillionsofoperationalhours.Whileitisgenerallyacceptedthatthesesensorsprovideearlywarningofabnormalcondition,theindustrywillbenefitfromastandardpracticefordatausageandinterpretation.1.Scope1.1Thispracticecoverstheminimumrequirementsforanonlineinductivesensorsystemtomonitorferromagneticandnon-ferromagneticmetallicweardebrispresentinin-servicelubricatingfluidsresidingingearboxesanddrivetrains.1.2Metallicweardebrisconsideredinthispracticecanrangeinsizefrom40µmtogreaterthan1000µmofequivalentsphericaldiameter(ESD).1.3Thispracticeissuitableforusewiththefollowinglubricants:industrialgearoils,petroleumcrankcaseoils,poly-alkyleneglycol,polyolesters,andphosphateesters.1.4Thispracticeisformetallicweardebrisdetection,notoilcleanliness.1.5ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedi...
