Designation:D7669−15StandardGuideforPracticalLubricantConditionDataTrendAnalysis1ThisstandardisissuedunderthefixeddesignationD7669;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.INTRODUCTIONThisstandardprovidesspecificguidelinesfortrendanalysis,astheyareappliedtoconditionmonitoringofmachinery.Themainpurposeoftrendanalysisistolearnhowrapidlythemachineandfluidaredeteriorating.Asignificantchangeintrendisindicativeofadevelopingfailure.Interventionintheearlystagesofdeteriorationismuchmorecosteffectivethanfailureofthemachine.Maximumreliabilityofin-servicemachinecomponentsandfluidsrequiresaprogramofconditionmonitoringtoprovidetimelyindicationsofperformanceandremainingusablelife.Toachievethesegoals,aconditionmonitoringprogramshouldmonitortherateofprogressionofthefailurebyincludingsufficientteststodeterminetherateofdegradation,increaseofcontaminants,andquantityandidentityofmetaldebrisfromcorrosionorwear.Theconditionmonitoringprocessdeterminesthepresenceofoil-relatedfailuremodes,allowingremedialmaintenancetotakeplacebeforefailureandsubsequentlyexpensiveequipmentdamageoccurs.Inordertodiagnoseandpredictmachineryandfluidcondition,therateofchangeofmachineconditionmustbetrended.Equipmentmaintainersexpectconditionmonitoringinformationtoclearlyandconsistentlyindicatemachinerycondition,thatis,therate-of-changeofcomponentdamageovertimeandtheriskoffailure.Trendingutilizesacomparisonofaconditionparameterwithtime.Forexample,plotsofacondition-relatedparameterasafunctionoftimeisusedtodeterminewhentheparameterislikelytoexceedagivenlimit.Forecastingtheexpectedbreakdownofamachinewellinadvanceenablestheoperatortominimizethemachine’sdowntime1.Scope*1.1Thisguidecoverspracticaltechniquesforconditiondatatrendanalysis.1.2Thetechniquesmaybeutilizedforallinstrumentationthatprovidesnumerica...
