振动分析和仪器的艺术达芬奇.ppt

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TheArtof

Instrumentation

VibrationAnalysisBacktotheBasics–ForwardtotheFuture

OurObjective…TheobjectiveofConditionMonitoringistoprovideinformationthatwillkeepmachineryoperatinglongerattheleastoverallcost.WhatitisNOT:EstablishnewmeasuredpointrecordsMeanstoshowanalyticalbrillianceTheanswertoeveryproblem!

BacktotheBasics…VibrationSimpleHarmonicMotion1OscillationaboutaReferencePoint2ModeledMathematicallyas…3

BacktotheBasics…Period,TRMSUnitCirclePeak-to-Peak0toPeak0

BacktotheBasics…BasicSignalAttributesStaticSlowlyChangingTemperatureBasicSignalAttributesDynamicSensormustrespondinfractionsofaSecondVibration,Amperage,Pressure

BacktotheBasics…DynamicSignalFundamentalsAmplitudeFrequencyTimingShapeAmplitudeProportionaltotheseverityofvibratorymotionExpressedasPeaktoPeakZerotoPeakRMSFrequencyDeterminedbythereciprocalofthePeriodCPSorHzRPMOrdersTiming,orPhaseRepresentedbythetimedelaybetweentwosignalsLeadingLaggingSignalShapeWaveformSimpleComplexPatternRecognition

PeakandRMSComparison

RelationshipsofAcceleration,VelocityandDisplacement

TheBigPictureRemoteAnalysisandDiagnosticsSensor(s)CablesSignalConditioningDataAcquisitionStorageCommunications030405060102

DisplacementSensorsElementsProbe,matchedextensioncable,Driver

DisplacementSensorsHowitWorks: Thetipoftheprobecontainsanencapsulatedwirecoilwhichradiatesthedrivershighfrequencyasamagneticfield.Whenaconductivesurfacecomesintocloseproximitytotheprobetip,eddycurrentsaregeneratedonthetargetsurfacedecreasingthemagneticfieldstrength,leadingtoadecreaseinthedriversDCoutput.ThisDCoutputisusually200mV/milorinasimilarrange.

DisplacementSensorsPro’sandCon’sPro’sMeasuresDisplacementRuggedCon’sLimitedFrequencyRange(0-1000Hz)SusceptibletoelectricalormechanicalrunoutInstallationIssues

VelocitySensorsPro’sandCon’s