>> P.260
Glossary/PrecautionsGlossary1.LinearityTruevalueTruevalueThisisaspecifiedvaluethatdefinesthemaximumerror*thatmaybeindicatedbytheLSMaftercalibration**,anywherewithinitsmeasuringrange,whenmeasuringaworkpieceinthecenterofthemeasuringregion.Notethatthelinearityspecificationdoesnotincludethecalibrationerrorspecificationofthecalibrationgagesthemselves.Thiserrormustbeaddedseparately.*Thedifferencebetweentheresultofmeasuringadimensionandthetruevalueofthedimensionmeasured.**OptionalcalibrationgagesareavailableforeachmodelofLSMtoprovideappropriatehighandlowcalibrationpoints(HiCALandLoCALonthediagram).2.RepeatabilityIdealrelationship:measuredvalue=truevalueTruevalueMaximumerror=LinearityIdealrelationship:measuredvalue=truevalueTruevalueMaximumerror=LinearityMaxLinMeasuredvalueLoCALHiCALLoCALHiCALLoCALHiCALLoCALMeasuredvalueHiCALMeans,inthecenterofameasuringregion,thedispersion(±2σ)ofmeasurementvaluesastheresultofcontinuousmeasurementfor2minuteswiththenumberofscansforaveragingsetat512times(2048timesforLSM-6902H)withoutmovingaworkpieceofthemaximummeasurementdiameteroneachmeasuringunit.ParallelerrorParallelerrorUp-downerrorUp-downerrorParallelerrorUp-downerrorParallelerrorUp-downerror3.PositionalerrorMeansanerrorwithreferencetothemeasurementvalueatthecenterofthemeasuringregionifaworkpieceisdisplacedinthemeasuringregion.Apositionerrorconsistsofanup-downerrorandaparallelerrorasshowninthefollowingfigure.Thiserrorseparatelyaffectsmeasurementaccuracy.4.MeasuringregionTheLSMprovidesnumericvaluesforwhichtheaccuracy(linearity+positionerror)isguaranteedonlyifaworkpieceislocatedwithintheprescribedspacedomain.Thisdomainiscalledthemeasuringregion.Ameasuringregionisdeterminedby[laserbeamscanningdirectionrange]x[opticalaxisdirectionrange].Toperformmeasurementwithaminimumoferror,itisnecessarytomeasureaworkpieceatthecenterofthismeasuringregion.Asanexampleinthefigureright,workpieces1,2,5,and6cannotbemeasuredbecausetheseareoutsidethemeasuringregion.Forworkpieces3and4,apositionerrorisaddedtoalinearityerror.asecanigdirectionLaserscanningdirectionMeasuringregionMeasuringregionMeasuringregionMeasuringregionLaserscanningdirectionLaserscanningdirectionOpticalaxisdirectionOpticalaxisdirectionOpticalaxisdirectionOpticalaxisdirection5.BeamdiameterAandwidthAABBLSM-6902HLSM-500SBeamdiameterABeamwidthB*Referencevalue200µm300µm80µm120µmAB5-47LSM-501SLSM-503SLSM-506SLSM-9506LSM-512SLSM-516S120µm170µmB240µm340µm600µm800µm600µm800µm1200µm1600µm1200µm1600µm