>> P.242
Glossary/PrecautionsGlossary1.LinearityTruevalueTruevalueThisvalueindicatesthemaximumerroramountindividuallygeneratedinaccordancewitheachdimensionatthecenterofthemeasuringregion(themeasuredvaluedeviationfromthetruevalueswheneachdimensionoftheworkpieceismeasured).Itreferstothedeviationvaluefromtheidealvaluewhenmeasuringtheworkpieceatthemeasuringregioncenteruponcalibrationwithoneoftheoptionalcalibrationgagesavailableforeachmodelofthisdevice.*Doesnotincludetheerrorgeneratedduringcalibrationwhenjudgingdimensionvalues.Thisisaddedseparately.2.RepeatabilityIdealvalueTruevalueMaximumerroramount=LinearityIdealvalueTruevalueMaximumerroramount=LinearityLoCALHiCALLoCALMeasuredvalueHiCALLoCALMeasuredvalueHiCALLoCALThismeans,inthecenterofthemeasuringarea,thedispersion(±2σ)ofmeasurementvaluesastheresultofcontinuousmeasurementfor2minuteswiththenumberofscansforaveragingsetat512times(2048timesforLSM-6902H)withoutmovingaworkpieceofthemaximummeasurementdiameteroneachmeasuringunit.ParallelerrorUp-downerrorUp-downerrorParallelerrorUp-downerrorParallelerrorParallelerrorUp-downerror3.PositionalerrorThismeanstheerrorwithreferencetothemeasurementvalueatthecenterofthemeasuringregionifaworkpieceisdisplacedinthemeasuringregion.Positionalerrorconsistsofup-downerrorandparallelerrorasshowninthefollowingfigure.Thiserrorseparatelyaffectsmeasurementaccuracy.4.Measuringregion(1)Precisionguaranteedvalues(linearity+positionalerror)canbeobtainedonlywhentheworkpieceiswithinapredeterminedspace.Thisspaceiscalledthemeasuringregion.Themeasuringregionisdefinedbythescandirectionofthelaserbeamandthedirectionoftheopticalaxis.Tominimizeerror,measurementmusttakeplaceatthecenterofthemeasuringregion.(1),(2),(5),and(6)inthefigurebelowareoutsidethemeasuringregionandthuscannotbemeasured;for(3)and(4),positionalerrorisaddedtolinearityerror.Lasescandirection(6)Laser(3)scandirection(5)(6)(4)5.BeamdiameterAandwidthABBBeamdiameterABeamwidthB*ReferencevalueOpticalaxisdirectionAABLSM-02-A80µm120µm5-29(1)(5)Measuringregion(3)(1)(5)(1)Measuringregion(6)(2)(3)Laserscandirection(4)(2)Laserscandirection(6)(4)(3)OpticalaxisdirectionMeasuringregion(2)Measuringregion(2)(5)(4)OpticalaxisdirectionOpticalaxisdirectionLSM-30-A240µm340µmB
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