>> P.211
MeasuringRange•Whenchoosingameasuringrangeforamicrometerhead,allowanadequatemargininconsiderationoftheexpectedmeasuringrange.Sixmeasuringranges,5mmto50mm,areavailableforstandardmicrometerheads.•Eveniftheexpectedmeasuringrangeissmall,suchas2mmto3mm,itwillbecosteffectivetochoosea25mm-strokemodelaslongasthereisenoughspaceforinstallation.•Ifalongmeasuringrangeofover50mmisrequired,theconcurrentuseofagaugeblockcanextendtheeffectivemeasuringrange.(FigureD)FigureDGaugeblockHead’smeasuringrangeObtainedmeasuringrange•Inthisguide,therange(orstrokeend)ofthethimbleisindicatedbyadashedline.Forstrokeends,considerthethimbleasmovingtothepositionindicatedbythelinewhendesigningthejig.Ultra-neFeedApplications•Dedicatedmicrometerheadsareavailableformanipulatorapplications,etc.,whichrequireultra-nefeedoradjustmentofspindle.ThimbleDiameter•Thediameterofathimblegreatlyaffectsitsusabilityandthe"fineness"ofpositioning.Asmall-diameterthimbleallowsquickpositioningwhereasalarge-diameterthimbleallowsnepositioningandeasyreadingofthegraduations.Somemodelscombinetheadvantagesofbothfeaturesbymountingacoarse-feedthimble(speeder)onthelarge-diameterthimble.GraduationStyles•Careisneededwhentakingareadingfromamechanicalmicrometerhead,especiallyiftheuserisunfamiliarwiththemodel.•The"normalgraduation"style,identicaltothatofanoutsidemicrometer,isthestandard.Forthisstyle,thereadingincreasesasthespindleretractsintothebody.•Onthecontrary,inthe“reversegraduation”style,thereadingincreasesasthespindleadvancesoutofthebody.•The"bidirectionalgraduation"styleisintendedtofacilitatemeasurementineitherdirectionbyusingblacknumeralsfornormal,andrednumeralsforreverseoperation.•Micrometerheadswithamechanicalorelectronicdigitaldisplay,whichallowdirectreadingofameasurementvalue,arealsoavailable.Thesetypesarefreefrommisreadingerrors.Afurtheradvantageisthattheelectronicdigitaldisplaytypecanenablecomputer-basedstorageandstatisticalprocessingofmeasurementdata.05504525204505NormalgraduationstyleReversegraduationstyle052520208010900090108020BidirectionalgraduationstyleGuidelinesforSelf-madeFixturesAmicrometerheadshouldbemountedbythesteminanaccuratelymachinedholeusingaclampingmethodthatdoesnotexertexcessiveforceonthestem.Therearethreecommonmountingmethodsasshownbelow.Method(3)isnotrecommended.Adoptmethods(1)or(2)whereverpossible.(1)Clampnut(2)Split-bodyclamp(3)Setscrewclamp(Unit:mm)MountingmethodPointstokeepinmindStemdiameterMountingholeFittingtolerancePrecautionsFaceAø9.5ø10ø12ø18ø9.5ø10ø12ø18ø9.5ø10ø12ø18G7+0.005to+0.020G7+0.006to+0.024G7+0.005to+0.020G7+0.006to+0.024H50to+0.006H50to+0.008CareshouldbetakentomakeFaceAsquaretothemountinghole.Thestemcanbeclampedwithoutanyproblematsquarenesswithin0.16/6.5.Removeburrsgeneratedonthewallofthemountingholebytheslittingoperation.M3×0.5orM4×0.7isanappropriatesizeforthesetscrew.Limitcountersinkingintostemto90º×0.5andbecarefulnottodamagethestemintheprocess.03-48
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