L-17SurftestPerforms brilliantly in many situations such as in the quality control room, on the factory oor and on the production line. Mitutoyo operates a policy of continuous improvement that aims to provide the customer with the benet of the latest technological advances.Therefore the company reserves the right to change any or all aspects of any product specication without notice.LL-17Surftest (Surface Roughness Testers)Quick Guide to Precision Measuring Instruments■ ISO 1302: 2002 Notation method of surface texture ■ ISO 4287: 1997 Geometrical Product Specications (GPS) –Surface Texture: Prole method– Terms, denitions, and surface texture parameters■ ISO 4288: 1996 Geometrical Product Specications (GPS) –Surface Texture: Prole method– Rules and procedures for the assessment of surface texture■ ISO 3274: 1996 Geometrical Product Specications (GPS) –Surface Texture: Prole method– Nominal characteristics of contact (stylus) instrumentsFeed deviceColumnProbe (pickup)ProbeStylus (contact element)WorkpieceFixtureBaseMeasuring loopTransducerTracedproleStylus tipReferenceproleReferenceguide skidNominalform removalPrimaryproleADconverterProle lter λSAnalysis according to ISO 4287AmplierFeeddeviceSurfaceMeasure-mentloopExternaldisturbancesDrive UnitZ-axis Signal Transfer UnitInput/OutputInput/OutputTotal proleA prole lter is a phase-correct lter without phase delay (cause of prole distortion dependent on wavelength).The weight function of a phase-correct lter shows a normal (Gaussian) distribution in which the amplitude transmission is 50% at the cutoff wavelength.■ Elements of Contact Type Surface Roughness Measuring Instruments ■ Data Processing Flow■ Surface Proles■ Metrological Characterization of Phase Correct FiltersSurface proleon the real surfaceTracedproleTotalprolePrimary prolePrimary proleparametersRoughness proleWaviness proleRoughnessprole parametersWavinessprole parametersLow-pass lterof cutoff value λsHigh-pass lter of cutoff value λcBand-pass lter that passes wavelengthsbetween cutoff values λc and λfMeasurementAD conversionSuppresses irrelevant geometry of the surface such as inclination of a at feature and curvature of a cylindrical feature using the least squares method.Denition: Prole that results from the intersection of the real surface and a plane rectangular to it.Denition: Locus of the center of the stylus tip that traces the workpiece surface.Denition: Data obtained by quantizing the measured prole.ISO 3274: 1996 (JIS B 0651: 2001)ISO 11562: 1996(JIS B 0632: 2001)(JISB0651)60°60°60°90°90°90°R2µmR5µmR10µmR2µmR5µmR10µmStylus ShapeA typical shape for a stylus end is conical with a spherical tip.Tip radius: rtip = 2 µm, 5 µm or 10 µmCone angle: 60°, 90°In typical surface roughness testers, the taper angle of the stylus end is 60˚ unless otherwise specied.Static Measuring ForceNote 1: The maximum value of static measuring force at the average position of a stylus is to be 4.0mN for a special structured probe including a replaceable stylus.Nominal radius ofcurvature of stylus tip:µmStatic measuring force atthe mean position ofstylus: mNTolerance on staticmeasuring forcevariations: mN/µm25100.75 0.75 (4.0) Note 10.0350.2 Maximum sampling lengthµmλcmmλsµmλc/λsRelationship between Cutoff Value and Stylus Tip RadiusThe following table lists the relationship between the roughness prole cutoff value λc, stylus tip radius rtip, and cutoff ratio λc/λs.Note 1: For a surface with Ra>0.5µm or Rz>3µm, a signicant error will not usually occur in a measurement even if rtip = 5µm.Note 2: If a cutoff value λs is 2.5µm or 8µm, attenuation of the signal due to the mechanical ltering effect of a stylus with the recommended tip radius appears outside the roughness prole pass band. Therefore, a small error in stylus tip radius or shape does not affect parameter values calculated from measurements. If a specic cutoff ratio is required, the ratio must be dened.Maximum rtipµmNote 1 Note 2 Note 2 0.08 0.25 0.8 2.5 8 2.5 2.5 2.5 8 25 0.5 0.5 0.5 1.5 5 30 100 300 300 300 2 2 2 5 10ISO 4287:199750100λsλcλfAmplitude Transmission %WavelengthRoughness proleWaviness prolePrimary ProleProle obtained from the measured prole by applying a low-pass lter with cutoff value λs.Roughness ProleProle obtained from the primary prole by suppressing the longer wavelength components using a high-pass lter of cutoff value λc.Waviness ProleProle obtained by applying a band-pass lter to the primary prole to remove the longer wavelengths above λf and the shorter wavelengths below λc.■ Denition of ParametersRpSampling lengthAmplitude Parameters (peak and valley)Maximum peak height of the primary prole PpMaximum peak height of the roughness prole RpMaximum peak height of the waviness prole WpLargest prole peak height Zp within a sampling lengthISO 4287: 1997, Amd.1: 2009Sampling lengthRvMaximum valley depth of the primary prole PvMaximum valley depth of the roughness prole RvMaximum valley depth of the waviness prole WvLargest prole valley depth Zv within a sampling lengthZpSampling lengthRzZvMaximum height of the primary prole PzMaximum height of the roughness prole RzMaximum height of the waviness prole WzSum of height of the largest prole peak height Zp and the largest prole valley depth Zv within a sampling length In Old JIS and ISO 4287-1: 1984, Rz was used to indicate the “ten point height of irregularities”. Care must be taken because differences between results obtained according to the existing and old standards are not always negligibly small. (Be sure to check whether the drawing instructions conform to existing or old standards.)Mean height of the primary prole elements PcMean height of the roughness prole elements RcMean height of the waviness prole elements WcMean value of the prole element heights Zt within a sampling lengthmmPc, Rc, Wc = Ztii=11Sampling lengthZt1Zt2Zt3Zt4Zt5Zt6Total height of the primary prole PtTotal height of the roughness prole RtTotal height of the waviness prole WtSum of the height of the largest prole peak height Zp and the largest prole valley depth Zv within the evaluation lengthEvaluation lengthSamplinglengthRtRzRzRzΣPrimary prolePrimary prole


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