Quick Guide to Precision Measuring Instruments

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PG54Sampling lengthZt1Zt2Zt3Zt4Zt5Zt6Evaluation lengthSamplinglengthRtRzRzRzPa, Ra, Wa = |Z(x)|dx 0l∫ 1lPc, Rc, Wc = Zti i = 1m∑ 1mPq, Rq, Wq = Z2(x)dx 0l∫ 1lAmplitude Parameters (average of ordinates)Arithmetical mean deviation of the primary prole PaArithmetical mean deviation of the roughness prole RaArithmetical mean deviation of the waviness prole WaArithmetic mean of the absolute ordinate values Z(x) within a sampling lengthRoot mean square deviation of the primary prole PqRoot mean square deviation of the roughness prole RqRoot mean square deviation of the waviness prole WqRoot mean square value of the ordinate values Z(x) within a sampling lengthMean 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 lengthTotal 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 lengthwith l as lp, lr, or lw according to the case.with l as lp, lr, or lw according to the case.RpSampling lengthMaximum 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 lengthRpSampling lengthRzRvMaximum 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 pro-le valley depth Zv within a sampling lengthDenition of ParametersISO 4287: 1997, Amd. 1 :2009Amplitude 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 lengthIn 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.)Sampling lengthRvSurftest (Surface Roughness Testers)