FACTORS INFLUENCING UNCERTAINTY EVALUATION FOR SURFACE ROUGHNESS MEASUREMENTS

Abstract − The nominal conditions for measuring surface roughness when using stylus instruments are specified in ISO 3274. Deviations from these nominal conditions lead to significant deviations of the measured roughness parameters. An uncertainty evaluation has been made on five roughness parameters for three calibration standards. The methods and procedures for uncertainty evaluation are to i) calibrate and evaluate the uncertainty in the condition for the measuring instrument, ii) evaluate the influence of each individual deviation on the results of measurement, and iii) combine the effect of these individual uncertainties on the final result of measurement. A study has been carried out on the influence of different contributors on the combined uncertainty associated with the assessment of roughness parameters. From the results the major contributors affecting the uncertainty of measurement on different roughness parameters are given