Abstract: | A fundamental problem in a/d conversion of a measurment signal of surface profile id discussed from the viewpoint of a limit of sampling error in the time domain. A comparison is also made of the results of autocorrelation function, power spectrum and profile parameters such as Rmax, Ra etc, obtained from the sampled surface profile in the time domain and in the longitudinal domain. It is suggested that the minimization of sampling error may be attained by the use of a digital displacement transducer attached to the usual surface measurement instrument. |