METHOD OF OPTIMAL MEASUREMENT STRATEGY FOR ULTRA-HIGH-PRECISION MACHINE IN ROUNDNESS NANOMETROLOGY

Talyrond-TR is a modern sensitive instrument in nanometrology. The performance of Talyrond-TR machine is very important to find an optimal result in roundness measurement. In this paper, the experimental evaluation method of Talyrond-TR 73 machine is designed by using reference standard hemisphere. The influence of Talyrond machine performance in roundness measurement is presented. Signal responses of ten metrological strategic parameters have been analyzed and discussed. Deviation in roundness measurement strategies corresponding to four reference algorithms (LS), MZ, MC; MI) and two software fitting filters (2CR and Gaussian) with four spectral frequency ranges (1:15, 1:50, 1:150; 1:500 upr) are obtained through repeated arrangement, comparison and achieved. Experimental results revealed that the lowest deviation in roundness has been investigated by using MZ reference algorithm. The average of total roundness indicates low deviation by about 65.6% and 57.3% at using 2CR- and Gaussian-filter respectively, which proved the machine reliability within application range. Furthermore, the evaluation method was performed experimentally to establish reference data sets for circular, cylindrical and spherical objects. The sets of established data at different strategic parameters have been postulated to satisfy the ability of the proposed method to correlate the roundness measurements within the application range. The experimental result ensures that the proposed evaluation method is reliable and effective. Moreover, expanded uncertainty in measurement has been estimated and confirmed the degree of confidence for the proposed method