Automatic interference comparator (AIC) is a high precision one-dimensional length measurement machine for investigation and calibrations of line scales, linear encoders and length gauges. This paper emphasizes a novel electronic subdivision method for the AIC to realize precision measurement, which is composed of integer fringe counting, fraction fringe counting and electronic strobe. The realization of the whole system is based on FPGA. A standard line scale has been calibrated by this method on the AIC of the National Institute of Metrology(NIM) in China. The experimental results show the measurement repeatability is less than 7.5 nm, which demonstrates the feasibility of the new signal processing method.

Date Published: 10 October 2013
PDF: 7 pages
Proc. SPIE 8916, Sixth International Symposium on Precision Mechanical Measurements, 89161X (10 October 2013); doi: 10.1117/12.2035599

Published in SPIE Proceedings Vol. 8916:
Sixth International Symposium on Precision Mechanical Measurements
Shenghua Ye; Yetai Fei, Editor(s)