Output signal accuracy calibration of autocollimators

Abstract

Modem photoelectric autocollimators are one of many mechanical displacement measuring instruments used for precision position determination during linear and circular motion. Usually it works with a mirror or polygon making one of the classical and most accurate means of precise plane angle determinations. Calibration of autocollimators has always been a complicated task since small angle steps must be generated with a very high angular precision. In this paper an approach for calibration of autocollimators against a precise rotary table is described. Two custom made photoelectric autocollimators with the unknown characteristics were calibrated, and the results of the calibration with the typical curves of autocollimators systematic errors and primary analysis of the results are presented in the paper.