A method and the results of investigating the random error of an optical angle encoder

Abstract

The random error of the A-205 optical angle encoder, the angular scale of which is produced by holography, and which forms part of various dynamic goniometric systems, is investigated. A method of determining the random error which enables the potential and actual accuracy of the encoder to be determined is proposed. Results are presented which show that the random error of a single measurement with the encoder in an angle-measuring system with air bearings is less than 0.01″.