Abstract
The system has been developed to calibrate some kinds of angular encoders automatically with high accuracy. This paper describes the multi-reading-head method which is a new selfchecking method and introduces the system and the calibration results of encoders. The characteristics of the system are followings: (a) Adopting the time-conversion method, a slight angular difference is detected with high resolution and high precision. (b) Adopting the multireading-head method, the calibration of masterscale can be done without angular standard. (c) Referring to the masterscale calibrated, some kinds of angular encoders are calibrated. (d) The calibration is done automatically by the micro-computer system which controls the compiling and handling of data. The followings became clear after the calibration. (1) The relative-angleposition-errors are measured with 0.01'' resolution and their standard deviations are about 0.01''. (2) The calibration values of all graduations of masterscale and subscale are obtained with an accuracy of 0.3'' in about 5 minutes.
