This paper describes the automatic calibration system for an angle encode which is installed at the AIST (National Institute of Advanced Industrial Science and Technology). The system uses the Equal-Division-Averaged (EDA) method that is one kind of the self-checking method. This system has great performance of the calibration with small uncertainty. In this paper we try to explain the factor of uncertainty of this system. The dominant uncertainty factor is the eccentricity of shaft between the system and an external rotary encoder. The influence from other factors is very small about 0.01" or less.
This paper describes the automatic calibration system for angle encoders which is installed at the AIST. The system uses the Equal-Division-Averaged (EDA) method that is one kind of the self-checking method. Both of the reference standard and the object angle encoders are calibrated at the same time against all encoders graduations within only one hour. The resolution and an uncertainty are 0.001 inch and approximately +/- 0.05 inch, respectively. This equal- division-averaged method is hoped to become the national standard method for the calibration of angle encoders.