Calibration of a high precision rotary table

In order to calibrate a high precision rotary table, a calibration system was established to measure the position error and repeatability of rotary table. The position error was measured with a polygon, an index table and an autocollimator to separate the angular error of the polygon from the position error of the rotary table, and the position error of rotary table was calculated using least square method. The rotary table was compensated and calibrated with the position error measured. The repeatability of the rotary table established through 10 times full circle rotations was 0.02 arc second. The measurement results indicated that the combination calibration method was suitable for the calibration of a high precision rotary table. It was found through the analysis that the angular measurement uncertainty was 0.08 arc second.