Performance testing of a novel angle comparator with inner and outer shafts

Abstract The angle comparator is a key device for calibrating angle devices, and its performance seriously affects the accuracy of angle calibration. In order to achieve high-precision angle reproduction, a new type of inner and outer axis angle comparator was developed, its angle measurement performance was tested, and the diagonal position error was compensated. Firstly, the structure of an internal and external axis angle comparator based on dual drive of ultrasonic motor and torque motor is briefly introduced. Then, the external cross-calibration method for the full fillet position error of the angle comparator and the testing and evaluation method for motion resolution were studied. Finally, the angle measurement performance of the angle comparator was tested and compensated, and the measurement results were analyzed and verified. The experimental results show that the compensated internal and external axis angle comparator has an angular position error of 0.08”, a measurement uncertainty of 0.03” ( k =2), and a motion resolution of 0.018”, indicating that the developed instrument has a stable high-precision calibration ability in the sub arc-second level.