Precision angle sensor and its calibration techniques

A high-precision angle sensor and a new method for calibrating precision angle sensor without any accurate reference instruments were described. Two angle sensors with compensating devices which compensate the thermal drift of light source were developed and calibrated by themselves. The measurement ranges of the two angle sensors are 180'', and the resolutions are 0.003'' and 0.004'' respectively. The repeatability error of the evaluated mean sensitivity was improved to 0.015% by compensating device. The repeatability of the calibrated linearity error was reduced to 0.015''.