Application of Moire Fringe Electric Interpolation in Calibration Instrument for Radial Gratings
Shengjia Zhou · 1989
The moire fringe electric interpolation plays an important part in the processing of the measuring information in the calibration instrument for gratings. Due to the sample-interpolation measurement the dynamic and static calibration is realized in the calibration instrument for gratings. The interpolation number can be raised up to more than 10000 by the combination of the sample-holder and the carrier modulation interpolation. In order to raise the accuracy of the interpolator itself, we developed self-check method. The self-check circuits can generate three ideal signals, sine, cosine and the sample signal that are together input to the interpolator. After the control and calculation of microcomputer, the interpolation error is given. Then, the concerned chains and components of the interpolator are regulated. By using above method, the relative interpolation accuracy of the interpolator itself has been raised to 0.001.