利用光干涉现象的光电变换法能保证对大工作行程上的线性位移进行高精度测量。借助光电法计数干涉条纹及测量其小数部分能够从1/8波长或更高的精度来进行位移测量。在相当小的移动速度下的位移测量方法发展得最快,然而动态测量法却还处在发展的初 The photoelectric conversion method using light interference can ensure high-precision measurement of the linear displacement on a large working stroke. By counting the interference fringes by photoelectric method and measuring the fractional part thereof, the displacement measurement can be performed from 1/8 wavelength or more. Displacement measurement at the relatively small moving speed is the fastest growing method, however, the dynamic measurement method is still in its early stages of development