针对直流光栅测试系统分辨率低、精度难以提高的问题,提出了一种动静态测量结合、大小数记数分离的直流光栅测试系统。在光栅付相对移动的动态测量过程中,获得当量数为1/4光栅栅距的大数记数,在相对移动开始之前和结束之后的静态时刻,获得当量数为1/360光栅栅距的小数记数,最后通过大小数的正确结合,获得测量结果。 Aiming at the problem of low resolution and high precision of DC grating test system, this paper presents a DC grating test system combining dynamic and static measurement and separation of large and small numbers. In the course of the dynamic measurement of the relative movement of the grating, a large number of counts of the 1/4 grating pitch is obtained, and the equivalent number of 1/360 grating pitch is obtained at the static moment before and after the relative movement Fractional count, and finally the correct combination of large and small, get the measurement results.