【摘要】 介绍了衍射法测量变间距光栅线密度的测量系统。该测量系统由激光器、准直镜、光栅转动台（含角度测量仪）、直线工作台、光栅调节架、探测器和待测光栅组成。分析了系统中各种误差对测量精度的影响，以及变间距光栅参数的变化对光学系统的影响和补偿办法。计算表明，该系统的测试精度满足光束线对光学系统的性能要求。更多还原

【Abstract】 The groove density parameters are important to VLS plane gratings monochromator. It is necesary to make sure that the parameters were specified and their errors were acceptable. A diffraction method was used to measure the groove density of VLS grating for system. It included a light source (He - Ne laser), a collimator, a goniometer with angle encoder, a autocollimator, a linear stages, a detector(CCD) and the guting to be tested. The main error sources in the measuring system were analyzed in details. It turned out that the measuring system proposed was adequated for our purpose. A compensation method was analyzed for the monochromator if the groove density parameters were deviated from the design value.更多还原