单色仪是一种分光仪器，它通过色散元件的分光作用，把一束复色光分解成不同波长的单色光。文章提出了针对三光栅扫描色散机构单色仪的标定方法。对于采用正弦扫描机构的单色仪多采用多项式拟合方法实现波长标定，其精度高低取决于标定点数的多少。在全波长范围内，多项式拟合标定方法的精度有限。文章根据三光栅扫描单色仪的实际设计方案，采用正弦曲线拟合方法。光栅方程本身符合正弦规律，少量的标定点就可以满足拟合精度要求。适当选取待定参数，可以大幅度减少拟合运算过程中的计算复杂性。根据仿真软件的分析结果，其波长拟合偏误差小于

Monochromator is a spectroscopic instrument, which decomposes a polychromatic light into monochromatic light with different wavelengths using spectral dispersive element. This paper presents a new calibration method for three-grating monochromator. For the monochromator adopting sinusoidal scanning, its accuracy depends on the number of calibration points. This paper uses sine curve fitting method according to the design of three-grating scanning monochromator. Since grating equation is in compliance with the law of sine, a small number of calibration points could meet the requirements of fitting accuracy. Appropriate parameters to be determined are selected, which significantly reduces the computational complexity in the process of fitting. The analysis results of simulation software show that the wavelength fitting error is less than 0.5 nm.