一种基于渐变滤光片的2～14μm常温红外光谱辐射测试技术

An 2～14μm Ambient Infrared Spectroradiometric Measurement Technology Based on Linear Variable Filter

研究了一种基于渐变滤光片的2~14μm常温红外光谱辐射计,实现了2%测量波长的分辨率。针对单片渐变滤光片的波长范围限制,采用三块渐变滤光片拼接的方式与光谱融合算法,实现了2~14μm宽波段覆盖。采用精密步进电机和位置传感器方案进行精密光谱分光,实现了2%测量波长的光谱分辨率。采用斩光和数字正交锁相放大方案,实现了微弱红外光谱信号的探测。用于驱动渐变滤光片的步进电机采用近似函数控制算法和阶梯变频加速型运动律控制方案,实现了高精度步进控制和0.1转/s^10转/s的不同光谱测量速度。最后,简要介绍了红外光谱辐射计的标定方法及结果。

A 2 to 14 p.m ambient infrared spectroradiometer based on linear variable filters with spectral resolution of 2% measurement wavelength is studied. According to the wavelength range limit of a single slice gradient filter, the coverage of the 2 to 14p.m wide band is realized by combining three pieces of variable filters with a spectrum fusion algorithm. By using a scheme containing a fine stepping motor and a position sensor to carry out fine spectrum splitting, the spectral resolution of 2% measurement wavelength is realized. By using the chopping and digital orthogonal lock-in amplifier scheme, the detection of weak infrared spectral signals is realized. For a stepping motor used to drive variable filters, the approximate function control algorithm and step frequency conversion acceleration motion law are used. Thus, fine step control and 0.1scan/second to 10 scan/second variable spectrum scanning speed are achieved. Finally, the calibration method and result of the spectroradiometer are presented.