近红外光谱仪中调制器的误差分析

The Error Analysis on Modulator of NIR Spectrophotometer

调制器的误差会引起调制波频率和形状的变化 ,从而影响近红外光谱仪器检测信号的强度。就此分析了调制器各种常见的源误差 (如调制盘偏心误差、调制盘的轴心偏离狭缝中心的误差、直流电动机的轴向晃动误差、直流电动机的稳定性误差、调制盘齿形误差等 )对调制波的影响 。

When the modulator(or optical chopper)of the NIR spectrophotometer was error,the frequency and shape of modulating wave would be changed,and the measuring signal of the spectrophotometer must be smaller.The errors of the modulator mainly come from the modulator plate,which include its eccentricity,the departure of its axes form the slit center,and its dentate error,etc.and from the direct current electromotor,which include its axial shake and its instability.These errors had been analyzed,and their infections to the measuring signal had been discussed theoretically.