近红外光谱仪中的微弱信号检测技术

The Technique of Acquiring Weak Signal in NIR Spectrometer

介绍了近红外光谱仪的应用和近红外光谱仪中的信号特点。自然光的干扰是在开发此类仪器时遇到的主要困难 ,在了解近红外光谱分析仪中的信号和噪声特点后 ,采用切光的办法来对光信号进行调制可有效的克服这一问题 ,使信号变得容易处理。而通过采用相敏检测的方法又可大大提高信噪比。文章系统的介绍了弱信号的提取方法 ,解决了近红外光谱仪中信号提取问题 。

The applied field of Near Infrared Spectroscopy (NIRS) and the characteristics of NIRS are introduced.The noise of natural light is the main difficulty to develop these instruments.A good method to solve this problem is to modulate the light signal through optical chopper according to the characters of noise and signal,which makes the signal easier to process.The ratio of signal to noise (S/N) is greatly improved through the phase sensitivity detection.The method of acquiring the weak signal,which can solve the problem of getting signal in NIR spectrometer,is introduced.The circuit,which works well in real application,is presented.