提出一种利用波长调制与谐波检测技术测量环境湿度的新方法。利用可调谐二极管激光光谱吸收技术, 选择948 nm波段的H2O分子吸收谱线作为特征谱, 并采用反射式开放气室, 研制了光路系统结构简单、易于调节的新型湿度传感器样机。实验结果表明, 该激光湿度传感器响应频率为40 Hz, 湿度测量误差在±1.2%以内, 能够满足对湿度高动态、高精度测量的需要。

A new method to measure the environmental humidity with wavelength modulation technology and harmonic detection technology was proposed based on tunable diode laser absorption spectroscopy. H2O molecular absorption spectra of 948 nm band were selected as the characteristic spectra, and reflective open gas cell was used. The new humidity sensor prototype was developed, and the structure of the optical system was simple and easy to be adjusted. Experimental results show that the response frequency of the laser humidity sensor is 40 Hz and humidity measurement error is within ±1.2%, which can meet the requirements of humidity measurement with high dynamic and high precision.