多气体红外光学传感器的研究

Research on Multi-gas Infrared Optical Sensor

为了解决目前红外光学传感器只能进行单一气体检测的问题,基于红外光谱吸收原理,设计了可以同时测试三种气体的光学传感器。提出了一种内壁由相交的双椭圆球面旋转构成,且具有折叠反射光路的圆筒式气室结构,解决了微气室结构实现高聚光度与集成度的关键技术问题。传感器内部有四个单通道探测器(一个参考通道和三个测试通道)和一个红外光源。通过对气室的合理布局,实现了一个传感器测试多种气体。利用响应通道输出信号与参考通道输出信号求比值计算气体浓度的方法,消除了外界环境对测试结果的影响。经过测试,在气体浓度较低的范围内,传感器的最大测量误差仅为±0.05%。

In order to solve the problem that the current infrared optical sensor can detect only a single gas. A three-gas optical sensor is presented for simultaneously detecting three gases based on the principle of infrared absorption spectrum. The new novel gas cell structure comprises two crossed elliptical surfaces with a folded reflection-type optical path is proposed. A new cylinder gas cell structure has been designed which solved the key problem about high degree of convergence and integration technology is achieved in the miniature gas cell structure. The sensor contains four single-channel detectors （one to acquire the reference signal and the others for the response signal） and an infrared light source. Through the rational distribution of the gas chamber, one sensor achieved multi-gas detection. Gas concentration calculation method adopting the ratio of the response channel output signal to the reference channel output signal removed the disturbance influence from the outside environment. The test results show that the largest measurement error of the sensor is only ± 0. 05 % when gas concentration in the lower range.