基于红外热辐射光源的光声气体分析仪

研制了一种基于红外热辐射光源的光声气体分析仪，给出了该光声气体分析仪的设计理论、硬件结构、软件系统和实验测试结果。根据红外热辐射光源的光谱特性，通过比较吸收气体在不同吸收带中多线的综合吸收系数，确定了光声池的最优设计参数、滤光片的中心波长和带宽。实验结果表明，该光声气体分析仪对CO，NO和H₂S的极限检测灵敏度分别达到1.6×10-6,4.5×10-6和4.0×10-4(被测气体与背景气体的分压比)，并且对0～987×10-6 的CO测量显示了其良好的测量重复精度和线性度。此外，通过增加特定中心波长的滤光片还能够对其他多种小分子气体实现高灵敏度、实时、连续、自动地测量。

IR Thermal-Emitter Based Photoacoustic Spectrometer for Gas Detection

An IR thermal-emitter based photoacoustic spectrometer for gas detection was developed. The function and structure of the hardware and the software for the spectrometer were presented. Based on the analysis of spectral characteristics of the IR source, the integrated absorption coefficients of absorption gases at different absorption bands were compared, thus the optimum parameters of the photoacoustic cell and the IR filters were determined. The experimental results showed that the detection limits of 1.6 x 10(-6), 4.5 x 10(-6) and 4.0 x 10(-4) for CO, NO and H2S gases could be obtained respectively. The repeatability and linearity were also tested for CO gas in the concentration range of 0-987 x 10(-6), and the results are fairly satisfactory. In addition, many other kinds of gases can be measured with the same spectrometer, simply by adding some corresponding IR filters.