[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.