Photoacoustic Spectrum Detection of CO Based on Optimizing Non-resonant Photoacoustic Pool

摘要

SF6 is an excellent insulating gas, which is often used in GIS. In case of overheating or partial discharge in GIS, SF6 will decompose. In case of micro-water and micro-oxygen existing in GIS, here come products such as SO2, SOF2, SO2F2, H2S and CO will be produced when the reaction involves solid insulation materials. In this paper, the component CO were quantitatively measured by photoacoustic spectroscopy detection technology, and the structure of the photoacoustic pool operating in non-resonant mode was optimized theoretically. The design basis of the photoacoustic pool was obtained and the radius of the photoacoustic pool was selected as 2mm.For the quantitative measurement of sample gas by using the photoacoustic effect of gas, the gas absorption spectrum line that can avoid the cross-interference of other gas components should be selected as the characteristic spectrum line. Based on this, the CO gas characteristic spectrum line is 6380.3cm−l. The experimental structure shows that the linearity between the gas concentration of CO and the amplitude of the photoacoustic signal is very high, that is, the gas concentration can be accurately calculated through the measurement of the photoacoustic signal value of the gas. The lower limit detection is 3.63ppm.