A correction method for self-broadening effect in absorption spectrum gas sensing field

Abstract

The invention discloses a self-widening effect modification method in the field of absorption spectrum gas sensation, that is, a method based on a Lambert-Beer absorption law and used for analyzing and detecting gas concentrations. The modification method for detecting gas concentrations by using an absorption spectrum analysis method on the basis that the influence of self-widening of a gas uponan absorption spectrum is sufficiently considered belongs to the field of gas sensation. According to the method, light absorbancy is not in a direct ratio relationship with a gas concentration and needs to be modified for a certain degree, in addition, the influence of self-widening of a gas upon line widths and light absorbancy needs to be taken as essential influence factors, and by adopting the method, the measurement precision of gas concentrations to be tested can be improved.

Description

technical field [0001] The invention is based on the Lambert-Beer absorption law, and by fully considering the influence of gas self-broadening on the absorption spectrum, the correction method for detecting gas concentration by the absorption spectrum analysis method is formed, and relates to the technical field of gas sensing. Background technique [0002] With the development of high-polluting industries such as petroleum, chemical industry, and vehicles, the detection of toxic and harmful gases in exhaust gas is becoming more and more important, and gas detection technology has become an indispensable technology. Absorption spectroscopy is a common method for detecting gas concentration at present. The direct absorption method is widely used in the industrial field because of its advantages of simple operation and direct measurement of gas concentration. [0003] The patentee is the Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, and the inven...

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Problems solved by technology

[0003] The patentee is the Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, and the inventors are Liu Wenqing, Tang Yuanyuan, etc. The invention patent "trace gas detection device and method based on mid-infrared quantum cascade laser direct absorption spectroscopy" involves the method (5) It is mentioned in the previous step that the peak value of the absorbance curve is used to invert the gas concentration, but the above-mentioned absorption method detection method has the following shortcomings, that is, the linear function is regarded as a constant when measuring the gas concentration, that is, the linear function is regarded as irrelevant to the concentration of the gas to be measured, In fact, when the concentration of the gas to be measured gradually increases, the self-broadening of the gas to be measured gradually takes the dominant position, and the linear function has a certain functional relationship with the concentration of the gas to be measured, which leads to the fact that our calculated results are different from the actual The concentration has a large deviation, resulting in inaccurate measurement of the concentration of the gas to be measured

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