Gas concentration linear measurement method based on adaptive differential absorption spectrum technology

Abstract

The invention provides a gas concentration linear measurement method based on an adaptive differential absorption spectrum technology. The method comprises the following steps of collecting and processing the full-spectrum data of a gas to be measured, automatically selecting a measurement wave band by an adaptive sliding window and calculating an estimation coefficient, adaptively and dynamically screening an optimal estimation coefficient, inverting an optimal measurement concentration value of the gas to be measured and calculating a relative measurement error. According to the method, the automatic division of the measurement wavebands is completed through the adaptive sliding window, and the estimation coefficients under different measurement wavebands are calculated; by adaptively and dynamically screening the optimal estimation coefficient of the to-be-measured gas, inverting the optimal measurement concentration value of the to-be-measured gas, and calculating the relative measurement error, the feasibility of the method is verified; according to the invention, the non-linear effect in the gas measurement process based on the differential absorption spectrum technology is eliminated, the problem of difficulty in calibration in gas measurement is solved, the measurement precision is improved, the accurate measurement of the gas with unknown concentration is finally realized, a detection limit is expanded, and the gas dynamic measurement is realized.

Description

technical field [0001] The present application relates to the technical field of gas detection, in particular to a linear gas concentration measurement method based on adaptive band selection and differential absorption spectroscopy. Background technique [0002] In recent years, the content of various suspended particles in the atmosphere has exceeded the standard, leading to smog weather, which in turn has caused problems such as turbid atmosphere, blurred vision, deterioration of visibility, and affecting the normal operation of human body systems. The main components of smog are sulfur dioxide, nitrogen oxides, and inhalable particulate matter. The gaseous pollutants mainly come from automobile exhaust and coal combustion, and are transformed into pollutants such as nitrogen oxides and metal oxide particles in the air. , It is easy to cause environmental disasters such as the Maas Valley incident; the formation of acid rain causes soil acidification, corrosion of buildin...

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Problems solved by technology

[0004] In current research results, when DOAS technology is used to measure polluted gases, some discrete wavelengths with obvious differential absorption structure and corresponding absorption lines are selected according to certain rules to invert the gas concentration. If the ratio is very low, the transmitted light intensity received by the spectrometer is weak, and there must be errors in the measured concentration value; for the full-spectrum measurement method, it is only suitable for the measurement of low-concentration gases. If the concentration is too high, it will lead to saturated absorption in the band with strong absorbance. phenomenon, resulting in measurement errors

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