Method for simultaneously measuring multicomponent gas based on cavity ring-down spectroscopy

Abstract

The invention discloses a method for simultaneously measuring multicomponent gas based on cavity ring-down spectroscopy. A broadly tunable light source outputs a light beam, and the light beam enters a gas cell with two ends provided with plano-concave high-reflectance endoscopes. The gas cell is filled with a multicomponent gas mixture having absorption spectrum within laser tuning range. Output wavelengths of the laser undergo tuning, ring-down signals are detected under different wavelengths, ring-down time under different wavelengths is obtained through single exponential fitting, and a relation curve of absorption coefficient and wavelength is further obtained. A spectral line of the measured gas mixture and a standard absorption line of each single gas in the database undergo fitting treatment, and concentrations of different gases in the gas mixture can be simultaneously calculated. By the utilization of the broadly tunable laser light source, a gas absorption spectrum with richer contents can be obtained, and multiple gases can be measured at real time. Macromolecules with wide spectrum absorption undergo concentration detection, and the detection result is not influenced by light source fluctuation.

Description

technical field [0001] The invention relates to the technical field of gas concentration detection, in particular to a method for simultaneously measuring multi-component gases based on optical cavity ring-down spectroscopy. Background technique [0002] Multi-component gas detection technology is an important detection method necessary for industrial production process control, environmental monitoring, national security and other fields. Especially in the detection of atmospheric environment, there are many types of common pollutant gases, and there is an urgent need for multi-component, high-sensitivity, real-time detection methods. The traditional measurement method is to use multiple electrochemical sensors to measure different gases, but the test accuracy of this method is limited, and it is difficult to meet the low-concentration target gas detection. [0003] At present, methods for gas detection using the infrared spectral characteristics of gases have been develop...

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Problems solved by technology

[0005] The technical problem to be solved by the present invention is: in view of the lack of precision of traditional multi-component gas detection instruments and the difficulty of performing multi-component simultaneous measurement of gases with broad-spectrum absorption characteri

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