Concentration quantification method of broadband cavity strengthening type atmosphere NO2 detection system

Abstract

The invention discloses a concentration quantification method of a broadband cavity strengthening type atmosphere NO2 detection system. The detection system is equivalent to a light optical path difference absorption spectrum (DOAS) detection system, the characteristic of the stable oxygen dipolymer content in atmosphere is utilized to obtain a light-absorbing optical path of the detection system, and the size of the concentration of the atmosphere NO2 is quantified. The quantification method comprises the following steps: determining an effective optical path function; selecting a measuring wave band, and calculating an effective optical path of an oxygen dipolymer absorption peak wavelength; calculating a correction factor of a gas absorption cross section, and correcting the absorption cross section of the gas; calculating the optical thickness to obtain the concentration of a gas pillar by virtue of DOAS matching; calculating the absorption optical path, and calculating the concentration of the atmosphere NO2. Compared with the existing method, the concentration quantification method provided by the invention has the advantages that the reflectivity of a lens is not needed to be calibrated, the operation process of the detection system is simplified, and the influence of a calibration error of the reflectivity of the lens on the quantification result is avoided.

Description

technical field [0001] The invention relates to a method for quantifying the concentration of atmospheric trace gases based on optical measurement, more particularly to a broadband cavity enhanced atmospheric trace gas NO 2 Concentration quantification methods for detection systems. Background technique [0002] Atmospheric NO 2 The content is in the range of sub ppbv to hundreds of ppbv, to measure NO in the atmosphere 2 content, it is necessary to require measurement techniques with high sensitivity. Broadband cavity-enhanced absorption spectroscopy technology is a highly sensitive optical measurement method, which uses an optical resonant cavity composed of high-reflectivity mirrors to increase the absorption optical path, thereby improving detection sensitivity. Then according to the fingerprint absorption characteristics of the gas, the gas components with extremely low concentration can be identified. At present, the technology has realized the NO 2 Highly sensiti...

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