Monitor for measuring concentration of polluted gases by long-optical-path white cell DOAS (Differential Optical Absorption Spectroscopy) method

Abstract

The invention discloses a monitor for measuring the concentration of polluted gases by a long-optical-path white cell DOAS (Differential Optical Absorption Spectroscopy) method. The monitor is characterized by comprising a light splitting device, a white cell set and a multichannel spectrograph, wherein the light splitting device scatters a light source for detecting spectral wavebands of the polluted gases with all components; the white cell set consists of white cells connected by a gas path pipeline in series; the start end of the white cell set is connected with the gas path pipeline introduced with sample gas, and the tail end of the white cell set is connected with a sampling pump; the spectral wavebands scattered by the light splitting device are respectively fed into incidence ports of the corresponding white cells through optical fibers; the spectral wavebands passing through all the white cells are respectively and correspondingly fed into all channels of the multichannel spectrograph through emitting ends of all the white cells and are used for performing spectral analysis. According to the monitor disclosed by the invention, detection precision of the polluted gases ishigh; meanwhile, a monitoring optical light is simple in design and adjustment, and the maintenance amount is small.

Description

technical field [0001] The invention relates to the technical field of gas concentration monitoring, in particular to a monitor for measuring the concentration of polluted gas by the long optical path White cell DOAS method. Background technique [0002] In the 1970s, differential absorption spectroscopy (DOAS for short) has been used to measure NO2 and NO3 in the stratosphere; in the late 1970s and 1980s, Platt et al. applied DOAS technology to atmospheric measurements and took advantage of the technology ; In the late 1980s, the system established by the DOAS method began to be commercialized and used to measure ambient air quality, continuous emissions from factories, and process gases. [0003] DOAS gas monitors use the characteristic absorption of light radiation by molecules for gas analysis. Different gas molecules have their own characteristic absorption "fingerprint" spectra. When a beam of light passes through the atmosphere, the light will be selectively absorbed...

AI Technical Summary

Problems solved by technology

Since the monitoring optical path is an open space, the optical path spectrum of the system is easily disturbed by environmental factors such as ambient temperature, humidity, and aerosols in the air, resulting in certain system errors, and even in bad weather (rainstorms, sandstorms, etc.) cannot be performed stably Normal monitoring work

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