Cavity ring down aerosol extinction spectrometer

Abstract

The present invention relates to a cavity ring down aerosol extinction spectrometer, which comprises an optical path system, an electrical circuit system and a gas path system, wherein the optical path system comprises a light source, an optical cavity and a light adjustment system, the gas path system comprises a sample gas path, a protection gas path, an electromagnetic triple valve, an aerosol filter and a gas pump, the electromagnetic triple valve and the aerosol filter are arranged on the front portion of the optical cavity, the gas pump is arranged on the rear portion of the optical cavity, the electromagnetic triple valve, the aerosol filter and a relay form an automatic zero calibration device, the electrical circuit system comprises an optical path control part and a data acquisition part, the optical path control part comprises a digital delay generator, and the data acquisition part comprises a photomultiplier tube, a stabilized voltage power supply, a computer and a high-speed data acquisition card. The cavity ring down aerosol extinction spectrometer has the following advantages that: accuracy is high and can achieve 10<-1> Mm<-1>, time resolution is high and can achieve 20 s, and in situ measurement is performed on the sample so as to provide less influence on the sample.

Description

technical field [0001] The invention relates to the field of measurement of atmospheric aerosol extinction coefficient, in particular to an optical cavity ring-down aerosol extinction instrument. Background technique [0002] Atmospheric aerosols refer to particles or liquid droplets suspended in the air, which can scatter and absorb light. Under the combined action of the two, light will attenuate when passing through the atmosphere. The attenuation effect of this atmospheric aerosol on light can be accurately expressed by its extinction coefficient. From the perspective of existing technologies at home and abroad, in order to measure the extinction coefficient of atmospheric aerosols, the astigmatism coefficient and absorption coefficient of the aerosol are usually measured separately, and the sum of these two coefficients is the extinction coefficient of the aerosol. At present, the measurement of scattering coefficient is relatively mature, and it can realize accurate a...

AI Technical Summary

Problems solved by technology

[0009] In addition, unlike gas molecules, atmospheric aerosols are very easy to adhere to the surface of the high-reflective mirror. Without protection, the reflectivity R of the high-reflective mirror will continue to decrease with the adhesion of particles, and the ring-down time will decrease, making the measurement The sensitivity is greatly reduced

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