In-situ online collection analysis meter and method for aerosol carbonaceous components

Abstract

The invention discloses an in-situ online collection analysis meter for aerosol carbonaceous components and an operation method. The meter comprises a carrier gas path system and a sampling-analyzing gas path system. The carrier gas path system comprises a main He gas path, a He gas purging path, a He / Ox gas path and a He / CH4 gas path. The sampling-analyzing gas path system comprises a sampling and analyzing-oxidizing furnace and an analyzing gas path. The online collection analysis method sequentially comprises the steps of sampling, purging, OC analyzing, EC analyzing, methane quantifying, methane determining, meter cooling and standby. According to the meter, other structures except quartz film are not arranged in a laser light path, so the accuracy of the light path is guaranteed; cutting points are calibrated at the same time through transmission lasers and reflection lasers, and change in blackness of the film is reflected comprehensively; a valve body is designed to greatly lower the quantitative error of internal standard gas of methane, so the stability of the internal standard gas is guaranteed, and the accuracy of measured results of EC and OC is improved; the gas paths are designed to guarantee the singularity of components of carrier gas in the systems and the stability of the system background at the analysis phase.

Description

technical field [0001] The invention relates to an environmental quality monitoring instrument, in particular to an aerosol carbonaceous component in-situ online collection analyzer and an online collection and analysis method thereof. Background technique [0002] Carbonaceous components in atmospheric aerosols usually account for 10-70% of the mass concentration of atmospheric fine particles and are an important component of atmospheric fine particles. It can be divided into three categories: organic carbon (Organic Carbon, OC), elemental carbon (Elemental Carbon, EC) and carbonic acid carbon (Carbonate Carbon, CC). OC refers to a mixture containing hundreds of organic compounds (such as aliphatics, aromatics, acids, etc.), mainly derived from emissions from primary combustion processes, biological emissions, and gaseous organic pollutants participating in photochemical reactions and gas particle conversion. process emissions. EC usually refers to a kind of amorphous car...

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Problems solved by technology

However, there are still some deficiencies in the structure and function of commercial online aerosol carbonaceous component analyzers: 1. The cutting point calibration method is single, and only one of the transmission laser calibration method or reflection laser calibration method is used, which cannot comprehensively reflect the film The change of blackness; 2. The heat on the quartz film is mainly transferred from the structure in contact with the quartz film inside the quartz tube and the surrounding air, and the heating is slow and uneven; 3. A quartz sheet is fired inside the furnace tube , it will be polluted during use, which will affect the accuracy of the optical path; 4. The use of carrier gas is wasteful and unreasonably distributed: the methane internal standard gas is discharged throughout the process, causing a large waste; the amount of carrier gas is not constant throughout the analysis process , changing from helium to helium + oxygen will cause background fluctuations and affect the measurement results

5. The structure of the valve body controlling the methane quantitative loop has a large dead volume, which will lead to instability of the methane peak

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