System and method for measuring nitric oxide in a small amount of gas

Abstract

The invention discloses a system and method for measuring nitric oxide in a small amount of gas. The system and the method are used for measuring a trace of nitric oxide in the gas sample. The ppbv (parts per billion by volume)-level concentration can be detected by the system by using only milliliters of gas sample. The system comprises sample instruction units, a reaction unit and a detection unit. The analysis procedures are as follows: the quantitative gas sample introduced by the sample instruction units is delivered into the reaction unit and mixed the reaction gas provided by the system; at the same time, the ultraviolet light source in the system emits ultraviolet light, and the gas sample is subjected to chemical reaction to produce another reaction product which can be very easily detected by the detection unit; and after the reaction finishes, a piston of the reaction unit pushes the reaction product into the detection unit. Due to the high efficiency of reaction, the detected concentration of the reaction product and the concentration of the nitric oxide have linear corresponding relationship, thus after the concentration of the reaction product is calculated through the generation of signals of the reaction product in the detection unit, and the concentration of the nitric oxide in the gas sample can be calculated.

Description

technical field [0001] The invention relates to a system and method for measuring the concentration of nitric oxide in a small amount of gas, which is suitable for meteorological and environmental departments to monitor the concentration of nitric oxide in ecological system emission sources or for scientific research units to use for nitric oxide concentration in other emission sources Emission measurement. Background technique [0002] Nitric oxide is not only an indirect greenhouse gas, but also an important air pollutant component; it and volatile ammonia (NH3) in the ecosystem indirectly have an important impact on climate and ecological environment by promoting the formation of aerosol particles and other processes. Nitric oxide emitted by terrestrial ecosystems is transported and deposited through the atmosphere, which can not only affect nearby ecosystems, but also affect the carbon and nitrogen cycle and gas emission process of marine ecosystems. Since nitrogen-cont...

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Problems solved by technology

[0003] The currently widely used chemiluminescence method for measuring nitric oxide is an online detection device. The sample gas flow rate must be maintained at 800-1000 ml per minute or even higher, and continuous sample input is required. It takes at least 5-10 minutes to obtain a stable test data. liter sample volume, which is not possible for samples from ecosystem emissions

In particular, the culture experiments in some laboratories cannot meet such a large sample volume

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