Differential optical absorption spectroscopy air quality detection system

Abstract

The invention provides a differential absorption spectrum air quality inspecting system, which comprises a photo source, a photo source launching device, a photo source receiving device, a spectroscope, photovoltaic conversion equipment and a data processing system. The photo source launching device and the photo source receiving device are separately positioned on the two sides of the photo source, a light path which goes through the gas to be inspected is formed of the light sent out by the photo source through the photo source launching device and the photo source receiving device, and thelight signal produced is imported into the spectroscope through optical fiber, and the light signal is then transformed into electrical signal through the photo electricity commutating equipment; Finally, the data processing system adopts the signal analysis method of the Fourier transformation to process the spectrum, and the absorbance curve line of the gas inspected is obtained; and the density of the gas inspected can be obtained according to the intensity of the absorbance curve line and the Lambert-beer law.

Description

Technical field [0001] The invention belongs to the field of air quality detection, and particularly relates to a detection system using differential absorption spectroscopy technology. Background technique [0002] In recent years, air pollution has become a matter of great concern. People’s awareness of environmental protection has increased, making environmental monitoring, especially air quality monitoring, more and more close to people’s lives, rather than pure scientific activities. Environmental conditions, including air quality, are also an important factor in evaluating the investment environment. Air pollution is very serious to human life, production and damage to the natural world, so the monitoring, control and treatment of air pollutants have important practical significance. [0003] Differential absorption spectroscopy technology is an optical method that has emerged in air quality monitoring. It uses the narrow-band absorption characteristics of gas molecules in ...

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Problems solved by technology

[0026] (2) When fitting the curve of the low-frequency part, the high-frequency part of the lamp spectrum cannot be filtered out, so in the subsequent processing, the high-frequency part of the lamp spectrum will be included in the absorption spectrum of the gas, causing the calculation results to appear large error

[0027] (3) There are many mathematical calculation steps in the data processing process, which increases the calculation error in the processing process itself;

[0028] (4) In the concentration inversion calculation, the least square method is used to fit and evaluate the entire absorbance curve. If there are many types of gases, the accuracy of the concentration inversion calculation will decrease; The gas will also have a greater impact on the inversion calculation of gas concentration

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