Automatic focusing laser PM2.5 dust sensor

Abstract

The invention discloses an automatic focusing laser PM2.5 dust sensor. The automatic focusing laser PM2.5 dust sensor comprises a sensor body and a detection system; the detection system comprises a laser diode, a lens, and a photodiode; and in conjunction with the detection system, the sensor also comprises a temperature control mechanism; the temperature control mechanism includes a PCB circuitboard, a temperature sensing component, and a telescopic component; one end of the telescopic component facing the airflow channel is fixedly mounted with the laser diode, and the other end is fixedlymounted with the PCB circuit board; the lens is fixedly arranged between the laser diode and the air flow channel; and the temperature sensing component and the telescopic component are electricallyconnected to the PCB circuit board separately. According to the invention, through the cooperation of the temperature control mechanism and the detection system, the focus that offsets due to the temperature change is returned to the original position; therefore, the detection accuracy of the detection system to a gas to be detected is improved.

Description

technical field [0001] The invention relates to the technical field of air quality detection, in particular to an automatic focusing laser PM2.5 dust sensor. Background technique [0002] PM2.5 dust is only a small component in the earth's atmosphere, but it has an important impact on air quality and visibility. Compared with coarser atmospheric particulate matter, PM2.5 particles have a small particle size, are rich in a large amount of toxic and harmful substances, have a long residence time in the atmosphere, and have a long transportation distance, so they have a greater impact on human health and atmospheric environmental quality. . In order to monitor the quality of the air environment, a detection device with a laser PM2.5 dust sensor is usually used to detect the air. [0003] At present, the laser PM2.5 dust sensor mainly focuses on the refraction and focusing of the circular lens in the laser system, and analyzes and detects the concentration of PM2.5 particles a...

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Problems solved by technology

[0003] At present, the laser PM2.5 dust sensor mainly focuses on the refraction and focusing of the circular lens in the laser system, and analyzes and detects the concentration of PM2.5 particles according to the change of the laser from refraction to focusing, and the use environment of the detection device is relatively complicated. It usually involves high temperature or low temperature environment. In different temperature environments, the refractive index of the lens will change with the change of temperature, which will cause the focus of the optical system to shift, thus affecting the detection accuracy.

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