Particulate matter concentration sensor based on true root-mean-square detection

Abstract

The invention relates to a particulate matter concentration sensor based on true root-mean-square detection. The particulate matter concentration sensor comprises a voltage stabilizing power supply circuit, an air pump, a laser device, a detection casing, a silicon photodiode, a signal conversion and filtering circuit, and a true root-mean-square detection circuit. The air pump is used for sucking the particulate matters in air into the detection casing; the particulate matters sequentially pass through a narrow air path, and are irradiated by the laser to generate a pulse light signal; the pulse light signal is converted into a fluctuating current signal by the silicon photodiode; the current signal is converted into a voltage signal by the signal conversion circuit; the voltage signal is filtered into a voltage fluctuating signal with zero average value by a high-pass filter, and the voltage fluctuating signal is converted into direct current voltage by the true root-mean-square detection circuit, and is used as an output signal of the sensor; the higher the concentration of the particulate matters in the air is, the larger the light fluctuating is, and the larger the output signal is; the concentration of the particulate matters is detected by the principle. The particulate matter concentration sensor has the advantages that the structure is simple, the power consumption is lower, the property is reliable, the convenience in use is realized, the anti-interference capability is high, and the like.

Description

technical field [0001] The invention relates to the technical field of measuring the mass concentration of particulate matter in the atmosphere, in particular to a particulate matter concentration sensor based on true effective value detection. Background technique [0002] The mass concentration of atmospheric particulate matter is one of the important factors to evaluate the quality of air. It not only seriously affects visibility, but also has a very serious impact on human production, life and health. In modern life, with the improvement of people's requirements for air quality, people need to know the air quality of their environment in order to better arrange various production and living activities; at the same time, air purifiers have become standard equipment for many families. , in order to reduce energy waste, people need to detect air quality in real time to decide whether to turn on the air purifier. All of the above require a fast and accurate means of detecti...

AI Technical Summary

Problems solved by technology

The manual weighing method has high detection accuracy, but it requires professional equipment and personnel, and the measurement period is long, which is not suitable for continuous measurement; the β-ray method and micro-vibration balance method have high detection accuracy and can achieve continuous measurement, but the instruments are precise and expensive , and the maintenance cost is extremely high, it is not suitable for families and general public places; the light scattering method can realize continuous measurement, the structure is simple, and the cost is very low, but the detection accuracy of this detection method is not high, especially affected by external factors such as temperature and humidity And internal factors such as the power fluctuation of the laser during long-term operation have a great influence, and professional equipment is required to calibrate after a period of operation

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