Piezoelectric resonant type PM2.5 monitoring system

Abstract

A piezoelectric resonance PM2.5 monitoring system, based on the piezoelectric resonance frequency difference method, adopts a modular design, mainly including a control unit, and an electrostatic deposition sampling unit, a piezoelectric resonance unit, and a frequency test unit connected to the control unit respectively and a display unit; the electrostatic sedimentation sampling unit mainly includes an impact inertial classifier and an electrostatic precipitator; the piezoelectric resonance unit mainly includes a piezoelectric quartz crystal resonator, an amplifier and a low-voltage power supply. The piezoelectric quartz crystal resonator is a double quartz crystal resonator composed of two identical piezoelectric quartz crystal oscillator circuits. The relationship model between the piezoelectric resonant frequency and the quality of the piezoelectric wafer is established, and it is determined according to the change of the piezoelectric resonant frequency. For the mass concentration of PM2.5, one oscillating circuit of the double quartz crystal resonator is the measurement terminal, and the other oscillating circuit is the reference terminal. The PM2.5 particle collection rate of the present invention is stable, and its monitoring sensitivity is not affected by many factors including ambient temperature.

Description

technical field [0001] The invention relates to PM2.5 monitoring, in particular to a piezoelectric resonance PM2.5 monitoring system. Background technique [0002] PM2.5 refers to fine particles with a particle size below 2.5 μm, which has become the primary pollutant in the urban atmosphere at home and abroad. The piezoelectric crystal oscillator method, also known as the piezoelectric crystal oscillator frequency difference method, is a method for measuring the PM2.5 mass concentration based on the change of the resonance frequency of the piezoelectric element. It has the advantages of high monitoring sensitivity, good selectivity, and relatively simple equipment, and has become increasingly popular. People in the relevant industry pay attention to it, but its defect is that the collection rate of PM2.5 particulate matter is not stable enough, and its monitoring sensitivity is easily affected by many factors including ambient temperature. Contents of the invention [00...

AI Technical Summary

Problems solved by technology

The piezoelectric crystal oscillator method, also known as the piezoelectric crystal oscillator frequency difference method, is a method for measuring the PM2.5 mass concentration based on the change of the resonance frequency of the piezoelectric element. It has the advantages of high monitoring sensitivity, good selectivity, and relatively simple equipment, and has become increasingly popular. People in the relevant industry pay attention to it. The defect is that the collection rate of PM2.5 particulate matter is not stable enough, and its monitoring sensitivity is easily affected by many factors including ambient temperature.

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