Long service life optical dust concentration sensor

Abstract

The invention provides a long service life optical dust concentration sensor which comprises an upper cover, a base, a circuit board, a fan and a light source component, wherein the circuit board is arranged above the base; the light source component is arranged above the circuit board; the fan is arranged above the light source component; the circuit board is covered with the upper cover; the fan, the circuit board and the light source component are covered inside with the upper cover; a microprocessor, a driving circuit, an external communication interface, a power supply interface, a temperature sensor, a humidity sensor, a phase lock synchronous processing circuit and a front amplifier are welded on the circuit board. Compared with the prior art, the sensor has the beneficial effects that from increase of signal to noise ratios of signals, light scattering principles are organically combined with light modulation techniques, weak useful signals which are generally covered by noisecan be extracted by using a phase lock synchronous demodulation processing method, and after the signals are processed by using related circuits and on-board microprocessors, particle sizes and related concentrations of air dust granules can be obtained.

Description

technical field [0001] The invention is a long-life optical dust concentration sensor, which belongs to the field of sensor equipment. Background technique [0002] With the continuous improvement of people's requirements for the performance of air purification equipment, higher and higher requirements are put forward for the working life, working temperature range, working stability and sensing accuracy of the supporting dust sensor. Most of the dust concentration sensors used in the field of air purifiers are designed based on the 'light scattering theory'. In order to make the sensor have sufficient sensitivity, it is an effective way to increase the intensity of excitation light. For this reason, semiconductor laser diodes are commonly used as light sources for such dust sensors. Due to the limitation of the characteristics of the semiconductor laser diode, its working life is insufficient compared with the life requirement of the sensor for the excitation light source...

AI Technical Summary

Problems solved by technology

[0007] (1) The working life of the light-emitting element is short, which cannot fully meet the requirements of the purifier for its life;

[0008] (2) The allowable working environment temperature range of the light-emitting element is narrow, especially when the ambient temperature is higher than 70°C.

[0009] The anti-interference ability and long-term stability and reliability of the product are not ideal

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