Update: 2019-08-21 17:36 Source: LUFTMY
The principle of air purification can be seen as three steps: discovery, purification and release. Air purifiers detect indoor pollutants, filter them, and then expel clean air. Only when these three steps are well coordinated can air purifiers exert their maximum effect.
How can the air purifier quickly perceive the changes of indoor air quality, feed back to users, and change gears can undoubtedly be more effective in cleaning air and saving energy and prolonging life? That is to find that the pollutant is a switch for the air purifier to start working. The air purifier finds that pollutants are achieved through the "eyes" inside the product. This eye refers to a dust sensor.
Based on the principle of light scattering, high quality infrared diode is used as light source. The photodetector receives scattered light and converts it into electrical signal. The analog and digital signals are output through precise filter and amplifier circuit processing and CPU algorithm conversion.
HPD05 infrared PM2.5 sensor schematic diagram
Directly output PWM signal, PWM width is the current concentration value (1ms = 1ug/m3), can also output the dust concentration value (unit ug/m3) through IIC serial signal.
Application fields of Leftmy PM2.5 infrared sensor: air conditioner with purification function, air purifier, vehicle purification equipment, portable detector, fresh air system, intelligent detector, etc.