This is a multifunction air quality monitor that can be detected not only the concentration of particles and formaldehyde but also the value of temperature and humidity.
As the particle concentration sensor it can be used to obtain the number of suspended particles in the air by laser. It also integrates in it an electrochemical probe for formaldehyde and an one- chip sensor for temperature and humidity.
The sensor can be inserted into variable instruments related to the environment parameters in the air or other environmental improvement equipments to provide correct data in time.
Working principle: Laser scattering principle is used for such sensor, i.e. produce scattering by using laser to radiate suspending particles in the air, then collect scattering light in a certain degree, and finally obtain the curve of scattering light change with time. In the end, equivalent particle diameter and the number of particles with different diameter per unit volume can be calculated by microprocessor based on MIE theory. Please find the functional diagram of each part of sensor from Figure 1 as follows. The function of formaldehyde detector is based on the electrochemical theory and math algorithm.