PM2.5 is one of the main air pollution now

^{Air pollution is geting more and more worse in recent years.
Smoke, total suspended particulate matter, particulate matter (PM10), fine particulate matter (PM2.5).
Nitrogen dioxide, sulfur dioxide, carbon monoxide, ozone, volatile organic compounds and so on.
Particle counter can check the fine particulate matter. both PM2.5 and PM10.
Also with the laser particle counter can get the current temperature and humidity.}