Handheld particle counter check particulate matter

PM is short of particulate matter. The meaning of PM2.5 means fine particulate matters under 2.5μm.
The source of PM2.5 is complex, and the composition is complex.
PM2.5 mainly deals with respiratory system and cardiovascular system.
So we should use handheld particle counter in home to check air quality around us.
To confirm the air good to breath or not. some family use the air purifer to clean the bad air.
We can use the laser particle counter to confirm the air purifier features and capability too.