Difference between handheld particle counter PM100,PM10,PM2.5

The difference between particle counter PM100,PM10,PM2.5

Diameter greater than or equal to 100 micron particles in the atmosphere for total suspended particles in
the air(PM100)

Atmospheric particulate matter is less than or equal to 10 microns in diameter are inhaled particulate
matter(PM10)
Diameter less than or equal to 2.5 micron particles in the atmosphere which can go directly to the alveoli
(PM2.5)