What are the PM values, and what size particles do they represent ?

PM values shown on sensors like the E and E-Lite, the particle count is cumulative. So, for example, on the E-Lite:

- PM1.0 includes all particles between 0.3um and 1.0um

- PM2.5 includes all particles between 0.3um and 2.5um

- PM4.0 includes all particles between 0.3um and 4.0um

- PM10 includes all particles between 0.3um and 10um

Also on commercial PM sensors like the Sensirion SPS30 uses on the E-Lite model, some PM levers are interpolated rather than measured. Here is a text from the Sensition documentation about this: