Wow! I wonder how they'll verify?
Counting PM2.5 Particles
The easiest way to monitor particle concentrations of PM2.5 is to use a particle counter. Setra's particle counters are designed to monitor both particle counts and VOCs. Our particle counters can measure particles as small as 0.3 microns and provide multiple particle size readings at once.Oct 1, 2020
https://www.setra.com/blog/measurin...2.5 Particles,particle size readings at once.