Question

Why PM2.5 is measured at traffic signals or major junctions?​

Answer 1

There are also several ways to express the amount of PM2. 5 in the air. A photometer will typically output the “transparency” of the air, while an optical particle counter will output a particle count (the actual number of particles in the air). A BAM will output a mass concentration.

Answer 2

Answer:

To measure PM10 and PM2. 5, extract a sample of gas at a predetermined constant flow rate through an in-stack sizing device. The particle-sizing device separates particles with nominal aerodynamic diameters of 10 micrometers and 2.5 micrometers.