The process of determining PM10 and PM2.5 emissions is technically demanding requiring the use of over 40 calculations. To measure PM10 and PM2.5, a sample of gas is extracted from the stack at a predetermined constant flowrate through in-stack cyclone(s). The sizing device separates particles with nominal aerodynamic diameters of PM10 and PM2.5. The flow rate used to extract the gas sample is critical in ensuring that correct particle sizing occurs.
Once a sample is obtained, it is analysed gravimetrically to determine the particulate mass for each size fraction.
For PM10/2.5 emissions six inch sampling ports are always required and in some cases where the gas velocity is high six inch ports are required for PM10 sampling.(See pictures below)
Standard method 5 probe used for particulate sampling fitting through a 4" port fitting
Picture showing that the Method 201A PM10 cyclone does not fit through a 4" port fitting
Picture showing that the Method 201A PM10 cyclone does fit through a 6" port fitting