Division 2.2.2.4 Determination of the background corrected concentration

The average background concentration of the gaseous pollutants in the dilution air shall be subtracted from measured concentrations to get the net concentrations of the pollutants. The average values of the background concentrations can be determined by the sample bag method or by continuous measurement with integration. Equation (7-33) shall be used:

Where:

c _gas

net concentration of the gaseous pollutant [ppm] or [% vol]

c _gas,e

emission concentration in the diluted exhaust gas, on a wet basis [ppm] or [% vol]

c _d

emission concentration in the dilution air, on a wet basis [ppm] or [% vol]

D

dilution factor [see equation (7-28) of point 2.2.2.2] [-]