ABSTRACT
The pollutant extracted from the sampled gas is collected in some appropriate medium. After the percent isokinetic calculation has demonstrated that the average Environmental Protection Agency (EPA) Method 5 sampling velocity is within 10% of the average stack gas velocity, the particulate concentration and mass emission rate are calculated. Many continuous emission monitors directly measure the concentration of the pollutant of interest in the extracted gas. At a minimum, concentration-based regulations specify maximum allowable pollutant mass per volume of exhaust gas at standard temperature and pressure. More typically, concentration-based regulations overcome the dilution possibility by specifying a correction of reported pollutant concentration to that in gas with a specific CO2 or O2 concentration or percent excess air. Different stack temperatures, gas pressures, and different dilutions with excess air could mean actual concentrations bear little relationship to optimum rate of pollutant emission for that type of source.
