Aerosol deposition in the sampling train of PM CEMS

A variety of particulate matter continuous emissions monitoring systems (PM CEMS) have been developed since 1960. The USEPA, in 1996, proposed performance specification to evaluate the acceptability of a PM CEMS. However, this performance test process did not include aerosol deposition loss, which is critical and essential from the perspective of aerosol sampling. A typical sampling train of the PM CEMS was evaluated in the present study. The aerosol penetration through all components of the sampling train were evaluated experimentally and theoretically. The aerosol deposition in the sampling train was significant, up to 40% for 10 ?m aerosols. This loss would result in significant underestimation of the PM emission. There is a gap between the model and experiment, especially for the elbow inlet and the elbow connector to the sensor, where the principal deposition mechanism is inertia impaction. The adoption of a pre-separator might eliminate most of the aerosol deposition.