Coating of impaction surfaces of cascade impactors: Necessary for sampling ambient aerosols in rural and suburban areas?

Abstract

Field experiments with low-pressure cascade impactors (Type AERAS LPI 3010.06) have been carried out to determine whether coating of the impaction surfaces is necessary for the correct determination of aerosol mass size distributions in rural and suburban areas. In general, an impactor with coated surfaces collects up to 100% more giant particles ( d a > 1 μm), and more than 20% more total mass, than an uncoated reference impactor. Also, the size distribution is in much better agreement with optical particle counter data, and the total mass is closer to values determined with a high-volume filter sampler, than in the case of the uncoated impactor.