Calibrating Particulate Air Samplers with Monodisperse Aerosols.: Application to the Andersen Cascade Impactor

Monodisperse aerosols of methylene blue dye generated via a spinning disk and polystyrene latex aerosols generated via atomization have been applied in calibrating a multistage cascade impactor, the Andersen sampler, Model 0203. The reported method obviates many difficulties encountered with the size-count method of calibration commonly employed. Collection efficiency characteristics of the Andersen sampler are computed directly from mass retained at the deposition sites, since concurrent size distribution information on each aerosol generated indicates that values for number and mass median diameter are nearly equal. Experimental methods of generation, sampling, mass determination, and aerosol evaluation are presented with representative data. Collection efficiency curves obtained for the various stages of the Andersen sampler are given with computed values of effective stage cutoff diameters for aerodynamically equivalent unit-density spheres. Results are compared with those of previous experimenters.