Stage Response of an Andersen Cascade Impactor to Monodisperse Droplets.

摘要

Stage responses for an Andersen Mark III cascade impactor have been experimentally determined using monodisperse oil droplets. The impactor was operated upright and fully assembled so that interstage interference and wall losses could be properly studied. Interstage losses reached a maximum of about 15% for particle aerodynamic diameters of about 10 mu m. The observed stage responses, defines as the fraction of particles entering the impactor that are collected on a stage, showed maxima that fell significantly short of unity (as low as 0.6). Physically, maxima less than unity indicate that a monodisperse aerosol is never collected exclusively on one stage, but is distributed among several stages and internal losses. Correlations for the stage responses are presented so that the experimental results can be used to determine size distributions with available data-inversion algorithms. One potential application of this technique is the characterization of droplet clouds generated by explosive events. 21 refs., 4 figs., 2 tabs.