Deposition uniformity on filter cassettes when the sampling is not isokinetic and isoaxial

The EPA protocol for the sampling of asbestos fibers was tested in a low speed wind tunnel using monodisperse fluorescein particles as a surrogate. The primary objective of the test were to examine whether the deposition on the filters were homogeneous when the sampling was not isoaxial or isokinetic. The Wilcoxon Sum of Ranks test was used to check whether there were statistically significant inhomogeneities in the deposition.