This following comes from the Marple Impactor Operator's Manual (p. 18-19).
Use of cascade impactor data requires knowledge of the cut-points of the impactor stages. Table
8-1 gives the experimentally determined cut-points at the designed flow rate of 2 liters per minute.
|Impactor Stage No.||Cut-Point* Dp (Microns)|
*Aerodynamic equivalent particle diameter for spherical particles of uniform mass
density in air at 25ºC and 1acfm.