Abstract: Apparatus for analysis of particulate material employs a stack of spaced sieves permanently joined to form a sieve column. Clean-out ports are provided for inter-sieve spaces. In one embodiment the clean-out ports communicate with a common passage that is closed by a removable rod. In another embodiment individual clean-out ports are closed by separate plugs. Guard sieves are provided to protect the usual sieves at the ends of the column.

Abstract: This invention relates generally to the field of particle chromatography, and more specifically to a method and apparatus employing the cascade principle for the purpose of characterizing particles according to subtle differences between the individual particle contours, by passing the particles through a repetitive series of sieves in a column, that have the same mesh size and are dimensioned to pass the entire sample, and wherein the particle characterization is based upon resident time of the similarly shaped particles within the column.