Apparatus for semi-automatic grain-size separation of small samples.

A semi-automatic sieving apparatus for separation of small samples (50-500 mg) of granular material into several uniform grain-size fractions is described. The achieved separations are reproducible, yielding more than 95% of the initial sample. Such separations are needed for investigations of surface phenomena in very fine powders. It is demonstrated that the apparatus is very suitable to handle highly radioactive materials, keeping the radiation doses very low for the operator. The separations into several fractions are faster, cleaner, and more reproducible than those obtained in ordinary hand-sieving techniques.