Method and apparatus for determining the shape characteristics of particles, Heffels, C.M.G (1995)

To determine the shape characteristics of particles, a light beam (preferably a laser beam) is directed onto a transparent cell containing particles flowing therein and the intensity of the light scattered by the particles is measured with the aid of a photodetector array or a mask containing programmable light valves, comprising one or more concentric rings or parts of rings, at least one of which is provided with one or more isolated segments.