A SHAPE FACTOR TO CHARACTERIZE THE QUALITY OF SPHEROIDS

A shape factor e(R) has been devised to describe how the form of spher ical particles approaches that of a true spheroid, based on a two-dime nsional image analysis. Both the deviation of shape from a circle towa rds an ellipse and surface irregularities influence the value of e(R). Using a set of model figures such as squares, triangles, diamonds and stars, it could be shown that e(R) clearly differentiates between dif ferent polygonally symmetric figures, even in the case where common sh ape descriptors such as the aspect ratio provide equal values. The val ue of e(R) is 1.0 in the case of a perfect spheroid, while ellipticity and surface roughness lead to a significant change in the value.