THE USE OF PROJECTED AREA DISTRIBUTION-FUNCTIONS IN PARTICLE-SHAPE MEASUREMENT

The measurement of particle shape by image analysis and light scatteri ng depends, inter alia, upon projected area. Non-spherical particles e xhibit a range of values for projected area and perimeter. The distrib ution functions for these variables, together with their mean values, are useful as signatures for specific shapes. When the results from in dividual, random orientations are being used as starting points for fu rther computation, we investigate how many results are needed to give good agreement with the actual distribution functions. Choosing the cu be as an example, it is shown how experimental data may be used to det ermine size using maximum-likelihood estimators. Adequate accuracy can be obtained with a modest number of data. The question of whether it is better to use a random or regular set of directions is investigated . (C) 1998 Elsevier Science S.A. All rights reserved.