Improved tables for the evaluation of sphere size distributions including the effect of section thickness.

The problem of determining the size distribution and population density of a population of spherical particles randomly distributed throughout a transparent matrix from data obtained by transmission microscopy on parallel plane-faced sections of known field area and thickness may be readily solved by the use of matrix algebra. The solution presented in this paper may be used to construct conversion matrices whereby the particle size distribution and the numerical density can be calculated directly from the frequency distribution of the observed diameters; the only mathematical processes necessary being mulitplication and addition. Specimen conversion matrices valid for a wide range of conditions are presented in the appended tables.