The calculation of true particle size distributions from the sizes observed in a thin slice

Abstract

Particle size distributions obtained from measurements in a thin section are usually a distorted version of the true distribution. When there is negligible overlap of images the conversion of the observed distribution involves the solution of a Volterra integral equation of the second kind. A closed form of solution is obtained for spherical particles, but it requires numerical integration. In practice a simple linear transformation of the frequencies in an observed histogram is more useful. The method is applied to delustrant and pigment particle sizes seen in a micrograph of a slice of polymer chip or extruded fibre.