ESTIMATION OF AVERAGE PARTICLE-SIZE FROM VERTICAL PROJECTIONS

A new stereological relationship is derived for the estimation of aver age size (average width) of a collection of convex particles in a 3D m icrostructure. The average size is estimated from measurements perform ed on projected images of the microstructure generated by total vertic al projections. The stereological relationship is as follows: (D) over bar = (I) over bar(C)/2N(O)beta. (D) over bar is the average width, ( I) over bar(C) is the average absolute number of intersections between the specifically oriented and regularly spaced cycloid shape test lin es and particle boundaries observed in the total vertical projections, No is the total number of particles observed in the total vertical pr ojection and the parameter beta is a characteristic of the measurement grid: it has units of reciprocal of length, The result is applicable to any arbitrary collection of convex particles; the particle orientat ions need not be isotropic. Only 'intersection counts' are required; i t is not necessary to measure sizes of the particles in the projected images.