DETERMINATION OF MEAN PARTICLE-VOLUME, A MONTE-CARLO SIMULATION

Either length measurements or area measurements may be made on a sampl e of profiles for the purpose of estimating the mean volume of a popul ation of convex particles. Diameters of spheres, caliper diameters of ellipsoids and intercept lengths are available length measurements. Pr ofile areas can be evaluated by planimetry or point counting. Either a ll the available profiles in random sections or point sampled profiles can be utilized. We have applied a Monte Carlo simulation to compare several of the stereologic methods for the estimation of the mean Volu mes of spheres and ellipsoids. Populations of spherical, prolate ellip soidal and oblate ellipsoidal particles were subjected to random secti oning and measurement. Diameter, point sampled intercept length, area and point sampled area were measured in the case of the spherical part icles. With the ellipsoids, the same measurement excepting diameters w ere performed. The measurements were converted to volumes by the appro priate equations, and the means, the standard deviations of the means and the 95% confidence intervals were determined for increasing sample sizes. All the methods provide estimates that converge on their theor etical mean volumes. The area measurements and particularly the point sampled area measurement show some advantage over the length measureme nts, but differences among the methods are small, not entirely consist ent over the different cases and unlikely to be significant in most re al applications. (C) 1997 Elsevier Science Ltd.