Size Determination With the Haemacytometer*

Abstract

The articlc describes a quick microscope method for determining the average parThe method is an adaptation ticle size of ground materials under 200-mesh in size. of the blood-count cell or haemarytometer.

Measurement of Specific Surface Areas of Nonporous Powders by a Pressureecline Liquid-Permeability Method.

“…Microscopical measurements of surface area and particle size Glass spheres: The specific surface area and particle size of the 70-to 100mesh sample of glass spheres was determined with the light microscope, using four independent methods: (1) The projected-area method or Kenrick method (11,21,22) was employed to determine the specific surface directly. This method is based on the principle that the mean projected area of particles having no reentrant surfaces is one-quarter of the total surface area.…”

Precise Measurements of Particle Surface Area with Microscope

“…SA represents the summation of areas of the projected images of n convex particles mounted in random orientation, a type of mounting not normally obtained on microscope slides. 1 Present address, Box 776, Bartlesville, Okla. 2 Present address, Continental Oil Co., Ponca City, Okla. Photomicrographs or tracings from projections of fields from microscope slides are required for making particle surface-area measurements by the projected-area method.…”