Microscopic characterization of particle size and shape: an inexpensive and versatile method

A variety of methods exists for measuring individual particle dimensions as a means of characterizing particle size, size distribution, and shape. The equipment described in this report belongs to the class of semiautomatic non-TV-interfaced analyzers. Unlike many existing image analysis systems, three-dimensional form measurements and texture data for the calculation of particle size and shape parameters can be determined easily and directly from each particle profile using this system. Essentially all data are collected directly from the particle and recorded by the computer with no intermediate steps. Much of the system consists of general-purpose and relatively inexpensive, commercially available hardware and software. Using this method, particle size, size distribution, and qualitative or quantitative shape information can easily and rapidly be obtained simultaneously. Particle length and width characterization, for example, can take less than 15 min. The equipment is versatile and flexible in measurements and calculations. The size and shape parameters to be measured are determined by the researcher and not the instrument. The ease with which this information can be obtained from small samples early in the development process makes it a valuable tool for the formulator.