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Many types of solid materials must be ground or milled into finer particles for dispersion in appropriate liquid vehicles. The physical properties of the resulting dispersions, often called "grinds", depend not only on the actual size of the individual particles, but also on the degree to wh ich they are dispersed.
The Fineness-of-Grind Gage is used to indicate the fineness of grind or the presence of coarse particles or agglomerates in a dispersion. It does not determine particle size or particle size distribution.
Grind gages are used in controlling the production, storage, and application of dispersion products produced by milling in the paint, plastic, pigment, printing ink, paper, ceramic, pharmaceutical, food, and many other industries.
The Fineness-of-Grind Gage is a flat steel block in the surface of which are two flat-bottomed grooves varying uniformly in depth from a maximum at one end of the block to zero near the other end. Groove depth is graduated on the block according to one or more scales used for measuring particle size.
The degree of dispersion is indicated in Microns or "Hegman". The Hegman scale ranges from 0 to 8 with numbers increasing as the particle size decreases.
- o Hegman = 100 microns particle size
- 4 Hegman = 50 microns particle size
- 8 Hegman = 0 microns particle size
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