Fineness of Grind

A grind gauge is an instrument used to quickly evaluate the quality of a dispersion.

The grind gauge is an instrument that indicates the fineness of grind or the presence of coarse particles and agglomeration in a dispersion. It is commonly used to determine how finely ground the particles of pigment are dispersed in a sample of paint.

The grind gauge consists of a steel block with one or more machined grooves. The depth of the grooves varies steadily between a minimum and maximum value. A sample is placed on the grind gage and a machined scraper is drawn at a constant rate beginning at the deeper end of the groove. The gauge is then viewed at a 20-30 degree angle. Scratches will form in the wet coating in the grooves. The point where the scratches begin indicates the grind. A scale aside from the groove corresponding to the particle size indicates the grind reading.