This precision grindometer is used to determine particle size and the fineness of grind of particles in printing inks according to the National Printing Inks Research Institute (NPIRI) scale.

As ink particles are so fine the two grooves of the gauge have a gentle gradient allowing a scale of 2.5µm for better resolution. 

The groove width is 25mm (0.98”) and the groove length is 165mm (6.5”). The NPIRI scale is displayed alongside the microns scale. The NPIRI gauge and its scraper are made of hardened stainless steel.