Due to the wide gloss range from very matte surfaces to mirror-like surfaces, the differences in the energy level of the reflected light can be...

Due to the wide gloss range from very matte surfaces to mirror-like surfaces, the differences in the energy level of the reflected light can be huge. As the measurement system (optics and electronics) cannot be linear over this wide range, different measurement geometries are needed in order to cover the full range of gloss values with a constant quality of the result (linearity).

The measurement geometry has to be selected depending on the glossiness of the surface.

In order to determine the appropriate geometry the following procedure is used:

1. Measure at 60°
2. On matt surfaces, if the result @60° <10 GU à use 85° geometry
3. On high gloss surfaces: if the result @60° >70 GU à use 20° geometry