A glossmeter measures specular reflection. The light intensity is registered over a small range of a pre-defined reflection angle. The intensity is dependent on the material and the angle of illumination. In case of nonmetals (coatings, plastics) the amount of reflected light increases with the increase of the illumination angle. The remaining illuminated light penetrates the material and is absorbed or diffusely scattered dependent on the color. Metals have a much higher reflection and are less angle dependent than non metals.

 

 

So for different materials, we need different angles gloss meter.

 

How many different angles shall we have for gloss meter?

 

High Gloss - 20° or micro-gloss 20˚

 

A smooth and highly polished surfaces reflect images distinctly. The incident light is directly reflected on the surface, i.e. only in the main direction of reflection. The angle of incidence is equal to the angle of reflection.

 

Semi Gloss - 60° or micro-gloss 60˚

 

On rough surfaces the light is diffusely scattered in all directions. The image forming qualities are diminished: A reflected object does no longer appear brilliant, but blurred.

 

The more uniform the light is scattered, the less intense is the reflection in the main direction and the duller the surface will appear.  We have several models with 60 degree, such as NHG60, HG60, etc.

 

High and Semi Gloss - 60/20°  

 

One Gloss meter does double work. 

 

Low Gloss or Mat - 85° or micro-gloss 85˚

 

On very rough surfaces the light is diffusely scattered in all directions. The image forming qualities are much diminished: A reflected object no longer appears brilliant, but almost non-existent.

 

Measure all three modes - TRI-gloss (20°/60˚/85˚)

 

When one requires measuring all three types of surfaces described above, we have two gloss meters that simultaneously measures all three geometries. They are NHG268 and HG268 with 20°/60˚/85˚.