Glossary - Elcometer 480 Guia Del Usuario

16 CARE & MAINTENTANCE
The gauge does not contain any user-serviceable components. In the
unlikely event of a fault, the gauge should be returned to your local
Elcometer supplier or directly to Elcometer. The warranty will be
invalidated if the gauge has been opened.

17 GLOSSARY

17.1 GLOSS
Gloss is the visual sensation associated with the brightness of direct
light reflected in a surface. Surfaces with high reflectance are
determined as glossy; less reflective surfaces are semi-gloss or matt.
Glossmeters quantify this effect by measuring light reflection from a
sample at defined angles.
The measurement angles most commonly used for gloss are 20°, 60°
and 85°. The most appropriate angle should be selected dependent on
the glossiness of the sample surface. Using the correct measurement
geometry increases resolution and improves the correlation of results
with human perception of quality.
To determine the correct measurement angle the surface should be
assessed with the 60° geometry:
- Matt surfaces which measure below 10 GU at 60° should be
assessed with the 85° angle.
- High gloss surfaces which measure above 70 GU at 60° should
be assessed using the 20° angle.
The 60 degree angle is best employed on mid gloss samples
measuring between 10 and 70 GU.
17.2 HAZE
Haze describes the milky halo or bloom seen on the surface of high
gloss finishes. It is caused by microscopic surface texture which
diffuses light adjacent to the main component of the reflected light.
Surface haze can be problematic in most coating applications
including automotive manufacture, powder coatings and other high
gloss coatings. It can be attributed to a number of causes including
incompatible materials in a formulation, poor dispersion and problems
encountered during drying/curing/stoving.
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