How do I use a gloss meter to measure gloss?

    A glossmeter (also gloss meter) is an instrument designed to measure the specular reflection (gloss) of the object surface. Gloss is determined when a beam of light is projected at a fixed intensity and angle onto the object surface and measuring the amount of reflected light at an equal but opposite angle.

     Gloss is an important aspect of our visual perception of objects. Gloss is related to the surface of the product, the texture and the way the sample is illuminated and viewed. Surfaces with high reflectivity are considered as glossy, shiny or lustrous, while surfaces with lower reflectance are considered to be semi-glossy or matt. Gloss can be measured by several different techniques. One of them is the use of an optical instrument called a gloss meter. The gloss meter provides quantifiable gloss measurements, expressed in gloss units (GU).

Gloss measurements come in a variety of different geometries, each depending on the type of surface being measured. For non-metals such as paints and plastics, the amount of reflected light increases as the angle of illumination increases, because some light penetrates the object surface and then be absorbed or diffused by the object surface, depending on its color. Metals have a higher reflectivity and therefore less dependence on angle. Gloss meter is an instrument used for the gloss measurement. Different object surfaces require different measuring angles.

   The measurement scale of the gloss meter, the unit of glossiness (GU) is based on the highly polished reference standard for black glass with a defined index of refraction and a mirror reflectance of 100GU at a specified angle. This standard is used to establish a calibration point with an upper limit of 100 and a lower endpoint of 0 on a completely matt surface. This scaling applies to most nonmetallic coatings and materials (paints and plastics) as they are usually within this range. For transparent materials, these values can also be increased due to multiple reflections within the material.
     For other highly reflective materials (mirror, coated/raw metal components), higher values can be achieved up to 2000 glossiness units.

     ISO2813，ISO7668,ASTM D523,ASTM D2457，DIN 67530，GB/T9754, GB/T13891，GB/T7706, GB/T8807
     All the indicators of the gloss meter have reached the requirements of the first-class working machine in the national JJG 696-2002 "specular gloss meter and gloss board" metrological verification procedures.