Gloss is a property of the appearance of an object. Glossiness describes the spatial geometric distribution of reflected light on a material surface. There are various methods to measure the glossiness of the sample surface, and mirror reflection is mostly used in the world at present. In this method, the standard plate and the measured sample are illuminated respectively at the speed of light under the specified incidence Angle, and the reflected light of the sample and the standard plate is measured according to the specified acceptance conditions on the mirror reflection Angle.
The key of gloss measurement is to specify the measurement conditions. Due to different material properties and gloss levels, it is necessary to select different mirror Angle and light speed incidence conditions and acceptance conditions. It can be seen from the gloss measurement standard that when testing the gloss of different materials, different measurement angles should be selected. In general, low gloss samples are measured at large angles and high gloss samples are measured at small angles.
For universal materials, generally choose 60 degrees universal glossometer.
For high gloss materials, generally choose 20 degrees gloss meter.
Glossometer 60° and 20° application range:
We often do not know how to choose the gloss measurement Angle when using the gloss meter. All light sources reflect off a surface, and the level of the amount of reflected light is called the surface gloss value. Gloss values are measured in gloss units (GU), corresponding to a standard value of approximately 100GU. Gloss can be divided into 3 general ranges: low gloss, half gloss and high gloss.
All the angles are calculated from a vertical perspective. Each range is measured at its own Angle. To figure out which Angle to measure from, 60° is a good place to start. If the result is between 10 and 70GU, the coating can be called semi-gloss, measured with this Angle. If the result is less than 10GU, the product is called low gloss and should be measured with 85°; If the result is higher than 70GU, the product is high gloss and is measured with 20°.