HORIBA's Gloss Checker series provide an easy-to-use and an objective way of inspecting surface luster, eliminating ambiguity of subjective observations. HORIBA's Gloss Checker series give numerical value to glossiness, which can be utilized in quality control and process benchmarks.
When light shines on an object, some part of it is reflected, refracted or absorbed. There are basically two ways in which the light reflects off a surface, specular and diffuse reflections. Horiba gloss checker detector measures the percentage of specular reflection. The incident angles can be set at 2 different angles of 20° and 60° (IG-331) to suit different surface conditions. Standard setting of incident angle for most applications is 60°.
Specular reflection is the mirror-like reflection in which incident angle is identical to reflection angle in respect to surface normal. A polished surface gives more specular reflection and less diffuse reflection.
Diffuse reflection is the matte reflection in which incident light is reflected in a broad range of scattered angles. A sheet of frosted glass or cardboard gives less specular reflection and more diffuse reflection. We perceive such a surface to be matte or dull.