What is a gloss meter instrument?

Before introducing gloss meter, let's learn what is gloss firstly.
Gloss is measured by shining a known amount of light at a surface and quantifying the reflectance. The angle of the light and the method by which the reflectance is measured are determined by the surface.
Gloss is determined using a Gloss Meter which directs a light at a specific angle to the test surface and simultaneously measures the amount of reflection. The type of surface to be measured determines the gloss meter angle to be used and thus the gloss meter model.
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.
For those different material, their gloss is very different, and it needs different angle gloss meter to measure.
A glossmeter (also gloss meter) is an instrument which is used to measure specular reflection gloss of a surface. Gloss is determined by projecting a beam of light at a fixed intensity and angle onto a surface and measuring the amount of reflected light at an equal but opposite angle.
gloss meter
There are a number of different geometries available for gloss measurement, each being dependent on the type of surface to be measured. For non-metals such as coatings and plastics the amount of reflected light increases with a greater angle of illumination, as some of the light penetrates the surface material and is absorbed into it or diffusely scattered from it depending on its colour. Metals have a much higher reflection and are therefore less angularly dependent.
Many international technical standards are available that define the method of use and specifications for different types of glossmeter used on various types of materials including paint, ceramics, paper, metals and plastics. Many industries use glossmeters in their quality control to measure the gloss of products to ensure consistency in their manufacturing processes. The automotive industry is a major user of the glossmeter, with applications extending from the factory floor to the repair shop.
For measuring surface gloss, NHG268  ,NHG60 ,HG268,HG60,YG268,YG60 gloss meter is just the right tool. This measurement apparatus originally developed to measure the gloss on a variety of surfaces. Currently, these two models are being utilized to evaluate masonry finishes, floors, stone surfaces at the factory, molding, coated surfaces, printed matter, paint and ink, leather, rubber, ceramics, film, etc.