Luster basic knowledge principle and testing instrument

Gloss test principle

Glossometer mainly measures the glossiness/reflectance of the surface of an object.
The gloss is calculated by reflecting the incidence Angle of the light source back to the corresponding Angle receiver. The gloss unit is GU
Generally divided into: single Angle: 60° measurement
Multi-angle: 20°, 60°, 85° three-angle measurement

What is light spot: Measuring the area of light emitted during the hole test, not measuring the hole size.

Roughness and gloss misunderstanding

The difference between roughness and gloss

Surface roughness refers to the small spacing of the machined surface and the unevenness of the small peaks and valleys. The distance (wave distance) between the two peaks or two troughs is very small (below 1mm), and it belongs to the microscopic geometry error. The smaller the surface roughness, the smoother the surface.

Surface roughness and surface finish are the same concept, and surface finish is another name for surface roughness. There are corresponding comparison tables for surface finish and surface roughness.

Surface roughness meter Surface roughness measurement using roughness meter (size detection instrument) detection;

The surface glossiness is the strength of the diffuse reflection of the object surface to the light, which can be measured by the surface glossiness. Surface gloss To the naked eye, the surface diffuse reflection is strong, it is closer to the mirror effect, then the gloss is high, on the contrary, the surface diffuse reflection is weak, then the gloss is low, so the gloss is also called mirror gloss.

Handheld gloss meter

                                CS-300 single Angle gloss meter                                                            CS-300S microporous gloss meter       

                                        Test diameter 2*3mm                                                                                Test diameter 2*3mm

Gloss units and national standards

What is the unit of gloss?

In China, our general saying is how much gloss is, for example, the gloss is 60 degrees, it can be understood as a gloss of 60GU or 60%.
What does GU stand for? Gloss meter unit we call the Gloss unit, the international practice symbol is expressed as GU, is the acronym of gloss unit, according to the provisions of JIs standard, gloss unit can be written as a percentage sign or number, the domestic gloss meter generally measured range is 0~ 200GU~ 1000GU.

National standards for gloss:
一、gloss meter 20° reference standard: DIN-67530, ISO-2813, ASTM-D2457 GB 9754, GB 8807, ISO-8254, ASTM-D523, which is mainly used for high gloss ink, paint, paper, plastic, stone, light casting coated paper and so on.

二、gloss meter 60° reference standard: ISO-2813, DIN-6750, ASTM-D2457, ASTM-C584, ASTM-D523, GB 9754, GB 8807, GB 9966 It is mainly used for medium gloss coated paper, marble, ceramics, paint, ink, plastic and so on.

三、gloss meter 85° reference standard: ISO-2813, DIN-67530, ASTM-D523 GB9754 It is mainly used for camouflage coating, low gloss paint and so on.

Handheld gloss meter difference

Gloss meter is generally distinguished by the test Angle,
Spot size, range differentiation