I. What is gloss meter?

A gloss meter (glossmeter) is an glossiness measurement euipment which is used to measure the specular reflection (gloss) on the object surface. It can measure the gloss of materials such as paint, automotive, marble, printing paper, plastics, ceramic, stone, bamboo, leather and many other materials. Gloss testers provide quantifiable glossiness measurements, expressed in gloss units (GU).

II. How to use a gloss meter?

Many people is concerned about how to operate a gloss meter. Simple operation would benefit lots of users. The method of using different gloss meters will be different. If the instrument has too many buttons and requires cumbersome settings, it is relatively complicated for non-professionals to use. Using 60° gloss meter of portable size, we can complete the specular reflection gloss measurement with single hand.

III. How does the gloss meter work?

The gloss meter contains a light source, a screen, a receiver as well as a display screen. The measurement principle is shown in the figure below. 

Principle of the gloss meter

The gloss meter usually has various test angles. This angle refers to the occurrence light and the line perpendicular to the plane. Typical geometric angles of 20 degree, 60 degree and also 85 degree. Under the specified light source and geometric angle, a beam of light is irradiated onto the measured object surface. Then the ratio of the luminous flux reflected back from the object surface to the light flux reflected by the standard board multiplied by 100 is the measured object gloss. (The standard board adopt the perfect polished black glass with a refractive index of 1.567 and a gloss of 100)

IV. Tips about choosing gloss meter

1. Gloss meter measurement accuracy

There are three grades of gloss meters: standard gloss meter, first-grade working gloss meter and second-grade working gloss meter. The high-precision gloss tester can meet the standards of first-class working gloss meter. And the reproducibility of the instrument (for multiple tests under the same test conditions of one instrument, the data is stable) and the repeatability (for multiple tests of the same batch of instruments under the same test conditions, the data is consistent) are very good.  Gloss meter meets the Chinese national standard of first-class working gloss meters.

2. Gloss meter functions

Gloss meters of different brands are different. The function can be selected according to your actual need.Several functions are important in selecting gloss meter, we will list these functions in the following part:

2.1 High precision

Gloss tester precision plays a significant role in gloss measurement. High precision means that measure the same test material, the measured data will not exceed the accuracy of the gloss meter. (Different gloss meters have different measurement accuracy).

2.2 For quality controle

The gloss meter support switch between normal mode and QC mode, applicable to different scenes. Normal mode: quick reading after put and test; QC mode: realize quick check on incoming material by setting upper and lower limit value and judge "Pass" or not.

2.3 Power-on self-inspection

Not all the gloss detectors have this function. Lshtec gloss meter with the power-on self-inspection function can automatically judge whether the standard board is contaminated and give a prompt to avoid inaccurate measurement caused by the standard board contamination affecting the standard value.

2.4 Other functions

Besides these functions, other functions are also quite useful. Lshtec gloss checker has small size and is easy to carry. The Lshtec glossmeter also provides free PC software and has stable data.

V. 60 degree gloss meter analysis

As shown in the figure above, the specular reflection ability of low-gloss materials is weak.

If a 20-degree angle gloss meter is used for measurement, the light flux received by the detector is very weak after being reflected by the material surface. The data is small comparing with the light reflected by black glass. When measuring low-gloss materials with different gloss levels, the measured value changes a little. The resolution is not accurate enough to distinguish the subtle glossiness differences.

Similarly, if the 85 degree gloss meter is used to measure high gloss materials, the resolution is not accurate enough to distinguish the glossiness differenc too. Therefore, it is recommended to choose 85 degree gloss meter for low gloss materials and 20 degree gloss meter for high gloss materials. If you need to measure the materials with medium gloss, you can choose 60 ° gloss meter and 60 degree angle gloss meter performs better when measuring the surface of high gloss and low gloss materials.

It can be seen from the curves of the three different angle gloss meters measuring different gloss materials: 60-degree angle glossmeters are better than 85-degree glossmeters when measuring high-gloss materials and better than 20-degree gloss when measuring low-gloss materials.

Most 60 degree gloss meters have a test range of 200GU, so 60 degree gloss meters are suitable for testing the surface gloss of most materials. Take the Lshtec gloss meter as an example, with a universal angle of 60 °, a gloss measurement range of 200GU and1000GU and a resolution of 0.1GU. In this way, no matter the high gloss or low gloss material can be tested, there is enough resolution to distinguish the difference in gloss of different materials. There is also a large enough range to meet the test requirements of high gloss materials.