How is gloss level measured

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 measured using a Gloss Meter also known as a Glossmeter 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.

The measurement results of a glossmeter are related to the amount of reflected light from a black glass standard with a defined refractive index, and not to the amount of incident light. The measurement value for this defined standard is equal to gloss units. Materials with a higher refractive index can have a measurement value above gloss units GU , e.

In case of transparent materials the measurement value can be increased due to multiple reflections in the bulk of the material. Due to the high reflection capabilities of metals values of up to GU can be reached. Glossmeters and their handling procedures had to be internationally specified to allow comparison of measurement values. The angle of illumination is of high influence. In order to obtain a clear differentiation over the complete measurement range from high gloss to matte, 3 different geometries, i.

In this case study, 13 samples were visually ranked from matte to high gloss and measured with the 3 specified geometries. In the steep slopes of the curves the differences between the samples can be clearly measured, while in the flat part the measurement geometry no longer correlates with the visual. Gloss measurement for any application, whether you are dealing with specific applications or need a universal solution for high to matte gloss samples, www.

Gloss Introduction. Paint-Coating Instr. For transparent materials, these values can also be increased due to multiple reflections within the material. Each glossmeter is setup by the manufacturer to be linear throughout its measuring range by calibrating this to a set of master calibration tiles traceable to NIST National Institute of Standards and Technology.

In order to maintain the performance and linearity of the glossmeter it is recommended to use a checking standard tile. This standard tile has assigned gloss unit values for each angle of measurement which are also traceable to National Standards such as NIST. The interval of checking this calibration is dependent on the frequency of use and the operating conditions of the glossmeter.

It has been seen that standard calibration tiles kept in optimum conditions can become contaminated and change by a few gloss units over a period of years. Standard tiles which are used in working conditions will require regular calibration or checking by the instrument manufacturer or glossmeter calibration specialist.

A period of one year between standard tile re-calibration should be regarded as a minimum period. If a calibration standard becomes permanently scratched or damaged at any time it will require immediate recalibration or replacement as the glossmeter may give incorrect readings.

International standards state that it is the tile that is the calibrated and traceable artefact not the gloss-meter, however it is often recommended by manufacturers that the instrument is also checked to verify its operation on a frequency dependent on the operating conditions. The glossmeter is a useful instrument for measuring the gloss of a surface. However, it is not sensitive to other common effects which reduce appearance quality such as haze and orange peel.

Haze : Caused by a microscopic surface structure which slightly changes the direction of a reflected light causing a bloom adjacent to the specular gloss angle. The surface has less reflective contrast and a shallow milky effect.

Orange Peel : An uneven surface formation caused by large surface structures distorting the reflected light. A surface with orange peel and haze. Two high gloss surfaces can measure identically with a standard glossmeter but can be visually very different. The glossmeter is used in many industries from paper mills to automotive and are used by the producer and the user alike. Wood flooring distributors want to check their stock to maintain the integrity of their stock allocation.

When wholesale orders are filled from two or more different production runs a gloss meter can verify if the finish of that run is close enough to a preceding run to send out on a job site. Wood flooring dealers are always comparing the finish of their showroom samples to the actual product they receive from distributors and manufacturers.

Gloss meters can help verify a major inconsistency that might impact negatively a project installation later. Wood flooring installation contractors who perform sand and finish operations on site site-finishers need to know the gloss level of the finish type they are using; water-based urethanes, oil-modified urethanes, deep penetrating oil, conversion varnishes, etc.

Wood flooring inspectors get asked occasionally to verify gloss levels from two or more conflicting lots or runs to establish whether or not there was a problem with a previous order fulfillment. Mixing production runs does not always look good to a discriminating consumer with a sharp eye.

This happens more often than people realise. Low cost easy to use gloss meter. The instrument provides full statistical analysis with trend graphs. Designed specifically for low gloss applications such as automotive interior trim. Designed for measuring the gloss of very small and curved parts such as extruded plastic parts, tablets. Cookie information is stored in your browser and performs functions such as recognising you when you return to our website and helping our team to understand which sections of the website you find most interesting and useful.

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