Formal name: Gloss-meter or Glossimeter
What this techniques measures: This technique uses a range of geometries to measure surfaces from matte to high-gloss finishes. Some of the most common are the 20°, 45°, 60°, 75°, and 85° geometries. Gloss-meters are available in single-angle meters and in combination meters. Combination meters,or tri-gloss meters, allow you to measure three angles simultaneously. Gloss is measured by shining a known amount of light at a surface at a specific angle and measuring the amount of reflected light. The type of substrate or material is a determining factor of what angle or geometry to use. Measurements are taken as gloss units.
Examples of chemical substance(s) or physical feature(s) identified:
The following are the various geometries and recommendations for use:
- 20° is for high gloss coatings, plastics, and related materials
- 60° is for semi gloss coatings, plastics, and related materials
- 85° is for low gloss coatings, plastics, and related materials
- 45° is for semi gloss ceramics and film
- 75° is for low gloss paper and vinyl
Tri-gloss meters typically use the 20°, 60°,and 85° geometries. These meters can be used on the aforementioned materials, but also on brightened metal.
Phases it can be used to examine: solids
Is the technique quantitative? This technique is quantitative. Most meters allow for a statistics mode that calculates the arithmetic mean and standard deviation of a user defined group of measurements. The meters also allow for a comparative analysis. This is done by establishing a reference point or control and measuring samples.
Is this technique destructive or non-destructive:This technique is non-destructive. Meters are often small and portable, allowing for in-situ investigation.
Size of sample necessary to use this technique:The sample size is dependent on the meter and the geometry used; examples:
- 20°: 3x4 mm oval-10.5 mm circle
- 60°: 3x6 mm oval-10x20 mm oval
- 85°: 10x54 mm oval
Examples of how this technique is used in the field of art conservation: This method allows the conservator to attain quantitative data for the appearance of gloss on a substrate. These may be observable or minute changes that have occurred after a treatment has been applied. This technique can also be used to monitor the condition of a material over time.
Risks associated with using this technique:There are not any associated risks when using the glossmeter. However, the gloss meter is best used with flat substrates.
Cost to purchase this instrument:~$3000.00-$6000.00 This often includes the instrument, software, USB cable, and carrying case.
Annual costs to maintain this instrument:~$400.00-$1,100.00 Most manufacturers require factory maintenance every one to two years. This may also be called preventative maintenance. Often times this includes cleaning of optics, control calibration, firmware and software update, and certification. Additional maintenance can include re-certification for the standard.
Sample analytical costs:None associated
Complementary Techniques: This instrument is often used with other techniques that measure physical characteristics.
- Dry-film Thickness Gauge
- Visual observation
Links to external resources/databases: