Gloss is a vital aspect to measure when it comes to the visual appearance of objects.
Manufacturers of different products will typically specify the need for different levels of gloss, depending on the product.
Manufacturers of cars or magazines, for example, typically aim for a higher gloss finish than companies coating military or naval vehicles.
So how do you measure gloss?
Typically, using an optical instrument called a glossmeter, which provides the user with quantifiable gloss measurements, expressed in gloss units, or GUs.
This video shows you how to measure gloss using a gloss meter - specifically the Elcometer 480 Glossmeter.
CONTENTS
0:04 - What is gloss?
1:25 - How do you measure gloss?
2:58 - How does a glossmeter work?
3:40 - What measurement angle should you use?
5:41 - What is a gloss meter capable of?
The perception of gloss can relate to a product’s finish, texture, and how a sample is illuminated and viewed.
Surfaces with high reflectance are perceived as glossy, shiny or lustrous, whilst less reflective surfaces are perceived as semi-gloss or matt.
In many instances a high gloss finish implies high quality, and it’s important to ensure that the level of gloss not only remains consistent across the product, but also across manufacturing batches; otherwise customers may, on the one hand, see this as a defect or an indication of poor quality; or in the case of road signs or military vehicles, it can negatively affect their performance.
This is why we use a glossmeter to objectively measure gloss.
The gloss measurement range is from 0-2000GU, where 0GU is a perfect matt finish that reflects absolutely no light, and 2000GU is perfect mirror that reflects all of the light.
Glossmeters measure gloss by directing light at a fixed angle (known as the angle of incidence), onto the test surface. The glossmeter measures the amount of light that gets reflected off the surface through a photo detector, which is positioned at the same angle opposite to the light source. Typically, the more light that’s reflected, the glossier the surface is, as high gloss surfaces reflect light distinctively.
Semi-gloss and matt surfaces, on the other hand, diffuse the light, scattering it in all directions. The more uniformly the light is scattered, the less intense the reflection of light onto the photo detector, resulting in a lower gloss reading.
To ensure you take gloss measurements that best represent the visual appearance of the surface, several measurement angles are used. These angles have been defined by National & International Standards bodies, and the various Test Methods. These angles are typically 20°, 60°, and 85°; and for some industries 45° and 75° are also used.
Glossmeters are typically supplied having either a single 60° measurement angle, dual 20° and 60° measurement angles, or triple 20°, 60° and 85° measurement angles.
Gloss Range // 60° value // Measure with
High Gloss // more than 70GU // 20°
Semi Gloss // 10 - 70GU // 60°
Low/Matt // less than 10GU // 85°
The Elcometer 480 Glossmeter is available as either a simple entry level 60° glossmeter or state of the art Single, Dual or Triple angle gloss meter variants.
Gloss meters can be supplied with or without statistics or memory to store readings; data output via USB or Bluetooth to export those readings into a spreadsheet; or into data management software, such as ElcoMaster® for example - which allows you to generate professional inspection reports, instantly. And that’s only just the beginning.
For more information on the Elcometer 480 gloss meter range, please contact Elcometer at sales@elcometer.com, or visit our website: www.elcometer....
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Click here to download the video script in English: www.elcometer....
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STANDARDS:
AS/NZS 1580.602.2, ASTM C584, ASTM C523, ASTM D523, ASTM D1455, ASTM D2457, ASTM D4039, ASTM E430, ASTM E2387, BS 3900 D5, DIN 67530, ECCA T2, EN 12373-11, EN 13523-2, ISO 7668, ISO 2813, ISO 13803, JIS K 5600-4-7, JIS Z 8741, TAPPI T 653 (20°)
2 окт 2024
