Appearance measurement is a way of putting numbers to characteristics of surfaces that we see. The ability to independently quantify appearance allows for products to be similar whenever and wherever the product is manufactured or coated.
Elcometer provide a comprehensive range of hand held instruments to measure most of the individual characteristics that generate
the overall appearance of a material or coating - including gloss, haze, shade, opacity & color.
Glos - The ability of a surface to reflect light without scattering is known as Gloss. Gloss is measured by directing a constant power light beam at an angle to the test surface and then by monitoring the amount of reflected light. Different surfaces require different reflective angles. Elcometer Glossmeters cover the range necessary to measure almost any surface from high gloss to matt, from large to small surfaces - flat or curved.
Haz - Some materials appear to have considerable difference in gloss yet give comparable readings when measured with a glossmeter at one angle. These materials can be separated by measuring at a second angle and comparing the two readings. Haze is defined by ASTM D4039 as the difference between gloss at 60? and the gloss at 20?.
Shad - This is the measurement of darkness or lightness of a surface. Only shading is measured, irrespective of color, and is referred to as "Ëœwhiteness". The test surface is illuminated at an angle of 45? and the intensity of scattered light at the perpendicular (O?), is measured on a grey scale, where black is 0% and white is 100%.
Opacit - This is the degree to which a coating will obscure the surface to which it has been applied. Opacity is measured in a similar way to shade, however opacity, or hiding power, as defined by ISO 2814 involves measuring whiteness of a known film of test material on both a black (less than 5%) and a white (greater than 75%, less than 85%) substrate. A full range of opacity test charts are available, see pages 33-38 for further information.
Colou - The ability of a material to absorb certain wavelengths of light and reflect others. For example a black material reflects no light across the complete color spectrum, whereas a pure white material reflects all of the light. All other colors reflect light at different points of the spectrum. Color is quantified by the material's Red, Green and Blue (RGB) values
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