Gloss is an important attribute of surface appearance, it changes our perception of colours and influences our overall visual experience.
Gloss affects objects by the interaction of incident light with the surface and observer and depends on variables such as illumination angle, surface profile, physical characteristics and observation conditions.
For many products, gloss can play an important part in their visual acceptability and for quality purposes should be monitored with precision instrumentation particularly when it varies through the Gloss is an aspect of the visual perception of objects that is as important as colour when considering the psychological impact of products on a consumer. In other words, "Gloss Sells" Gloss has been defined as the attribute of a surfaces that causes it to have a shiny or lustrous, metallic appearance.
The gloss of a surface can be greatly influenced by a number of factors, for example the smoothness achieved during polishing, the amount and type of coating applied or the quality of the substrate
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.
The Rhopoint IQ is a precision instrument that measures gloss using the following parameters in a single button push: 20/60/85° Gloss, Haze, Reflected Image Quality (RIQ), Distinctness of Image (DOI)
Gloss is a measurement proportional to the amount of light reflected from a surface measured at 20° (high gloss finishes) 60° ( mid gloss finishes ) and 85° ( matt finishes) Haze: Reflection haze is scattered light caused by micro texture and is measured adjacent to the main gloss component. The gloss value is determined by directing a light, which has a similar wavelength to the human eye, at a specific angle to the test surface and measuring the amount of specular reflection.
The optics is set in an aluminium block giving optical bench accuracy and stability. To ensure international standard compliance, the light source is supplied from long-life tungsten halogen lamps. Place the gloss meter on the surface to be measured, press the required angle button and the gloss reading will appear on the display. This reading will be held until another reading is taken.
Trade practice recognizes the following gloss levels, in increasing order of gloss: flat (or matte) practically free from sheen, even when viewed from oblique angles (usually less than 15 on 60-degree meter); eggshell- usually 20-35 on 60-degree meter; semi-gloss-usually 35-70 on 60-degree meter; full-gloss-smooth and almost mirror-like surface when viewed from all angles, usually above 70 on 60-degree meter.
The instrument will automatically switch off when not in use. Easy to read two-line alphanumeric display with back lighting, powered by internal rechargeable batteries, battery voltage can be checked on the display. Rhopoint IQ (Gonio photometer) 20°/60°/85°- http://www.rhopointinstruments.com/.../rhopoint-iq.../
Paint Surface - Light Reflection - TOGWT
1. Gloss as an aspect of the measurement of appearance by W Ji, MR Pointer, RM Luo, J Dakin
2. Surface correlation effects on gloss by R Alexander-Katz, RG Barrera - Journal of Polymer Science
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