Surface Gloss Limits

Surface Gloss Limits One of the most important parameters used to complete the appearance of an object is surface gloss. Surface gloss is an optical property that indicates how well a surface reflects light in the specular reflection (mirror-like) direction. Surface gloss measurement is performed using electronic gloss meters called Glossmeters. Light rays emitted from the light sources in these devices are reflected from the measured surface at specific angles (such as 25°, 60°, 80°) and reach the sensors in the device. A proportional calculation is made between the amount of light reaching the sensor and the light rays emitted from the light source. The measured gloss is based on black glass with a refractive index np = 1.567. Assuming the surface is ideally polished, it is used for natural light beams on the plane. When specular reflection occurs, the brightness value emitted from the light source is defined as 100.0 GU. As a numerical value, GU (Gloss Unit) is the unit of gloss. The amount of light flux reflected from the surface in GU is calculated as a ratio to 100 GU. The calculated gloss unit can also be expressed as a percentage alongside the numerical value. Regardless of a product's surface gloss level, the manufacturer must ensure consistency in meeting the designed engineering requirements. For example, for a product with high gloss such as white goods, the customer's perception of uniform gloss throughout the product body is of critical importance. For this reason, surface gloss control in the quality control process requires high accuracy. Gloss limits are acceptable tolerance levels as defined by the user and allow readings to be compared with pre-defined maximum values or approved samples (standards). This allows the user to ensure consistency of products and parts, for example on an automobile production line. Using the Elcometer 480 Gloss Meter, you can record and store up to 40 different limit standards consisting of the nominal or target value required for readings and differential, low and high limits for gloss and haze. This allows users to obtain readings that they consider "good" or "acceptable" after the limits have been recorded and ensures that subsequent samples meet the same limits. References • Heron, C. (2021), Gloss Limit Standards, The E News, 2 – 2021, 18. • https://www.elcometer.com/media/480-accurate_1.jpg Burak Demirağ Sales Engineer Mega Danışmanlık Temsilcilik Dış Ticaret A.Ş.