ASTM D523 Test Requirements for Specular Gloss

EUROLAB laboratory provides testing and compliance services within the scope of ASTM D523 standard. ASTM D523 covers the measurement of specular gloss of non-metallic samples for gloss meter geometries of 60º, 20º and 85º.

The geometry of the angles and holes is chosen so that these procedures can be used as follows:

• The 60º geometry is used to compare most samples and to determine when 20º geometry might be more applicable.
• The 20º geometry is advantageous for comparing samples with gloss values ​​greater than 70 to 60.
• The 85º geometry is used to compare samples for brightness or near-grazing brightness. It is most frequently applied when the brightness values ​​of the samples are lower than 60 at 10º.

Luster is related to the capacity of a surface to reflect more light in some directions than others. Aspects associated with mirror (or specular) reflection normally have the highest reflections. Measurements made with this test method relate to visual observations of surface gloss made at roughly corresponding angles.

Gloss ratings measured according to ASTM D523 are obtained by comparing the specular reflectance from the sample with that on a black glass standard. Since specular reflection also depends on the surface refractive index of the sample, the measured gloss ratios change as the surface refractive index changes. However, when obtaining degrees of visual brightness, it is customary to compare specular refractive indices.

Because instrumental ratings are more affected by changes in surface refractive index than visual ratings, discrepancies between visual and instrumental gloss ratings may occur when comparing high-gloss specimen surfaces that differ in refractive index.

This standard does not purport to address all, if any, safety concerns associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health and environmental practices and to determine the applicability of regulatory restrictions prior to use.

EUROLAB assists manufacturers with ASTM D523 test compliance. Our test experts, with their professional working mission and principles, provide you, our manufacturers and suppliers, the best service and controlled testing process in our laboratories. Thanks to these services, businesses receive more effective, high-performance and quality testing services and provide safe, fast and uninterrupted service to their customers.