ASTM D523 Evaluation of mirror glossiness

ASTM D523 is the standard test method for specular glossiness. This is a direct measurement using a "Glossiness Meter". Usually measurements will be made on a flat, uniform and clean surface. Measurements can be made on smaller surfaces i.e. 1cm2 but it is best to use larger surfaces and take multiple data points to ensure uniform sample surfaces and report representative results.

Uses and factors to consider

Specular glossiness is used for the measurement of the ability of a surface to reflect more or less light. This test method allows 3 Glossiness Meter geometries at 60, 20 and 85 °, of which 60 ° is the most common one. 20 ° geometry is used for the measurement of high gloss value samples, i.e. above 70 units, while 85 ° geometry is used for the measurement of low gloss value samples, i.e. values below 10 units.

Specular glossiness measurements according to ASTM D523 are also affected by the surface refractive index of the sample, and the glossiness level of the measurement varies with the surface refractive index. Therefore, it is also important to consider this parameter when evaluating products against product specifications.

Typical experimental parameters for ASTM D523 glossiness testing

Sample/Product Quantity: 1 sample, 10 readings

Sample size: 3 "X 6"

Conditioning and testing, temperature: 23 ± 2 ℃

Adjust and test relative humidity: 50 ± 5%