2 сентября, 2015 
Pokraskin 1.4.2.1
Light Stability Accelerated Tests
Light stability is a material property. It is defined as the resistance of coatings towards changes caused by the action of global radiation (daylight phase: standard illuminant D 65), possibly in the presence of moisture. In coatings, light and moisture can lead to chalking and changes in gloss and color. For standards, see Table 1.1 (“Light stability”). Apparatus: testing cabinets, equipment for wetting the test plates, equipment for producing airflow.
Evaluation of Color Changes (see Section 1.3.2)
Color changes are differences in lightness, chroma, and hue such as exist between identical samples with different histories. Evaluation methods are particularly suitable for the determination and evaluation ofcolor changes that occur following physical and chemical stresses on pigmented materials. The CIE tristimulus values X, Y, and Z of the samples or of different test locations on a sample are determined with a colorimeter. The CIELAB color difference is calculated for each sample or test location from the tristimulus values before and after the stress (see Section 1.3.2). Apparatus: spectrophotometer.
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