BS 2782-5 Methods 530A and 530B-1976 塑料的试验方法.风化下光学和颜色性能.黄色指数测定.近似白色或近似无色材料的测定
Methods of testing plastics - Optical and colour properties, weathering - Determination of yellowness index - Determination of the colour of near-white or near-colourless materials
These methods describe instrumental procedures for measuring the colour of non-fluorescent, near-white opaque or translucent plastics materials, or near-colourless transparent plastics materials.
Method 530A is applicable where the only characteristic of significance is yellowness. A 'yellowness index' is specified for use in appropriate cases.
Method 530B is more general and is applicable where a fuller description of colour and lightness characteristics is required.
Both methods are applicable to the transmittance of trans-parent and translucent plastics materials and to the reflect-ance of opaque plastics materials and suitably backed translucent plastics materials.
The methods are of particular value in measuring changes produced by ageing processes.
note: * Fluorescence can be readily detected by visual examination in a dark room under ultra-violet illumination,
+ Commission International de I'Eclairage.