塑料.透明材料总透光率的测定.第1部分:单光束仪器

[中文适用范围]： 本文件涵盖了使用具有指定 CIE 标准光源和光电探测器的单光束光度计测定平面透明且基本无色的塑料在光谱的可见光区域的总透光率。 本文件不适用于含有荧光材料的塑料。 本文件适用于厚度不超过10毫米的透明模塑材料、薄膜和片材。 注 1：总透光率也可以通过双光束分光光度计测定，因为该方法不仅适用于分析目的，也适用于质量控制。 注 2：基本上无色的塑料包括那些带有微弱着色的塑料。 注 3：如果仪器能够容纳厚度超过 10 毫米的样品，则可以对其进行测量，但结果可能无法与使用厚度小于 10 毫米的样品获得的结果进行比较。 [外文原描述]： This document covers the determination of the total luminous transmittance, in the visible region of the spectrum, of planar transparent and substantially colourless plastics, using a single-beam photometer with a specified CIE Standard light source and photodetector. This document cannot be used for plastics which contain fluorescent materials. This document is applicable to transparent moulding materials, films and sheets not exceeding 10 mm in thickness. NOTE 1 Total luminous transmittance can also be determined by a double-beam spectrophotometer as in ISO 13468-2. This document, however, provides a simple but precise, practical and quick determination. This method is suitable for use not only for analytical purposes but also for quality control. NOTE 2 Substantially colourless plastics include those which are faintly tinted. NOTE 3 Specimens more than 10 mm thick can be measured provided the instrument can accommodate them, but the results might not be comparable with those obtained using specimens less than 10 mm thick.