瓷砖.第18部分:光反射值（LRV）的测定

[中文适用范围]： 本文件旨在定义一种测试方法以确定陶瓷砖（包括马赛克砖）的光反射值（LRV）。适用于固体颜色、多色和色调不均匀的瓷砖表面，包括具有火焰效果、斑点或纹理的不同类型的表面。 [外文原描述]： The objective of this document is to define a test method to determine the light reflectance value (LRV) of ceramic tiles, including mosaic tiles. It is applicable to solid-coloured, multicoloured and non-uniform shade tile surfaces including tile with flame effects, speckled or textured with different types of finishing.