搪瓷耐化学侵蚀的测定 第3部分：用六角形容器或四边形玻璃容器进行耐碱性溶液化学侵蚀的测定

Vitreous and porcelain enamels—Determination of resistance to chemical corrosion—Part 3:Determination of resistance to chemical corrosion by alkaline liquids using a hexagonal vessel or a tetragonal glass bottle