AES Studies of Grey Spots of the Surface of Fluorescent Lamp
Chen Qiuxia Zhang Chunsi Zhu Huanxin Yang Jianmin(Shanghai Institute of Metallurgy, Academia Sinica) (Shanghai Second Factory of Electronic Tube)
Some grey spots are often found in the surface of fluorescent lamp during production, which make the ratio of qualified lamps comes down. The result of AES studies indicates that the grey spots are very thin films which contain less Ca, K, Na than other places in the lamp surface. The grey spots are caused by the overlong storage before baking which allows lamps to avoid the reaction of glass of lamp with air, especially CO2, so that to form Ca, K, Na salts in some places of the surface of lamp. During baking process these salts evaporate from the surface of lamp, causing some grey spots which are of less alkali elements.