METHOD OF SEALING THE ELECTRODE IN HIGH-PRESSURE MERCURY LAMP

摘要

The method for preventing the oxidization or vaporisation of the tungsten electrode comprises steps for: (a) melting and fixing an intermediate glass (2) on the top side of a qualtz tube (1); (b) inserting an tungstem electrode (3) into the tube and melting the glass by torch flame while supplying the N2 or inert gas; (c) and coating a carbon layer (5) at the boundary of the glass with thickness of 0.8-1.5 mm but not contacting with the glass so that the tungsten electrode at the boundary is not melted or vaporised because of the higher melting point of the carbon than the glass one.