GLASS COATING ON LEAD-THROUGH CONDUCTORS IN A LOW-PRESSURE SODIUM DISCHARGE LAMP

摘要

The low pressure sodium discharge lamp has a discharge vessel (1) having pinch seals (2) through which current conductors (4) extend towards electrodes (3) inside the discharge vessel (1). The current conductors (4) each have a first glass coating (5), which extends form inside a pinch seal (2) into the discharge vessel (1) and a second lime glass coating (6) abutting the first (5) and extending to outside the discharge vessel (1). A new first sodium resistant glass coating (5), which is substantially devoid of borate, is defined.