LOW-PRESSURE MERCURY VAPOR DISCHARGE LAMP

摘要

The low-pressure mercury vapour discharge lamp has a filling of mercury and an inert gas, and the glass discharge vessel (1) is provided on the inner surface (4) of the wall (3) with a film (6) of trifluoride and/or oxyfluoride of at least one element, which is trivalent at most, which is selected from lanthanides, lanthanum, scandium and yttrium. The film (6) counteracts transport of mercury from the discharge vessel to the wall (3) and of alkali from the wall (3) to the discharge vessel (1). In this manner, a decrease of the lamp's efficiency and of the service life are counteracted.