LOW PRESSURE MERCURY VAPOUR DISCHARGE LAMP

摘要

Low-pressure mercury vapour discharge lamp is provided with a discharge vessel and a first and a second end portion (12a). The discharge vessel encloses a discharge space provided with a filling of mercury and a rare gas in a gastight manner. Each end portion (12a) supports an electrode (20a) arranged in the discharge space. An electrode shield (22a) encompasses at least one of the electrodes (20a) and has, according to the invention, the form of a snail shell. Preferably, the electrode shield (22a) is spiralled. Preferably, the electrode shield (22a) is made from a ceramic material. Preferably, the electrode shield (22a) is covered with a material which reacts with or forms an alloy with alkaline earth metals, which is released by the electrode (20a). The lamp according to the invention has a comparatively low mercury consumption.