Abstract: A low-pressure mercury vapour discharge lamp according to the invention is provided with a radiation-transmitting discharge vessel (10) which encloses a discharge space (11) in a gastight manner and comprises mercury as well as a rare gas. Mercury is also present in a vapour pressure control member (21) which is in communication with the discharge space (11) during nominal operation. The discharge lamp has means (40) for maintaining a discharge in the discharge space (11). The vapour pressure control member (21) forms part of a mercury control member (20) which also comprises mercury transport control means (22) which limit the mercury transport from the discharge space (11) to the vapour pressure control member (21), at least while the lamp is out of operation, to such an extent that this transport is at most 5 ng/h.cm.sup.3, measured at room temperature and in the presence of a saturated mercury vapour in the discharge vessel, per unit volume of the discharge space.

Abstract: An electrodeless low-pressure discharge lamp is provided with a lamp vessel which is closed in a gastight manner, which surrounds a discharge space, and which contains a filling of mercury and rare gas. The lamp vessel has a cavity and a collar where the cavity is open towards the exterior, an electric coil being accommodated in the cavity and support with an amalgam being arranged in the discharge space. The collar is made of metal and the support of the amalgam is fastened to the collar. This construction counteracts degeneration of the amalgam.