| abstract |
Low-pressure mercury vapor discharge lamp has an at least partly substantially cylindrical discharge vessel ( 10 ) with a length L dv and with an internal diameter D in . The discharge vessel ( 10 ) encloses, in a gastight manner, a discharge space ( 13 ) provided with a inert gas mixture and with mercury. The discharge vessel ( 10 ) comprises discharge means (electrodes 20 a; 20 b ) for maintaining a discharge in the discharge space ( 13 ). According to the invention, the ratio of the weight of mercury m Hg in the discharge vessel ( 10 ) to the product of the internal diameter D in and the length of the discharge vessel L dv is given by the relation: Formula (I), wherein C≦0.01 μg/mm 2 . Preferably, 0.0005≦C≦0.005 μg/mm 2 . Preferably, the discharge vessel ( 10 ) contains less than 0.1 mg mercury. The discharge lamp according to the invention operates under unsaturated mercury conditions. n m Hg D in × L dv = C ( 1 ) |