Abstract: To decrease a power consumption of a fluorescent lamp, the fluorescent lamp is provided with a high efficiency fluorescent coating, generating more light upon receipt of a conventional amount of radiation. Decreasing the power supplied to the lamp decreases the radiation supplied to the fluorescent coating and thus the light output of the lamp. Due to the increased light output of the fluorescent coating, the light output level of the fluorescent lamp may be kept substantially equal to a light output level of a conventional lamp.

Abstract: A low-pressure mercury discharge lamp with a lamp vessel having a first lamp vessel portion (La1) with a first electrode (E11) and a first luminescent layer which radiates white light of a first color temperature during lamp operation and a second lamp vessel portion (La2) with a second electrode (E12) and with a second luminescent layer which radiates white light of a second colour temperature different from the first during lamp operation. The first lamp vessel portion and the second lamp vessel portion are interconnected by a connection which allows a filling of mercury and a rare gas in both portions to pass and together enclose a discharge space. The discharge space contains only one further electrode (E13) for both the first and second lamp vessel portions.

Abstract: A method of selecting low-pressure mercury discharge lamps comprising a luminescent layer, the luminescent layer being excited and the low-pressure mercury discharge lamps being selected in dependence on the emission spectrum of the visible light emitted by the luminescent layer. The luminescent layer is excited by a light source arranged outside the low-pressure mercury discharge lamp and which generates ultraviolet radiation having a wavelength above 300 nm. This makes it possible to use the presence of a blue-luminescent substance in the luminescent layer as a selection criterion for both leaky and intact low-pressure mercury discharge lamps.

Abstract: A circuit arrangement and a method suitable for operating a low-pressure mercury discharge lamp which includes circuitry for adjusting the average amplitude of the current provided to the lamp as well as circuitry for adjusting the modulation of the current provided to the lamp.