the Vienna Astralux Uvalux 4L sunlamp was intended for body- and face tanning
Vienna Astralux Uvalux 4L
Basically, conventional tube lights (TL) for lighting
purposes were low-pressure mercury vapour glow
discharge lamps that were coated at the inside with
phosphorus powder. Through fluorescence this
powder converted the ultraviolet radiation of the
lamp into light of a colour whose hue depended on
the exact chemical structure of the coating. Leaving
out the phosphorus coating and making the glass
tube out of quartz glass instead of conventional
glass provided a relatively cheap ultraviolet radiator.
The output of such a lamp however, was lower than
that of a high-pressure mercury vapour arc
discharge lamp and the wavelengths of the emitted
ultraviolet rays were much shorter. By using a
special coating again, the short waved ultraviolet
radiation could be converted to wavelengths in the
more effective longer ultraviolet areas. Sometimes
an additional filter was added to block some or all of
the light, leading to "black lights" as used in
discotheques or for forensic investigations. For therapeutic treatment there was no
strict reason for a strong filtering of the light. Because of the low heat production the
distance between the lamps and the treated face or body could be kept low without
becoming uncomfortable, making UV tube-lights very well suited for body- and face
tanners like the Vienna Astralux Uvalux 4L sunlamp on display here.