the Vienna Astralux Uvalux 4L sunlamp was intended for body- and face tanning
Vienna Astralux Uvalux 4L
Basically, conventional tube lights (TL) for
illumination 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.