Sperti P108 Miami sunlamp
ULTRAVIOLET-RADIATION
It was Johann Ritter who, in 1801, for the
first time proved the existence of
ultraviolet radiation. It was known in
those days that silver chloride turned
black under the influence of light and that
it reacted more violently on blue light than
that it did on red light. Ritter refracted the
light with help of a prism and he noticed
that the silver chloride still reacted
strongly in the invisible area just beyond
the last visible blue light. He called this
'chemical radiation', later referred to as
ultraviolet radiation. Ultraviolet rays can
be generated by heating up the filament
of an incandescent lamp to higher temperatures than required for illumination
purposes but ultraviolet radiators based on gas discharge like the Sperti P108 Miami
sunlamp on display here, have proven to be much more efficient.
Ultraviolet radiation with wavelengths between 400 and 315 nanometers (UV-A) is
responsible for the tanning of pigment that is already available in our skin. UV-B on
the other hand, with wavelengths between 315 and 280 nm, stimulates the production
of new pigment and of vitamin-D. Ultraviolet radiation with wavelengths around 365
nm is frequently used in insect traps. Ultraviolet radiation with wavelengths from 300
up to 185 nanometers (UV-C) is used to kill bacteria in hospitals, for sterilisation of
food and for the purification of drinking water. Natural- and artificial UV-A and UV-B
are key-elements in the process of tanning of the human skin but their positive
influence on our health reaches furthers than that.
