Osram Ultra-Vitalux Sun Tanning Source

After the introduction of the earliest incandescent lamps for therapeutic and sun-tanning applications, such as the American 'CX' and the European Osram 'Vitalux' and Mazda 'Vite' lamps, developments took a different direction on each side of the Atlantic. America was first to introduce the use of a mercury discharge to raise the proportion of UV radiation, and its S-1 and S-2 lamps were characterised by a medium pressure mercury arc in parallel with a tungsten filament. Meanwhile in 1937, German Osram introduced its 'Vitalux-U' lamp, later re-named 'Ultra-Vitalux' as featured here.

It comprises a high pressure mercury arc tube in series with a tungsten filament, the latter forming the electrical ballast for the arc. The high pressure arc very considerably elevated the percentage of erythemal radiation to about 5x greater than sunlight, creating the first of the modern suntan lamps.

The outer bulbs of all ultraviolet lamps are fabricated in a special glass free of iron oxide, to allow the transmission of UV radiation. Soft glasses tend to discolour and lose their UV transmission over time due to the process of solarisation. The Osram Ultra-Vitalux is unusual in that its glass has a slight pinkish colouration, due it being doped with about 0.2% of nickel oxide. The colour has no particular purpose, but was found the slow the rate of degradation and enable the production of a lamp having improved UV maintenance during life. In 1941 GE copied the Osram approach of a high pressure self-ballasted lamp with the introduction of its "RS Sunlamp", featuring a novel reflector bulb to facilitate its use and with a further improved hard glass bulb. In 1943 Osram copied the GE concept of an integrated reflector and applied it to its pink-glass Reflector Ultra-Vitalux.
Manufacturer: Osram GmbH
Lamp Power: 300 Watts
Lamp Current: 1.30 Amps
Lamp Voltage: 230 Volts
Cap: E27s/50x55 Nickel Plated
Bulb Finish: Inside Frosted neodymium glass
Bulb Type: A-110
Overall Length:
Light Centre Length: N/A
Electrodes: Backwound tungsten
Atmosphere: Arc Tube : Argon Outer : Nitrogen
Luminous Flux: N/A
Luminous Efficacy: N/A
Colour Temperature & CRI: N/A
Chromaticity Co-ordinates: N/A
Rated Life: Not Published
Factory: Berlin, Germany
Date of Manufacture: November 1957
Original / Present Value: Not Known
References: 1) Die Entwicklung Neuer Künstlicher Lichtquellen, A. Rüttenauer, Technisch-Wissenschaftliche Abhandlungen aus dem Osram-Konzern, 1931, pp.77-82.
2) Der Osram Ultra-Vitalux Strahler, K. Larche, Technisch-Wissenschaftliche Abhandlungen der Osram-Gesellschaft, 1953, pp.43-48.
3) US Patent 2,212,879 - Electric Discharge Lamp - H.Kalsing, H.Krefft, F.Rössler - Osram KG - Filed 1938-Aug-16.