Osram Squirted & Sintered Tungsten, French

The first tungsten filament lamps of the German Osram company were produced by the Auergesellschaft in 1906, based on the work of Fritz Blau and Hermann Remani. They produced a paste of tungsten particles in an organic binder, which was squirted into filaments according to the methods developed by Auer for the Osmium filament lamp in 1898-99. The filaments were then heated to carbonise the binder and render them conductive, and further heated by electric current in an inert atmosphere to form tungsten carbide. Finally they were heated in wet hyrdogen, the heat cracking the water and the resulting oxygen removing the carbon to yield pure tungsten, whose particles were sintered together by prolonged heating. The filament mount construction of the 1906-style lamps was such that they could only be used vertically cap-up to avoid filament sag.

In 1908 Osram introduced an improved universal-burning lamp. This development was facilitated by a change in the design of the filament mount assembly. At the far end, fine wires of refractory metal are used to hold each of the hairpins under tension as they expand during operation, thereby preventing sag.

The Aurgesellschaft then underwent a perod of considerable international expansion, and formed tungsten lamp factories in Britain and France. The French operation was established in 1909 at a new factory in Puteaux, Paris, where this lamp was produced according to the German design. Within three years later however, it had been discontinued and entirely replaced by the still superior drawn tungsten filament lamp based on the patents of General Electric of America, with whom Osram was swift to acquire a patent license.

Manufacturer:	La Lampe Osram S.A.
Lamp Power:	Approx. 25 Watts
Lamp Voltage:	125 Volts
Lamp Current:	Approx. 0.27 Amperes
Cap Type:	B22d/25x26	Brass + vitrite
Bulb Type:	S-60	S-19 in eighths/inch
Bulb Finish:	Clear	Soda-lime glass
Filament Type:	5S-2	5x Hairpin
Atmosphere:	Vacuum
Luminous Flux:	314 lumens
Luminous Efficacy:
Luminous Intensity:	25 Bougies
Beam Distribution:	N/A
Colour Temperature & CRI:	CCT: 2400K	CRI: Ra 100
Chromaticity Co-ordinates:	CCx: 0.486	CCy: 0.415
Rated Lifetime:	1000 hours
Burning Position:	Universal
Overall Length:
Light Centre Length:
Factory:	Puteaux	France
Date of Manufacture:	1909-1912
Original Value:	Unknown


References:	1) 100 Years Osram, Osram Centenary Book 2006, pp.17-19.
	2) The History of N.V. Philips Gloeilampenfabrieken vol. 2, A.Heerding, publ. Cambridge University Press 1988, p.166.
	3) History of the Electric Lamp, Fin Stewart, publ. 2013, pp.154-155, 176-178.
	4) An Illustrated History of Electric Lighting, Adam Allerhand, publ. Bez Budja Press 2016, pp.372-372.