Osram Dulux-L 24W Compact Fluorescent

Following the launch of Philips' PL* compact fluorescents in 1981, it immediately became clear that they would set an important new standard. By 1983 Osram had caught up and introduced its Dulux-S equivalent, with squared U-bend instead of copying the original Philips pi-shape.

Whereas Philips had developed its original range to replace miniature fluorescent tubes in home lighting, Osram was first to capitalise on professional markets by replacing linear fluorescents with compacts having just a third of the length. This required extending the concept to much higher powers. Although Osram and Philips had jointly agreed the standards for these lamps during development, Osram was first to market in 1984, and Philips followed later in 1985.

This lamp is representative of the first high-lumen variant. It would not have been practical to simply increase the length of the original lamps, because the discharge voltage would become too high for operation on ordinary mains voltages. The inner diameter of the tubes was therefore increased from 10mm to 15mm, to achieve high powers and with a lamp voltage suitable for compatibility with the existing range of linear fluorescent ballasts. The large G32 cap is a scaled-up version of the G23 interface used on smaller lamps, but since the high power lamps were intended for professional applications, it was desirable to have 4-pins to allow use with electronic and dimmable control gear. The rectangular post on the cap was originally intended to house a glowbottle starter for a 2-pin version, but a few months after their launch it was decided to offer only 4-pin lamps. In 1985 the dead space was eliminted and this lamp became obsolete, replaced by a shorter model with 2G11 cap.
Manufacturer: Osram GmbH
Lamp Power: 24 Watts
Lamp Current: 0.340 Amps
Lamp Voltage: 91 Volts
Cap Type: G32q-1 PBT
Bulb Type: T-18 T-6 in eighths/inch
Bulb Finish: BAM, CAT, YOX phosphors Soda-lime glass
Electrodes: Triple Coil Tungsten Triple carbonate emitter
Atmosphere: Argon + Hg
Luminous Flux: 1,800 lm @ 100h
Luminous Efficacy: 75 lm/W @ 100h
Colour Temperature & CRI: CCT: 3000K CRI: Ra 81
Chromaticity Co-ordinates: CCx: CCy:
Lifetime: 5000 hours
Warm-up & Re-strike Time: 2 minutes Instant
Burning Position: Universal
Overall Length: 340 mm (314 mm without pins) 17 1/8 inches
Lighted Area: 300 x 38 x 17.5 mm
Factory: Augsburg Germany
Date of Manufacture: 1985 June Date Code: rd6
Original Value:
References: 1) Osram Lamp Catalogue 1985 Germany p.24
2) Die Brennlagenabhängigkeit de Lichtstrom-Temperaturverhaltens bei Dulux-Lampen, D.Hofmann, Technisch-wissenschaftliche Abhandlungen aus der Osram-Gesellschaft Band 12 (1986) pp.248-255