GE LU70/90/T10/27 - Compact Tubular HPS

HPS lamps for the American market have traditionally had considerably larger dimensions than the rest of the world. For instance the first 70W lamp was introduced by GE in USA in 1975, and despite the small arc tube, it was only offered in the oversized ED23½ bulb of 75mm diameter, with E39 mogul base. Part of the reason for this was because the smaller E26 medium lampholders were not rated to withstand the necessary ignition voltage.

It was not until 1980 that GE launched smaller HPS lamps for the American market, following the development of a suitable E26 medium screw lampholder. The new lamps were made with a smaller B17 bulb of 54mm diameter, and were made available in 50W and 70W, and from 1981 also 35W. Meanwhile in Europe, compact HPS lamps were offered right from the outset with E27 screw bases and even more compact T12 glass bulbs of just 38mm diameter.

It took almost a decade before the Americans followed suit, and at the Lighting World exhibition of 1989, GE introduced a range of 35W, 50W and 70W bulbs in ultra-slim T-10 (32mm diameter) bulbs. The small diameter tubular envelope set a new standard in small HPS lamps and was quickly copied in Japan, and although some European manufacturers also switched to slimmer T10 bulbs, the standard has remailed T12.

This particular lamp has been produced in USA for export to Europe, and features GE's compact T10 bulb around a 70W high voltage arc tube for 220-250V mains supplies. The arc tube features GE's traditional external amalgam reservoir construction, with single wire seal at the opposite end.
Manufacturer: General Electric Company U.S.A.
Lamp Power: 70 Watts
Lamp Current: 0.98 Amps
Lamp Voltage: 90 Volts
Cap Type: E27s/27 Brass + vitrite
Bulb Type: T-32 T-10 in eighths/inch
Bulb Finish: Clear Lead borosilicate glass
Electrodes: Backwound Tungsten Ba2CaWO6 Emitter
Arc Length:
Atmosphere: Inner: Na,Hg | Xe Outer: Hard Vacuum
Luminous Flux: 6,000 lm (@ 100 hrs) 5,400 lm (average)
Luminous Efficacy: 85.7 lm/W (@ 100 hrs) 77.1 lm/W (average)
Colour Temperature & CRI: CCT: 1900K CRI: Ra 22
Chromaticity Co-ordinates: CCx: CCy:
Rated Lifetime: 24,000 hours to 50% survival
Warm-up & Re-strike Time: 5 minutes approx 2 minutes
Burning Position: Universal
Overall Length: 143 mm 5 5/8 inches
Light Centre Length: 100 mm 4 inches
Factory: Ravenna, OH U.S.A.
Date of Manufacture: May 1992 Date Code: 53 ∙-
Original Value: Unknown
 
References: 1) General Electric USA Large Lamp Catalogue, Form ILD9200, 1991-92.
2) GE Lighting Press Release, New Additions to Compact Lucalox HID Family, 9th May 1989.