Claude Metal Halide MI-1000W 380V

The French manufacturer Claude was one of the earliest pioneers in the development of metal halide lamps, but only ever made high power versions of 2000W and 1000W for use on mains voltages of 380-415V. Metal halide technology becomes progressively more difficult to master at lower powers, and the original Claude process was rather unique in that it could only achieve the necessary chemical purity with arc tubes having a certain minimum length.

The Claude MI-series employs the same chemistry as GE's original metal halides, being dosed with the iodides of sodium, indium and thallium plus lithium as an impurity from the quartz. The company developed a unique process to purify these to the necessary extent, in which the halides are first dosed into the arc tube, then while on the vacuum pump an oscillating furnace distils the salts back and forth from one end to the other. A liquid nitrogen trap around the exhaust tube prevents the halides from being pumped away. After several cycles the impurity content is decreased sufficiently, mercury is dosed and the arc tube is sealed off.

A heavy-wall quartz sleeve is applied around the arc tube support frame to limit sodium loss by the photoelectric effect. The cap has a porcelain insulator to better withstand high voltage ignition peaks. The rest of the construction is similar to ordinary mercury lamps.

This 1000W-380V lamp appears to have been a unique product to Claude - its competitors favoured a 1000W lamp for use on 220-240V mains. Soon after the 1980 takeover of Claude by Sylvania, this lamp was delisted and replaced by an externally sourced low-voltage version.
Manufacturer: Claude
Lamp Power: 1000 Watts
Lamp Current: 4.5 Amps
Lamp Voltage: 245 Volts
Cap Type: E40s/65x50 Ni plated brass + porcelain
Bulb Type: T-65 T-21 in eighths/inch
Bulb Finish: Clear Borosilicate glass
Electrodes: Backwound Tungsten No Emitter
Arc Length: 95 mm 33/4 inches
Atmosphere: (Na,In,Tl)Ix, Hg | Ar Outer: Vacuum
Luminous Flux: 81,000 lm
Luminous Efficacy: 81.0 lm/W
Colour Temperature & CRI: 4050K Ra 65
Chromaticity Co-ordinates: CCx: 0.380 CCy: 0.385
Rated Lifetime: 10,000 hours
Warm-up & Re-strike Time: 3-4 minutes 5 minutes
Burning Position: Horizontal ± 20°
Overall Length: 382 mm 15 inches
Light Centre Length: 240 mm 91/2 inches
Factory: Reims France
Date of Manufacture: Approx. 1985 Date Code: V0189
Original Value: Unknown
References: 1) Claude Catalogue Lampes à Décharge, Juillet 1986.