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Medium Pressure Mercury HgH 1000 |
It was furthermore customary in many parts of continental Europe to name lamps according to their output in dekalumens (1 dekalumen = 10 lumens). Thus this HgH 1000 lamp is a 10,000 lumen device, drawing some 265 watts. It was joined by the larger HgH 2000 (450W) and the smaller HgQ 300 (75W) and HgQ 500 (120W) types.
The arc tube here is fabricated from aluminosilicate glass that has been blown into a mould, to form the desired shape. The end sections around the electrodes are of reduced diameter, the purpose being to increase the temperature here slightly, and attain a faster run-up time than usual. Heat reflectors of platinum paint are applied behind the electrodes to provide extra thermal insulation. The electrodes take the form of open tungsten coils containing an emissive pellet - most likely of thorium oxide.
The end seals are of typical Osram style, found also in many of the spectral lamps having hard glass discharge tubes. Two molybdenum rods are first sealed into a graded sealing glass, and it is remarkable to note that the seal is made almost without oxide on the wire (the colour remains silvery). This assembly is then fused into the end of the arc tube. The arc tube is supported resiliently between a pair of spiral springs. Small ridges in the outer jacket keep these springs in place.
| Manufacturer: | Osram GmbH | |
| Lamp Power: | 265 Watts | |
| Lamp Current: | 2.7 Amps | |
| Lamp Voltage: | 125 Volts | |
| Cap Type: | E40s/45 | Brass + Porcelain |
| Bulb Finish: | Clear | Borosilicate hard glass |
| Bulb Type: | T-46 dimpled | T-15 in eighths/inch |
| Overall Length: | 285 mm | 11¼ inches |
| Light Centre Length: | 190 mm | 7½ inches |
| Arc Length: | 110mm | 4⅜ inches |
| Electrodes: | C-6 Open Coil | Thoria pellet emitter |
| Atmosphere: | Inner: Hg | Ar (1 atm) | Outer: Nitrogen |
| Luminous Flux: | 10,000 lm | (@ 100 hours) |
| Luminous Efficacy: | 37.7 lm/W | (@ 100 hours) |
| Colour Temperature & CRI: | CCT: 5400K | CRI: Ra 6 |
| Chromaticity Co-ordinates: | CCx: 0.337 | CCy: 0.421 |
| Burning Position: | Vertical ± 45° | |
| Rated Lifetime: | Not published | |
| Warm-up & Re-strike Time: | 5 minutes | 5 minutes |
| Factory: | Berlin-A | Germany |
| Date of Manufacture: | October 1945 | Date Code: mT3 |
| Original & Present Value: | CH Fr 50,- (1937) | |
