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Philips HPI/T 400W 5th Generation |
Earlier designs attempted to limit the variation from lamp-to-lamp by providing a deliberate cold spot, thanks to a sharply-defined cylindrical arc tube. Although effective, that arc tube had to be hand-formed from three pieces of quartz - a labour-intensive operation. The intentional cold-spot also imposed a limit on vapour pressures, and light quality / efficacy.
The lamp featured on this page was made possible as a result of improved process control in shaping the quartz arc tube dimensions. It employs a single-piece quartz body of narrow diameter, whose central portion has been inflated to a larger diameter. The shape of the area around the electrodes has been precisely formed by blow-moulding during the process of pinch-sealing the quartz. The small increase in cold spot temperature brings about a small improvement in efficacy and colour. The result is a simpler and better arc tube, whose costs could be further cut by transfering its production to the high speed automatic MH360 machine, according to a design that Philips inherited from its takeover of Westinghouse.
The mount frame has also been simplified, the new shape allowing welds to be made directly to the arc tube. This delivers improved mechanical strength while also eliminating the former metal support strap at one end of the arc tube.
| Manufacturer: | NV Philips Gloeilampenfabrieken | |
| Lamp Power: | 390 Watts | |
| Lamp Current: | 3.4 Amps | |
| Lamp Voltage: | 125 Volts | 700V Ignition |
| Cap Type: | E40s/45 | Ni plated brass + vitrite |
| Bulb Type: | T-46 | T-16 in eighths/inch |
| Bulb Finish: | Clear | Borosilicate glass |
| Electrodes: | Double Coil Tungsten | Radioactive ThO2 emitter |
| Arc Length: | 41.5 mm | 1 5/8 inches |
| Atmosphere: | (Na,In,Tl)Ix, Hg | Ne-0.5%Ar | Outer: Ne-40%N2 |
| Luminous Flux: | 30,500 lm (@ 100hrs) | 29,200 lm (@ 2000hrs) |
| Luminous Efficacy: | 78.2 lm/W (@ 100hrs) | 74.9 lm/W (@ 100hrs) |
| Colour Temperature & CRI: | CCT: 4500K | CRI: Ra 65 |
| Chromaticity Co-ordinates: | CCx: 0.377 | CCy: 0.386 |
| Rated Lifetime: | 12,000 hours | 50% survival, 70% flux |
| Warm-up & Re-strike time: | 3 minutes | 5 minutes |
| Burning Position: | Horizontal ± 20° | |
| Overall Length: | 275 ± 8 mm | 11 inches |
| Light Centre Length: | 175 ± 8 mm | 7 inches |
| Factory: | Turnhout | Belgium |
| Date of Manufacture: | January 1996 | Date Code: 6A |
| Original / Present Value: | ||
