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Powerball HCI-T Ceramic Metal Halide |
The fundamental difference is that the arc tube has been redesigned from a cylindrical shape to a new ellipsoidal form. Ellipsoidal arc tubes made in a single piece of ceramic have been known before, but are extremely expensive due to the advanced production methods that are required. The Powerball arc tube is made in two parts with a seam around the centre, and is the result of a co-operative project between Osram, Sylvania and NGK Insulators of Japan. It has the advantage that it is much cheaper to manufacture than the single piece ceramic arc tube.
An ellipsoidal shape is advantageous because it ensures that the arc tube temperature is more uniform than in the usual cyldindrical design. Crucially the ends run hotter, and this means that less metal halide salt dose is required. Corrosion of the ceramic by the halides is then substantially reduced and this allows overall arc tube temperature to be raised slightly, with this having a consequent benefit in terms of raising lamp efficacy and colour rendering. Thus Osram's Powerball design is able to raise luminous efficacy to 104 lm/W and colour rendering is increased from Ra85 to Ra89.
The new arc tube also has much lower thermal mass than earlier designs. This results in a faster run-up time and also a much shorter delay before hot-restriking the discharge.
| Manufacturer: | Osram GmbH | |
| Lamp Power: | 248 Watts | |
| Lamp Current: | 2.9 Amps | |
| Lamp Voltage: | 105 Volts | |
| Cap: | E40s/45 | |
| Bulb Finish: | Clear | |
| Bulb Type: | T-46 | |
| Overall Length: | 226 mm | |
| Light Centre Length: | 150 mm | |
| Electrodes: | Backwound tungsten | |
| Atmosphere: | Inner : Argon | Outer : Hard Vacuum |
| Luminous Flux: | 25,800 lm | |
| Luminous Efficacy: | 104 lm/W | |
| Colour Temperature & CRI: | CCT : 3000K | CRI : Ra 89 |
| Chromaticity Co-ordinates: | Not published | |
| Rated Life: | Not published | |
| Factory: | Spandau, Germany | |
| Date of Manufacture: | May 2002 | |
| Original / Present Value: | ||