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Canadian Ceramalux C150S56 High Pressure Sodium |
A notable feature of the design is the sealing method employed for the arc tube, which employs niobium-1% zirconium end caps both as the electrical feedthroughs and to close the ends of the arc tube. This sealing method was employed in the days when the alumina arc tubes could be manufactured only as straight open-ended tubing, without a reduction in diameter at the ends to facilitate sealing in smaller diameter electrical feedthroughs.
The electrodes are spot-welded to a small tab of niobium inside the cup, and a strip of nickel tape welded to the outside forms the current conductor to the frame of the lamp. Three small indents in the side of the cup form point-contacts with the external surface of the PCA, and initially hold the cup in place by friction.
A coating of the frit sealing glass powder was applied to the inner surface of the niobium-zirconium cup, this being one of the early compositions based on the oxides of calcium, aluminium and magnesium. It is not the most effective seal and many failures at the niobium interface were reported. Several years later Westinghouse improved the bond with a coating of silicon on the niobium. Later modifications allowed this coating to be eliminated by including boric oxide and silica in the frit glass. The final changes came when the monolithic seal was invented, employing PCA with ceramic end plugs through which a thin Nb-Zr tube could be sealed.
| Manufacturer: | Canadian Westinghouse Company | |
| Lamp Power: | 150 Watts | |
| Lamp Current: | 1.8 Amps | |
| Lamp Voltage: | 100 Volts | |
| Cap Type: | E39s/41 | Brass + vitrite |
| Bulb Finish: | Clear | Lead borosilicate glass |
| Bulb Type: | BT-90 | BT-28 in eighths/inch |
| Overall Length: | 211 mm | 8 5/16 inches |
| Light Centre Length: | 127 mm | 5 inches |
| Arc Length: | 63.6mm | 2½ inches |
| Electrodes: | Backwound Tungsten | Barium Calcium Tungstate |
| Atmosphere: | Na,Hg | Xe | Outer: Hard Vacuum |
| Luminous Flux: | 14,000 lm | (@ 100 hrs) |
| Luminous Efficacy: | 93.3 lm/W | (@ 100 hrs) |
| Colour Temperature & CRI: | CCT: 2100K | CRI: Ra 22 |
| Chromaticity Co-ordinates: | CCx: 0.523 | CCy: 0.415 |
| Burning Position: | Universal | |
| Rated Lifetime: | 24,000 hours | to 50% survival |
| Warm-up & Re-strike Time: | 3-4 minutes | 1 minute |
| Factory: | Trois Rivières, Quebec | Canada |
| Date of Manufacture: | March 1974 | Date Code C4 |
| Original & Present Value: | ||
