| 摘要 |
PURPOSE:To obtain a halogen lamp of long life, by filling in the glass bulb a gas including an inert gas and phosphine during the evacuation process, so that the oxide produced may be reduced by the phosphine. CONSTITUTION:As the gas to be filled in the glass bulb during the evacuation process, an inert gas of nitrogen, argon, or mixture of them with a small amount of phosphine is used. The phosphine, when the filament in the glass bulb is heated for illuminating, easily resolves into PH and hydrogen by the heat. The PH can reduce the tungsten oxide produced since the PH becomes phosphorus oxide taking the oxygen from the tungsten oxide. The amount of the phosphine to be added to the inert gas should be between 0.1% and 3% by volume. |
