摘要 |
A cathode shield for a gas discharge lamp having a predetermined size hole proportional to the diameter of a cup and the diameter of the glass envelope of the gas discharge lamp. A conductive cup is placed around an electrode or a filament. The cup is covered with an insulator material having a hole therein. The diameter of the hole in the cover has a proportional relationship to the diameter of the envelope of the lamp and the diameter of the cup. The ratio of the diameter of the envelope and the hole in the cover ranges between 3.5 and 4.5. The ratio of the diameter of the cup and the hole in the cover ranges between 2.0 and 3.0. It has been determined that these ratios improve current loads without changing discharge characteristics. Additionally, lower temperature operation and starting is facilitated with increased service life. The cathode shield is particularly applicable to germicidal lamps used in water treatment due to the cooler starting and operating temperatures required.
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