The Development of Water-Cooled Quartz Mercury Lamps

Abstract

From the Cooper-Hewitt mercury lamp of 1902, operating at a pressure of 0.0003 atmosphere and an efficiency of 18 lumens per watt, there have been developed lamps in hard glass and in fused quartz with pressures up to 200 atmospheres and efficiencies of 40 lumens per watt and above. At the highest pressures water-cooling is required, and a careful coordination of the designs of lamp, jacket, and ballast is required for successful operation. Brightness-distribution and spectral-energy data are given for the A-H6 and two experimental water-cooled lamps. Photoengraving, television, and searchlight applications of the A-H6 water-cooled lamp are discussed.