Abstract
A SERIOUS difficulty in television studios is the necessity of providing about double the light required by an ordinary cinema studio without subjecting the occupants and contents to intolerable heat. This difficulty has been largely overcome by the General Electric Co. of America at the television station at Schenectady, New York, by the use of a battery of four water-cooled quartz mercury arc units, containing twelve argon-filled lamps having a light output equivalent to that provided by nearly 30,000 watts of incandescent light, but they give off practically no appreciable amount of heat. According to the Electrical Reviewof August 25, the lamps are about the size of a cigarette and have an exterior of quartz. Surrounding the tube is another quartz jacket through which water passes at the rate of three quarts a minute, dispersing about 90 per cent of the heat generated. The twelve 1,000-watt lamps used have a total light output of about 800 thousand lumens, while the same wattage of incandescent lamps would provide only 330 thousand lumens. The possibility of a burn from incandescent lamps, caused by the infra-red radiation, greatly inconveniences performers who appear before the television camera. In the case of the new lamps, more than 90 per cent of the infra-red radiation is absorbed by the circulating water. The cooling system of the lamps is equipped with a pressure-operated switch and magnetic valve, since the water in the jacket must be moving before the lamp is lighted and because the lamp must be turned off automatically in the event of failure or reduction of the water supply. During operation a pressure of more than 1,000 1b. per sq. in. is developed within the quartz jacket.
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Water-cooled Lamps for Television. Nature 144, 506 (1939). https://doi.org/10.1038/144506a0
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DOI: https://doi.org/10.1038/144506a0