GB302643A - Improvements in electric discharge devices - Google Patents

Abstract

302,643. Claude Neon Lights, Inc., (Assignees of Beck, L. L.). Dec. 19, 1927, [Convention date]. Vacuum tubes; low-pressure metallic-vapour apparatus.-A lamp giving light from the positive column contains mercury and a mixture of rare gases such as argon which produces light of a colour similar to that produced by mercury, a heat-producing gas such as helium, and a diluent such as neon. The discharge develops sufficient heat to maintain mercury vapourized and the light remains constant at low external temperatures. For example the discharge in a lamp containing mercury, 30 per cent of neon, and 70 per cent of helium at a pressure of 7.5 millimetres of mercury maintains its blue colour down to 28‹ F. and to-49‹ F. at a pressure of 30 millimetres; argon may be added, for example, in an amount equal to 0.5 or 2 millimetres. The amount of mercury may be three to four grammes per fifteen feet of tubing. Reference has been directed by the Comptroller to Specifications 5589/11, 12157/14, and 187,976.