Improvements in or relating to apparatus for controlling temperatures

Abstract

Abstract 537,155. Temperature-variable resistances. BERRY, A. E., and MARPLES, C. H. March 28, 1940, No. 5572. [Class 37] ln a device for controlling the temperature of furnaces . &c. a fusible salt 5 which is a non- conductor of electricity when in its solid state fuses when heated and becomes conducting thereby closing a circuit between electrodes 3, 8 which may operate relays to cut off the heating. Suitable salts to use are a mixture of sodium nitrate with potassium nitrate or barium nitrate, potassium sulphate, sodium chloride, or a mixture of sodium chloride and potassium chloride. Suitable choice of these would produce maintaining temperatures of from 290‹C. to 1060‹C. For the higher temperatures the electrodes are preferably of platinum and are mounted in a vessel of silica, Fig. 2 (not shown).

Inventors

No inventors recorded.

Bibliographic Details