An Electrical-Resistance Method of Determining the Mean Surface Temperature of Tubes

The author describes a new method for determining the mean surface temperature of condenser tubes through which a steady radial flow of heat occurs. The method consists in using the tube itself as a resistance thermometer. The author explains that when a steady longitudinal flow of electricity is superimposed upon the given radial flow of heat, the actual current being so small as not to involve appreciable Joulean heat, the temperature gradients associated with the flow of heat affect the electrical resistance of the tube material, and expressions for the mean temperature of the inner and outer tube surfaces can be derived from applications of physical laws. These expressions are derived by the author.