A Temperature Scale for Tungsten

Temperature variation of the resistance of tungsten from 273°K to 3655°K.—In the range from 273°K to 1500°K measurements were made of the resistance of coils of pure, well-aged, tungsten filaments (diam. 2.61 mils) placed in the center of a constant temperature compartment of an alundum resistance furnace through which a stream of pure dry hydrogen was continuously passed. Temperatures were measured by a carefully standardized chromelalumel thermocouple. In the range 1200°K to 3655°K tungsten filaments (V shape, length 40-50 cm, diam. 2.61, 5.00 and 9.85 mils) were mounted in lamp bulbs and their resistances measured. Temperatures were determined by pyrometering against a standard lamp. The specific resistance of tungsten was found to vary from 5.00×${10}^{-6\mathrm{}}$ ohm cm at 273°K to 117.1×${10}^{-6\mathrm{}}$ at 3655°K.