The True Temperature Scale of Carbon

Spectral emissive power of Acheson graphite at 0.660μ.—The spectral emissive power of Acheson graphite for the wave-length 0.660μ has been determined for the temperature range from 1250°K to 2700°K. The observations were made on a small tubular graphite resistance furnace with a hole in the wall and are best summarized by the relation: $\epsilon =0.984-5.8\mathrm{}\times {10}^{-5\mathrm{}}T$. Measurements of the temperature distribution along the furnace afford determinations of the ratio of resistivity to thermal conductivity at three temperatures.