The True Temperature Scale of Carbon

Abstract

Spectral emissive power of Acheson graphite at 0.660\ensuremath{\mu}.---The spectral emissive power of Acheson graphite for the wave-length 0.660\ensuremath{\mu} has been determined for the temperature range from 1250\ifmmode^\circ\else\textdegree\fi{}K to 2700\ifmmode^\circ\else\textdegree\fi{}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: $\ensuremath{\epsilon}=0.984\ensuremath{-}5.8\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}T$. Measurements of the temperature distribution along the furnace afford determinations of the ratio of resistivity to thermal conductivity at three temperatures.