Features of Co/C and Ni/C eutectic transitions for use in thermocouple thermometry

Abstract

Eutectic cells of Co/C and Ni/C for use in thermocouple calibration were manufactured and tested to investigate their melting and freezing characteristics using type B thermocouples. It was observed that the melting and freezing behaviour of Co/C and Ni/C systems are very similar. The freezing plateaus were found to be flatter than those of melting, but the melting points were closer to the ideal transition temperatures, which is an extrapolated value to zero temperature difference from the set temperature to induce melting/freezing, than the freezing points. Based on the observed results, the melting process is recommended for use when calibrating thermocouples.