Progress in the development of thermocouple calibration at Rh-C eutectic point

The rhodium-carbon (Rh-C) eutectic-point (1657 °C) cell having an outer diameter of 44 mm and a height of 297 mm was constructed for thermocouple calibration. The melting and freezing curves at the Rh-C eutectic point were evaluated using type R thermocouples. The repeatability of the melting and freezing curves, the effect of the surrounding temperature, and the heat flux effect in the cell were evaluated.