The Cr-C eutectic and peritectic phase transitions have been observed at nominal temperatures of respectively 1 742 °C and 1 826 °C. Despite some advantages compared to many other temperature fixed points, as the good reproducibility of the peritectic phase transition, suitability for contact thermometry, or the low price of the material, the Cr-C has not been extensively investigated. Only a few papers have been published mainly focusing on the difficulties encountered during the construction of the cells. In this paper, the characterisation of two Cr-C fixed point cells, from their construction, to the ITS-90 temperature determinations at the eutectic and the peritectic phase transitions is summarised. The reproducibility of the melting plateaus and their sensitivity to the carbon proportion in the mixture are discussed.

Key words

high temperature fixed points
contact thermometry