Characterization of UME-Made Co-C Eutectic Fixed-Point Blackbody Cells

Eutectic phase transitions are commonly considered for use as fixed points in future 20XX temperature scales. Despite their potential as possible interpolation points in a high-temperature radiation thermometry scale (1000 A degrees C and above), more studies on the reproducibility of the plateau temperature values are required. Various ongoing research projects on the long-term stability and reproducibility of the eutectic fixed points will likely improve the uncertainties enough to allow for their use as reference (or secondary) temperature points. In this article, the long-term reproducibility results of Co-C eutectic plateau realizations performed in the UME Radiation Thermometry Laboratory over four years, along with studies of the dependence on furnace heating/cooling rate and the short-term (1 day) repeatability, are presented. These measurements were performed with a monochromatic radiation thermometer calibrated according to ITS-90.