High Temperature Fixed-Point Blackbodies Based on Metal-Carbon Eutectics for Precision Measurements in Radiometry, Photometry and Radiation Thermometry

摘要

Re-C, TiC-C and ZrC-C metal-carbon eutectics cells were developed and investigated at VNIIOFI (Russia) for use as high-temperature fixed-point blackbodies for precise measurements in radiometry, photometry and radiation thermometry. Two types of cells containing cavities with 4 mm and 10 mm diameters were designed that allow using them in radiance and irradiance modes, respectively. The melting temperatures of Re-C, TiC-C and ZrC-C were found to be 2747.5 K, 3033.8 and 3154.1 K respectively. The reproducibility of the Re-C fixed points was found to be 0.04 to 0.09 K, depending on the cell. The reproducibility of TiC-C and ZrC-C melting temperatures was 0.05 K and 0.09 K respectively. The pyrolitic-graphite blackbody BB3200pg was used as a furnace for heating eutectics. The new TiC-C and ZrC-C fixed-point cells with 16 mm cavity diameter and a new furnace BB3500MP are under development now.