Realization of High-Temperature Reference Point of the Temperature Scale for the Phase Transition of a δMoC–C Metal-Carbon Compound

We present the results of development of a prototype of cavity-type model of black body in the form of a graphite ampoule filled with a δMoC–C eutectic alloy of molybdenum with carbon that realizes a high-temperature reference point (HTRP) of 2856 K on the temperature scale. It is shown that the created ampoule may serve as a precision “type-A” optical radiation source. We justify the approaches to the evaluation of the uncertainty components of emissivity of the ampoule cavity equal to 0.9997 with an extended uncertainty of 0.00016 (k = 2) depending on the geometric and physical parameters with the help of numerical algorithms based on the Monte-Carlo method.