Abstract
At high temperatures (from 600 °C to 962 °C), the uncertainty of calibration by comparison of industrial platinum resistance thermometers and thermocouples is limited by the instability and the reliability of the standard platinum resistance thermometer and by the lack of uniformity of the temperature in the operating volumes of furnaces equipped with comparison blocks. To improve the performances of such calibrations by comparison, we studied the possibility to connect simultaneously several pressure-controlled heat-pipes filled with different working fluids to the same pressure control system. The experimental apparatus, called “temperature amplifier”, is composed of two heat-pipes filled with Sodium and water. This paper is a progress report on this study and presents the relevant uncertainties.