A Robust Printed Circuit Hot‐Wire Sensor for High‐Temperature Thermal Conductivity Measurement in Chloride Molten Salt

This study introduces an innovative printed circuit hot‐wire sensor specifically designed to measure the thermal conductivity of highly corrosive molten salts at high temperatures. The sensor body, fabricated from alumina (Al 2 O 3 ), ensures durability and performance in extreme conditions, with a tantalum (Ta) hot‐wire that is electrically insulated via anodizing. This novel design incorporates a protective mechanism for the hot‐wire, addressing its fragility and enhancing sensor integrity. Validation experiments using water and glycerol demonstrated measurement accuracy within 5% of established data at temperatures below 250°C. Furthermore, thermal conductivity measurements of KCl–MgCl 2 , including uncertainty, showed consistency within 20% of literature values in the 450°C–800°C range. This study confirmed the possibility that the sensor can exhibit relatively good performance even in high‐temperature, corrosive environments, and also discussed methods to further improve the accuracy of the sensor developed in this study.