Causes of change in the thermoelectric characteristics of tungsten-rhenium thermocouples

A study has been made of the causes of thermal and emf variation under vacuum and in the most favorable media, viz., hydrogen and oxygen. The main causes of instability are component diffusion along the wires, recrystallization and component redistribution in the temperature pattern, and the tendency for deposits of a second phase to form in VR-$3$–$5$ alloys, which is due to the anomalous electronic structure. The stability of such thermocouples is improved by using another material with a similar electronic structure.