Abstract: A thermocouple assembly for the continuous measurement of the temperature of a molten phase contains first and second ceramic elements contacting each other at a first junction and forming thereby a first thermocouple, a second thermocouple formed of two different conducting elements contacting each other at a second junction located on the first ceramic element and a third thermocouple formed of two different contacting elements contacting each other at a third junction located on the second ceramic element. Both positive legs or both negative legs of the second and third thermocouples are connected to a first measuring device. Both legs of the second and third thermocouple are connected respectively to a second and third measuring device as well as to a process for the measurement of the temperature of a molten phase.