SELF-CALIBRATING THERMOCOUPLES - MODELING AND DESIGN

To investigate thermocouples with integrated miniature fixed-point cel ls RC-Models have been taken into consideration. Calculations of the d ynamic behaviour and the influence on the resulting calibration uncert ainty are performed. Two prototypes of self-calibrating thermocouples with Au- and Al-fixed-point cells and software for an automatic determ ination of the fixed-point and recalibration have been developed both for being used as operational standard and for selected industrial mea suring applications. Their design presents a remarkably good long-term stability at temperatures far above the melting point of fixed point materials just as in case of abrupt temperature changes.