Evaluation of inhomogeneity of Pt/Pd thermocouples

The inhomogeneity of the Pt/Pd thermocouples annealed at 450/spl deg/C for 10 h and 850/spl deg/C for 100 h were evaluated by scanning the thermocouples in the temperature gradient region of the scanning facility. Through measurement using the scanning facility, the heat treatment temperature that decreases the inhomogeneity and the drift in emf at high temperature may be optimized effectively.