PLATINUM-BASED THERMOCOUPLE

摘要

There is proposed a Pt vs. Pt-Rh based thermocouple such as an S thermocouple (Pt vs. Pt-10%Rh alloy) or an R thermocouple (Pt vs. Pt-13%Rh alloy) having temperature characteristics equivalent to those of conventional ones and being free from disconnection of a wire during handling and use. The present invention is characterized in that, in the Pt-PtRh based thermocouple of Pt vs. Pt-Rh alloy, a Pt wire has a Pt purity of 5N or higher and has an oxide dispersed therein. As for the Pt wire of the thermocouple according to the present invention, it is preferable that a Zr oxide in an amount of 0.02 to 0.5 mass% in terms of Zr is dispersed therein.