Development of Low Drift Nickel Based Thermocouples for High Temperature Applications

Abstract

Recent progress on the new nickelbased thermocouples for hightemperature applications developed at the Department of Materials Science and Metallurgy in the University of Cambridge is described in this paper. Isothermal drift at temperatures above 1000 آ°C as a function of the thermocouple diameter has been studied for both conventional nickelbased thermocouples and the new nickelbased thermocouple. The new nickelbased thermocouple experiences a much reduced drift compared to conventional sensors. Tests in thermal cyclic conditions have been undertaken on conventional and new nickelbased thermocouples, showing a clear improvement for the new sensors at temperatures both higher and lower than 1000 آ°C. The improvements achievable with the new nickelbased thermocouple in both isothermal and thermal cycling conditions suggest that the new sensor can be used at high temperatures, where current conventional sensors are not reliable, as well as at temperatures lower than 1000 آ°C with improved performance compared to the conventional sensors.