Thermoelectric Stability of Graphite-Based Thermocouples

This paper describes the design of newly developed graphite-based thermocouples and the results of investigation of their thermoelectric stability up to temperatures of about 1950 °C in graphite-containing atmospheres. All investigated combinations of different graphite grades revealed considerable thermoelectric drifts above approximately 1600 °C. With the most promising combination of isostatically pressed carbon and glassy carbon as the sensitive elements, drift rates of less than 0.1 K·h^?1 could be achieved in use at 1500 °C. This allows at least short-term use of the graphite-based thermocouples at specific applications where metallic thermocouples cannot be reliably used.