Development of a High-Temperature Sensor for a Gas Turbine Engine

A reliable high-temperature thermocouple for sensing turbine inlet temperature of a gas turbine engine has been developed. This sensor employs noble-metal thermoelements but retains the high signal level associated with base-metal thermocouples. A unique system of secondary junctions, contained within the device itself, allows transition to relatively inexpensive standard thermocouple materials. The development of different sampling type protective probes, including an air-cooled design, accompanied the development of the thermoelements.

Some of the unsuccessful as well as the successful steps in the development are discussed, and some thoughts on future temperature sensors are given.