What materials are jet engine thermocouples typically made of?

Jet engine thermocouples are primarily made of chromel and alumel because these materials provide the necessary temperature sensing capabilities required for high-performance applications, such as those found in jet engines. Chromel, an alloy of nickel and chromium, and alumel, an alloy of nickel, manganese, and aluminum, are specifically chosen for their ability to maintain stable and accurate readings over a wide range of temperatures.

In the harsh environments present within jet engines, the thermocouples must withstand extreme temperatures and corrosion. Chromel and alumel are effective at these high temperatures, often exceeding 1000 degrees Celsius, which is essential for correctly measuring engine performance and ensuring safe operation.

The other materials mentioned, such as nickel and chrome, steel and copper, or aluminum and brass, do not meet the specific thermal and chemical resilience requirements necessary for effectively functioning as thermocouples in the demanding conditions of jet engines. Therefore, chromel and alumel are indeed the most suitable choice for jet engine thermocouples, enabling accurate temperature monitoring and safety in turbine operations.