New sensors open way to lower aircraft emissions

Research lead

Measurement scientists at the National Physical Laboratory (NPL) in the UK have reduced the uncertainty of thermocouple temperature sensors at high temperatures to within a degree. This could allow manufacturers to increase the efficiency of jet engines and lower aircraft emissions.

Aircraft engines are more efficient at higher temperatures, but this requires thermal treatment of engine components at very specific high temperatures in excess of 1,300 °C. If the heat treatment temperature deviates too much from the optimal temperature, the treatment may be inadequate.

Thermocouples are calibrated using materials with known melting points (fixed points), but the available reference materials in the region of the very high temperatures required to treat jet engine components have a large uncertainty compared with the lower temperature fixed points.

Using a new type of metal alloy, scientists at the laboratory have identified a range of reference points for thermocouples beyond 1100 °C. This added confidence in thermal sensors will enable component manufacturers to improve thermal treatments and produce engine parts for engines that can run at higher temperatures.

The National Physical Laboratory is the UK’s national measurement laboratory.