The thermocouple developed by Heichal et al. was successfully
modified to measure accurate surface temperatures in aluminum
combustion chamber components. The primary modification was
the addition of a thick copper layer at the surface to conduct heat
away from the constantan wire. Using FEA, the optimal thickness
of the copper layer was found to be between 100 and 125 lm for
accurately measuring the true temperature swing. The addition
of this layer will introduce a modest delay in peak temperature
occurrence of less than 5 CA. The thermocouple is very accurate
at measuring average temperatures, a task which is less sensitive
to copper thickness. If the thermocouple is used to measure temperatures
under a TBC, a wide range of copper thicknesses can be
tolerated while still producing accurate measurements.