ORIGINAL: downunder
Gas turbines have thermocouples placed just downstream from the last stage of turbines but before the afterburner (if it has one). Their purpose is to give an indication of the turbine blade temperatures because it's a bit hard to put a thermocouple directly on the blade

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Oh really? I put all sorts of sensors on turbine blades. If we're lucky, they stay put for a while and actually give good data. Check out
www.tasnn.com.