Mark Wrathall wrote:
The fire loops used on commercial turbines are made up with a cross section
like coax cable. The shield and core are solid metal, separated by a low
melting point salt which insulates as a solid. When melted, it conducts,
shorting the two conductors, and turning on the light in the cockpit
(basically).

Sounds more like the twisted pair with a low melting temp insulator, I think we are more interested in the fact that there is something too hot or on fire than specifically where it is and how hot it is... the outcome will be the same if we don't get our butt on the ground. The fire detection loop was meant to be a two state device; things are good or things are bad.
On the other hand, it may be simpler to implement the same outcome on a more reliable basis with thermocouples.
...Chrissi

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