stoves and hot water heaters use a thermocouple in the flame to sense when to shut down the gas
No I think you will find it is a bi-metallic strip.http://en.wikipedia.org/wiki/Bimetallic_strip
am very sorry to have wasted your time, as there was an OBVIOUS answer of which I had overlooked. Here it is:http://www.sparkfun.com/products/9405I have a propane grill. Duh!