Pyrostat

noun

1. An automatic sensing device that activates an alarm or extinguisher in case of fire.
2. A high-temperature thermostat.
3. An automatic draft-regulator for chimneys, smoke-pipes, and smoke-stacks. See draft-regulator, under regulator.
4. An apparatus for maintaining constancy of temperature; a thermostat; specifically, a thermostat for high temperatures.
5. a thermostat designed to operate at high temperatures