Universal Gas Thermocouples 600mm – 1800mm. They are used for sensing the temperature of gas pilot burners and are used in conjunction with ignitors.
What and how are gas thermocouples used?
Gas thermocouples are a safety device; they will only allow the main gas valve to open if it detects a millivolt signal. This is done with the sensor tip getting hot via a pilot flame. The millivolt signal caused the magnetic plunger to energise open to allow gas flow when this gets hot.