Waoh,,,,this is not a thermocouple, this is a Bourdon tube pressure gauge. The bulb that
sits in the water jacket contains ether which is liquid at room temperature. The tube
leading from it is hollow and connected to the Bourdon tube temperature gauge. When
the ether warms up it vaporizes and the pressure increase in the system caused the
Bourdon tube to straighten out. The needle is attached to the end of the Bourdon tube and
moves across the temperature calibrated scale.
No thermocouple action here.
Denny Graham
Sandwich, IL
