Thermocouple temperature sensor with connection detection circuitry

A method for connecting a thermocouple to a transmitter, the method comprising:

• connecting first and second cold junction ends of the thermocouple to first and second terminals of the transmitter, respectively;
• exposing a process end of the thermocouple to a first environment with a first temperature and exposing the cold junction ends of the thermocouple to a second environment with a second temperature;
• sensing temperature with the thermocouple to produce a thermocouple signal as a function of a difference between the first temperature and the second temperature;
• sensing temperature with a cold junction temperature sensor to produce a cold junction sensor signal as a function of the second temperature;
• and
• reconnecting the thermocouple to the transmitter so that the first cold junction end is connected to the second terminal and the second cold junction end is connected to the first terminal if there is a positive correlation between the cold junction sensor signal and the thermocouple signal.

An assembly comprising:

• a thermocouple having a process end and a cold junction end, wherein the cold junction end has first and second cold junction terminals;
• a cold junction sensor supported near the cold junction end and configured to measure temperature at the cold junction end;
• and
• a circuit electrically connected to the cold junction sensor and electrically connected to the first and second cold junction terminals, wherein the circuit is configured to:
• produce a thermocouple signal as a function of voltage across the first and second cold junction terminals,
• produce a cold junction sensor signal as a function of temperature of the cold junction end as measured by the cold junction sensor, and
• calculate a correlation between the thermocouple signal and the cold junction sensor signal.