Circuit provides cold-junction compensation. (Design Ideas).

THE ACCURACY OF ANY CIRCUIT or System that uses a thermocouple to determine the temperature of a process is limited by the accuracy of the method used to perform cold junction compensation. In a thermocouple measurement, two wires of dissimilar metal join together at the "hot," or measurement, junction. The isothermal termination of the thermocouple wires provides a second "cold," or reference, junction. The potential across the thermocouple is proportional to the temperature difference between the two junctions. Thus, to determine the absolute temperature of the hot junction, you