LM335 thermocouple cold junction compensation thermocouple circuit

Thermocouples can measure high temperatures. In the thermocouple measurement circuit, the thermoelectric potential of the thermocouple and the temperature
of the temperature measuring node and the reference node (cold junction) must be kept constant . The circuit shown in the figure is a LM335 thermocouple cold junction compensation thermocouple circuit . It uses LM335 to measure the cold junction temperature (LM335 is attached to the cold junction of the thermocouple). LM 335 outputs a voltage proportional to the absolute temperature . AD581 is an IO. OOV reference voltage generator that provides a stable reference voltage. RP, and RP2 are used for calibration, and R3 and R4 determine their resistance according to the use of different types of thermocouples .