cold junction compensation

Definition

The appropriate product category Digital Panel Indicators: Also called reference junction compensation. When measuring temperature using thermocouples, the reference terminal may not be held at 0°C, but at the surrounding temperature of T1°C instead. Without any compensation, the thermocouple output will be reduced by T1°C. This is compensated by adding potential difference to the internal amplifier corresponding to T1°C.

The appropriate product category Temperature Controllers: The thermo-electromotive force of the thermocouple is generated according to the temperature difference between the hot and cold junctions. If the cold junction temperature fluctuates, the measurement data will fluctuate even if the hot junction temperature remains stable. For this reason, a separate sensor built into the controller is used to monitor any changes in the cold junction (terminal connected to the thermocouple), and the controller automatically compensates for these changes to keep the cold end of the device at 0 °C. This is called cold junction compensation.