Abstract: The thermocouple is one of the common temperature sensors used in thermometers.In the measurement of temperature,it is difficult to maintain stable temperature for the thermocouple cold junction,so the results need cold-junction compensation.In this paper,the cold junction temperature measured by PT1000 is sent to the MCU of the host computer after A/D conversion to convert the resistance value by software into a voltage value,which is added to the voltage applied to the thermocouple,and then the effects of the temperature change in the cold junction is eliminated by the compensation module.Tests show that the method is accuracy and stable.

Key words: thermocouple;cold junction compensation;temperature sensor