As shown in FIG constituted by ISO102 and INA101 have to eliminate ground loops, and high-end off cold junction compensation thermocouple amplifier. This circuit uses the K-typ
e thermocouple temperature detected at the scene, the temperature signal is converted to a voltage signal after amplification instrumentation amplifier INA101 to ISO102, ISO102 after the isolation amplifier output. Wherein the resistance Rc for setting INA101 gain. The characteristics of this circuit is interfering K-type thermocouple and ISO102 secondary ground is connected, that the formation of the same potential, thereby eliminating ground loops caused. Using 1N914 diode as thermocouple cold-junction compensation, lM resistors high off circuit.