Electrically isolated thermocouple amplifier

Hi, i am ramprasad ,

i need the Electrically isolated thermocouple amplifier with channel to channel isolation , i am working with the three phase power supply line .in each phase transmission  line dissipate some amount of heat when it maximum load or Maximum current flow , i need to calculate the heat by attaching the thermocouple directly to the transmission line .due to this direct attachment small amount of current flowing through thermocouple. like that i need to calculate the all the three phase transmission line. help me for the isolation or give me alternative solution .Suggest me best amplifier for this issue. 

Thanks for the replay