Isolated analogic in multiple thermocouples

Hi,

I Have a projet witch I need a logger of 4 different thermocouples, but as arduinos analogic in use a commun ground I can't use it because it can generate a short circuit in my system.

someone knows a circuit (preferable DIY) where I can Isolate and amplify the channels and read them one at a time?

Thanks

Four of these boards will work using an analogue input for each. However, the thermocouple wires will have to float.