Hi well you will need a cold junction chip really, if you read the terminal board manual this will provide you with information on how to do this. However this is only for one channel.http://www.picotech.com/document/pdf/ad ... uide-5.pdf
Really the USB-TC08 is designed for having multiple channels.http://www.picotech.com/thermocouple.html
Why do you want to use the ADC20? Do you know that you can use an ADC20 and USB-TC08 together. In fact you can have up 20 USB devices.