Cold junction compensation
A recent solution to the problem of controlling a reference junction temperature is to use a 'cold-junction compensator'. This is an integrated
circuit that monitors the temperature of the reference junction, (which is allowed to adopt the ambient temperature), and then introduces an appropriate voltage into the circuit to produce the total voltage that would have occurred had a reference junction temperature been used and held at 0oC. The chip will often also amplify the thermoelectric voltage.