I am trying to read the thermocouple voltage of a Hakko T12 tip which has the heating element present in series with the thermocouple. The problem is that 24V DC will be present on T+/T- of the thermocouple when the heater is being powered. I have seen people get around this problem using OP amps that have overvoltage protection like the ADA4177. The problem with this is I want to have good temperature accuracy and that would mean that I would have to add an external ADC and also add cold junction compensation. Ideally I would like to use something like the MAX31855 which already does everything I want but I can't come up with a solution that would prevent 24V going to it and also maintain its accuracy. Would something like diode clamping work or should I be looking in another direction?