Problems with op amp thermocouple circuit
Be aware that using a thermocouple like this will basically only give you a signal that depends on the temperature difference between the thermocouple tip and the connection to your opamp's input.

The signal is very small (41 uV/deg C), so generally opamp offset voltages will provide more signal than your thermocouple will. For this reason, to get good results you need to use an offset compensated (auto-zeroed) opamp; even then it's hard to get accurate results.