.Thermocouples are very sensitive, requiring a good amplifier with a cold-compensation reference. This is a very simple sensor to use, and if your microcontroller has analog input capability, you'll be ready to go really fast!
The AD8495 K-type thermocouple amplifier from Analog Devices is so easy to use, Adafruit have documented the whole thing on the back of the tiny PCB. Power the board with 3-18VDC and measure the output voltage on the OUT pin. You can easily convert the voltage to temperature with the following equation: Temperature = (Vout - 1.25) / 0.005 V. So for example, if the voltage is 1.5VDC, the temperature is (1.5 - 1.25) / 0.005 = 60°C
Goes great with our 1m K-type thermocouple (not included). Not for use with any other kind of thermocouple, K type only!