Hackday’s Bil Herd explains things again with a great video detailing how to make a thermocouple amplifier.

A Thermocouple is a terrific way to measure temperature. The effects of temperature change on dissimilar metals produces a measurable voltage. But to make that measurement you need an amplifier circuit designed for the thermocouple being used.

Source: How to Build a Thermocouple Amplifier | Hackaday