Type K is one of the most common general-purpose thermocouples, with a sensitivity of approximately 41 μV/°C. It is inexpensive; its potential range is –270°C to +1,372°C; and it is relatively linear.

You can see the video below, which includes an underwhelming teardown. The device is a J thermocouple and a decidedly vintage analog meter. What’s inside? Nearly nothing. So why did the meter ...

Different thermocouple types have different combinations of metal in the wires and are used to measure different temperature ranges. For example, J type thermocouples are made with iron and constantan ...