A thermocouple is an electrical device that joins two different conductors at electrical junctions, with a temperature difference between the joints. This produces a temperature-dependent voltage that can be interpreted as a temperature measurement.
Thermocouples are among the most widely used temperature sensors, as they are inexpensive, interchangeable, equipped with standard connectors, and can measure a wide range of temperatures.
Thermocouples are more suitable for industrial applications that do not require a great deal of accuracy, because they cannot reliably measure small temperature changes within 1 degree C. Thermocouples can be used for industrial processing, manufacturing, power production and other applications that only require more general temperature readings.