The phenomenon whereby a variation in electrical potential along the length of a conductor is produced by a variation in temperature along its length.
The effect is typically observed when two thermoelectrically dissimilar conductors are joined, with the joined ends held at a different temperature from the opposite ends. This results in an electrical potential difference across the opposite ends. This potential difference provides the basis for measuring temperature in a thermocouple, and can also be used to generate electrical power.
Late 19th century; earliest use found in Journal of the Chemical Society.