Thermoelectromotive force

Japanese: 熱起電力 - ねつきでんりょく（英語表記）thermoelectromotive force

In a closed circuit with two types of metals (or semiconductors) in contact at both ends as shown in the figure, if the temperatures of the two junctions are different, an electromotive force is generated and a current flows. This is called a thermoelectromotive force or a thermocurrent. This phenomenon was discovered by T. J. Seebeck in 1821 and is called the Seebeck effect. The magnitude and direction of the thermocurrent are determined only by the combination of the two metals A and B and the temperatures of the two junctions. This closed circuit is called a thermocouple and is widely used to measure temperature. If you make a thermocouple by choosing any two of the following Hankel thermoelectric series, a current will flow from the metal on the left to the metal on the right at the hot side joint.
However, the temperature range is 10 to 30°C, and the order varies slightly depending on the temperature. The thermoelectromotive force is a composite effect of the difference in the Peltier effect due to the difference in temperature between the two junctions, and the Thomson effect due to the difference in temperature between both ends of metals A and B.

Source: Encyclopaedia Britannica Concise Encyclopedia About Encyclopaedia Britannica Concise Encyclopedia Information

Japanese:

図のような2種類の金属 (または半導体) を両端で接触させた閉回路で，2つの接点の温度が異なっていると起電力が生じて電流が流れる。これらを熱起電力，熱電流という。この現象は 1821年 T.J.ゼーベックにより発見され，ゼーベック効果と呼ばれる。熱電流の大きさおよび向きは2種の金属AとBとの組合せと，2接点の温度だけとで決る。この閉回路は熱電対と呼ばれ，温度測定に広く用いられている。次のハンケルの熱電列のうち，任意の2つを選んで熱電対をつくれば，左の金属から右の金属へ向う電流が高温側の継ぎ目で生じる。
ただし，温度範囲は 10～30℃であり，順序は温度により少し違ってくる。熱起電力は2接点の温度の違いによるペルチエ効果の差と，A，Bそれぞれの金属について両端温度の差によるトムソン効果を合せた合成効果である。

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