The hot junction temperature of the thermocouple is 820 ° С, and its free ends are 20 ° С.

The hot junction temperature of the thermocouple is 820 ° С, and its free ends are 20 ° С. Determine the temperature coefficient of materials if the emf of the thermocouple is 8 mV.

To find the temperature coefficient of the material (thermoelectric coefficient), we will use the formula: E = α * (Tg – Tx), whence we express: α = E / (Tg – Tx).

Values of variables: E – EMF of the used thermocouple (E = 8 mV = 8 * 10-3 V); Тг – hot junction temperature (Тг = 820 ºС); Тх – temperature of free ends (Тх = 20 ºС).

Let’s calculate: α = E / (Tg – Tx) = 8 * 10-3 / (820 – 20) = 1 * 10-5 V / K.

Answer: The Seebeck coefficient is 1 * 10-5 V / K.