The emf is called the Seebeck emf (or thermo/thermal/thermoelectric emf). The ratio involving the emf and temperature difference may be the Seebeck coefficient. A thermocouple steps the difference in possible across a cold and warm end for two dissimilar products. This possible variance is proportional into the temperature difference between https://3alem-eladwa.com/category/%d9%83%d9%87%d8%b1%d8%a8%d8%ac%d9%8a-%d9%85%d9%86%d8%a7%d8%b2%d9%84/