The amount of voltage produced by the dissimilar metals when heated is measured in millivolts. Therefore, thermocouple leads are designed to provide a specific amount of resistance in the thermocouple circuit (usually very little).
A For the thermocouple leads are designed to provide a specific amount of resistance in the thermocouple circuit (usually very little). The amount of voltage produced by the identical metals when heated is measured in millivolts；
B The amount of voltage produced by the approximate metals when heated is measured in millivolts. Therefore, thermocouple leads are designed to provide a specific amount of resistance in the thermocouple circuit (usually very little)；
C Because of thermocouple leads are designed to provide a specific amount of resistance in the thermocouple circuit (usually very little).The amount of voltage produced by the different metals when heated is measured in millivolts；