Problems need attention when using thermocouple

Thermocouple is actually a kind of energy converter, it converts heat energy to electricity, to our common temperature measuring element, it directly measure temperature, and the temperature signals into a thermoelectric emfs, through electrical instrument ( Secondary instrument) Converts the temperature of the measured medium for thermocouple thermoelectric potential, when use several problems should be paid attention to the following:

1, the thermocouple thermoelectric potential is thermocouple temperature on both ends of the work on the function of the poor, rather than the thermocouple cold end with the job, temperature difference on both ends of the function;

2, the size of the thermocouple thermoelectric potential produced by, when material is uniform thermocouple, has nothing to do with the length and diameter of thermocouple, only with the thermocouple at the ends of the material composition and temperature on the

3, when the two thermocouple wire thermocouple material component is determined, the size of the thermocouple thermoelectric potential, only related with the thermocouple temperature difference; If the thermocouple cold end temperature keeping, this into the thermocouple thermoelectric potential is only the end of the single value function of temperature. Two different welding material A conductor or semi-conductor A and B, form A closed loop, as shown. When the conductor A and B two persistent point temperature difference between 1 and 2, occurs between the electromotive force, thus forming the size of A current in the circuit. Thermocouple is in using this effect to work.