What's the difference between a thermistor and the working principle of the thermocouple _ instrument

If the concentration of electrons and holes respectively n, p, mobility, mu mu n p respectively. Because of n, p, u n, u p is a function of T depend on temperature, so the conductivity is a function of temperature, therefore can be calculated by measuring conductivity of high and low temperature, and can make the resistance - Two kinds of different ingredients of conductor ( Called the thermocouple wire or hot electrode) Two ends synthesis loop, when the junction temperature is not at the same time, in the circuit will generate electromotive force, this kind of phenomenon called the thermoelectric effect, and the electromotive force called thermoelectric potential. Thermocouple is to use the principle of temperature measurement, which directly used for measuring the medium temperature is called at the end of the working side ( Also known as the measuring end) , on the other side called cold end ( Also known as compensation) ； The cold end through compensation conductor should be connected to the digital display table or meter, display instrument will point out the thermocouple thermoelectric potential. Thermocouple is actually a kind of energy converter, it converts heat into electricity, using thermoelectric potential generated by the measuring temperature, the thermocouple thermoelectric potential, we should pay attention to the following questions: 1: 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, and only at the ends of the thermocouple material composition and temperature difference; 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, this kind of phenomenon called the thermoelectric effect. Thermocouple is in using this effect to work.