Thermocouple and thermal resistance are the contact temperature measurement of temperature, although the same is measuring the temperature of the object, but the principle and characteristics of them are not the same.
First of all, introduce thermocouple, thermocouple temperature device is the most widely used in temperature measurement, the main features of the kiss is wide, the performance is stable, and has the advantages of simple structure, good dynamic response, more able to remote 4-20mA signal, which is convenient for automatic control and centralized control. Temperature measurement principle of the thermocouple is based on thermoelectric effect. Two different conductor or semiconductor connected to form a closed loop, when the two junction temperature is not at the same time, the loop will produce thermal potential, this phenomenon is called the thermoelectric effect, also known as the Seebeck effect. Thermoelectric generation in closed circuit potential has two potential; the potential temperature and contact potential. The potential temperature refers to both ends of the same conductor potential due to the temperature of different, different conductors with different electron density, so the potential they have is not the same, but the contact potential by definition refers to two different conductor in contact, because different electron density and their resulting in electron diffusion certain, potential formed
