The working principle of thermocouple thermometer and what are the advantages and disadvantages?

Thermocouple has become the current temperature measurement in the field of one of the most widely used thermometer table. But many people don't know how it works and the advantages and disadvantages, this instrument will give everyone said once: thermocouple is composed of two different metals or alloys of A and B and measuring instrument and closed road, A, B be hot electrode, A, B welding connection point 1 be measuring side, also be end or hot end work, on the other side of the contact as reference, also become the reference side. When measuring temperature, speak in the measured temperature of the measuring junction of the thermocouple, the reference side, under normal temperature and then through wires connected to the measuring instrument. Because the temperature is different, both ends of the thermocouple, in the thermocouple loop is the electromotive force is generated. Use numerical measuring instrument measured electromotive force, can be converted to the corresponding temperature or directly measuring instrument indicates that the temperature being measured. The thermocouple what are the main advantages and disadvantages of? The following specific said: ( 1) Advantages are: A. Measuring temperature range, can be in 1 k ( - 273 c) To measure the temperature range of ~ 2800 c; B。 Simple structure, easy manufacture, use, installation and maintenance is very convenient; C。 Performance is stable, accurate and reliable; D。 Thermal inertia small, fast dynamic response; E. Can be multi-point measurement, remote transmission, facilitates concentration detection and control. F。 Widely used in industrial production and scientific research in the field of temperature range. （ 2) Shortcomings mainly include: A: using the reference side must be constant, otherwise it will affect the accuracy of measurement.