Thermocouple is good or bad judgment? - Shanghai dragon instrument electric appliance co. , LTD

USES more and more widely in the production of the thermocouple has become the industry one of the most commonly used temperature detecting element, it has high measurement precision, wide measuring range, simple structure, convenient use, etc. We know through various channels and analysis products, for the majority of netizens to present various industry knowledge. Then we have to understand the thermocouple is good or bad judgment? Thermocouple temperature measurement is the basic principle of two kinds of different ingredients of closed loop conductor material composition, when when there is a temperature gradient at both ends, loop will have an electric current passes through, the existed between the electromotive force on both ends - — Thermoelectric emf, this is the so-called seebeck effect. Two different components of homogeneous conductor electrode as heat, the temperature is higher for work at the end of the end, one end of the low temperature as the free end, usually free end under a constant temperature. Thermocouple in use after a period of time, there will be wear and tear, and may even damage, generally the stand or fall of thermocouple and thermocouple wire in it ( Silk) , but how to judge the stand or fall of I line, will discuss this problem simple. First determine the appearance of the thermocouple wire is no problem, it is good or bad, have to go through testing to determine. Will stay thermocouple wire wear measurement thermocouple special porcelain sleeve, with standard platinum-rhodium thermocouple in the tube furnace, the hot side insert tube furnace in a porous soaking with metal in the cylinder made of nickel. Put their compensation the cold end of the wire in the ice water to keep zero degrees Celsius in the container. Hold the tube furnace at the allowable maximum temperature of thermocouple, and keep the stable range. This time use after testing qualified, hui sten potentiometer, measure standard thermocouple and under test thermocouple thermoelectric potential difference and record. According to the records of thermoelectric potential difference, check grade table find out their corresponding temperature, if the thermocouple out-of-tolerance under test, can be judged to be unqualified.