Thermocouple is a kind of common temperature measuring instrument, the scope of application is also very extensive. All of the instruments in the process of using are there will be a certain fault, thermocouple is no exception, thermocouple is also there will be some problems when using. Thermocouple common fault, fault phenomenon, display instrument indicates a negative; Possible reasons: digital display table with thermocouple wiring is wrong or thermocouple have short circuit phenomenon; Processing method: correct wiring, or find out short circuit, reinforced insulation. Fault phenomenon: thermocouples table indicating infinity; Possible reasons: thermocouple or loosen the lead wire short circuit or terminal; Methods: the change in resistance or welding and tighten the screw connection, etc. Fault phenomenon: show the thermocouple indicated value is lower than the actual value or unstable value; Possible reasons: protecting tube with metal dust, dust, dirt and thermocouple short circuit between terminal; Methods: to remove scrap metal, cleaning dust, water, etc. , find the short circuit point reinforced insulation. Fault phenomenon: thermocouple value changes with the temperature relation; Possible reasons: thermocouple wire material corrosion metamorphism; Deal with method: replace thermocouple; Above is the thermocouple common failure, the user when using thermocouple to the above fault can refer to this article, can effectively solve the problem, for the user to reduce unnecessary trouble to improve work efficiency.