Thermocouple perfect measurement note release date: 2019 - 06 - 05 viewed: zero

Whether what kind of products, if you can't very good use, so it can't bring you what you want as a result, the thermocouple as such, and it is more demanding, need to be more careful, can let you get the most perfect data, want to make better use thermocouple, and maintain good accuracy, so let's see what needs to be done! First, because caused by improper installation, actually this we emphasized many times before, this is very important, the location of the thermocouple installation and insertion depth cannot reflect the reality of the furnace temperature, etc. , in other words, the thermocouple should not be in too close to the door and heating, the depth of the insert should be at least 8 ~ 10 times the diameter of the protection tube; Thermocouple protection tube and the wall between the interval of missing adiabatic material overflow or cold air invading the furnace heating, so the space between the thermocouple protection tube and furnace wall hole used refractory mortar or insulating material such as asbestos rope jam to avoid cold and hot air convection and affect the accuracy of temperature measurement; Thermocouple cold end is too close to the furnace temperature over 100 ℃; The installation of thermocouples should as far as possible to avoid the strong magnetic field and strong electric field, so should not be thermocouple and the power cable line in order to avoid interference caused by errors within the same catheter; Thermocouple cannot be installed in a few measured medium flowing area, when measured with thermocouple tube gas temperature, thermocouple must be made against the flow direction of installation, and fully contact with the gas. Followed by the error, introduced about thermal inertia, due to the thermal inertia of thermocouple made instrument indicated value behind the change of the measured temperature, this influence is particularly acute in rapid measurement. So should be used as thermal electrode is small, small thermocouple protection tube diameter. Temperature measuring environmental permits, even protecting tube can be taken. Due to measurement lag, using thermocouples detect temperature fluctuations of the amplitude of the furnace temperature fluctuation amplitude of the small. Measurement lags behind, the greater the fluctuation amplitude of the thermocouple is smaller, and the actual temperature difference. When using the time constant of thermocouple temperature or temperature control, instrument display temperature fluctuation is small, but the actual furnace temperature fluctuations can be quite large. In order to accurately measure temperature, should choose small thermocouple time constant. With thermocouple time constant is inversely proportional to the heat transfer coefficient, heat the density and specific heat is proportional to the diameter, material, such as to reduce the time constant, in addition to the increased heat transfer coefficient, the most effective way is to try to decrease the size of the hot end. Use, usually USES the material with good thermal conductivity, thin, small diameter of the tube wall to protect casing. In the precision of temperature measurement, using unprotected casing bare wire thermocouple, thermocouple easy damaged, should be timely correction and replacement.