The cause of the thermocouple measurement error

Thermocouple can measure how many degrees? Its model representation method? What are the connections? Product selection what's the point? How to install the measurement data is accurate? The structure of the thermocouple is simple, but still in use will appear all sorts of problems. For example, improper installation or use, will cause large error of measurement, even certified thermocouple will be due to improper operation, when use is unqualified, in reducing atmosphere such as carburizing, if do not pay attention to, K type thermocouple will out-of-tolerance by selective oxidation. In order to improve the measuring precision, reduce the measuring error, prolong the service life of the thermocouple, requires the user should not only have instrument operation skills, but also should have physical, chemical and material aspects of knowledge. There are many types of thermocouple measurements of material, different material different measuring range, product selection requires the user to provide maximum temperature and the commonly used measurement temperature, as well as to the accuracy of measurement requirements to determine what materials of the thermocouple.

the cause of the china-made thermocouple measurement error: error: the introduction of improper installation installed instrumentation is also an important link, we strengthen the attention, the installation is bad not only affect the measurement accuracy and could reduce the service life, such as 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.