Thermocouple is a very common temperature sensor in scientific research and production. Although the structure is simple, it will produce large measurement error if we do not pay attention to it in use.
In the temperature measurement system, the temperature sensor thermocouple is very commonly used. However, the field personnel think that the structure of the two wires of the thermocouple is simple. If the thermocouple is not tested or used correctly before use, there will still be various problems in the field use. For example, improper installation or use will cause large measurement error. Even the thermocouple qualified by verification will not be qualified in use due to improper operation.
In reductive atmosphere such as carburizing, if you do not pay attention, K-type thermocouple will be out of tolerance due to selective oxidation. In order to improve the measurement accuracy, reduce the measurement error and prolong the service life of thermocouple, the user should not only have the operation skills of instrument, but also have the knowledge of physics, chemistry and materials.
Thermocouple is an essential temperature sensor for modern temperature measurement, and it is also a very simple and common temperature measurement instrument. The temperature error and product maintenance of thermocouple in the process of use are serious problems faced by the site. If it is not used properly, it will cause direct economic loss or misjudgment. Thermocouple plays an indispensable role in temperature measurement According to the existing problems, the main factors affecting the measurement error are discussed in detail
1. The insertion depth, response time, thermal radiation and thermal resistance of the temperature sensor are discussed. The points for attention in the use of thermocouple wire heterogeneity, shunt error of armored thermocouple, selective oxidation of K-type thermocouple, K state, service atmosphere, insulation resistance and thermocouple deterioration are pointed out.
2. Model selection: sometimes the actual needs of the site are not fully considered in the site selection, but the theoretical thinking is used to select the type, and the temperature adaptation range is too large or too small
3. The control of material is uncertain
4. The site environment is not fully considered
5. Skills of field operators
On 2018-08-08 11:45:46
