Thermocouple errors and correct use

Thermocouples are commonly used temperature sensors in scientific research and production. Although their structure is simple, careless use can still result in significant measurement errors.
In temperature measurement systems, thermocouples are commonly used as temperature sensors, but on-site personnel believe that the two wire structure of thermocouples is simple. If thermocouples are not tested or used correctly before use, various problems will still occur during on-site use. For example, improper installation or use can cause significant measurement errors, and even calibrated thermocouples may become unqualified during use due to improper operation. In reducing atmospheres such as carburization, if not taken seriously, K-type thermocouples may also exceed the tolerance due to selective oxidation. In order to improve measurement accuracy, reduce measurement errors, and extend the service life of thermocouples, it is required that users not only have operational skills in the field of instruments, but also have knowledge in various aspects such as physics, chemistry, and materials.
Thermocouples are an essential temperature sensor in modern temperature measurement, as well as a simple and ordinary temperature measuring instrument. Temperature errors and product maintenance during the use of thermocouples are serious problems that can cause direct economic losses or false alarms and misjudgments. Thermocouples play an indispensable role in temperature measurement. In response to the current problems, Detailed exploration of the main factors affecting measurement errors:
1. The insertion depth, response time, thermal radiation, and thermal impedance of temperature sensors should be noted, including the heterogeneity of thermocouple wires, shunt error of armored thermocouples, selective oxidation of K-type thermocouples, K-state, usage atmosphere, insulation resistance, and thermocouple degradation.
2. Selection: Sometimes on site, the actual needs of the site are not fully considered in the selection process, and theoretical thinking is used for selection. The temperature adaptation range is too large or too small
3. Uncertain material control
4. The on-site environment was not fully considered
5. Skills of on-site operators