How to control the stability of the thermocouple

Thermocouple is a highest accuracy in measuring sensor development, economy the best product, so it became the most widely in our use of temperature measuring element of a type, it directly measured temperature.

the appearance of all kinds of thermocouple is often due to the need to vary, but they are roughly the same basic structure, usually by the hot electrode, insulation sleeve to protect the main parts such as pipe and connection box, and usually display meter, recording meter and electronic regulator. In order to get the feeling of hot end point of the absolute temperature, you must test the cold end temperature and adjust the thermocouple output accordingly. Now, the cold end at the input to the thermocouple signal processing unit with the temperature usually rely on materials with high heat conductivity of stay. Thermal conductivity of 381 w/mK copper is an ideal material. Input connection must be electrical isolation, hot even road to the piece. The signal processing unit ideally should be in the same temperature environment.

the stability of the thermocouple, due to the use of temperature, atmosphere is different, so the stability of the thermocouple what to control? For the same kind of sensors, such as K type thermocouple, the highest temperature also changes with different diameter, diameter of the same type K thermocouple is also due to the difference of structure, the stability of also have very big difference. When choosing a thermocouple, must consider: in view of the conditions of use common temperature and highest temperature; Using atmosphere such as REDOX; Vibration resistance. For prefabricated thermocouple, the influence of the atmosphere, first of all depends on the protecting tube material and structure of the thermocouple, therefore, familiar with and master all kinds of protection tube materials physics, chemical properties, it is very necessary. Commonly used in powder metallurgy industry, for example, molybdenum tube as the thermocouple protection tube, under the 1600 ℃ of H2 atmosphere, good use effect. However, molybdenum tube under oxidizing atmosphere, a very short time because of oxidation and erosion!

related knowledge:

how to correctly use the thermocouple temperature sensor from the architecture of the thermocouple to understand the working principle of thermocouple,

the most detailed thermocouple selection rules

thermoelectric potential compensation of thermocouple temperature corresponding to different table

the difference between the thermocouple and thermal resistance