How to control the stability of the thermocouple?

Thermocouple is a * high accuracy in measurement sensor development, economy * good products, so it has become the current we * in the use of temperature measuring element to a wide range of a type, it directly measured temperature. The appearance of all kinds of thermocouple is often due to the need to vary, but their basic structure is roughly same, 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. Thermocouple measuring the hot end and cold end temperature difference between. In order to get excellent sense of hot end point 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? On the same kind of sensors, such as K type thermocouple * high 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 commonly used high temperature and * use 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!