The Graduation Mark and Differences of Thermocouples

There are some graduation mark of Single Disposable Thermocouple : S, R, B, N, K, E, J, T, etc., which S, R, B belong to precious metal thermocouple, and N, K, E, J, T belong to low metal thermocouple.

T, S graduation mark is characterized by strong oxidation resistance. It is suitable for continuous use in oxidizing, inert atmosphere, long-term use temperature of 1400 DEG C, short-term temperature of 1600 DEG C.

Of all the thermocouples, the S graduation mark has the highest accuracy and is usually used as a standard thermocouple;

Compared with the S graduation mark, the R graduation mark is about 15% larger than that of the thermal electromotive force;

The thermal emf of B graduation mark at room temperature is very small. It generally does not use the compensation wire during measurement. Its long-term use temperature of 1600 DEG C, short-term temperature of 1800 degrees. The utility model can be used in oxidizing or neutral atmosphere, and can also be used in short time under vacuum condition.

The characteristics of N graduation mark is the high temperature oxidation resistance of 1300 DEG C, the reproducibility of long-term stability and short-term thermal cycling of thermal electromotive force, resistance to nuclear radiation and low temperature resistant performance is good, which can partially replace the S graduation mark thermocouple;

K graduation mark is characterized by strong oxidation resistance. It is suitable for continuous use in oxidizing, inert atmosphere, long-term use temperature of 1000 DEG C, short-term temperature of 1200. It is the most widely used type in all kinds of thermocouples;

E graduation mark is characterized by the use of thermocouples, the thermoelectric EMF, that is, the highest sensitivity. Suitable for continuous use in oxidizing and inert atmosphere, the use of temperature 0-800 c;

The characteristics of J graduation mark is not only can be used for oxidizing atmosphere (using the temperature limit of 750 DEG C), it can also be used for reducing atmosphere (temperature limit of 950 DEG C), and resistance to hydrogen and carbon monoxide gas corrosion, which is used for oil refining and chemical industry;

The T graduation mark is characterized by the highest degree of accuracy in all low - metal thermocouples, typically used to measure temperatures below 300 C.