Thermonuclear models are mainly S-type, R-type, B-type, N-type, K-type, E-type, J-type and T-type. Which, S, R, B are precious metal thermocouple (ie platinum and rhodium thermocouple), N, K, E, J, T are cheap metal thermocouple.
S-type thermocouple is characterized by good oxidation resistance, suitable for use in oxidizing, inert atmosphere, long-term use temperature of 1400 ℃, the maximum temperature can reach 1600 ℃. S type thermocouple is the most accurate thermocouple;
R-type thermocouple compared with the S-type, thermoelectromotive force greater, other features are more similar.
B-type thermocouple at room temperature thermoelectromotive force is very small, so in the general measurement do not use compensation wire. Its long-term use temperature is 1600 ℃, short-term 1800 ℃. Can be used in oxidizing or neutral atmosphere, but also in the vacuum under the premise of short-term use.
N-type thermocouple is characterized by high temperature oxidation resistance at 1300 ℃, long-term non-turbulence of hot electromotive force and good reproducibility of short-term heat cycle, good resistance to nuclear irradiation and low temperature resistance, and can be used as S-type thermocouple replacement;
K-type thermocouple is characterized by good oxidation resistance, long-term use temperature of 1000 ℃, the maximum temperature of 1200 ℃. In all thermocouples, K-type thermocouple is the most widely used;
E-type thermocouple in the commonly used thermocouple, with the maximum thermoelectromotive force, that is, the highest agility. Long-term use temperature 0-800 ℃;
J-type thermocouple is characterized by both for the oxidizing atmosphere (upper temperature of 750 ℃), can also be used for reducing atmosphere (the use of the upper temperature of 950 ℃), and resistance to H2 and CO gas erosion, and more for refining and chemical fields ;
T-type thermocouple in all cheap metal thermocouples with the highest degree of accuracy, usually used to measure the temperature below 300 ℃.
