Common Thermocouple Types and Characteristics There are several key types of thermocouple wire graduation numbers, such as S, R, B, N, K, E, J, T, etc. Among them, S, R, B belong to precious metal thermocouples, and N, K, E, J, T belong to cheap metal thermocouples.Get more news about K Type PEEK THERMOCOUPLE wire,you can vist our website! The k-type thermocouple extension wire and cable is a...