When certain dissimilar metals are joined, they produce a measureable electric current. The voltage produced is directly proportional to the temperature difference between the materials. When selecting thermocoupling alloys, it is important to keep in mind the application temperature range, environment, accuracy required and length of service. For more information on which alloy is best for you, contact a Leading Edge material specialist.
Used in conjunction with Chromel® in type K thermocouples, Alumel®1 is made of nickel, manganese, aluminum and silicon.
Used with Alumel® in type K thermocouples and with Constantan in type E thermocouples, Chromel®2 is made of nickel and chromium.
Constantan is a copper-nickel alloy used in a variety of thermocouple applications. It is paired with iron, copper and Chromel® to form types J, T and E thermocouples, respectively. Known for its high electrical resistivity and its ability to perform consistently despite changes in temperature, Constantan is also widely used throughout the electronics industry.
For use in extremely high-heat environments, type C thermocouples are made from alloys containing different rhenium-tungsten ratios. Rhenium-Tungsten is also used in traditional tungsten applications when greater ductility is desired.