Thermocouple Wire:

There are multiple types and grades of thermocouple wire. Each type of thermocouple wire has a specific combination of metal alloys. This combination is what defines the type of thermocouple. For example, a type K thermocouple is made when a wire of Nickel-Chromium is welded to a wire of Nickel-Alumel. The grade of the wire is dependent not only on the combination of alloys used, but also on the purity of those alloys. These are used to manufacture the thermocouple probes.