The electrical measurement of temperature requires that the entire measurement chain (temperature sensor, cable connection points) consist of the same combination of materials (thermocouple method).
With MC-Thermocouple pressure contacts, such measurement chains can be extended or the connections can be designed as plug contacts.
The most common combination of materials is NiCr-NiAl with the code letter K.
The positive part is of nickel-chromium, (CHROMEL), the negative part of nickel-aluminium (ALUMEL).
The thermal e.m.f. of the type K is 4,095mV for 100°C.