Resistance temperature devices (RTD):
The high temperature dependance of the electrical resistance of metals (Platinum, Nickel, Copper...) and other conducting materials (semiconductors, ionic and ceramic conductors) is used for electrical temperature measurement in the industry. Platinum (Pt100, Pt500, Pt1000) and Nickel (Ni120, Ni1000...) resistances have the advantage of a high long term stability. The ceramic and semiconductor sensors (NTC, PTC...) have the advantage of a wide resistance range and high temperature sensitivity in limited temperature ranges.
In order to avoid systematic measurement errors, it is necessary to use special, to the sensor type appropriate cables for connection between a temperature sensor and the evaluation device. In case of Thermocouple one distinguishes between extension cables (Conductor out the same alloys as the Thermocouple itself) and compensation cables (Conductors out of alternative alloys). In general compensation cables are cheaper than extension cables but have constricted tolerances. For temperature resistance sensors (RTDs) Copper cables with different conductor cross sections are available.