In the same period when Seebeck discovered the thermoelectric effect, Sir W. Davy discovered that the resistivity of metals depends on the temperature. Fifty years later, Sir. W. Siemens used platinum as an element in a resistance thermometer. His decision proved to be very accurate, as platinum is still used in all precision resistance thermometers.
Less precise resistance thermometers are made with nickel or its alloys. These resistance thermometers have the defect of being fairly linear, tend to become less accurate over time and have a limited operating temperature. Therefore, platinum resistance thermometers are used to ensure correct measurements.
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