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How does a platinum resistance thermometer measure temperature?
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platinum group
Rhodium foil and wire.
A platinum resistance thermometer measures temperature by utilizing the relationship between the electrical resistivity of platinum wire and temperature.
Because the electrical resistance of platinum is relatively high and varies markedly with temperature, it serves as a precise indicator for thermal conditions. This property is so reliable that the International Temperature Scale, which ranges from −259.35 to 961.78 °C, is defined specifically in terms of a thermometer constructed with platinum wire. As the environment surrounding the wire heats or cools, the resistance changes in a predictable manner, allowing for accurate temperature measurement.12