explain why platinum rod is used in resistance thermometer
Resistance thermometer Platinum is the best metal for RTDs due to its very linear resistance–temperature relationship, highly repeatable over a wide temperature range. The unique properties of platinum make it the material of choice for temperature standards over the range of −272.5 °C to 961.78 °C. It is used in the sensors that define the International Temperature Standard, ITS-90. Platinum is chosen also because of its chemical inertness.