Industrial RTDs for measurements are usually made from

Question

Question

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ISRO IPRC Technical Assistant Mechanical 21 April 2016 Official Paper

Answer 1

Explanation:

Resistance Temperature Detector (RTD)

A Resistance Temperature Detector (RTD) used to change in electrical resistance of a metallic conductor to determine the temperature.
Platinum is the best metal for RTD due to its linear resistance-temperature relationship, over a wide range (−272.5° C to 961.78° C) for precise measurement.
The resistance increases as the temperature of the sensor increases.
An RTD is a passive device.
It does not produce an output on its own.
External electronic devices are used to measure the resistance of the sensor by passing a small electrical current through the sensor to generate a voltage.
Typically 1 mA or less measuring current, 5 mA maximum without the risk of self-heating.