RTD and PT
Resistance Temperature Detectors are usually very accurate and can be used to measure a wide range of temperatures.
RTD’s basically consist of a thin wire wrapped around a non conducting core, like glass or ceramic. The resistance in the wire will change with temperature. Different metals have different properties, but the nice thing is that the resistance-temperature relationship is very linear in a wide range, which makes conversion easier.
A common metal in RTD’s is Platinum due to it’s very wide linear range from almost absolute zero to 1000°C. Platinum based RTD’s are also referred to as PT-sensors.
The resistance of an RTD only changes a fraction of an ohm per degree, so a sensitive amplifier is required to boost the signal to something that can be measured with the ezeio