PT 100 sensor

A PT 100 sensor is a temperature sensor which works by measuring electrical resistance through platinum (Pt) metal. A PT 100 sensor can measure temperatures up to 600 °C

The resistance in the metal increases as temperature rises. The resistance at 0°C is 100 ohms – hence the name PT 100. PT 500 and PT 1000 sensors with corresponding resistance at 0°C are also available. 

Therefore, the PT 100 sensor can also be used for reading temperature.

More precise
The sensor measures more precisely than other types of electrical-resistance sensors such as KTY and NTC, which use other metals, but is also more expensive. A PT 100 sensor can measure temperatures up to 600°C, where the others are limited to around 150°C.

Three-wire sensors
Sensors that are connected with longer cable lengths may give imprecise readings, due to the cable’s inherent electrical resistance. This can be compensated for through the use of three-wire sensors, where the third wire measures resistance in the cable. However, this requires a regulator that can handle it.