PT 100 temperature sensors are the most common type of platinum resistance thermometer. Often resistance thermometers are generally called Pt100 sensors, even though in reality they may not be the RTD Pt100 type. Pt refers to that the sensor is made from Platinum (Pt). 100 refers to that at 0°C the sensor has a resistance of 100 ohms (Ω). A resistance thermometer is a type of temperature sensor. It consists of an element that uses resistance to measure temperature. Common names for Resistance Thermometers include RTDs (short for resistance temperature detector), RT, Pt100 RTD, or Pt1000. Pt100 probes can be protected in several ways and the temperature sensors are designed to get the best measurement of your process.