Resistance temperature detector is often used for low temperature detection in industrial temperature measurement. Compared with other types of temperature sensors, resistance temperature detector is measured based on the characteristic that the resistance of a metal conductor increases with the increase of temperature.

In most people's impression, the resistance temperature detector is determined by the value of the index number. In fact, the idea is true. However, more data show that the thermal resistance can be either a negative temperature coefficient sensor or a positive temperature coefficient sensor. However, it is generally used in the measurement of low temperature environment, and its maximum temperature cannot reach the temperature of the thermocouple sensor. The high precision of the thermal resistance makes up for its deficiency.

In a word, resistance temperature detector is a detector that detects temperature by using the characteristics of the resistance of a conductor changing with temperature.