Thermistor is a type of sensitive element. The resistance value of the thermistor will change with the change of temperature. Different from the general fixed resistance, it belongs to a type of variable resistance and is widely used in various electronic components. Unlike resistance thermometers, which use pure metal, the materials used in thermistors are usually ceramics or polymers. The positive temperature coefficient thermistor has a larger resistance value when the temperature is higher, and the negative temperature coefficient thermistor has a lower resistance value when the temperature is higher. They both belong to semiconductor devices. Thermistors usually achieve high accuracy over a limited temperature range, typically -90°C to 130°C.