What Is a Thermistor Temperature Sensor?

A thermistor is a special type of solid temperature sensor. This sensor does not act like a thermometer; instead, it works more like electrical resistors that are sensitive to temperature.

Function

• The primary function of a thermistor is to detect changes in temperature. However, unlike a thermometer, a thermistor responds to temperature changes by showing changes in electrical resistance. The resistance is measured by channeling a small, measured amount of electrical current through the thermistor and gauging the drop in electrical voltage.

Types

• There are two types of thermistor temperature sensors: the negative temperature coefficient thermistor and the positive temperature coefficient thermistor. Each measures temperature in a different ways. In NTC thermistors, the resistance decreases as the temperature rises, while in PTC thermistors, the resistance increases as the temperature rises.

Uses

• Because they are relatively small compared to thermometers, thermistor temperature sensors are often used inside of other temperature-sensing devices. Digital medical thermometers usually work with the help of thermistor temperature sensors, as do certain components of cell phones, transport vehicles and media devices. This is because thermistors work better in conjunction with electricity than standard thermometers, which can be dangerous due to their glass-and-mercury composition.