Thermistor is a kind of sensor resistor. The resistance value of thermistor varys with the change of temperature, which is different from general resistor. As a kind of variable resistor, it is widely used in various electronic components. Unlike resistance thermometers using pure metal, the materials used in thermistors are usually ceramics or polymers. They also have different temperature response properties. Resistance thermometers are suitable for a wide temperature range, while thermistors usually achieve high accuracy in a limited temperature range, usually from -90℃ to 130℃.
Thermistors include positive temperature coefficient (PTC) and negative temperature coefficient (NTC) thermistors. With the temperature rising and decreasing slowly, the resistance of thermistor will gradually increase and decrease respectively. Therefore, the thermistor can be used as a sensing device for measuring temperature in the circuit due to its sensitivity to temperature, which can be employed in many industries like thermistor medical applications.
The accuracy of the thermistor thermometer reaches 0.1℃, and the temperature sensing time can be less than 10s. Thermistor is not only suitable for granary thermometers, but also can be used for temperature measurement in food storage, medicine, scientific farming, ocean, deep wells, high altitude, glaciers, etc.
1. Its sensitivity is high, and the temperature coefficient is 10 to 100 times larger than that of metal.
2. The thermistor resistor has a wide working temperature range. Normal temperature devices are suitable for -55℃ to 315℃, high temperature devices are suitable for temperatures higher than 315℃ (up to 2000℃ at present), and low temperature devices are suitable for -273℃ to 55℃.
3. With small size, thermistor can measure the temperature of voids, cavities and blood vessels in organisms that cannot be measured by other thermometers.
4. The thermistor value can be arbitrarily selected from 0.1 to 100 kΩ.
5. It is easy to be processed into complex shapes and can be mass-produced.
6. It has good stability and strong overload capability.
Because of its unique performance, semiconductor thermistor can be used not only as a measuring element such as measuring temperature, flow rate, liquid level and so on, but also as a control element such as temperature thermal switch, current limiter and circuit compensation element. Thermistors are widely used in various fields, such as household appliances, power industry, communication, military science and aerospace and so on.