Thermistor
Time : Feb 03 2015Source :analogtechnologies Author : Analog Click :
Thermistor is a kind of sensitive element. There are two kinds of thermistors based on different the temperature, which are PTC and NTC. It has a typical characteristic that it is sensitive on temperature. It shows different resistance value when it is under different temperature.
When the temperature goes up, PTC is with higher resistance values while the NTC thermistor is on the opposite. But both of them belong to semiconductor apparatus.
Main characteristic of thermistor
a. It has very high sensitivity. Its temperature coefficient resistance is more 10 times than metal. It can check the different among 10-6°C.
b. It has wide temperature range. The usual temperature is available among -55°C～315°C. The high temperature devices can be applied under more than 315°C. The low temperature can be applied under about -273°C～-55°C.
c. Small volume, measurement range is very wide, which is much more than other ordinary thermometers. For example, cavity, biological blood vessels in the body and other interspaces.
d. Convenience, you can select anyone between 0.1Ω-100kΩ.
e. They can make into any shape through processing. Also make a large quantity.
f. Good stability and it has a good load-bearing.
Thermistor is the electronic component for instrumentation line compensation of the temperature and difference temperature electronic couple compensation and so on.
We use the special self-heating NTC thermistor. It may be come true that the thermistor’s gain control and forms RC stable oscillator circuit, delay circuit and protective circuit.
The temperature of self-heating is higher than environment temperature. The thermistor number relates to the heat dissipation reason. Pit meter, flow meter, gas analyzer and thermal conductance, which all use the thermistor’s characteristic. It will be made of special detecting element. PTC thermistor is mainly applied to electrical equipment which can be protected when the temperature is too high, contactless relay, middle temperature, increasing control. Electrical machine starts time delay, color TV auto degauss, fire alarm, temperature compensation and so on.
