Thermistor is a temperature sensor for electrical measurement of temperature. Its principle is based on the variation of semiconductor resistance with temperature. It is made up of semiconductor materials. Oxides of metals such as manganese, cobalt, magnesium etc are used for thermistor manufacturing. As the temperature increases, the resistance decreases for thermistor due to semiconductor property. It’s response between resistance and temperature is nonlinear. Negative Temperature Coefficient (NTC) thermistor exhibit a decrease in electrical resistance when subjected to an increase in body temperature and Positive Temperature Coefficient (PTC) thermistor exhibit an increase in electrical resistance when subjected to an increase in body temperature.
Applications: 1. As current-limiting devices for circuit protection, as replacements for fuses. 2. As resistance thermometers in low-temperature measurements 3. Thermistor can be used to monitor the temperature of an incubator 4. Thermistors are also commonly used in modern digital thermostat 5. Consumer Appliance industry for measuring and controlling the temperature such as Toasters, coffee makers, refrigerators, freezers etc