Thermistor is a sensitive element whose resistance value changes slowly with the change of temperature. Within the range of operating temperature, the resistance value increases with the temperature rise is a positive temperature coefficient (PTC) thermistor, and the resistance value decreases with the temperature rise is a negative temperature coefficient (NTC) thermistor.
The resistance value of metal thermistor increases linearly with the rise of temperature, and the temperature coefficient of resistance is about 0.004k-1.
The resistance value of ordinary negative temperature coefficient thermistors decreases exponentially with the rise of temperature. The temperature coefficient of resistance at room temperature is -0.02k-1 ~ -0.06k-1.
The resistance value of the critical thermistor (CTR) will decrease sharply with the rise of temperature near a certain temperature, and its variation can reach 2-4 orders of magnitude.