1. Measure the temperatureAs a temperature measurement thermistor sensor is generally simple in structure and low in price. Thermistors without outer protective coating can only be used in dry places; Sealed thermistor is not afraid of moisture erosion and can be used in harsh environments. Because the resistance value of thermistor sensor is large, the resistance and contact resistance of its connecting wire can be ignored. Therefore, thermistor sensor can be used in the remote temperature measurement of thousands of meters, and the measurement circuit is mostly bridge.

2. Temperature compensationThe thermistor sensor can compensate the humidity of some components in a certain temperature range. For example, the moving coil in the meter head of the moving coil is wound by copper wire. As the temperature increases, the resistance increases, causing the temperature error. Therefore, in the loop of the moving coil, the thermistor with negative temperature coefficient can be connected in parallel with the mangano-copper wire resistance and then connected in series with the compensated component, so as to offset the error caused by the internal temperature change.

3. Overheat protectionOverheat protection is divided into direct protection and indirect protection. For small current occasions, the thermistor sensor can be directly connected to the load to prevent overheating damage to protect the device, for large current occasions, can be used for the protection of relays, transistor circuits, etc. For example, a mutant thermistor sensor is embedded in the stator windings of a motor and connected in series with a relay. When the motor is overloaded, the stator current increases, causing heat. When the temperature is greater than the mutation point, the current in the circuit can change from a few tenths of a milliampere to a few tens of milliampere, so the relay action, so as to achieve overheating protection.

4. Liquid level measurementWhen a certain heating current is applied to the NTC thermistor sensor, its surface temperature will be higher than the surrounding air temperature, and its resistance value is small. When the liquid is higher than its installation height, the liquid will take away its heat, so that the temperature drops and the resistance value rises.