How to use an NTC temperature sensor?

An NTC temperature sensor is a temperature sensor that uses an NTC thermistor as the temperature-sensitive element. An NTC thermistor is a resistor with a negative temperature coefficient. Its resistance value decreases as the temperature rises and vice versa. NTC temperature sensors have been widely applied in the field of temperature measurement and control due to their excellent performance characteristics. The following is the basic usage method of NTC temperature sensors:

I. Wiring Method

The wiring method of NTC temperature sensors mainly depends on their application scenarios and measurement requirements. The following is a common wiring method for NTC temperature sensors:

Pin identification: NTC temperature sensors typically have two or three pins. Two pins are used to connect the power supply and measurement circuit, while the third pin (if any) may be used for grounding or other special functions.

Power connection: Connect the two main pins of the NTC temperature sensor to the positive and negative terminals of the power supply respectively, or to the input terminal of the measurement circuit.

Voltage divider circuit: In some cases, it may be necessary to use a resistor in series with the NTC temperature sensor to form a voltage divider circuit, thereby measuring the resistance value change of the NTC temperature sensor.

Grounding treatment: If the NTC temperature sensor has a grounding pin, it should be connected to the grounding terminal of the system to ensure the accuracy and safety of the measurement.

Signal amplification: In some high-precision measurement applications, it may be necessary to use an operational amplifier to amplify the signal of the NTC temperature sensor to improve measurement accuracy.

When wiring, be sure to pay attention to the following points:

Pay attention to the pin polarity of the NTC temperature sensor to ensure correct connection. If the pins are connected in reverse, it may cause measurement errors or damage the sensor.

Wires of moderate length and uniform diameter should be selected for connection to reduce line impedance and signal loss. Meanwhile, the wires should have good insulation performance to avoid short circuits or leakage.

When choosing an NTC temperature sensor, it is necessary to consider whether its measurement range matches the actual application scenario. At the same time, when wiring, attention should be paid to the maximum operating temperature of the sensor to avoid exceeding its tolerance range.

Ii. Testing and Calibration

Test conditions: When testing NTC temperature sensors, it is necessary to ensure the consistency of test conditions, including constant current sources, constant temperature fields, and the accuracy of the test instruments, etc.

Reference voltage test: The interchangeability accuracy, linearity and temperature coefficient of the sensor can be verified by testing its reference voltage value at 0℃.

Calibration: If there is an error in the sensor, it can be corrected through calibration. Calibration usually requires the use of standard temperature sources or other measuring devices for comparison and adjustment.

When using NTC temperature sensors, the following points should also be noted:

Avoid subjsting the sensor to excessive mechanical stress or vibration to prevent affecting its measurement accuracy and lifespan.

When used in high-temperature or humid environments, appropriate protective measures should be taken, such as installing protective covers or sealing rings, etc.

Regularly maintain and calibrate the sensors to ensure their long-term stable operation.

The usage method of NTC temperature sensors includes understanding their working principle, correct wiring, conducting tests and calibrations, as well as paying attention to application scenarios and matters. By using and maintaining NTC temperature sensors correctly, precise measurement and control of temperature can be achieved, providing strong support for applications in various fields.