Working principle and application precautions of end face thermal resistor

End-face thermal resistor is a common temperature measuring instrument, which uses the influence of temperature on thermoelectric effect to measure the temperature of an object.

1. Working principle

It consists of two different metals A and B. One end of metal A is placed on the surface of the object to be measured as the measuring end, and the other end is connected to a temperature-stable heat source; the two ends of metal B are connected to a voltmeter respectively.

When metal A contacts the surface of the object to be measured, the potential difference generated by the temperature difference causes current to flow between metals A and B. The magnitude of this current is related to the thermoelectric potential coefficient, the cross-sectional area of ​​the metal and the temperature.

By measuring the current and the potential difference between the two metals, the temperature difference can be calculated and the temperature of the object to be measured can be obtained. A specially designed circuit is usually used to measure the potential difference and current, and convert them into digital signal output.

2. Application precautions

End-face thermal resistors have the advantages of high precision, fast response, and strong anti-interference ability, so they are widely used in various industrial fields. However, the following points should be noted when using them:

1. Make sure that the measuring end is in good contact with the surface of the object to be measured to avoid measurement errors.

2. Choose the right thermoelectric pair material and wiring method to ensure measurement accuracy.

3. Pay attention to the use environment to avoid damage caused by too high or too low temperature.

4. Calibrate regularly to ensure its measurement accuracy and stability.

End-face thermal resistor is a commonly used temperature measurement instrument with the advantages of high precision, fast response, and strong anti-interference ability. When using it, you need to pay attention to choosing the right thermoelectric pair material and wiring method to ensure good contact and avoid damage caused by too high or too low temperature.