Question: 5 ways to teach you how to use thermocouples correctly?

Answer: Thermocouple is a highly accurate and economical product in the development of measuring sensors. It directly measures temperature and converts the temperature signal into a thermoelectromotive force signal. It is converted into the temperature of the measured medium by an electrical meter (secondary meter). In order to improve the accuracy in the measurement, reduce the error in the measurement, and extend the service life. Based on many years of field experience, our company introduces the measurement errors and precautions of thermocouples in more detail here, so that everyone can use thermocouples better.    

Pay attention to the following 5 issues:

1. The graduation number of the thermocouple must be consistent with the thermocouple required by the temperature measurement and control instrument used;

2. Reasonably select the material and outer diameter of the outer sheath of the thermocouple. The surface of the outer sleeve should be kept clean. If there is a stain on the surface, the thermal resistance will increase, and the measured temperature will be lower than the actual temperature;

3. The location where the thermocouple is installed should be as far as possible from the environment with strong electromagnetic fields, and avoid high-power power lines, so as to avoid additional interference signals from the temperature measuring instrument;

4. The thermocouple cannot work at a high allowable temperature for a long time, otherwise, the material of the thermocouple will change, which will increase the measurement error and damage the thermocouple. In the measurement of low temperature, in order to reduce the thermal inertia of the thermocouple, a bottomed or outcrop type thermocouple can be used;

5. The electrodes and the outer tube should be checked regularly for intactness. If it is found that the local diameter becomes thinner or the outer tube surface is seriously corroded, stop using it immediately and replace it with a new thermocouple. After the thermocouple is damaged, the damaged end can be removed, or the measuring end and the reference end can be reversed and re-welded. After calibration, it can still be used.