The reason why the thermal resistance is not accurate

Thermal resistance will inevitably present some problems in the application process, for example, the appearance indication value is lower than the practice value, or the indication value may be unstable, what is the reason for this formation?

1. It may be that the depth of the thermal resistance element is not enough to reach a certain position, that is, it is not top to the end of the maintenance sleeve. To solve this problem, let's first find out the length of the casing, and then choose the appropriate thermal resistance element. When installing the thermal resistance element, ensure that the top part of the casing end; Probably cleaning iron and dust out of the maintenance casing.

2. It may be caused by water in the maintenance tube. In this case, we should clean up the water in the maintenance tube in time, and dry the wet part; Work together to seal the maintenance casing to prevent water from entering again.

3, thermal resistance measurement circuit short circuit or grounding will also lead to the appearance of the indicating value is lower than the practice value, if the external circuit short circuit or grounding, with a multimeter to check the short circuit or grounding part and eliminate; However, if the thermal resistance element is short-circuited or grounded, the thermal resistance should be replaced.

The measurement accuracy of thermal resistance is very important. If the measurement accuracy is not accurate, such products must not be used, otherwise they will bring many wrong results to production. So, how to ensure high accuracy of thermal resistance measurement?

In practice, the three-wire connection method is usually selected, and the resistance signal can be directly transmitted to the control system through the cable. Therefore, as a kind of resistance of the bridge arm, a wire between them can be directly connected to the power supply end, and it is necessary to pay attention to the data and length of the cable is the same, in order to prevent resistance changes and ensure the measurement accuracy of the measuring instrument.

In addition to paying attention to the wiring mode, there is also the application environment of thermal resistance. Although this kind of thermal resistance can be used in low temperature environment, but if the application environment of thermal resistance is not correct, including the device is not correct, it will directly affect the measurement data and measurement accuracy. So be aware of that. All it takes is the right device and the right application to make a full match.