Reasons for anti-interference of wear-resistant thermocouples

Temperature sensors play an important role in the production process, and wear-resistant thermocouples are commonly used measuring components due to their high temperature measurement, durability, and fast thermal response time. But sometimes we encounter some external interference when using wear-resistant thermocouples for measurement. Below are effective measures to prevent interference with wear-resistant thermocouples.

Firstly, let's understand the reasons for system interference: various automation instruments, control systems, and actuators are required in the production process. The signal transmission between them includes small signals at the millivolt and microampere levels, as well as large signals at tens of volts, even thousands of volts and hundreds of amperes. There are both low-frequency DC signals and high-frequency pulse signals, and it is often found that the signal transmission between instruments and equipment interferes with each other, causing instability and even misoperation of the system. The reason for this is mainly due to the potential difference between the signal reference points of instruments and equipment, which forms a "grounding loop" and causes distortion during signal transmission, in addition to the performance reasons of instruments and equipment such as anti electromagnetic interference. Due to some devices requiring grounding to ensure measurement accuracy or safety, it is difficult to achieve equipment without grounding. The solution is to use isolated safety barriers. Due to the use of a three party isolation method, there is no need for system grounding lines, and signal lines do not need to be grounded together, thereby improving the reliability of the entire system.

We have solved the interference caused by the system. When installing wear-resistant thermocouples, if conditions permit, we can hang them in the air to prevent them from coming into contact with the refractory bricks on the furnace wall. Insulation is also used to isolate the wear-resistant thermocouples from the brackets. This method can effectively prevent high-temperature leakage interference, which we call the isolation method. In addition, we use shielded compensating wires between the wear-resistant thermocouple and the instrument to make the measurement of our wear-resistant thermocouple more convenient and effective.