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The nitrogen generator suddenly stopped working; after replacing the temperature transmitter, it worked normally. http://yunrun.com.cn/tech/2583.html The quality of the temperature transmitter is directly related to the accuracy, stability, and reliability of the temperature measurement signals. This article discusses the troubleshooting of faults caused by temperature transmitters resulting in signal jumps, which lead to the system shutting down. 1. Description of the fault phenomenon: The nitrogen generator unit in a certain factory suddenly stopped operating. An immediate investigation was carried out to determine the cause of the shutdown. It was found that on the display screen of the nitrogen generator, both the temperature at the heater inlet and the temperature at the heater outlet showed normal values. However, the temperature inside the heater fluctuated by more than 10°C, exceeding the upper limit set for the shutdown interlock mechanism, which led to the inability of the nitrogen generator to function properly. 2. Fault analysis: The main reasons that may cause fluctuations in the temperature display are: ① Poor contact at the wiring terminals of the control module. ②Fault in the analog input terminal of the control module. ③The control program has no filtering. ④The 380V power supply for the heater generates electromagnetic interference on the 4-20mA current signal transmitted by the integrated temperature transmitter on the heater. ⑤The temperature transmitter inside the heater is faulty or has poor interference resistance. 3. Fault handling: ① Considering the possibility of poor contact at the wiring terminals, the analog input terminal corresponding to the switching temperature was located using the wiring diagram of the nitrogen generator; its contact was checked and found to be good, so the possibility of poor contact was ruled out. ②Using a process verifier, a standard 4-20mA current signal was sent directly to the controller on-site, and the temperature displayed on the screen did not change. ③The analog input AI module that processes the temperature signal from inside the heater, located behind the controller, was removed and replaced with an AI module of the same type. The temperature displayed on the screen continued to fluctuate, so a fault in the control module was also ruled out. 4. Treatment method and results: The temperature transmitter module inside the heater was replaced with an isolated temperature transmitter YR-ER212, and the YR-ER212 module was configured. As a result, the temperature displayed on the screen inside the heater no longer fluctuated; the temperature indication was normal, and the fault was resolved. Those who work with instrumentation know that imported temperature transmitters from brands such as Kemo, Rosemount, and E+H enjoy a good reputation; they offer excellent quality, are durable, but their prices are high. When opting for domestic temperature transmitters, there are concerns that their stability and accuracy may not meet the required standards. Such concerns do exist objectively! Domestic temperature transmitters are characterized by a competitive landscape marked by low prices and poor quality, which is detrimental to improving the quality and technical standards of such devices. The Changhui isolated intelligent temperature transmitter YR-ER212 was introduced to the market amid such competition. The isolated intelligent temperature transmitter YR-ER212 has reached a quality level comparable to that of imported temperature transmitters. We hope that more professionals in the instrumentation field will come to know about and use this high-quality domestic product. Changhui Instruments offers a free trial version; please visit http://yunrun.com.cn/product/293.html to take a look!