Talking about the Fault Analysis of Field Instrument System

Field instrument measurement parameters are generally divided into four parameters: temperature, pressure, flow, and liquid level.

According to the different measurement parameters, different field instrument faults are analyzed.

1. First, before analyzing the failure of the field instrument, it is necessary to thoroughly understand the production process, production process conditions and conditions of the relevant instrument system, understand the design scheme and design intent of the instrument system, and the structure, characteristics, performance and parameter requirements of the instrument system. Wait.

2. Before analyzing and inspecting the fault of the field instrument system, the operating personnel of the site shall be informed of the changes in the production load and the parameters of the raw materials, and the records of the fault meter shall be checked and a comprehensive analysis shall be conducted to determine the cause of the failure of the instrument.

3. If the meter records a dead line (a line with no changes in the line is called a dead line), or the record curve originally fluctuates, it suddenly becomes a straight line; the fault is likely to be in the instrument system. Because the current recording instruments are mostly DCS computer systems, the sensitivity is very high, and the change of parameters can be very sensitive to the reaction. At this point can artificially change the process parameters to see the curve changes. If it does not change, the basic conclusion is that the instrument system has a problem; if there is a normal change, it is basically determined that the instrument system has no major problems.

4. When the process parameters are changed, it is found that the recorded curve has abruptly changed or jumped to the maximum or the minimum. At this time, the fault is often in the instrument system.

5. Before the failure occurs, the instrument record curve has been performing normally. After the fluctuation, the recording curve becomes irregular or the system is difficult to control. Even the manual operation cannot be controlled. At this time, the failure may be caused by the process operating system.

6. When it is found that the DCS display instrument is not normal, you can go to the scene to check the indicator value of the same intuitive instrument. If they are very different, it is likely that the instrument system has failed.

In short, when analyzing the causes of field instrument failures, special attention must be paid to the changes in the characteristics of the measured control object and the control valve, which may be the cause of the failure of the field instrument system. Therefore, we must comprehensively consider and carefully analyze the field instrument system and process operating system to check the reason.