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Intelligent electromagnetic flowmeter in use failure analysis and elimination

Intelligent electromagnetic flowmeter is the most common measuring instrument. It is widely used in many fields. All the instruments will inevitably have faults in the process of use. Of course, the intelligent electromagnetic flowmeter is no exception. The fault of the instrument directly affects the measurement. The accuracy, the reasons for the failure in the measurement are various, the following is a detailed introduction to the failure analysis and troubleshooting of the intelligent electromagnetic flowmeter.

There are two kinds of faults generated by the intelligent electromagnetic flowmeter during operation:
1. The flowmeter itself is faulty, that is, the fault caused by damage to the instrument structural components or components.

2. Faults caused by external causes, such as improper installation of flow distortion, deposition and scaling.

First, intelligent electromagnetic flowmeter no flow signal output

1, the cause analysis

(1) The power supply of the instrument is abnormal;

(2) The cable connection is abnormal;

(3) The liquid flow condition does not meet the installation requirements;

(4) Damage to the sensor components or measurement of the inner wall with an adhesion layer;

(5) The converter components are damaged.

2, the solution

(1) Confirm that the power supply has been connected, check whether the voltage of each output of the power circuit board is normal, or try to replace the entire power circuit board to judge whether it is good or bad.

(2) Check if the cable is intact and the connection is correct.

(3) Check the direction of liquid flow and whether the liquid in the tube is full. For electromagnetic flowmeters that can measure forward and reverse, if the direction is inconsistent, it can be measured, but the set display flow rate does not match the positive and negative directions and must be corrected. If the sensor is too large, you can change the direction of the arrow on the sensor and reset the display meter symbol. If the pipeline is not filled with liquid, it is mainly caused by improper installation of the sensor. Measures should be taken during installation to avoid causing the liquid in the pipeline to be unsatisfactory.

(4) Check whether the electrode on the inner wall of the transmitter is covered with a liquid crust layer. For the measurement liquid that is easy to scab, it should be cleaned regularly.

(5) If it is determined that the converter component is damaged due to damage, replace the damaged component.

Second, the output value has fluctuations

Cause analysis

Most of these failures are caused by the measurement medium or the external environment. After the external interference is removed, the fault can be eliminated by itself. In order to ensure the accuracy of the measurement, such failures can not be ignored. In some production environments, the vibration of the measuring pipe or liquid is large, which may cause the circuit board's circuit board to loosen, which may also cause fluctuations in the output value.

2, the solution

(1) Confirm whether it is the cause of the process operation, the fluid does pulsate, at this time, the flowmeter only reflects the flow condition as it is, and the fault can be eliminated by itself after the pulsation is over;

(2) Electromagnetic interference generated by external stray currents. Check whether the large-scale electrical appliance or electric welder is working in the operating environment of the instrument. Make sure that the instrument is grounded and the operating environment is good.

(3) When the pipe is not filled with liquid or the bubble contains bubbles, both are caused by process reasons. At this point, the process personnel can be requested to confirm that the output value can be restored after the liquid is full or the bubble is recovered;

(4) The transmitter circuit board is a plug-in structure. Due to the large vibration of the pipeline or liquid in the field, the power supply board of the flowmeter is often loosened. If loose, the flowmeter can be disassembled and the circuit board re-fixed;

Third, the intelligent electromagnetic flowmeter measurement value does not match the actual value

1, the cause analysis

(1) Whether the transmitter circuit board is in good condition;

(2) When the liquid flow rate is too low, the measured liquid contains tiny bubbles, and the bubble rises gradually gathers above the pipe, and the liquid flow area changes. When the gas is too much, an interference signal is generated, which affects the measurement accuracy;

(3) The signal cable is not well connected or the insulation performance of the cable is reduced during use, resulting in inaccurate measurement; (4) The parameter setting value of the converter is not accurate;

2, the solution

(1) Check if the transmitter circuit board is intact. If the junction box is ingress or corroded by corrosive liquids, electrical performance may be degraded or damaged. The board should be replaced at this time;

(2) Ensure that the flow rate of the measured liquid in the pipeline is above the minimum flow limit value to enable the transmitter to work normally;

(3) Check whether the signal cable connection and the insulation performance of the cable are intact. If the signal cable is loose, reconnect it; if it is checked that the insulation of the cable does not meet the insulation requirements, a new cable is required.

(4) Re-set the converter set value and verify the zero and full scale values of the converter; 4. Intelligent electromagnetic flowmeter output signal over-full scale

1, the cause analysis

(1) There is an error in the signal cable wiring or the cable connection is broken;

(2) The parameter setting of the converter is incorrect;

(3) The converter does not match the sensor model;

2, the solution

(1) Check if the signal loop connection is normal or not. If the signal loop is disconnected, the output signal will be overfull. In this case, the signal cable should be reconnected correctly. At the same time, it is necessary to check whether the insulation performance of the cable is intact. If it does not meet the requirements, a new cable needs to be replaced.

(2) Check in detail the parameters of the converter and whether the zero point and full scale meet the requirements;

(3) If it is checked that the model of the converter and the sensor is not matched, you need to contact Jinhu Tianxin Instrument Co., Ltd. for exchange;

Five, zero instability

1, the cause analysis

(1) The pipe is not filled with liquid or contains bubbles in the liquid;

(2) Subjectively, there is no flow in the tube pump liquid and there is actually a slight flow.

(3) Reasons for liquids (such as poor conductivity of liquid conductivity, electrode contamination, etc.);

(4) The signal loop insulation decreases;

2, the solution

(1) The pipeline is not filled with liquid or the bubble in the liquid is the process reason. At this time, the process personnel should be requested to confirm that the output value can be restored after the process is normal;

(2) There is a slight flow in the pipe, which is not a malfunction of the electromagnetic flowmeter.

(3) If the impurity deposits on the inner wall of the measuring tube or scales on the inner wall of the measuring tube, or the electrode is contaminated, there may be a zero point change, which must be cleaned at this time; if the zero point does not change much, try to re-zero;

(4) Due to the influence of environmental conditions, dust, oil and the like may enter the inside of the watch case. Therefore, it is necessary to check whether the insulation of the electrode part is lowered or destroyed. If the insulation requirements are not met, it must be cleaned;

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