What are the reasons for the limited failure of electromagnetic flowmeters?

The measurement principle of electromagnetic flowmeter is Faraday's law of electromagnetic induction, which is an instrument that measures the flow rate of conductive fluid according to the electromotive force induced by the conductive fluid through the applied magnetic field, and the main components of the sensor are: measuring tube, electrode, excitation coil, iron core and yoke housing. The product is mainly used to measure the volume flow rate of conductive liquids in closed pipes and slurries, including highly corrosive liquids such as acids, alkalis, and salts.

Electromagnetic flowmeters are widely used in petroleum, chemical, metallurgy, textile, food, pharmaceutical, papermaking and other industries, as well as environmental protection, municipal management, water conservancy construction and other fields.

1. Changes in environmental conditions.

The main reason is the same as the fault environment during the commissioning period in the previous section, but the interference source does not appear during the commissioning period and intervenes during operation. For example, an electromagnetic flowmeter with unsatisfactory grounding protection will operate normally due to the absence of factory disturbance sources during the commissioning period, but during the operation period, new interference sources (such as pipelines near the measurement point or pipeline welding at a distance) interfere with the normal operation of the instrument, and the output signal fluctuates greatly.

2. Inner wall adhesion layer.

Since electromagnetic flowmeters have a much higher chance of measuring suspended solids or dirt than other flow meters, the probability of failure due to the adhesion layer on the inner wall is relatively high. If the conductivity of the adherent layer is similar to that of the liquid, the instrument can still output the signal normally, but the flow area is changed, forming a hidden fault of measurement error; If the layer is attached with high conductivity, the electromotive force between the electrodes will be short-circuited; In the case of an insulating adhesion layer, the electrode surface is insulated and the measurement circuit is disconnected. The latter two phenomena will make the meter inoperable.

3. Lightning strike.

Instantaneous high voltage and inrush current are induced in the lightning strike** circuit, and the meter will be damaged when it enters the instrument. There are 3 ways to introduce lightning damage meters: power lines, flow signal lines between sensor spoon converters, and excitation lines.

However, from the analysis of damaged components in lightning faults, most of the induced high voltages and inrush currents that cause the faults are introduced from the power supply lines in the control room, and the other two ways are few. It is also learned from the scene of the lightning accident that not only the electromagnetic flowmeter fails, but also other instruments in the control room often have lightning accidents at the same time.

Common faults of electromagnetic flowmeters include:1Electromagnetic flowmeters do not have a flow signal output, and this type of failure is common during use2

The electromagnetic flowmeter signal is getting smaller and smaller, or the signal drops suddenly3Electromagnetic flowmeter empty tube alarm 4It should be noted that the fault performance and causes of electromagnetic flowmeter may vary depending on different brands and models, so it is best to contact professional technicians for diagnosis and repair when encountering a fault.

Summary. There are several reasons why the electromagnetic flowmeter will have fewer readings:

1.The tube is not filled with liquid. When there is a small amount of gas in the tube, the measurement result will deviate from the actual value, resulting in a small error; When a large number of gases are present, the measured value is unstable and the output is shaky, and the measured value cannot be used as an accurate result.

2.The liquid to be tested contains solid components. It causes the electrode surface to be soiled, covered with the electrode or lining, resulting in a decrease in the flow area and a gradual decrease in the flow value.

3.Improper selection of electrodes or grounding rings. The electrode is in contact with the fluid medium to be measured, and the electrochemical reaction of the medium to be measured generates a polarization voltage.

Kiss. The reasons why the electromagnetic flowmeter will read less are:1

The tube is not filled with liquid. When there is a small amount of gas in the tube, the measurement result will deviate from the actual value, resulting in a small error; When a large number of gases are present, the measured value is unstable and the output is shaky, and the measured value cannot be used as an accurate result. 2.

The liquid to be tested contains solid components. It causes the electrode surface to be soiled, covered with the electrode or lining, resulting in a decrease in the flow area and a gradual decrease in the flow value. 3.

Improper selection of electrodes or grounding rings. The electrode is in contact with the fluid medium to be measured, and the electrochemical reaction of the medium to be measured generates a polarization voltage.

Summary. If the power supply is normal, the display screen is not lit, indicating that the meter head of the electromagnetic flowmeter is burned, or the display screen is broken, and it should be returned to the original factory for repair or replacement.

Two. The display screen is bright, and you can see that the flow rate is worth it, there is fluid flow in the pipeline, but there is no normal flow, there are two situations, first, the flow rate is lower than the lower limit of the flow meter calibration, and the flow meter cannot measure the small flow. Therefore, the normal flow value is not displayed.

Second, if there is a problem with the internal settings, you can consult the original engineer to solve it.

Third, the flowmeter body is flooded, resulting in the electrode not working normally, and the flow rate may not be displayed. According to the above three points, you compare them to see which situation it is.

The reason why the electromagnetic flowmeter does not go to the flow rate.

Hello dear, the display screen is not bright, first determine whether there is a power supply, if the power supply is normal, the display screen is not bright, said stupid rent Laming electromagnetic flowmeter meter head burned, or the display screen is broken, to return to the original factory for repair or replacement. Two. The display screen is bright, and you can see that the flow rate is worth it, there is fluid flow in the pipeline, but there is no normal flow, there are two situations, first, the flow rate is lower than the lower limit of the flow meter calibration, and the flow meter cannot measure the small flow.

Therefore, the normal flow value is not displayed. Second, if there is a problem with the internal setting, you can consult the original engineering consultant to solve it. Third, the flowmeter body is flooded, resulting in the electrode not working normally, and the flow rate may not be displayed.

According to the above three points, you compare and see what kind of situation is slippery.

What are the reasons why the electromagnetic flowmeter does not show the flow rate.

Hello, dear, please wait a moment.

The second. Hello, I will first show you the reason for the flow rate: blind omen First, the electromagnetic flowmeter does not display any value at all.

Analysis of the reasons:1The electromagnetic flowmeter is out of power.

2.The display meter circuit is burned out. 3.

The electromagnetic flowmeter was damaged by lightning. Second, the electromagnetic flowmeter just does not display the flow rate numerical analysis reasons: 1

There is a problem with the program setting of the electromagnetic flowmeter. 2.There is a problem with the sensor wiring.

Summary: If you encounter the situation that the electromagnetic flowmeter is not displayed, you can check the above reasons, and then take corresponding maintenance measures. I believe that the system will work well.

Your problem is an internal setup problem, and it is recommended that you have a professional fix it

(1) Reduce friction and anti-wear, reduce friction resistance to save energy, reduce wear to prolong mechanical life and improve economic benefits;

2) Cooling, it is required to discharge frictional heat out of the machine at any time;

3) Sealing, anti-leakage, dust-proof, anti-string gas;

4) Anti-corrosion and anti-rust, requiring protection of the friction surface from oil deterioration or external erosion;

5) Clean and rinse, and require the friction area to be cleaned and removed;

6) Stress dispersion and buffering, load dispersion and impact mitigation and shock absorption;

7) Kinetic energy transmission, hydraulic system and remote control motor and friction continuously variable speed, etc.

Summary. There are two ways to set the parameters (configuration) of the flowmeter, one is to use the buttons on the display panel, and the other is to use the handheld smart terminal.

Use the panel to set parameters.

The symbols commonly used on the panel of the LE series electromagnetic flowmeter are:

1) red (red) does not light up when it works normally, and flashes when there is an alarm;

2) The definition of the character is defined with a colon:", indicating that the displayed data is in the state to be set.

3) Unit display shows the flow unit.

4) Display the type of data display flow data, setting data and alarm.

5) The decimal point indicates the decimal point in the data.

6) Setup keys: These keys are used to change the type of data displayed and set data. There are 3 types of data display: traffic data display mode, setting mode, and alarm display mode.

How to set the fault current of the electromagnetic flowmeter.

There are two ways to set the parameters (configuration) of the flowmeter, one is to use the buttons on the display panel, and the other is to use the handheld smart terminal. Use the panel to set the parameters: The commonly used symbols on the panel of the LE series electromagnetic flowmeter are: (1) RED (red) does not light up when it works normally, and flashes when there is an alarm; (2) The definition character is defined with a colon: ", which means that the displayed data is in the state to be set, (3) the unit display, the display flow unit, (4) the type of display data display, the flow data, the setting data and the alarm, (5) the decimal point indicates the decimal point in the data, and (6) the setting key, these keys are used to change the type of data display and set data.

There are 3 types of data display: traffic data display mode, setting mode, and alarm display mode.

1.Traffic Data Display ModeThe traffic data display pattern represents the current flow value and the cumulative flow value, and Admaga can display 12 types of traffic data. The inlet flow display mode uses the D1 parameter to change the display items, and the detailed setting can refer to the user manual of the flow meter.

2.Setup mode: The setup mode is used to check the parameter content and overwrite the data. Just press "set.""key to bring up the mode from the normal mode of operation3

Alarm display modeWhen an alarm occurs, the alarm mode will replace the current mode to display the type of alarm, but this situation only occurs when the parameter number is changed in the current traffic display mode or set mode (the alarm is not displayed when the data item is in the section).

There are two ways to set the parameters (configuration) of the flowmeter, one is to use the buttons on the display panel, and the other is to use the handheld intelligent terminal.