Vortex flow meter is widely used in the field of flow measurement, but it may encounter various faults during use. In order to effectively troubleshoot the vortex flowmeter, we need to start from the source, gradually analyze the problem and take corresponding measures to solve it. The following is the troubleshooting method of vortex flowmeter to find problems from the source:

Understand the working principle of vortex flowmeter

The working principle of vortex street flowmeter is based on Karman vortex street principle. When a fluid flows through a vortex generator, it creates two asymmetric columns of vortices whose frequency is proportional to the velocity of the fluid. By measuring the frequency of the vortex, we can calculate the flow of the fluid.

Common fault causes and troubleshooting methods

The frequency of the instrument varies greatly

Possible causes:

• The straight pipe section does not meet the requirements: The liquid straight pipe section does not meet the requirements, and the straight pipe section is not long enough.
• Electromagnetic interference on site: Electromagnetic interference will affect the normal operation of the sensor.
• Flow is too small: below the lower limit of the instrument, the value is not linear change.

Troubleshooting method:

• Change the installation position and ensure that the length of the straight pipe meets the requirements.
• The filter function is strengthened and the sensitivity is reduced by dialing the dip switch.
• Change the meter factor to increase the flow rate (not recommended), or adjust the measurement range to fit the actual flow rate.

There is 50Hz interference on site

Possible cause: The cable is not shielded or grounded.

Troubleshooting method: Use shielded wires and ground them correctly to reduce electromagnetic interference.

There is no traffic signal on site

Possible causes:

• Instrument small signal excision too large.
• The power supply is not connected or powered off.
• The flow is too low to reach the signal trigger.
• Gauges with 4-20mA output are not set before delivery.

Troubleshooting method:

• Go to the parameter Settings to modify the small signal cut value.
• Check the power connection to ensure that the power supply is normal.
• Increase the flow rate or adjust the measurement range to suit the actual flow rate.
• Set the correct range.

The meter does not show the actual flow rate

Possible causes:

• The gasket is not in the center of the pipe when the pipe vibrates or is installed.
• Parameter Settings are incorrect or the customer has modified the parameters.
• The flow rate is too low and the lower limit is not linear.
• Temperature and pressure compensation meter, temperature and pressure failure.

Troubleshooting method:

• Reinstall the meter and make sure the gasket is in the center of the pipe.
• Check and restore the correct parameter Settings.
• Adjust the measuring range or optimize the measuring conditions.
• Check the temperature and pressure compensation device to ensure normal operation.

The instrument display for the 4-20mA output is inconsistent with the system display

Possible causes:

• The unit of parameter setting is not consistent or the range is not corresponding to the same.
• The 4-20mA output cable is too long (more than 1000 meters), and the loss is large.

Troubleshooting method:

• Check and unify the units and ranges of parameter Settings.
• Replace the appropriate cable length to reduce losses.

Professional troubleshooting skills

Touch inspection method: suitable for vortex flowmeter with screen display, observe the circuit reaction by applying interference signal to the circuit, and judge the fault circuit position. This method requires inspection experience.

Voltage measurement method: Use a multimeter and other equipment to check whether the internal components of the vortex flowmeter are working normally.

Resistance measurement method: Check whether the pin or sliding contact of electronic components is virtual welding, resistance change value and capacitor damage.

Device replacement method: Replace the components that may be damaged and observe whether the fault phenomenon disappears. Pay attention to the use of components or printed circuit boards with the same specifications.

Direct observation method: Observe the status of the switches, knobs, test probes, wires, interfaces and other components on the vortex flowmeter circuit, and whether there are problems with the internal line.

Waveform observation method: Use an oscilloscope to observe the voltage waveform of the vortex flowmeter, and compare it with the normal waveform, so as to find out the fault.

Signal tracing method: The electronic oscilloscope is used to observe the waveform and amplitude of the input and output signals of the amplifier from the signal input end to determine the problem of the vortex flowmeter.

Preventive measures

Correct selection and installation: Select the right vortex flowmeter model according to the characteristics of the measuring medium and the flow range, and install it in strict accordance with the installation specifications.

Regular maintenance: Regular maintenance and maintenance of vortex flowmeters, including cleaning detection components, checking cable connections, etc.

Environmental monitoring: Monitor the operating environment of the flow meter to avoid adverse effects such as strong electromagnetic interference or vibration.

Standard operation: Operate and maintain in strict accordance with the operating instructions to avoid faults caused by misoperations.

If you want to know more about the flow meter or flow meter selection, please consult the Aister flow meter manufacturer email: sales@aistermeter.com for help.