For electromagnetic (mag) flow meters, there is a second verification option that is less well known and often more practical: electronic verification. It checks meter health without needing flow through the pipe, faster and more flexible than a clamp-on verification. As a compliance verification, it can be used as an alternative to a clamp-on/flow-through verification only where prior agreement is in place with the relevant regional council.
Electronic verification is a method of assessing the accuracy and health of an installed electromagnetic (mag) flow meter by running a series of electronic tests on the meter's coils, electrodes, and transmitter, and comparing the results against the meter's original factory test data.
Where clamp-on verification compares a meter's reading against a calibrated reference meter under live flow conditions, electronic verification assesses the meter's internal condition electronically. If the key electronic parameters are within the original factory specifications, the meter is considered to be operating correctly and a pass result is issued.
Checks the resistance of the meter's electromagnetic coils. Coil resistance outside factory specification can indicate coil degradation or damage.
Measures the impedance between the meter's electrodes and the process fluid. High impedance can indicate fouling, coating, or electrode damage, all of which affect accuracy.
Verifies the empty pipe detection function is operating correctly. False signals can cause zero-flow readings or data gaps.
Verifies the transmitter is operating within specification, including output signals, display function, and configuration settings.
All test results are compared against the meter's original factory test certificate. Values within factory tolerance, pass. Outside, fail.
Not entirely. It assesses the meter's internal condition rather than directly measuring flow accuracy under current installation conditions, so clamp-on verification remains the most comprehensive method. As a compliance verification, electronic verification can be used as an alternative to a clamp-on/flow-through verification only where prior agreement is in place with the relevant regional council.
Yes. The electrode impedance test is specifically designed to detect fouling, coating, or electrode damage. High electrode impedance outside factory specification will result in a fail or advisory result.
Many Canterbury territorial authorities, including Christchurch City Council, will accept an Electronic Verification Certificate for compliance purposes, but only where there is prior agreement in place with the relevant regional council. Confirm and document that agreement with your specific council before scheduling, particularly outside Canterbury.
Generally faster than clamp-on verification, typically under an hour on site, depending on meter access and configuration.
Canterbury-based flow meter specialists. Blue Tick accredited. IANZ-calibrated equipment.
Get in touchNZ Flow Group offers electronic verification for mag flow meters across Canterbury for municipal, industrial, and irrigation applications.