Electromagnetic Meter Grounding: The 5-Step Checklist

Why grounding matters

The electromagnetic meter measures a tiny mV-level signal induced in the liquid. Any stray current through the liquid — from pumps, valves or cathodic protection — shows up as noise or offset in the reading.

The 5-step checklist

1. Equipotential bond — connect ground rings or grounding electrodes to the liquid so the sensor and fluid stay at the same potential.
2. Sensor earth — run the meter's earth terminal directly to the local earthing bar, not daisy-chained.
3. Cable screen — ground the signal cable screen at one end only, at the transmitter side, to avoid ground loops.
4. Pipe bonding — bond flanges and upstream/downstream pipework together when using PTFE-lined meters.
5. Separate power earth — keep the meter supply earth free of pump or motor inrush currents.

After the fix

If installation follows the checklist, the live reading should be stable within a few seconds. A Fluke-style multimeter check across the grounding electrode to earth should read near 0 Ω.

Send us a photo of your grounding arrangement if the reading still fluctuates — most cases are resolved by remote video inspection in an hour.