Remote earth potential procedure for continuity test

Remote Earth Potential Procedure

1. Place reference electrode at a location remote (10 – 30m) from all cathodically protected structures. The remote reference electrode is not directly over any buried metallic structure or shielded by such structure;
2. Be sure that reference electrode is in good contact with moist soil ;
3. Connect reference electrode to the negative terminal of voltmeter using a long spool of suitable wire.
4. Connect positive lead wire to voltmeter;
5. Place voltmeter on 2 volt or less DC scale;
6. Contact each buried metallic structure with the positive test lead without moving the reference electrode.
7. Test and measure voltage for each structure under investigation. Acquire data for each structure as quick as possible to avoid nature potential fluctuation and /or interference.

Electrical Continuity Criteria

ΔV≤ 2 mV, the structures are electrically continuous.
ΔV≥ 10 mV, the structures are electrically isolated.
10> ΔV>2 mV, it is inconclusive and further diagnostic testing is required