Earth Resistivity Test on concrete base

[Forum Researcher]

Hi, I am planning to conduct an Earth Resistivity Test on my property. The issue is that my building's basement is entirely covered with concrete and pavement, and we intended to use the Fall-of-Potential test method since there are no other equipment options available for rent in my location. However, I am unable to place the probes wherever I need to take the readings. Therefore, I have a few questions:

• Is it possible to use the other earthing rod/pit as one of the probes?
• Does the length of the probe matter? If yes, what changes may require in calculation of resistivity?
• Is there an alternative method to perform the test without expensive equipment?
• What are the best practices for situations like these?

 

[Nigel Goodwin]

For start give your location, as your question is entirely dependent on your local regulations.

 

[MaxHeadRoom78]

See the Youtube videos by Mike Holt.
Also https://forums.mikeholt.com/threads/earth-resistance-testing.55854/

 

[Tony Stewart]

Hi, I am planning to conduct an Earth Resistivity Test on my property. The issue is that my building's basement is entirely covered with concrete and pavement, and we intended to use the Fall-of-Potential test method since there are no other equipment options available for rent in my location. However, I am unable to place the probes wherever I need to take the readings. Therefore, I have a few questions:

• Is it possible to use the other earthing rod/pit as one of the probes?
• Does the length of the probe matter? If yes, what changes may require in calculation of resistivity?
• Is there an alternative method to perform the test without expensive equipment?
• What are the best practices for situations like these?

The Fall of Potential is simply like a 1 sided Kelvin bridge for current sensing avoiding the fringing effects on 1 side which is improved over a 2 point measurement but not a accurate as a 4 point Kelvin bridge method which may be hard to implement over great distances and line noise crosstalk.


Thus use the 2 point test suggested by Megger.