Earth Resistance Measurement

I advise you to read some application notes written by the earth ground measurement instrument manufaturers like Fluke and others.

http://support.fluke.com/find-sales/Download/Asset/2633834_6115_ENG_A_W.PDF

If you use the Internet search engines, you will find many files with useful information.

Hope this will be helpful.

Hello "Guest" and I hope 2007 brings you health and prosperity!

If your question is leading up to a grounding project, let me offer some advice:

I just did a large scale project for a friend to ground an Olympic size swimming pool at his aquatic club (people were getting shocks when touching hand rails). I used an instrument similar to the Fluke proposed by Mario. We were able to get readings well under 5 ohms (the accepted limit for sensitive areas) by building an equipotential grid under the pool. I also built a Ufer ground by tying the grid into the reinforcing bar of the concrete foundation as well as the screen that was embedded in the concrete walk ways. See the interesting link below. I remember Ufer grounds due to my work in dry sand of the Middle East.

http://www.psihq.com/iread/ufergrnd.htm

Welcome to CR4 PetroPower, I like your avatar. Be warned however my avatar started out black then went to red and finally blue with bloodshot eyes. I think it's from talking till I'm blue in the face to the perpetual motion machine loonies that a site like this attracts.

Anyway welcome aboard.

Thanks for the link.