Testing Earth Ground

Discussion in 'General Electronics Chat' started by AutoNub, Dec 7, 2011.

  1. AutoNub

    Thread Starter Member

    Oct 14, 2011
    If I have an 8 ft deep ground rod and want to test its effectiveness, can I simply measure the resistance between the local power outlet's ground and the earth ground in question? Will this give me any useful data? I measure about 6.5 Ohms between the utility ground and the isolated earth ground. I'm thinking the resistance between the two grounds should be (0+(the accumulative resistance (as determined by its resistivity or resistance per unit length) of the conductive material between the point of contact with my probe and the point of dissipation to ground)). Is this accurate? Thanks for the insights!
  2. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    <10Ω is good. Low enough resistance that no dangerous voltage level can "build up" on your ground without being dissipated.

    Resistance will go down if it rains or freezes.

    Is your local ground for an antenna, or some other purpose?
  3. Lundwall_Paul


    Oct 18, 2011
    It is not accurate. I have always used ground testers. Perhaps you can find an electrician who has one and have him measure it. Check out on line the Fluke 1625. Checking a ground rod cannot be checked with an ohm meter.