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How to Find Out What Your Ground Conductivity Is

Ground conductivity, also called frequency domain electromagnetics, refers to the ability of soil, stone and other ground materials to transmit an electrical current. Comprehensive measurements are difficult to obtain but useful for several industries. In particular, AM radio station operators and HAM radio enthusiasts use the calculations to determine the ability of their radio signals to propagate over a certain area. The better the ground conductivity, the better the ability of radio waves to be transmitted over it, especially in the case of low-frequency transmissions.

Things You'll Need

Metal rods
Light bulb
Light bulb base
Electrical cord
14.6 ohm resistor
Tape measure
Pliers
Flathead screwdriver
Multimeter

Instructions

- 1
  Obtain four rods made of some conductive metal, such as copper. They should each be 14 inches long and 9/16 inch wide.
- 2
  Drive each of the four rods 12 inches into the soil in a straight line, with each rod 18 inches apart.
- 3
  Attach the light bulb to the light bulb base. Connect one end of an electrical cord to one terminal of the light bulb base. This wire is the live wire.
- 4
  Wire the 14.6 ohm resistor to the other terminal of the light bulb base. Wire the opposite side of the resistor to rod No. 1.
- 5
  Connect the live wire to rod No. 4.
- 6
  Measure the voltage across the resistor using the multimeter. Note this number as V1.
- 7
  Measure the voltage of the soil directly between rods No. 2 and No. 3. Note this number as V2.
- 8
  Calculate the ground conductivity of your soil in milliSiemens per meter by dividing V1 by V2 and multiplying the resulting number by 21.

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