Ground Resistance Testing
Ground resistance of ground rods and grids is typically measured using the 3-stake fall of potential method where the electrode or grid can be easily disconnected. A good ground system is usually designed for the final measurement on the completed system to be between 5 and 10 ohms.
The 3-stake reading is the impedance of the system measured with approximately 100 to 300 Hz source potential. Many units are suitable for making routine maintenance checks using the FOP method as well as the slope or four potential method.
In some units, resistance reading, test status information and warnings are displayed in a LCD readout. Most testers will indicate excessive input noise and high-current probe resistance. Settings may be stored in memory for use in subsequent tests.
A digital test unit that measures earth ground resistance and calculates soil resistivity ranges in pricing from $860.00 to $2,295 or more, depending upon the manufacturer and equipment benefits. Usually this pricing does not include test leads and an equipment case which can run as much as an additional $400.00.
We recommend that you contact our valued manufacturers and distributors for your resistance testing equipment requirements.