A ground is a crucial part of an electrical system, as it routes electrical current to the earth and helps reduce the risk of electrical shock to personnel. The grounding system also routes unwanted electromagnetic interference (EMI) induced in the electrical system to ensure a stable facility.
The resistance of the grounding system to the earth may be affected by several factors like dry ground, partially uprooted stakes, corroded connections, and broken ground leads; therefore, performing routine resistance measurement of the grounding system ensures that the grounding rod has good contact with the earth.
One of the fastest and most convenient methods of measuring ground resistance is by using the clamp method. Instead of using multiple leads or poles, the device has a jaw that can be clamped around the ground rod. The device then gives you the resistance reading in a few seconds, saving time and making diagnostics faster.