The Fluke 1625-2 Advanced GEO Earth Ground Tester is able to measure earth ground loop resistances using only clamps. With this test method, two clamps are placed around the earth ground rod and each are connected to the tester. No earth ground stakes are used at all. A known, fixed voltage is induced by one clamp and the current is measured using the second clamp. Then the tester automatically determines the resistance of the earth ground rod.

This test method only works if a bonded earth ground system exists for the building or structure under test - most have this system. If there is only one path to ground, like at many residential applications, the stakeless method will not provide an acceptable value and the Fall of Potential test method must be used.

With stakeless testing, the earth ground rod does not need to be disconnected, leaving the bonded earth ground system intact during testing. Gone are the days of spending time placing and connecting stakes for each earth ground rod on a system, which is a major time saver. Users can also perform earth ground tests in places that were not always considered: inside of buildings, power pylons, or anywhere users do not have access to soil.

The Fluke 1625-2 is a distinctive earth ground tester that can perform all four types of earth ground measurements. It is also easy to use. For each test, the testers can report which stakes or clamps need to be connected and the large rotary switch can be used even with a gloved hand.