Ground Resistance Testers

Ground resistance testers verify that an earthing system will actually carry fault current to ground, a measurement that cannot be made with an ordinary multimeter.

Megger, AEMC, HT, Tentech and Amprobe cover this range. Three methods dominate. Three-pole fall of potential is the reference method and requires driving temporary stakes at distance, which is thorough but needs space. Four-pole adds a measurement of soil resistivity, used when designing a new grid. Clamp-on stakeless testing needs no stakes at all and is fast, but it only works on a multi-grounded system and measures a loop rather than a single electrode. Tell us the site conditions.