Soil Resistivity Testing Services

As a special service, ETTL has been helping clients make sure the grounding systems they are designing (or have already installed) will be compatible with the soil in which they are placed.

Almost everyone recognizes the importance of earth grounding for electrical systems -- the need to provide a low-impedance path to the earth for high currents from lightning strikes and power surges, as well as a path for low currents from RFI (radio frequency interference) and static build-ups -- and also to ensure that non-current carrying metal parts are at ground potential for the sake of personnel safety. What is not as well known is that soil resistivity (electrical resistance of the subsurface itself) varies widely, often within the same site, depending on soil type and density as well as depth. Which means that a soil resistivity "profile" can be crucial to grounding system design. If soil resistance is too high, the system may fail, resulting in loss of (or damage to) highly expensive electrical equipment, such as exists in TV towers, cellular towers, water towers, electrical billboards, elevator electrical systems and countless other types of installations.

In a recent project, soil resistivity services, as well as site assessment and geotechnical services, were carried out by ETTL for the tower at left below. With a completed height of 1600 feet, it was the tallest TV tower in East Texas. At right belolw, an ETTL engineer takes readings of soil resistivity at the tower site with an AEMC Digital Ground Resistance Tester, generating data for the design phase of the tower's grounding system.

For in-depth information about ETTL's Soil Resistivity
Testing Services, contact Robert Duke

ETTL Construction Materials Engineering Page

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