Resistivity survey

Resistivity survey is based on the ability of sub-surface materials to conduct an electrical current passed through them. There are extreme cases of conductive and non-conductive material, but differences in the structural and chemical make-up of soils mean that there are varying degrees of resistance to an electrical current. Although changes in the moisture content of the soil, as well as variations in temperature, can affect the form of anomalies present in resistivity survey results, in general, higher resistance features are interpreted as structures which have a limited moisture content, for example walls, mounds, voids, rubble filled pits, and paved or cobbled areas. Lower resistance anomalies usually represent buried ditches, foundation trenches, pits and gullies.

We offer a number of techniques that work on this principle:

• Resistivity survey using fixed probe arrays for area coverage
• High resolution resistance surveys over areas
• Multiplexed resistivity for shallow resistivity profiles through material
• Resistance tomography for deep resistivity profiles through sites and landscapes