ArchaeoPhysica Ltd on the WWW

Geoscan Research RM15 Electrical Resistance Meter

The RM15 has been the workhorse of archaeological studies for an extremely long time & deservedly so. The meter itself is the white box on top of the frame in the picture & it is connected by a multiplexor to a set of probes beneath, allowing various combinations of these to be used for different measurements.

The most common configuration is the twin-probe (similar to the pole-pole) where a pair of current & potential probes are moved during survey while a second pair remain fixed in the ground. As long as the separation of the pairs is more than 30 times the spacing of the probes in the mobile pair the result will relate fairly directly to the actual resistivity of the ground. By increasing the separation of the mobile pair, the potential measured is due to current flow deeper in the soil & hence survey at multiple apparent depths is possible.

Optimum results are obtained when the ground is in a state of hydrological flux, e.g., after light rain when undisturbed regions of the soil tend to dry out faster than disturbed ground.

Manufacturer

Geoscan Research, United Kingdom

Web site

http://www.geoscan-research.co.uk