SPONTANEOUS POTENTIAL MEASUREMENT
Instrumentation for geognostic investigation
The Spontaneous Potential method (PS) consists in determining on the surface, the differences of potential related to a natural electric field, linked to the underground circulation of aqueous electrolytic solutions in porous media. From the analysis of PS anomalies in the surface, it is possible to determine the intensity and position of the concentrations of ionic charges with both polarities. The test is carried out by positioning two electrodes: the first one close to the measurement station and the other one is moved on the following stations of the line; of both electrodes are moved, by keeping stable the interval between them, mapping the ground based on the spontaneous potential. The use of this method is useful in the mining field for the search of sulphides and graphite, but also in the archaeological field, indeed water circulations can be affected by underground archaeological structures, that could act as drain or as obstacle, and therefore, with the identification of PS anomalies, it is possible in general to find underground archaeological structures indirectly.