| Abstract: | The Mining Geophysics Institute of the University of Rome has tested focused electrode arrangements. These have been used both in the field for resistivity profiles in investigations for buried cavities and in the laboratory for model tests in an electrolytic tank with cylindrical and parallelepipedal bodies. Anomalous potentials due to superficial noise, assumed to be a hemisphere having an equatorial plane coinciding with the earth surface, have been calculated for focused current electrode arrangements. Similar anomalies have also been calculated for the Schlumberger arrangement. Model tests in an electrolytic tank have also been carried out for a Schlumberger arrangement and parallelepipedal buried bodies. It is interesting to know whether the focused current arrangements give better results than the Schlumberger arrangement. Since it is not possible to compare directly the results of the two arrangements, the comparison is made by considering the ratio of the anomalies to the superficial noise (considered as hemisphere) for Schlumberger and focused arrangements. The results of the comparison show that, generally, the focused arrangements give better results even in the presence of superficial noise. |
