11:15 AM - 11:30 AM
[SEM19-08] DC potential imaging of a granite surface
Keywords:electrical resistivity of rocks, laboratory tests, electrometer with extremely high input impedance, floating measurement, conductive epoxy
We have developed an experimental set-up to achieve the potential measurement of rock samples as follows. Potential of the rock sample with very high resistance was measured by using an electrometer with extremely high input impedance. Leakage current was prevented by “floating measurement”, in which circuits of measurements are separated from the ground. The high-density electrode arrangement on the rock sample surface is achieved by using electrodes made from conductive epoxy, which is not conventionally used as electrode.
Using these methods, we measured potential distribution on the granite surface into which direct current was injected. Obtained results agree roughly with numerical simulations, meaning the new experimental set-up reasonably works.