| 摘要 |
<p>In electrical geophysical prospecting and in well-logging, in which potential is applied to the earth to cause direct current (or low frequency alternating current) to flow between spaced electrodes and the potential is measured between other electrodes contacting the earth, difficulties are experienced due to the electrode chemistry at the electrode contacts with the earth. This phenomenon is usually called polarization, with spontaneous, usually varying potential being generated at the electrode contact. I have found it possible to use pairs of relatively closely spaced solid conductor electrodes instead of the individual electrodes formerly used, applying an alternating voltage between the two electrodes of each pair which minimizes polarization, and coupling the direct or low frequency A.C. potential between two such pairs either in applying a measuring current to the earth or in determining the resultant potential between other similarly arranged pairs of solid conductor electrodes in contact with the earth and also biased with alternating voltage. The alternating bias current is at least of the order of magnitude and perferably somewhat greater than the direct current in an electrode. 79191ART0152</p> |
