An apparatus apparatus to investigate the electrical conductivity of terrestrial formations (Machine-translation by Google Translate, not legally binding)

摘要

In apparatus for investigating the electrical conductivity of terrestrial formations, the combination of transmitting coils excited by alternating current, mounted for movement in the vicinity of said formations, receiving coils disposed in fixed relation to said transmitting coils for inductive coupling with these in such a way that the phase relationship between the exciting current in said transmitting coils and any voltage induced in said receiving coils will vary as a function of the electrical conductivity of the adjacent terrestrial formation, means that make the frequency of an alternating current signal vary according to of variations in said phase relationship, and means for obtaining indications of the frequency of said signal as a measure of the electrical conductivity of the formations. (Machine-translation by Google Translate, not legally binding)