Device for locating aquiferous layers comprises galvanometer placed on surface

摘要

A galvanometer is placed on the surface with its electrical terminals connected by an isolated wire on one side to an electrode moving in the drilled shaft and on the other to a terminal fixed to the earth. The moving electrode is displaced using a winch coil for the insulated wire in order to show the exact position of the aquiferous layers using the galvanometer if they are present. The moving electrode is lowered down the shaft and then raised slowly while the variations of the galvanometer are recorded. Variations between porous and permeable layers and layers which are not is clear on the resulting diagram as they have a higher potential.