Wenner arrays

During application of the method, a current is injected into the ground by a pair of surface electrodes and a resulting potential field is measured between a second pair of surface electrodes. A schematic of such a configuration called a Wenner array, is shown in Figure 8. The subsurface resistivity is calculated from the electrode separation, applied current, and measured voltage. 

The Wenner array should not be used unless the expected ground conditions are fairly simple. The Schlumberger array is less sensitive to lateral resistivity variations. 

Hgure 27.13 Wenner array used to measure soil resistivity... 

Soil resistivity measmements are frequently conducted with a resistivity meter connected in a Wenner array, as illustrated in Figure 27.13. Four electrodes are driven into the ground along a straight Kne, with an equal spacing, d, between each electrode. Cmrent, I, is passed between the two outer electrodes (called cmrent electrodes) Cj and C2, and the resulting voltage, V, is measured... 

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