Soil Electrical Resistivity Test at Padma Oil. In all geophysical surveys, Electrical Resistivity method is best and reliable to know geological formation of the area. This method has been used to find formation faults, formation bedding, bedrock, water saturated aquifers, mineral deposits, and hydrocarbon formations including Coal.
VES works most favorably in applications having good resistivity contrast between a target and surrounding formations If you are interested in applying VES to find Water, Mineral Deposits, Environmental contaminants.
All geological formations possess properties called electrical resistivity when the current flows through them. Resistivity thus is defined as the resistance offered by a unit cube of material to direct current flowing through it in a direction perpendicular to two of its opposite faces.
The numerical value of the resistivity is expressed in ohm-meter in general. Thus the electrical resistivity is principally based on the study of resistance offered by the sub-surface formation to the flow of current
On the other hand we can define resistivity by ohm’s law the amount of potential difference required to push a given current is directly proportional to the “Resistance”
Test Method
For Geophysical survey especially for the electrical resistivity test methods includes the arrangement of 4 poles those directly connected to the tester. Among this four poles two poles determines the potential difference (V) and another two poles are used to send the current (I) to the ground. From this two parameter the value of Resistance( R) is measured (equation..(i)).
After determining the resistance (R), resistivity is measured. To measure soil resistivity, two methods are possible: Wenner Square Method.