Direct Current Resistivity Methods

Direct current (dc) resistivity methods use artificial sources of current to produce an electrical potential field in the ground. In almost all resistivity methods, a current is introduced into the ground through point electrodes (C

1

, C

2

) and the potential field is measured using two other electrodes (the potential electrodes P

1

and P

2

), as shown in

Fig. 4.3-1

. The source current can be direct current or low-frequency (0.1 – 30 Hz) alternating current. The aim of generating and measuring the electrical potential field is to determine the spatial resistivity distribution (or its reciprocal - conductivity) in the ground. As the potential between P

1

and P

2

, the current introduced through C

1

and C

2

, and the electrode configuration are known, the resistivity of the ground can be determined; this is referred to as the “apparent resistivity”.