a) Resistivity Measurement Tools Grounding
To measure the grounding resistance value by:
1). Wearing a model four terminals (Methods Wenner) with swivel arm generator (DC).
2). Measurement prisoners by connecting grounding terminal E C1 to be measured, the terminal P2 to P and terminal C2 to R. Distance E – P – R is the same made in a straight line. Meters will provide a direct readout in custody and custody earthing calculated by the formula:
ρ (Rho) = 2. Π. a. R (ohm-m)
in which:
ρ (Rho) = soil resistivity (ohm-m)
a = distance between the electrode (meters)
R = resistance (ohms)
Π (Phi) = 3.14
3). Wearing Earth Tester (analog) based on the potential price.
E (ground electrode) to be measured and the auxiliary electrode P and R auxiliary electrode is placed in a straight line to the electrode E. Volt meter will point to the potential E – P. According to Ohm’s law, the potential difference will be directly proportional to the earthing prisoners.
Seen that prisoners enlarged with the position P farther away from the E, and the increase is rapidly reduced, and even at a certain distance from the E, the increase can be neglected because it is very small.
Requirements that must be considered are:
a). Electrode R to be quite far from the electrode E, so that the prisoners are not mutually closed area (over lap).
b). P electrodes should be placed outside the two regions prisoners, in this case placed on a flat area of the curve.
c). Electrode P must lie between the electrodes R and E, on the connecting line.
