Impulse Impedance Tests on Laboratory Model Earth Electrode

The investigation was carried out with the purpose of obtaining more information about electric discharges in sandy media. A cylindrical setup was chosen for impulse testing of earth rods to simulate the voltage gradients in the field when lightning propagates to earth rod. The temperature images at the surface of the sand and rod were captured during the experiment. The surface temperature increased slightly higher with the increased of voltages. The CDEGS validates the increase of electric field higher at the edge of the cylindrical test cell. And also for the first time, the conduction current in dry sand was observed. It would be expected that the current produced in dry sand be due to soil ionization and also thermal effect due to charge movement in the soil, since there are air voids in the dry sand.