Electra is composed of a central unit (2 kg, rechargeable battery
included) to be connected to any PC and of a very light cable along
which the small moduli to be connected to the electrodes are attached.
Each module has the double function of injecting current in the subsoil
and of receiving the signal, by amplifying and digitizing it directly at the
source (the electrodes). The signal is then transmitted to the central
unit in a digital form through the very simple, light and high performing
main cable, which prevents any cross-talk and signal degradation
Electra can inject any current in the subsoil (from continuous to
alternate) at different frequencies. Measurements in alternate current
are faster and more precise, since no time is needed for the signal
stabilization and induced polarization of the electrodes is minimized.
The possibility to inject different waveforms also opens the way to new
studies on the relations between the energization procedures and the