Electrical Imaging System in Alternate Current Mod. POLARES (ERT)

Applications: shallow detailed investigations of pollutant plums in the ground; archaeological surveys; waste site deposit monitoring; mapping and monitoring of salty water contamination of groundwater reservoirs along coastal areas

Until now electrical imaging applied to geophysical exploration have been using the same traditional method for acquiring data: an electric continuos current was applied between two electrodes and the correspondent voltage was measured between other two electrodes inserted in the ground, with an inversion of polarity for each measurement. The new POLARES uses a sinusoidal alternate current of variable frequency. The use of alternate current had shown great advantages, in particular considering the absolutely greater velocity of acquisitions, that may increase of at least 10 times in respect of standard DC measuring time. Moreover, the measurement of the ratio between Voltage and Current can be done in a sinusoidal condition for both module and phase (delay of a signal in respect of the other); these two information, obtainable with a single measurement, allow the system to acquire both resistivity and IP data.

The new POLARES is lighter, smaller, faster and more reliable in respect to the former generation of electrical imaging systems. Moreover, the use of a non-conventional PC extends working conditions to wide environmental humidity and temperature ranges.