Fast EIT data acquisition for geophysical applications

E. Zimmermanna, J. A. Huismanb, W. Glaasa, S. van Waasena

aElectronic Systems (ZEA-2), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany

bAgrosphere (IBG-3), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany

Abstract

In the field of geophysics, spectral electrical impedance tomography is used for structural characterization of soils and rocks. The polarizability of these materials is very low and the frequency range of interest extends from 1 mHz to some kHz. In order to decrease the measurement time, especially for the low frequencies, mathematically orthogonal signals injected simultaneously at all current electrodes will be used. In this contribution, we will discuss the advantages and disadvantages of the method in view of geophysical applications, present a system realization and illustrate the performance regarding the measurement time and phase accuracy in tomographic images.

Keywords: Electrical impedance tomography; impedance spectroscopy; orthogonal signals; spectral induced polarization; electrical soil and rock properties