In this paper, we propose a discussion of the theoretical design and move
towards the development and engineering of an induction probe for electrical
spectroscopy which performs simultaneous and non invasive measurements on the
electrical RESistivity \rho and dielectric PERmittivity \epsilon r of
non-saturated terrestrial ground and concretes (RESPER probe). In order to
design a RESPER which measures \rho and \epsilon r with inaccuracies below a
prefixed limit (10%) in a band of low frequencies (LF) (B=100kHz), the probe
should be connected to an appropriate analogical digital converter (ADC), which
samples in uniform or in phase and quadrature (IQ) mode, otherwise to a lock-in
amplifier. The paper develops only a suitable number of numerical simulations,
using Mathcad, which provide the working frequencies, the electrode-electrode
distance and the optimization of the height above ground minimizing the
inaccuracies of the RESPER, in galvanic or capacitive contact with terrestrial
soils or concretes, of low or high resistivity. As findings of simulations, we
underline that the performances of a lock-in amplifier are preferable even when
compared to an IQ sampling ADC with high resolution, under the same operating
conditions. As consequences in the practical applications: if the probe is
connected to a data acquisition system (DAS) as an uniform or an IQ sampler,
then it could be commercialized for companies of building and road paving,
being employable for analyzing "in situ" only concretes; otherwise, if the DAS
is a lock-in amplifier, the marketing would be for companies of geophysical
prospecting, involved to analyze "in situ" even terrestrial soils.Comment: 37 pages, 7 figures, 3 table