Design of an Induction Probe for Simultaneous Measurements of Permittivity and Resistivity n 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 ρ and dielectric PERmittivity εr of non-saturated terrestrial ground and concretes (RESPER probe). In order to design a RESPER which measures ρ and εr 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...