Electrical impedance spectroscopy as a technique for the surveillance of civil engineering structures: considerations on the galvanic insulation of samples

The use of electrical impedance spectroscopy to determine the physical properties of materials could be improved by analysing possible sources of error. This work explores how impedance results can be affected by current leakage caused by the lack of galvanic insulation from sample to ground. In order to know the effects of ground coupling, an electric equivalent model was developed to distinguish between the contribution of sample impedance and that of stray impedance. The model values agree with the measured values.