Some applications of impedance measurement
Surface-or volume-specific electromagnetic properties of materials, also called density quantities (Sec. 1.10), are often inferred from impedance measurements. The property of interest is given by a measurement model in which input quantities are the impedance value(s), and the physical dimensions of the chosen geometrical configuration. The model make assumptions (e.g., material linear response, homogeneity, isotropy) whose validity has to be carefully considered.