Full-range contactless conductivity detection

Conductivity is an important parameter whose detection has applications in multiple areas including metallurgical industry, coatings design, additive manufacturing and biomedical engineering. This paper proposes a contactless method of conductivity detection which does not affect the integrity of the sample under study, based on monitoring changes to both the resonant frequency and the quality factor of a split-ring resonator. We achieve a full-range conductivity detection with an error lower than 10% across 8 decades of the conductivity values ranging from 0.03 S/m to 6·10
⁷
S/m. Analytical results for conductivity dependence are verified by numerical simulations and by experimental data.