Wideband impedance spectroscopy from 1mHz to 10MHz by combination of four- and two-electrode methods

Abstract

Impedance Spectroscopy (IS) measurements allow to study a wide range of polarization mechanisms associated with different frequency ranges. Experimental devices usually cover limited frequency ranges with sufficient accuracy. We propose (a) a combination of four-electrode and two-electrode devices and (b) a data combination and mutual verification procedure using the actual sample under test. Hereby, we cover a frequency range from 1 mHz to 10 MHz. The data combination relies on the precondition that any dispersive disturbance decayed at some mutual point within an overlapping frequency range between 1 Hz and 45 kHz. We validate our data combination procedure by IS measurements on simple reference systems and comparison with widely accepted model functions, e.g. the complex refractive index model (CRIM) for high frequency behavior and Kramers-Kronig relations in terms of data consistency. In this respect, our suggested processing approach is superior to two selected alternative approaches. We successfully adapt typical empirical model functions, e.g. multi-Cole-Cole, to the resulting wideband data to show that they are fully applicable for further data analysis.

Influence of smectite and salinity on the imaginary and surface conductivity of volcanic rocks

“…Our design seems to be an appropriate compromise for studying large sample sets of natural volcanic rocks, with small and variable length l samp (between 20 and 30 mm), although a slightly more sophisticated system would likely lead to more accurate phase-angle measurements (e.g. Schleifer et al 2002;Volkmann and Klitzsch 2015). This sample holder was originally designed for measuring high phase-angles in the presence of sulphides and iron oxides (see results presented in Lévy et al 2019b) so that the maximum uncertainty of the phase-angle, 1 mrad (see Appendix C), was negligible compared to the high phase-angles observed (from 30 to 200 mrad).…”

“…We emphasize again here that this comparison is only given as additional information and that we have not tried to combine 2-and 4-electrode measurements to extend the frequency range of usable complex conductivity measurements, as done by Volkmann and Klitzsch (2015). Our 2-electrode measurements are only used to improve the formation factor determination.…”

Nano- to Millimeter Scale Morphology of Connected and Isolated Porosity in the Permo-Triassic Khuff Formation of Oman

“…In addition, micro-computed tomography (µCT), allows the construction of a 3D digital model of the porous network in a non-desctructive way [15,16]. Petropgraphic observations are supported by petrophysical measurements such as nuclear magnetic resonance (NMR) and electric resistivity measurements as they provide information about pore connectivity, porosity, pore-size distribution and permeability [16][17][18].…”

Tracking Magmatic Hydrogen Sulfur Circulations Using Electrical Impedance: Complex Electrical Properties of Core Samples at the Krafla Volcano, Iceland

“…If only dielectric absorption of water was causing the observed HF polarization, the phase angle should be only negative and much lower, considering a relative dieletric permittivity of water around r = 80 (Abdulsamad et al, 2016). A major contribution from the measuring electrodes is likely at these frequencies, as shown by previous studies (Abdulsamad et al, 2016;Lesmes & Frye, 2001;Volkmann & Klitzsch, 2015). Figure B1 compares the chemistry of the different sulfides and iron oxides for samples, analyzed by Electron Probe Micro-Analysis.…”