Interpretation of electrochemical impedance spectroscopy (EIS)circuit model for soils
来源期刊：中南大学学报(英文版)2015年第11期
论文作者：HAN Peng-ju ZHANG Ya-feng Frank Y. CHEN BAI Xiao-hong
文章页码：4318 - 4328
Key words：soil; electrochemical impedance spectroscopy (EIS); equivalent circuit; impedance; water content
Abstract: Based on three different kinds of conductive paths in microstructure of soil and theory of electrochemical impedance spectroscopy (EIS), an integrated equivalent circuit model and impedance formula for soils were proposed, which contain 6 meaningful resistance and reactance parameters. Considering the conductive properties of soils and dispersion effects, mathematical equations for impedance under various circuit models were deduced and studied. The mathematical expression presents two semicircles for theoretical EIS Nyquist spectrum, in which the center of one semicircle is degraded to simply the equivalent model. Based on the measured parameters of EIS Nyquist spectrum, meaningful soil parameters can easily be determined. Additionally, EIS was used to investigate the soil properties with different water contents along with the mathematical relationships and mechanism between the physical parameters and water content. Magnitude of the impedance decreases with the increase of testing frequency and water content for Bode graphs. The proposed model would help us to better understand the soil microstructure and properties and offer more reasonable explanations for EIS spectra.
HAN Peng-ju(韩鹏举)1, ZHANG Ya-feng(张亚芬)1, Frank Y. CHEN(陈幼佳)1, 2, BAI Xiao-hong(白晓红)1
(1. Department of civil engineering, Taiyuan University of Technology, Taiyuan 030024, China;
2. Department of civil engineering, the Penn State University, Harrisburg, PA 17057, USA)
Abstract:Based on three different kinds of conductive paths in microstructure of soil and theory of electrochemical impedance spectroscopy (EIS), an integrated equivalent circuit model and impedance formula for soils were proposed, which contain 6 meaningful resistance and reactance parameters. Considering the conductive properties of soils and dispersion effects, mathematical equations for impedance under various circuit models were deduced and studied. The mathematical expression presents two semicircles for theoretical EIS Nyquist spectrum, in which the center of one semicircle is degraded to simply the equivalent model. Based on the measured parameters of EIS Nyquist spectrum, meaningful soil parameters can easily be determined. Additionally, EIS was used to investigate the soil properties with different water contents along with the mathematical relationships and mechanism between the physical parameters and water content. Magnitude of the impedance decreases with the increase of testing frequency and water content for Bode graphs. The proposed model would help us to better understand the soil microstructure and properties and offer more reasonable explanations for EIS spectra.
Key words:soil; electrochemical impedance spectroscopy (EIS); equivalent circuit; impedance; water content
