Title :
Low-Cost Impedance Spectroscopy System Based on a Logarithmic Amplifier
Author :
Grassini, Sabrina ; Corbellini, Simone ; Angelini, Emma ; Ferraris, Franco ; Parvis, Marco
Author_Institution :
Dept. of Appl. Sci. & Technol., Politec. di Torino, Turin, Italy
Abstract :
Impedance spectroscopy (IS) involves measurements of impedance amplitudes, which often span more than six/seven decades. Currently available IS systems employ sophisticate front-ends to cope with this wide impedance range and, consequently, the cost of the measuring instrument greatly increases. This paper describes an alternative low-cost solution, which is based on a logarithmic front-end and on an off-the-shelf microcontroller board. Using these components, the cost remains below $100, while still having the capability of measuring over a frequency range of 0.01 Hz-100 kHz and for impedance values in the range of 100 Ω-10 GQ. The overall uncertainty remains below 5% of amplitude and few degrees of phase. The proposed system is, therefore, suitable for electrochemical impedance spectroscopy applications, as well as for bioelectrical impedance analysis.
Keywords :
amplifiers; electrochemical impedance spectroscopy; microcontrollers; bioelectrical impedance analysis; electrochemical impedance spectroscopy applications; frequency 0.01 Hz to 100 kHz; logarithmic amplifier; logarithmic front-end; low-cost impedance spectroscopy system; off-the-shelf microcontroller board; Current measurement; Frequency measurement; Impedance; Impedance measurement; Signal to noise ratio; Uncertainty; Bioelectrical impedance analysis (BIA); corrosion assessment; electrochemical impedance spectroscopy (EIS); impedance spectroscopy (IS); logarithmic amplifiers; logarithmic amplifiers.;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
DOI :
10.1109/TIM.2014.2371191