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This article describes a portable low-cost device for performing electrochemical impedance spectroscopy (EIS) measurements, which is based on an off-the-shelf TeensyDuino. The instrument does not make use of other components, such as operational amplifiers, so it can be readily set up by anyone having a Teensy device and some resistors. Teensy 3.2, Teensy 3.5, and Teensy 3.6 can be used to realize the EIS system. The instrument can measure the impedance in the frequency range from 0.01 to 50 000 Hz, and by selecting the shunt resistor, it can be adapted to different impedance values. No special instrumentation is required for the system calibration. The proposed system uncertainty is less than 5% for an impedance of up to $50 {~\mathrm {k\Omega }}$ , a value which is lower than the usual intrinsic uncertainty of most corrosion experiments. [ABSTRACT FROM AUTHOR]

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 ~\mathrm \Omega – 10 ~\mathrm G \Omega . 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. [ABSTRACT FROM PUBLISHER]

This paper describes design and test of a new impedance-measurement system for nonlinear devices that exhibits a seven-decade range and works down to a frequency of 0.01 Hz. The system is specifically designed for electrochemical measurements, but the proposed architecture can be employed in many other fields where flexible signal generation and analysis are required. The system employs an unconventional signal generator based on two pulsewidth modulation (PWM) oscillators and an autocalibration system that allows uncertainties of less than 3% to be obtained over a range of 1 k03A9 to 100 G03A9. A synchronous demodulation processing allows the noise superimposed to the low-amplitude input signals to be made negligible. [ABSTRACT FROM AUTHOR]