Reliability of electrochemical impedance spectroscopy measurements : results of round-robin testing - Archive ouverte HAL Access content directly
Conference Poster Year :

Reliability of electrochemical impedance spectroscopy measurements : results of round-robin testing


From the results of the Round-Robin (RR) tests on electrochemical noise (EN) measurements with dummy cells performed by the European Cooperative Group on Corrosion Monitoring of Nuclear Materials (ECG-COMON, since 2006 [1-2], it can be concluded that only very few commercial potentiostats are able to perform valid EN measurements. As an example, Fig. 1a shows the power spectral densities (PSDs) of the potential fluctuations measured by the participants of the RR test in 2017 using 3 identical resistors of 100 M connected in a ‘star’ arrangement and used in the conventional three electrode EN measurement setup using a zero-resistance ammeter. The aim was to measure the thermal noise of the resistors, which has a reproducible amplitude and is in the same range as for passive electrodes. This figure exhibits an extremely large scatter in the amplitude of the PSD, roughly ten decades above the thermal noise level, defined as the red line 6kTR, that is, five decades in volt! This large scatter is mainly due to the absence of anti-aliasing filters in most of the commercial potentiostats. This paper is aimed at guiding users of the EN technique by providing the minimum knowledge for EN measurements, including the necessary validation of the signals measured at different sampling frequencies by calculation of their PSDs. Two practical works performed with a commercial potentiostat (Gamry, Ref600) are proposed. The first one is devoted to the measurement of the thermal noise of three resistors of equal value, as in the RR tests. This allows the instrumental noise of the equipment to be determined. The second practical work concerns pitting corrosion of two identical aluminum electrodes in potassium chloride to show that the noise impedance is equal to the modulus of the impedance of the electrodes (Fig. 1b). A bias voltage is then applied between the electrodes to obtain one anode and one cathode which shows the difficulty of analyzing the measured EN in asymmetric systems
Fichier principal
Vignette du fichier
Pages de poster_2019_RR_final.pdf (763.58 Ko) Télécharger le fichier
Origin : Files produced by the author(s)

Dates and versions

hal-04016279 , version 1 (06-03-2023)


Attribution - CC BY 4.0


  • HAL Id : hal-04016279 , version 1


Rik-Wouter Bosch, Robert A. Cottis, François Huet, Kieu Ngo, Stefan Ritter. Reliability of electrochemical impedance spectroscopy measurements : results of round-robin testing. 11th International Symposium on Electrochemical Impedance Spectroscopy (EIS 2019), Jun 2019, Lège-Cap-Ferret, France. . ⟨hal-04016279⟩
0 View
0 Download


Gmail Facebook Twitter LinkedIn More