Influence of Probe Size and Probe Position for Local Electrochemical Impedance Spectroscopy
First, a non-negligible capacitance is observed in the high-frequency domains corresponding to a coupling capacitance between two of the micro-wires, as shown in Fig. 1.
Second, the position of the reference electrode for measuring the potential and calculating the local impedance plays a significant role . Indeed, depending on the location of the probe for measuring the potential, the measurement may be insensitive to local heterogeneity. As a result, such a measurement is no longer a local impedance measurement since it is obtained as a ratio of global potential to local current density.
In this paper, we present experimental results on platinum electrode and on the steel / copper system in order to characterize the influence of the probe size and the probe positioning. A specific attention will be paid to data analysis, and some guidelines for performing LEIS measurements (probe characterisation and probe positioning) will be presented.
 R.S. Lillard, P.J. Moran, H.S. Isaacs, A novel method for generating quantitative local electrochemical impedance spectroscopy, J. Electrochem. Soc. 139 (1992) 1007-12.
 V.M.-W. Huang, S.-L. Wu, M.E. Orazem, N. Pebere, B. Tribollet, V. Vivier, Local electrochemical impedance spectroscopy: A review and some recent developments, Electrochim. Acta 56 (2011) 8048-57.
 I. Annergren, D. Thierry, F. Zou, Localized electrochemical impedance spectroscopy for studying pitting corrosion on stainless steels, J. Electrochem. Soc. 144 (1997) 1208-15.
 E. Bayet, F. Huet, M. Keddam, K. Ogle, H. Takenouti, Local electrochemical impedance measurement: scanning vibrating electrode technique in ac mode, Electrochim. Acta 44 (1999) 4117-27.
Fig. 1: dual probe used for measuring local electrochemical impedance spectroscopy and equivalent circuit used for taking into account the stray capacitance ascribed to this setup.