Random and systematic error as a function of sample area in electrochemical impedance spectroscopy data
By Bonitz, Verena S.; Hinderliter, Brian R. & Bierwagen, Gordon P.
Published in Progress in Organic Coatings
NULL
2014
Abstract
The goal of this study was the evaluation of random and systematic error sources in electrochemical impedance spectroscopy (EIS) measurements that originate from the EIS equipment and measurement protocol in contrast to errors related to the coating/metal system. By using well-defined, homogeneous, and defect-free polyvinylfluoride (Tedlar®) release films, highly reproducible EIS spectra could be obtained. Thus, it was thus possible to study data variability originating from the EIS measurement procedure while keeping the film/metal system constant. Parameters gained from EIS spectra such as film resistivity, dielectric constant and exponent n of the non-ideal capacitance were evaluated as a function of sample area and compared to reference material properties. For larger sample sizes the values obtained by EIS experiments correlated well with the reference values, validating the EIS technique for the determination of absolute values for electrical properties of coatings. However, to obtain an accurate value for film resistivity and relative dielectric constant, a sample area of at least 11.4 cm2 was necessary to avoid the introduction of measurement artifacts. The implications of the findings for corrosion testing with small sample areas (e.g., as used in high-throughput corrosion testing) are discussed.
Microsoft is Ending Support for Windows 7
Microsoft will discontinue support for Windows 7 on January 14, 2020 which means Gamry will also be discontinuing support for Windows 7. If you are upgrading to Windows 10, like many companies and institutions, you need to be running Version 7 of our s oftware . Please note that only USB and Ethernet-based instruments can run in Version 7. Eligible users can download the latest version of our software through our online Client Portal .
If you haven't already registered your instrument, you can do so through the Client Portal .
Please email Technical Support if you have any questions regarding this transition. Please be sure to include your instrument model and serial number when contacting us.