Abstract
The objective of the study described in this paper was to examine whether fouling on an electrode surface can be monitored through impedance measurements using a modified Electrochemical Impedance Spectroscopy technique. The attempt was to evaluate a measurement system that could monitor fouling, within an electrochemical cell, by using EIS to find one single frequency to measure the impedance magnitude. An electrical potential difference was applied to the electrochemical cell to generate an electrical field to accelerate the deposition layer growth on one electrode. Experimental results show that the magnitude of the electrochemical cell impedance was in the range of 110 Ω over the duration of the experiment, which lasted one week. A measurable change in the impedance magnitude was detected when a deposition layer, caused by fouling, was present on one of the electrodes. The measurement frequency was selected specifically for the purpose to increase the deposition layer influence on the measured impedance magnitude, which was achieved by selecting a frequency that kept the capacitive reactance as low as possible. Results indicate that a measurement system, using one frequency, is capable of monitoring the deposition layer by measuring the magnitude of the electrochemical cell impedance.
Zusammenfassung
Die Untersuchungen in dieser Arbeit haben das Ziel festzustellen, ob Niederschläge (Fouling) auf einer Elektrodenoberfläche effektiv durch Impedanzmessungen unter Verwendung einer modifizierten elektrochemischen Impedanzspektroskopietechnik erkannt und überwacht werden können. Der Versuch bestand darin, ein einfaches Messsystem zu entwickeln und zu evaluieren, welches die Impedanzanalyse, bevorzugt bei nur einer einzigen, spezifischen Frequenz, vornimmt, um daraus Aussagen über das Fouling zu treffen. Um die Abscheidungsrate des Niederschlags zu erhöhen und damit die Experimente zu beschleunigen, wurde eine Potentialdifferenz zwischen die Elektroden der elektrochemischen Zelle angelegt. Die Messergebnisse zeigen, dass die Impedanz der elektrochemischen Zelle während des Versuchs, der insgesamt eine Woche dauerte, im Bereich von 110 Ω lag. Eine gut messbare Änderung des Betrags der Impedanz wurde festgestellt, als der Niederschlag an den Elektroden eine signifikante Stärke erreichte. Es konnte eine Messfrequenz gefunden werden, bei der der Einfluss der Schichtdicke des Niederschlags signifikant war und bei die die kapazitive Reaktanz gering gehalten werden konnte. Die Ergebnisse zeigen deutlich, dass ein Messsystem, das nur eine einzige Messfrequenz nutzt, in der Lage ist, Ablagerungsschichten über die Analyse des Betrags der Impedanz der elektrochemischen Zelle zu überwachen.
About the authors
Ronnie Anseth held a Bachelor of engineering in Cybernetics from Oslo University College (OUC) in 2009, and a Master of Technology in System and Control Engineering from Telemark University College (TUC) in 2011. Currently (2018) a PhD student at University College of Southeast Norway (USN). TUC merged with several university colleges into the University College of Southeast Norway (USN) in 2016.
University College of Southeast Norway, Telemark, Norway
Nils-Olav Skeie held a Master of Science in Cybernetic from Norwegian University of Science and Technology (NTNU) from 1985 and a PhD in Cybernetics from NTNU and Telemark University College (TUC) from 2008. TUC merged with several university colleges into the University College of Southeast Norway (USN) in 2016.He has industrial experience from 1985 to 2003 with system design, both software and hardware development, within the aviation and maritime sectors. He has academic experience from 2003, and been an Associate Professor at USN since 2008, teaching in measurement techniques, software design and system design on B.Sc. and M.Sc. levels. He supervises B.Sc., M.Sc. and PhD students.His main research areas are within smart cities and smart buildings, with focus on energy and welfare systems, soft sensors, sensor networks, and level measurements
University College of Southeast Norway, Telemark, Norway
Magne Waskaas is professor at University College of Southeast Norway, in automation. He graduated in physics at Norwegian University of Science and Technology, Trondheim and received a PhD in the field of magnetoelectrochemistry at the University of Oslo. His research interests include industrial measurements and effects of electric and magnetic fields on electrochemical processes.
University College of Southeast Norway, Telemark, Norway
Acknowledgement
The funding making this research possible was provided by the University College of Southeast Norway.
©2018 Walter de Gruyter Berlin/Boston
