Monitoring Corrosion in Sacrificial Anodes With Pulsed Eddy Current and Electromechanical Impedance: A Comparative Analysis
Published in IEEE Sensors Journal, 2022
This paper directly compares two complementary non-destructive sensing approaches for tracking corrosion of zinc sacrificial anodes used in cathodic protection systems. Using the same accelerated impressed-current corrosion rig, the authors instrument anodes with a PZT transducer for electro-mechanical impedance (EMI) measurements and deploy a pulsed eddy current (PEC) probe nearby. EMI sensitivity is quantified via the RMSD of conductance spectra around resonant peaks, while PEC analysis uses area-under-the-curve (AUC) features of time-domain responses. Finite element simulations corroborate the experiments.
Key Findings
- EMI shows very high sensitivity to the onset (incipient) corrosion but its sensitivity declines nonlinearly over time due to delamination of corrosion by-products.
- PEC shows excellent linearity across the full accelerated-corrosion duration and is therefore better suited for tracking cumulative material loss.
- An effective monitoring strategy would exploit EMI for early detection and PEC for lifetime tracking.
- FEM models and experimental measurements agree with the observed comparative performance.
Recommended citation: Tamhane D., Banerjee S., Tallur S. Monitoring Corrosion in Sacrificial Anodes With Pulsed Eddy Current and Electromechanical Impedance: A Comparative Analysis. IEEE Sensors J. 2022;22(8):8147–8154. doi:10.1109/JSEN.2022.3157646.
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