Electrochemical techniques correlation study of on‐line corrosion monitoring probes

Abstract

Electrochemical techniques, such as linear polarization resistance (LPR), weak polarization (WP), electrochemical impedance spectroscopy (EIS), are effective tools to characterize instantaneous corrosion rates. In this work, LPR, WP, EIS techniques have been applied to calculate corrosion rates based on various electrode probe systems. These include classical three electrode systems (CTES), three identical electrode systems (Three‐IES), three electrode systems of stainless steel as reference Three‐ES (SS‐RE), two identical electrode systems (Two‐IES). Weight loss coupons were used to set a baseline for comparison between the different electrode probe systems. Polarization resistances calculated by EIS and LPR follows the order: CTES/Two‐IES/Three‐ES (SS‐RE) > Three‐IES. Corrosion rates measured by various techniques follow the order: LPR > WP > EIS >> coupon. Then effects of electrode systems and the electrochemical techniques are discussed, and combinations of electrode probe systems and electrochemical techniques are suggested for industrial applications.