This paper presents a brief review of major techniques applied in carbon dioxide
corrosion testing and monitoring. The focus is on the advantages and disadvantages of
variously designed testing apparatus and monitoring devices for localized corrosion
detection and assessment. Critical factors affecting the reliability and accuracy of major
corrosion testing techniques are briefly discussed. It is concluded that major reasons that
lead to reporting of inaccurate corrosion rates and patterns include: (i) limitations in
conventional electrochemical and nonelectrochemical methods for localized corrosion
measurements, and difficulties in data interpretation; (ii) challenges in simulating localized
corrosion mechanisms and their changes with the extension of corrosion testing.
Underdeposit corrosion testing is presented as a case to illustrate challenges in simulating
localized corrosion processes and mechanisms. Experiment data have been presented to
show potential difficulties of the artificial pit electrode method in evaluating underdeposit
corrosion and its inhibitors. The wire beam electrode method has been used to study
underdeposit corrosion with and without inhibitor present. Several interesting corrosion
mechanisms have been revealed at different stages of underdeposit corrosion processes.
Keywords: Corrosion testing and monitoring, carbon dioxide corrosion, electrochemical
methods, corrosion sensor, localized corrosion, corrosion inhibition