CorroWatch is a monitoring system for early warning of the onset reinforcement corrosion. It can also be used to estimate the time before corrosion of reinforcement begins so that corrective measures may be taken early enough to minimize repair costs.
Principle The CorroWatch is a multi-probe device consisting of four black steel bars acting as anodes and a noble metal as the cathode. The bars are positioned at different elevations and when cast into concrete, CorroWatch allows determination of corrosion activity as a function of cover distance. In addition, the ERE-Probe (pg. 58) may be cast into the concrete for monitoring the potentials of the four black steel anodes of the CorroWatch.
By monitoring the potential drop of the four anodes as a function of time, the gradual penetration of the depassivation front can be tracked and the service life can be estimated reliably, based on the actual depth of the reinforcement.
Accuracy In terms of measuring the ingress of the depassivation front, the CorroWatch is just as accurate as if the penetration were monitored using normal black-steel reinforcement.