Tracking Down Rust (image) Fraunhofer-Gesellschaft Caption The passive sensor-transponder continuously monitors the protective coating of concrete bridges, allowing corrosion damage to be detected at an early stage. Credit Fraunhofer IMS Usage Restrictions The picture may be used for editorial purposes only. It is protected by copyright. The use is free of charge if the reference is mentioned. Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.