Development and validation of a novel IoT-enabled electrical resistance system for non-destructive monitoring of atmospheric corrosion in steel structures

Effective corrosion monitoring in steel structures is crucial for sustainability and safety. Traditional electrochemical techniques, while common, are complex, require technician presence, and often lack accuracy in on-site quantification of corrosion rates and metal thickness loss. Additionally, these systems are costly, typically restricting their use to high-budget Structural Health Monitoring (SHM) projects and leaving conventional structures, such as steel bridges, without adequate monitoring. To address this gap, this paper introduces LEROY (Low-cost Electrical Resistance Ohm Analyzer), an Arduino-based, Internet of Things (IoT)-enabled device designed as a low-cost Data Acquisition (DAQ) system for atmospheric corrosion monitoring (ACM) of steel structures. LEROY achieves high resolution in the milliohm range and stable electrical resistance (ER) measurements, providing a novel solution for non-destructive testing (NDT). Validated through tests on known resistors and steel samples (AISI 304HN and AISI 1010), LEROY demonstrated high accuracy, with a maximum relative difference of 0.59% compared to a commercial resistance meter. A six-month accelerated corrosion test further confirmed its ability to track corrosion progression in metal thickness loss and provide real-time updates on relative corrosion rates. Combining wireless data streaming with affordability, LEROY supports SHM applications in budget-constrained infrastructure projects, enhancing the maintenance and safety of steel structures.