Coating Health Monitor System with Fiber Optic Sensors

Coatings that protect the corrosion of critical infrastructure face harsh aggressive environments that lead to their degradation and failure. Monitors that can effectively assess the health of paint coatings on critical structures should provide valuable continuous information on the current state of the coating. As coatings undergo various stages of degradation, information on successive stages of this process is imperative to provide a complete picture of the coating health. Tanner Research proposes a method based on environmentally-stable, fiber optic sensors to monitor degradation mechanisms both at the microscopic as well as the macroscopic level in the coating, thereby providing a complete assessment of the coating decay. At the microscopic level, near infrared (NIR) spectral signatures of precursor chemical species and products of coating degradation will be monitored. Macroscopic degradations such as blistering and delamination will be sensed by bending induced transmission losses in the fiber. Together, these provide a complete description of the current health of the coating. In Phase I of this effort, we will demonstrate the feasibiliy of a fiber optic sensor embedded inside the coating matrix to provide information relevant to and correlated with coating degradation. Optical signatures that correspond to coating degradation will be identified and monitored using the fiber optic sensor.