Long period grating fiber optic sensors coated with gold film and pulse electroplated iron carbon layer for reinforcing steel corrosion monitoring

• Published in: IEEE transactions on instrumentation and measurement 2023-01, Vol.72, p.1-1
• Main Authors: Zhou, Guoshuai, Tang, Fujian, Li, Gang, Lin, Zhibin, Li, Hong-Nan
• Format: Article
• Language: English
• Subjects: Corrosion; Direct current; Electrochemical deposition; Fiber optics; Gold; Graphene; Iron-carbon coating; linear polarization resistance; long period grating fiber sensor; Microscopy; Monitoring; Nanowires; Optical fiber sensors; Optical fibers; Optical instruments; Penetration depth; pulse electroplating; reinforcing steel corrosion; Reinforcing steels; Sensors; Steel
• ISSN: 0018-9456; 1557-9662
• DOI: 10.1109/TIM.2023.3284925

Long period grating (LPG) fiber sensors sputter coated with an internal gold film and pulse electroplated with an external iron-carbon coating are characterized for reinforcing steel corrosion monitoring. The surface feature of the gold film was analyzed by using atomic force microscopy, and the microstructure of the iron-carbon coating was examined by using scanning electron microscopy. The transmitted light spectrum of iron-carbon coated LPG fiber sensors was measured using an optical instrument and the corrosion degree of the iron-carbon coating is simultaneously measured with electrochemical methods. Experimental results demonstrate that corrosion of iron-carbon coating leads to a shift of the resonant wavelength, which is linearly correlated with the corrosion penetration depth of the iron-carbon coating. The fiber optic corrosion sensors investigated in this study exhibits better performance than those with inner silver nanowire/graphene-based or silver-based films and outer direct current electroplated iron-carbon coatings.