Long period grating pair chloride ion sensor for early corrosion prevention

Novel Sensor Design Using Photonic Crystal Fibres for Monitoring the Onset of Corrosion in Reinforced Concrete Structures

“…In addition, the sensing principle is usually intensity-based, which is known to suffer from limitations of low signal-to-noise ratio and inaccuracy due to fluctuations of the light source. The long period grating (LPG)-based technique has also been reported for monitoring the corrosion of reinforcement in concrete [8,9] which takes full advantage of fibre sensitivity to the refractive index variation of the surrounding environment caused by the changes in ion concentrations [10,11]. More recently, strain measurements using Fibre Bragg Gratings (FBGs) have been reported, in an attempt to directly monitor the corrosion at the steel-concrete interface [12][13][14][15][16][17].…”

Reinforced concrete structural corrosion monitoring using Hi-Bi photonic crystal fibres in a fiber loop structure

“…However, this technique, based on optical intensity measurement, has shown limitations in terms of low signal-to-noise ratio and inaccuracy due to fluctuations in the light source. Long period grating (LPG)-based techniques have also been reported for monitoring the corrosion of reinforcement in concrete which take full advantage of fibre sensitivity to the refractive index variation of the surrounding environment caused by the changes in ion concentrations [4]. More recently, strain measurements using Fibre Bragg Gratings (FBGs) have been reported, in an attempt to directly monitor the corrosion at the steel-concrete interface [5][6].…”