In-Fiber Optic Salinity Sensing: A Potential Application for Offshore Concrete Structure Protection

Area of Science:

• Materials Science
• Chemical Engineering
• Sensor Technology

Background:

• Concrete structures face significant corrosion challenges in marine environments due to saline solutions.
• Salt concentration is a critical factor accelerating concrete and steel reinforcement degradation.

Purpose of the Study:

• To develop and investigate an optical fiber-based sensor for in situ salinity measurement.
• To address the need for effective monitoring of corrosive agents in marine settings.

Main Methods:

• Utilized bundled multimode plastic optical fiber (POF) as the sensor probe.
• Employed a concave mirror reflector with an intensity modulation technique.
• Investigated a refractive index (RI) sensing approach, validated by experimental results.

Main Results:

• Achieved a maximum sensitivity of 14,847.486 per refractive index unit (RIU).
• Demonstrated sensor functionality at a refractive index of 1.3525.
• Confirmed analytical findings align with experimental data.

Conclusions:

• The proposed optical fiber sensor is effective for in situ salinity monitoring in liquids.
• This technology can contribute to enhanced protection strategies for concrete structures in marine environments.
• The sensor's high sensitivity and in situ capability offer practical advantages for corrosion monitoring.