FBG applicability

1. Diagnostics of
structures and
geotechnical
monitoring
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Using fiber optic
technologies

2. Fiber optic sensing
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• Opposite features to telecom optical fiber
• Needs for react to:
• Bending
• Elongation
• Strain
• Pressure
• Etc.
Fiber Optic Sensing

3. Advantages of Fiber Optic Sensing
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Advantages
• High sensitivity and accuracy (µm)
• Monitor a multitude of sensors via a single fiber
• No installation of an expensive and complex sensor infrastructure on-site
necessary
• Resistant to: corrosion, chemicals, water and lightning
• Long-distance remote monitoring
• Passive: no need for electrical power at the measuring point

4. Advantages of Fiber Optic Sensing
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Advantages
• Small size, compact and lightweight
• Durability and reliability in demanding environments
• Multifunctionality: A large number of different parameters can be measured
• 100% passive: no need for electrical power at the measurement point
• Additional use of the already existing fiber-optic network

5. Sensor types
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Sensor types

6. Fiber Bragg Grating – FBG
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FBG Technology
• A Fiber Bragg Grating (FBG) is a type of distributed Bragg reflector
constructed in a short segment of optical fiber that reflects particular
wavelengths of light and transmits all others.

7. Advantages of FBGs
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FBG Advantages
• Immune to EMI/RFI
• Non-conductive and hence no special precautions needed for outdoor use or
usage under water
• Spark-free and hence safe in potentially explosive environments
• Long measurement distances
• Possible to multiplex, i.e. multiple sensors can be allocated within the same
optical fiber
• Excellent fatigue resistance: negligible effects for at least 2 million cycles for ±
0.24% straining

8. Different FBG sensors
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FBG Sensors
• Many different types of FBG sensors: Temperature, strain,
elongation, vibration, pressure, etc.
• Many different types of: mechanics, installation, cable
protection, etc.
• Proprietary development of new and custom-built
applications (asphalt sensor, tunnel lining, etc.)
• A lot of R&D activities

9. Various applications
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• Geo-technical monitoring
• Fundament stability monitoring
• Borehole deformation
• Mines
• Dams
• Buildings
• Telecom cabinets
• Manholes monitoring
• High temperature monitoring
• Power plants
• Tunnels
• Bridges
• Oil & Gas structures
• Wind & tidal energy structures
• Transportation
• Marine

10. www.safibra.cz
Safibra’s products
Monitoring systems
• SHM interrogation unit
• Perimeter security system
• Free space object monitoring

11. www.safibra.cz
system

12. SHM –Bridges monitoring
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Crack in the bridge fundament Real time response
Long-term observation Data for maintenance management

13. SHM –Bridges monitoring
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14. SHM – embankment monitoring
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Landslide caused by groundwater
Colored scale shows the degree of
deformation

15. Weight in motion system
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Parts:
• Fiber Optic FBG sensors in underlayer
• Detection Rings in underlayer
• Temperature sensors in underlayer
• System enclosure
Detection ring and FO sensor distances
All equipment in the bottom-layer of
asphalt and not extremely maintenance
sensitive as conventional

16. Weight in motion system
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Data Output
• Date/time
• Speed
• Length
• Distance between
vehicles
• Axle-weight
• Axle-group weight
• Total vehicle weight
• Axle distances
• Number of axles
• Category
• Bending front
• Weight per Wheel
• Width per Wheel
• Length per Wheel
• Wheel position
• Single or double Wheel
• Temperature under
asphalt top layer

17. Railways monitoring
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18. Cabinet / manholes monitoring
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19. Power pole /pylon
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20. Periguard
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Security system
Perimeter Monitoring and Protection
• Principle: Monitoring light changes in sensing fiber - specles
• Applications:
Fence Perimeter – chain link, ornamental, anti-climb
Underground perimeter – buried in gravel, sand, sod and
other materials

21. Object sense
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Objects monitor
Exact measurement of vertical change in position
• Principle: Change in intensity of reflected light is measured
• Applications:
– Displacement detection in geotechnical structures: rails,
walls, embankments, slopes, levees, roads, landfills
– Deformation of objects
– Monitoring of objects and buildings

22. www.safibra.cz
Safibra, s.r.o.
Černokostelecká 1621
251 01 Říčany
Czech Republic
Ing. Martin Dušek
Sales and project engineer
Fiber Optics & Photonics
Tel: +420 323 601 615
Fax: +420 323 606 007
Cell: +420 777 017 304
E-mail: martin.dusek@safibra.cz
www: http://www.safibra.cz
T h a n k y o u