FIBER OPTIC SENSING
Sensing Technologies
- Point and Distributed Sensing
- Full-Service Solution Provider
- Independent Fiber Optics Expert
- Own Production Facilites
- In-House R&D and Testing Center
Technologies Overview
Fiber bragg grating
A Fiber Bragg Grating (FBG) is a microstructure with a few millimeters length within an optical fiber.
- Monitor well defined points
- Sensors for strain, temperature, tilt, acceleration, displacement, etc.
- Up to 40 multiplexed sensors per channel
- Fiber Bragg Grating Technology
- up to 16 channels on one interrogation unit
Distributed Sensing
- Monitor parameters on the complete length of the fiber
- Strain and / or temperature
- Up to 50km with one device
- Raman and Brillouin sensing technology
Acoustic Sensing
Distributed Acoustic Sensing (DAS) relies on Rayleigh backscatter, which interacts with the optical fiber, exposed by acoustic waves.
- Monitor acoustic events
- Detect location with accuracy 1-10m
- Up to 50 km with one device
- Rayleigh sensing technology
Why Fiber Optics
Lifetime
Almost no maintenance. Cable lifetime >20 years
Passive Sensor
No electrical power at the measurement point
Long distance
Remote monitoring (50 km and more)
High sensitivity and accuracy
At sensing point Insensitive lead in to reduce disturbances
Harsh and explosive environments
Resistant to corrosion, lightning, etc.
Immune to EMI
Electromagnetic interference
FBG Sensing
A Fiber Bragg Grating (FBG) is a sensitive optical microstructure of a few millimeters length which is integrated into a standard single-mode fiber.
Fiber Bragg Gratings
- Act like a wavelength selective mirror
- Each sensor has his own unique wavelength
- Sensitivity to strain and temperature is intrinsic to FBGs
- Individual packaging and mechanics to measure different parameters
- Sensors can be close as a few mm or separated by a few km
System
- Monitor well defined points
- Sensors for strain, temperature, tilt, acceleration, displacement, etc.
- Individual sensor housing or direct integration into cables / FIMTs
- Up to 40 multiplexed sensors of different type per channel
- up to 16 channels on one interrogation unit
Case Studies
Canara bridge
- NBG provided system design / installation support and comissioning of FiberGuard system
- Integration with 72 video cameras (37 robotic ones) and automatic perimeter lighting
- Security alerts within 5 sec. of attempt and accuracy of 8 meters
- Keyprocessor access control system / Satel security alarm system / Commend intercom system
GMÜND
- 500m PeriGuard Fence based installation
- 200m FBGuard Fence based installation
- Roads and Structural Health Monitoring, Cabinet / manhole monitoring, Temperature sensing
DAS Sensing
A Distributed Acoustic Sensing (DAS) is a microstructure with a few millimeters in length.
Comparison
David Laister
Fiber Optic Sensing Specialist.
“Challenge me with your project”
