Fibre-optic sensors and infrastructure monitoring systems
Fibre-optic monitoring may use discrete sensing points or a continuous sensing fibre. FBG systems multiplex known measurement points for strain, temperature, displacement and other quantities. Distributed systems treat the fibre as a continuous sensor over long distances.
FBG sensors
Multiple points on one fibre, immunity to electromagnetic interference and suitability for harsh environments.
DAS systems
Distributed vibration and acoustic sensing for event detection along infrastructure routes.
DTS systems
Distributed temperature profiles over long distances for energy, industrial and linear infrastructure.
Structural and geotechnical monitoring systems
Structural monitoring commonly measures strain, temperature, displacement, force or vibration. Geotechnical projects add soil installation, cable protection, reference points and temperature compensation. Technology selection must therefore include sensor placement, cabling, mounting and alarm criteria.
FBG is appropriate when known measurement points and high-rate multichannel readout are required. Distributed sensing is useful when a continuous profile is needed or the event location is not known in advance. Both require a defined range, resolution, acquisition rate, long-term stability and data-system integration.
A useful enquiry includes the structure, mounting method, expected loads, route geometry and access conditions for the interrogator and associated equipment.
Fibre-optic monitoring for energy and industry
Fibre sensing is valued for passive measurement points, immunity to electromagnetic interference and long reach. DTS can monitor thermal profiles of power cables, pipelines and industrial processes. DAS records vibration and acoustic events, while FBG provides discrete strain and temperature measurement in structures and machines.
Detection and interpretation should be separated. The interrogator produces measurement data, while reliable alarms require baseline data, acceptance tests and validation under real operating conditions. Interfaces, archiving, time synchronisation and SCADA integration must also be specified.
Supporting field equipment is available under fibre meters and fusion splicers, while photonics laboratory equipment is listed under photonics and R&D.
How to select a fibre-optic monitoring system
Select the system for the phenomenon, not the acronym. Define the required range and accuracy, route length, event-location requirements, acquisition rate and environment.
- Discrete or distributed: known points or a continuous route profile.
- Measured quantity: temperature, strain, vibration, acoustic activity or a derived parameter.
- Spatial performance: reach, sampling interval and practical event-location resolution.
- Dynamics: response time and acquisition rate required by the event.
- Integration: data format, interfaces, alarms, archiving and time synchronisation.
Send a site diagram, route lengths, measurement ranges and expected data presentation.
Describe the asset and phenomenon
This makes it possible to compare FBG, DAS and DTS configurations.