Capteurs Distribués
Technologies avancées de fibres optiques offrant une surveillance continue le long des structures entières
La détection par fibre optique distribuée (DFOS) représente une approche révolutionnaire de la surveillance de la santé structurelle, transformant une fibre optique standard en milliers de capteurs virtuels. Contrairement aux capteurs ponctuels traditionnels qui mesurent à des emplacements discrets, les systèmes DFOS fournissent des mesures continues et spatialement distribuées sur toute la longueur de la fibre, de quelques mètres à des dizaines de kilomètres. Cette technologie permet une compréhension sans précédent du comportement structurel, détectant des anomalies localisées qui pourraient être manquées par les systèmes de surveillance conventionnels tout en fournissant simultanément des données de réponse structurelle globale.
Avantages Technologiques
- Des milliers de points de mesure avec un seul câble
- Couverture de grandes structures (jusqu'à 70km)
- Immunité aux interférences électromagnétiques
- Pas de composants électriques aux points de détection
- Mesure à la fois de la déformation et de la température
- Haute résolution spatiale (jusqu'à 1cm)
Pourquoi Choisir la Technologie DFOS?
La détection par fibre optique distribuée offre des avantages uniques pour la surveillance des infrastructures à grande échelle:
- Achieve up to 10,000+ measurement points with a single fiber cable
- Detect localized damage or anomalies anywhere along the structure
- Monitor inaccessible areas like tunnel linings and buried pipelines
- Immune to electromagnetic interference and lightning strikes
- Intrinsically safe for hazardous environments (no electrical signals)
- Simultaneous strain and temperature measurements
Applications
Long-Span Bridges
Monitor entire bridge decks, cables, and girders with continuous strain profiles revealing load distribution and structural response.
Tunnels & Underground Structures
Install fiber optics in tunnel linings to detect ground movement, convergence, and potential structural issues along the entire length.
Pipeline Monitoring
Continuous leak detection, temperature monitoring, and third-party intrusion detection along oil, gas, and water pipelines.
Dams & Embankments
Monitor deformation, seepage, and temperature gradients across large dam structures and earth embankments.
Railway Infrastructure
Track rail deformation, ballast settlement, and structural integrity of railway bridges and tunnels.
Our Distributed Sensing Technology
QUAD-S Monitoring deploys cutting-edge DFOS systems utilizing multiple interrogation techniques to meet diverse monitoring requirements. We provide complete turnkey solutions from fiber selection and installation to data interpretation and reporting.
BOTDA Systems
Brillouin Optical Time Domain Analysis for long-range (up to 50 km) strain and temperature monitoring with meter-scale spatial resolution.
OFDR Systems
Optical Frequency Domain Reflectometry providing millimeter spatial resolution for detailed strain mapping up to 70 meters.
DAS Systems
Distributed Acoustic Sensing for vibration and dynamic event detection along fiber cables up to 100 km.
Sensing Cables
Application-specific fiber optic cables optimized for strain coupling, temperature sensing, and long-term durability.
DFOS Technologies Comparison
| Technology | Range | Spatial Resolution | Measurement Type | Best Application |
|---|---|---|---|---|
| BOTDA | Up to 50 km | 0.5 - 1 m | Strain & Temperature | Long bridges, pipelines, tunnels |
| OFDR | Up to 70 m | 1 - 5 mm | Strain & Temperature | Detailed crack detection, joints |
| DAS | Up to 100 km | 5 - 10 m | Vibration & Acoustic | Intrusion detection, traffic monitoring |
Frequently Asked Questions
How does DFOS differ from traditional point sensors?
Traditional sensors measure at specific points (e.g., every 10 meters), while DFOS provides continuous measurements along the entire fiber—essentially thousands of sensors in one cable. This means you will not miss localized damage between sensor points.
Can DFOS measure both strain and temperature simultaneously?
Yes, BOTDA and OFDR systems measure both parameters simultaneously. Temperature compensation is crucial for accurate strain measurements, and DFOS provides this inherently.
What is the typical lifespan of a DFOS installation?
When properly installed and protected, fiber optic cables can last 20-50 years. The fibers themselves do not degrade, and interrogators can be replaced or upgraded without changing the installed cables.
Is DFOS suitable for dynamic measurements?
Standard BOTDA/OFDR systems are best for quasi-static measurements. For high-frequency dynamic measurements (vibrations, traffic), we recommend DAS (Distributed Acoustic Sensing) systems that can sample at kHz rates.
