Bolivian fiber optic grating strain gauges are based on fiber Bragg grating (FBG) technology, offering high sensitivity, durability, and EMI immunity for structural strain monitoring.

Sensor Design and Principle

Bolivian FBG strain gauges operate on the fiber Bragg grating principle, where strain applied to the fiber changes the grating period, shifting the Bragg wavelength. This shift is measured optically to determine strain with high precision. The sensors are typically housed in stainless steel casings to protect the fiber and allow for robust installation on steel, concrete, or composite structures . Laminated or pre-mounted versions are available for stiff surfaces, ensuring accurate strain transfer and long-term stability .

Mounting and Installation

• Surface mounting: Sensors can be spot-welded or attached with epoxy to metal or concrete surfaces, allowing rapid installation and immediate use for welded sensors, while epoxy-mounted sensors cure in under 24 hours .
• Embedded installation: Some sensors can be embedded into composite or concrete structures for long-term monitoring .
• Anchoring points: The FBG is fixed between two anchoring points inside the housing, often with a sliding mechanism to accommodate structural movement .

Performance and Sensitivity

• High sensitivity: Capable of detecting minute strain variations, comparable to or exceeding traditional foil strain gauges .
• Temperature compensation: Can be paired with FBG temperature sensors to correct for thermal effects .
• Fatigue resistance: Offers significantly higher fatigue life than conventional strain gauges, suitable for long-term monitoring .
• EMI immunity: Optical operation ensures resistance to electromagnetic interference, ideal for industrial or high-voltage environments .

Applications

Bolivian FBG strain gauges are suitable for:

• Civil engineering: Bridges, dams, buildings, pipelines, and tunnels .
• Aerospace: Lightweight and compact sensors for aircraft structural monitoring .
• Industrial monitoring: Pipelines, reservoirs, and mechanical testing .
• Dynamic measurements: High-bandwidth applications where rapid strain changes occur .

Data Acquisition

FBG strain gauges require an FBG interrogator to convert optical wavelength shifts into strain measurements. Systems like the HYPERION interrogator are compatible with these sensors, providing high-performance solutions for structural health monitoring .

Summary of Key Specifications

These specifications make Bolivian FBG strain gauges highly reliable for long-term structural monitoring in harsh environments, providing precise, non-invasive, and durable strain measurements .