FiberStrike®
Our systems for bridges utilize sensors with fiber Bragg gratings
- Established technology, internationally proven
- High resolution, accurate, field-reliable
- Small, lightweight, easy to surface-mount or embed into structures
- Simultaneous, real-time point sensing at speeds up to kHz
- Static and dynamic measurements with single instrument
- Wide temperature range: –65 to +300°C for standard fiber
- Radiation hardened fiber available
- Multiplexing – up to 40 –50 sensors per channel on a single fiber, regardless of sensor type
FBG Construction
- Using an intense UV source or high-power laser, a grating pattern is permanently “written” into a section of the glass fiber
- For broadband light input into fiber, the FBG reflects back one wavelength, called l Bragg
- All other wavelengths pass through FBG thus acts as a spectrally selective mirror
- Wavelength of Bragg is determined by the spacing (period) of the pattern
FBG Strain and Temperature Measurement
- Glass fiber is slightly elastic, so FBG can stretch
- If FBG stretches or changes temperature, FBG pattern pitch changes, causing l Bragg to shift
- Bragg is continuously sensed using an optical interrogator
- Bragg may be calibrated to quantify temperature and strain values
Multi-point Sensing on One Fiber
- Multiple FBGs, each tuned to a different l Bragg, may be written on one fiber
- FBGs operate independently and may be multiplexed on one fiber
