In long-term monitoring of dams or bridges, how is zero-drift guaranteed over several years?
For long-term monitoring of structures like dams and bridges, guaranteeing stability and minimizing drift over several years is a critical requirement. Fiber Bragg Grating (FBG) sensors inherently offer significant advantages in this regard, primarily due to their wavelength-encoded sensing principle.
Unlike electrical sensors whose signals are often intensity-based and susceptible to cable loss, connector degradation, and electromagnetic interference (EMI), FBG sensors encode the measured parameter (like strain or temperature) directly as a shift in the reflected Bragg wavelength. This wavelength is an absolute parameter, meaning the measurement is largely immune to fluctuations in light source intensity, fiber bending losses, or connector quality changes over time. This intrinsic characteristic contributes significantly to their long-term stability and resistance to drift.
Furthermore, FBG sensors are passive and intrinsically safe, making them robust for deployment in harsh or complex environments common in civil infrastructure.
For such applications, OFSCN® Alloy Tube Packaged Fiber Bragg Grating strain sensor and OFSCN® Fiber Bragg Grating Rebar Strain Gauge are commonly employed. The full metal encapsulation of the alloy tube sensors, for example, eliminates creep issues associated with adhesives, further enhancing long-term stability in structural applications.
Here are some standard product images:
You can find more detailed technical parameters on our website:
OFSCN® Alloy Tube Packaged Fiber Bragg Grating Strain Sensor
OFSCN® Fiber Bragg Grating Rebar Strain Gauge
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