What is the typical deviation when measuring the same physical quantity multiple times?
FBG sensors are known for their excellent measurement repeatability when measuring the same physical quantity multiple times. This high repeatability stems from several key characteristics of Fiber Bragg Grating technology:
- Wavelength Encoding: Unlike intensity-based sensors, FBG sensors encode the measured physical quantity (e.g., strain, temperature) as a shift in the Bragg wavelength. This wavelength shift is an absolute measurement, making it immune to power fluctuations in the optical fiber, connector losses, or light source intensity variations, which are common sources of error in other optical sensing methods.
- Intrinsic Stability: The Bragg grating itself is a permanent, stable structure inscribed within the optical fiber core. Once fabricated, its optical properties are highly stable over time, contributing to consistent measurements.
- Robust Packaging: The repeatability is further enhanced by the robust and application-specific packaging of the FBG element. For instance, OFSCN® Alloy Tube Packaged Fiber Bragg Grating strain sensors utilize full metal, seamless tube encapsulation, eliminating issues like adhesive creep that can affect long-term stability and repeatability in other sensor types. Similarly, our temperature sensors are designed for stable performance across their operating range.
The overall repeatability of an FBG measurement system is also influenced by the resolution and stability of the optical interrogator and the quality of the sensor’s calibration.
Below are examples of OFSCN products designed for high precision and stability, which inherently contribute to excellent measurement repeatability:
OFSCN® Alloy Tube Packaged Fiber Bragg Grating strain sensor
You can find more details here: OFSCN® Alloy Tube Packaged Fiber Bragg Grating strain sensor
OFSCN® 300°C Fiber Bragg Grating Temperature Sensor
You can find more details here: OFSCN® 300°C Fiber Bragg Grating Temperature Sensor
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