What are some limitations or drawbacks compared with metal foil strain gages?
FBG patches tend to be larger, thicker, and much stiffer than metal foil strain gages. Therefore, there is more reaction force to the specimen, and FBG sensors cannot be applied to small curvatures. A great variety of metal foil rosette strain gages are available, while the few available FBG rosettes tend to be rather large. FBG sensors normally cannot provide self-compensation of apparent strain. And, of course, in cases of small test installations with small or medium numbers of measuring points, FBG solutions are more expensive than comparable strain-gage systems. Q: What are some challenges for FBG sensor data acquisition? A: A main challenge is to get high resolution, high stability, and high measuring speed simultaneously. A strain value of 1 mm/m changes the wavelength of an FBG by only 1.2 pm; that’s only 0.8×10-6 of the fundamental wavelength of 1550 nm. If a resolution of 0.1 mm/m or even 0.01 mm/m is required, such as in the building of precise transducers, then resolution a
