Fiber optic strain gauge is welded directly into the surface of the metal structure (pipes, beams, etc.), and it has a protective silicone cover.Fiber optic strain sensors are durable and stable, widely used for civil engineering constructions, particularly they reinforce concrete structures exceptionally well.
Fiber Bragg Grating strain sensors demonstrate lots of advantages compared to the regular electrical strain gauges. Namely, they are immune to electromagnetic interference and power shortages. Compact size devices provide the most accurate measurements. FBGs are, literally, the best strain sensors right now.