FSI strain sensor array, fiber-optic sensor / 2071A

The FSI strain sensor array is a fiber-optic sensing system based on Fiber Segment Interferometry (FSI) that enables distributed highly sensitive strain measurements over a large dynamic range of up to 10,000 µε. The sensor consists of multiple configurable sensing segments (1 to 22 segments, 8 to 100 mm long) that allow both localized and distributed strain measurements within a single sensor. The system supports high sampling rates of up to 410 kHz when used with the compatible 2549A interrogator, enabling monitoring of fast dynamic events such as acoustic emission. Thanks to its very small diameter (155 µm) and extremely low weight (1 g/m), the sensor can be integrated into structures with minimal influence on their mechanical properties and is suitable for installations where space is limited. The fiber-based design makes the sensor non-invasive and fast to install, while its dielectric nature ensures intrinsic immunity to electromagnetic interference (EMI). This combination of high sensitivity, flexible configuration, and reliable operation makes FSI strain sensors well suited for structural monitoring and dynamic measurement applications.