Investigation of Distributed Optic Fiber Sensors Data Loss Due to Strain Gradient

Abstract

While measuring strain with OFDR sensors, local data loss might be observed despite adherence to the prescribed strain range. A possible cause of this loss is the magnitude of the local strain gradient. To verify this hypothesis, a custom sample is here designed to impose controlled strain gradients along the fiber path. The results confirm that the occurrence of data loss is influenced by the strain gradient. Additionally, it is found that the gage pitch of the optic fiber sensor plays a crucial role in the amount of data loss, with larger gage pitches showing a higher propensity for data loss, with a significantly lower threshold. These findings are consistent with observations from previous tests, including a four-point bending test. These results provide valuable insights into the limitations of OFDR fiber sensors under high strain gradient conditions and suggest that sensor design, including gage pitch, should be carefully considered in applications requiring precise strain measurements.