Bless: A fiber optic sedimeter

The working principle for a conceptually new sedimeter (BLESS — Bed LEvel Seeking System) is presented and experimentally tested. The proposed approach relies on the adoption of fiber Bragg grating arrays to measure temperature: the environment identification (flowing water vs. saturated soil) is achieved by means of the different temperature response to heat dissipation. The arrangement is potentially very robust with respect to the aquatic environment, as all vulnerable equipments are located above the water level, while only fiber optic and insulated electric wires with low DC voltage are immersed into water. A simple conceptual model can describe the thermodynamic response of the system. Experimental results fully confirm expectations. The technology can be considered ready for field installations.

► A new sedimeter for scour measurement has been designed and tested.
► Advantages of this sedimeter based on fiber Bragg grating arrays are shown with respect to traditional devices.
► Device numerical models fully agree with experimental results, allowing for a reliable design of in-field future installations.