An Optical Sediment Sensor Integrated with Flow Velocity Measurement

Abstract

Flow velocity measurement is usually conducted with SSC measurement to assess sediment mass transport at a given time and depth. However, flow velocity and sediment concentration measurements that were conducted by different sensors could result in time mismatch, and high cost for equipment. An optical sediment sensor integrated with flow velocity measurement based on cross-correlation principle was tested in this study. Flow experiments were conducted in the laboratory to examine the sensor performance on velocity measurement using a closed circulation system. A solution of blue colorant, Brilliant Blue FCF, was used as an artificial absorbent to create signal variation pattern when water flow that carries the colorant passed through the sensor. Flow velocity was calculated based on the patterns using the cross-correlation principle. The results indicated that the cross-correlation-based velocity sensor was capable of measuring water flow velocity using the dye injection method.