Author(s): Stefan Schafer
Linked Author(s): Stefan Schäfer
Keywords: Sediment transport; Optical measurement; Calibration; Physical experiments; Reservoir management;
Abstract: The authors present a measurement method that makes it comparatively inexpensive to carry out continuous measurements of sediment transport and display them in real time with very little computing power. The measurement method is part of a system for the continuous diversion or recirculation of sediments discharged from a flume or a laboratory canal. The core of the measurement method is a camera-optical gray value comparison of 8-bit grayscale images of a transparent measuring field, taken with a standard industrial camera. The measuring field consists of two transparent glass plates, one above the other, with a thin film of particle-laden liquid flowing between them (e.g. sand grains or plastic granulate in water). For each image, the concentration of the sediment in the liquid at a discrete point in time is first determined with the help of gray value comparison. The sediment transport ṁs [kg/s] derives from a calibration function, which was determined in advance from long-term measurements with several constant sediment concentrations. Comparative validation measurements showed measurement errors of around 5 percent for sediment concentrations between 0 and 20 percent.