Particle & Particle Systems Characterization, Vol.23, No.3-4, 313-320, 2006
Electrical resistance tomography for suspended sediment measurements in open channel flows using a novel sensor design
Understanding the transport and deposition of sediment (such as sand and clay) is essential to allow the modelling and prediction of sediment dispersal, and the development of depositional morphology, within modern environments and ancient sedimentary basins. Electrical Resistance Tomography (ERT) has previously been used to provide a measure of particle concentration within moving suspensions. ERT measurements normally employ electrodes around a circular boundary of a container that allows measurement of multiple projections. However, measuring the concentration of a flow in a rectangular channel without disturbing the flow cannot use these well-established sensor rings. This paper investigates the use of a linear sensor array in the channel bed, and a U-shaped sensor array in the channel bed and walls, to measure spatial and temporal gradients in sediment concentration/conductivity of a channellised flow. To overcome the problems with the effect of sediment-covered electrodes and the limited number of projection angles of a linear sensor configuration, the properties of a U-shaped sensor are explored. Due to the additional projection angles in a U-shaped sensor, improved reconstructions are obtained. This paper presents the first measurements of suspended sediment concentration and sediment deposition and test objects using linear and U-shaped tomographic sensors.