Ultrasonic measurements of suspended sediments: A concentration profiling system with attenuation compensation

This paper presents a novel approach to the profiling of suspended sediments, in which attenuation compensation of the backscatter profile is achieved without prior information on particle size or size distribution profiles. This new instrument employs two opposing ultrasonic transducers to measure not only the backscattering coefficient profile, but also the path integrated attenuation coefficient. An iterative algorithm is developed to solve the equations involved. Experimental investigations in a mixing tank and an open channel show that the system works well for concentrations up to 47 kg m(-3). This concentration is much higher than that which has previously been measurable without including attenuation compensation.