In situ acoustic backscatter: Characterising concentrated dispersions

Acoustic backscatter systems are an ultrasonic technique normally utilised for characterising particle size and concentration in large, dilute sediment suspensions. This book outlines their novel application for the in situ characterisation of concentrated dispersions of many arbitrary particles, including those in the colloidal size range. An alternative analysis technique is verified in conjunction with a correlative approach, for determining concentration from the measured acoustic backscatter strength. Sediment specific attenuation and backscattering constants are extracted directly from measurement, negating the requirement for heuristic expressions describing sediment specific attenuating and backscattering properties. The corresponding methods are then used to characterise the mobilisation and subsequent resettling of inorganic sediments mixed via jet impingement. Monodisperse colloidal organic latex particles are also manufactured via large-scale crossflow membrane emulsification, and characterised in situ. Additionally, attenuation and backscattering properties in the previously unmeasured colloidal size range, are fully normalised using the density ratio.