title: Attenuation of an ultrasonic beam by suspended particles and range of acoustic flow meters in sewer networks.
abstract: Ultrasonic flow meters are commonly used in wastewater management. Under certain circumstances, a reduction in the flow meter range may occur and cause significant error in the flow rate measurement. Attenuation due to suspended particles is one of the phenomena capable of reducing the flow meter range. The present paper examines attenuation resulting from re-suspended pond sediment over a wide range of concentration values. It appears that a formula established for sand suspensions provides a good estimate of ultrasound attenuation for these types of particles as well. Experiments conducted for wastewater under particle concentrations commonly encountered in sewer networks demonstrate that the attenuation by particles only contributes to a negligible extent towards intensity decay, in accordance with theoretical predictions. We also theoretically determine herein the operating conditions under which the range of an ultrasonic flow meter would be significantly reduced due to particle attenuation.
authors.affiliation: Département Géotechnique-Eau-Risque, Institut Français des Sciences et Technologies des Transports, de L'aménagement et des Réseaux, Route de Bouaye, CS 4, 44344 Bouguenais Cedex, France. frederique.larrarte@ifsttar.fr
authors.forename: Frédérique
authors.initials: F
authors.lastname: Larrarte
authors.forename: Pierre
authors.initials: P
authors.lastname: François
mesh_terms: D004323:Drainage, Sanitary / Q000379:methods*; D012722:Sewage / Q000737:chemistry*; D014465:Ultrasonics; D014865:Waste Disposal, Fluid / Q000379:methods; D014867:Water / Q000737:chemistry*; D014872:Water Movements
chemical_list: D012722:Sewage; D014867:Water