title: Sensing the characteristic acoustic impedance of a fluid utilizing acoustic pressure waves.
abstract: Ultrasonic sensors can be used to determine physical fluid parameters like viscosity, density, and speed of sound. In this contribution, we present the concept for an integrated sensor utilizing pressure waves to sense the characteristic acoustic impedance of a fluid. We note that the basic setup generally allows to determine the longitudinal viscosity and the speed of sound if it is operated in a resonant mode as will be discussed elsewhere. In this contribution, we particularly focus on a modified setup where interferences are suppressed by introducing a wedge reflector. This enables sensing of the liquid's characteristic acoustic impedance, which can serve as parameter in condition monitoring applications. We present a device model, experimental results and their evaluation.
authors.affiliation: Institute for Microelectronics and Microsensors, Johannes Kepler University Linz, Altenberger Str. 69, A-4040 Linz, Austria.
authors.forename: Hannes
authors.initials: H
authors.lastname: Antlinger
authors.forename: Stefan
authors.initials: S
authors.lastname: Clara
authors.forename: Roman
authors.initials: R
authors.lastname: Beigelbeck
authors.forename: Samir
authors.initials: S
authors.lastname: Cerimovic
authors.forename: Franz
authors.initials: F
authors.lastname: Keplinger
authors.forename: Bernhard
authors.initials: B
authors.lastname: Jakoby
keywords: Characteristic acoustic impedance; Fluid properties; Liquid condition monitoring; Pressure waves; Ultrasonic sensors; Viscosity sensors
references.citation: J Chem Phys. 2009 Mar 28;130(12):124519
references.pmid: 19334863
references.citation: IEEE Trans Ultrason Ferroelectr Freq Control. 2010 Jan;57(1):111-20
references.pmid: 20040434