title: Viscosity sensor utilizing a piezoelectric thickness shear sandwich resonator.
abstract: This paper describes a novel quartz crystal sensor for measurement of the density-viscosity product of Newtonian liquids. The sensor element consists of two piano-convex AT-cut quartz crystals vibrating in a thickness-shear mode with the liquid sample in between. This special set-up allows suppression of disturbing resonances in the liquid layer. Such resonances are generated in the common single-plate arrangements due to compressional waves caused by spurious out-of-plane displacements of the shear vibrating finite plate. The primary measurands of the sensor are the fundamental resonance frequency and the associated resonance Q-value, which are influenced by the viscously entrained liquid contacting the quartz surface. The sensor allows the measurement of samples with viscosities from almost zero (air!) up to 200 cP with a sample volume of 130 microl.
authors.affiliation: Institut für Theoretische Physik, Vienna University of Technology, A-1040 Wien, Austria.
authors.forename: R
authors.initials: R
authors.lastname: Thalhammer
authors.forename: S
authors.initials: S
authors.lastname: Braun
authors.forename: B
authors.initials: B
authors.lastname: Devcic-Kuhar
authors.forename: M
authors.initials: M
authors.lastname: Groschl
authors.forename: F
authors.initials: F
authors.lastname: Trampler
authors.forename: E
authors.initials: E
authors.lastname: Benes
authors.forename: H
authors.initials: H
authors.lastname: Nowotny
authors.forename: P
authors.initials: P
authors.lastname: Kostal