Viscosity sensor utilizing a piezoelectric thickness shear sandwich resonator.
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.
Thalhammer
R
R
Institut für Theoretische Physik, Vienna University of Technology, A-1040 Wien, Austria.
Braun
S
S
Devcic-Kuhar
B
B
Groschl
M
M
Trampler
F
F
Benes
E
E
Nowotny
H
H
Kostal
P
P