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 plano-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 micro l.
1998 IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 45:1331-1340
© 1998, by The Institute of Electrical and Electronics Engineers, Inc. All rights reserved.