This paper illustrates the application of the S-parameter concept for the analysis of the response of a piezoelectric sensor exploited for the discrimination of bentonite colloids of interest in construction engineering. The device is a millimeter-sized cantilever beam fully immersed in the suspension under examination. The beam is energized by a sweeping sinusoidal voltage: the electrical admittance is measured and the corresponding S-parameter is calculated. A procedure for the extraction of the lumped element circuital model is presented and the identification process clearly improves when the S-parameter response is used. Dealing with variable loading conditions, any change on density and/or viscosity of the interacting fluid determines a well-behaved variation of the frequency response associated with the principal modes of mechanical vibration. Inspection of response variations, especially in the S-parameter Smith chart and in the neighborhoods of resonance, allows the discrimination of different loading mixtures. Experimentation was carried out with 2.5%, 5.0%, 7.5% and 10.0% bentonite mixtures and the sensor has been able to fully discriminate between these different bentonite colloidal suspensions.
R. P. Paganelli, A. Romani, A. Golfarelli, M. Magi, E. Sangiorgi, M. Tartagni (2010). Modeling and characterization of piezoelectric transducers by means of scattering parameters. Part II: Application on colloidal suspension monitoring. SENSORS AND ACTUATORS. A, PHYSICAL, 160(1-2), 1-8 [10.1016/j.sna.2010.03.027].
Modeling and characterization of piezoelectric transducers by means of scattering parameters. Part II: Application on colloidal suspension monitoring
PAGANELLI, RUDI PAOLO;ROMANI, ALDO;GOLFARELLI, ALESSANDRO;MAGI, MICHELE;SANGIORGI, ENRICO;TARTAGNI, MARCO
2010
Abstract
This paper illustrates the application of the S-parameter concept for the analysis of the response of a piezoelectric sensor exploited for the discrimination of bentonite colloids of interest in construction engineering. The device is a millimeter-sized cantilever beam fully immersed in the suspension under examination. The beam is energized by a sweeping sinusoidal voltage: the electrical admittance is measured and the corresponding S-parameter is calculated. A procedure for the extraction of the lumped element circuital model is presented and the identification process clearly improves when the S-parameter response is used. Dealing with variable loading conditions, any change on density and/or viscosity of the interacting fluid determines a well-behaved variation of the frequency response associated with the principal modes of mechanical vibration. Inspection of response variations, especially in the S-parameter Smith chart and in the neighborhoods of resonance, allows the discrimination of different loading mixtures. Experimentation was carried out with 2.5%, 5.0%, 7.5% and 10.0% bentonite mixtures and the sensor has been able to fully discriminate between these different bentonite colloidal suspensions.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.