Improving the accuracy and operating range of quartz microbalance sensors by a purposely designed oscillator circuit

Author

Ferrari, Vittorio ; Marioli, Daniele ; Taroni, Andrea

Author_Institution

Dipt. di Elettronica per l´´Automazione, Brescia Univ., Italy

Volume

50

Issue

5

fYear

2001

fDate

10/1/2001 12:00:00 AM

Firstpage

1119

Lastpage

1122

Abstract

A method is presented to measure accurately the resonant frequency and to increase the functioning range of quartz microbalance sensors subject to heavy acoustic loading, such as encountered in in-liquid operation and with viscoelastic coating films. The method is based on an electronic circuit for the active cancellation of the crystal electrical capacitance, inserted in a phaselocked loop oscillator, which enables the tracking of the quartz series resonance with virtually zero error irrespective of the load. The principle is discussed, and experimental results confirming its successful application are presented

Keywords

crystal oscillators; electric sensing devices; microbalances; phase locked oscillators; acoustic loading; acoustic-wave transducer; active cancellation; crystal electrical capacitance; phase locked loop oscillator; quartz microbalance sensors; resonant frequency; tracking; viscoelastic coating films; zero error; Acoustic measurements; Acoustic sensors; Capacitance; Coatings; Elasticity; Electronic circuits; Frequency measurement; Oscillators; Resonant frequency; Viscosity;

fLanguage

English

Journal_Title

Instrumentation and Measurement, IEEE Transactions on

Publisher

ieee

ISSN

0018-9456

Type

jour

DOI

10.1109/19.963169

Filename

963169