A Compact Subsampling Impedance Analyzer for Resonating Sensors
Sprache des Titels:
Englisch
Original Buchtitel:
Proceedings Sensor 2009
Original Kurzfassung:
Resonant sensors are used in a wide range of applications, e.g. as microbalances, chemical sensors in liquid and
gaseous environments, and for physical property sensing of liquid and viscoelastic media [1]. Our sensor electronics
[2] will be used for the readout of resonant sensors for liquid properties, which means that the Q–factor of such
devices is much lower than that of resonators operating in vacuum or gaseous environments. Hence oscillator
circuits are not preferable evaluation circuits for this application. Moreover, the damping may be frequency
dependent, so measurement over a wide frequency range is mandatory. Besides the common method of using
precise laboratory instruments for the measurement of the impedance spectra of these sensors, various approaches
have been reported [3–8]. For the interpretation of the measurement results not only the amplitude but also the
phase angle of the sensor impedance is of interest allowing a more accurate characterization of the resonance
behavior. In this paper we introduce the system concept and some measurement results in comparison to results
obtained with a commercial lock–in amplifier.