Experimental investigations on gas detection using QCM sensor array and phase locked loop

Donald M Candelaria, University of Texas at El Paso


The need for new advances in gas detection and instrumentation has grown as a result of our civilization's progression into a new and dangerous world. As a consequence of this reality, the research summarized in this paper investigates the use of an array of coated quartz crystal microbalance (QCM) resonators, whose operation is utilized in a phase-locked loop compensation method. The current status of the QCM involves the simple case of open-loop operation, whereby continual use ultimately leads to sensor drift, irreversibility and hysterisis. This work proposes a QCM sensor array design whose resonant frequency is tracked by a variable feedback signal and the transduction feature is the continuous time voltage that results from a loop compensator (filter). Upon the design and construction of the sensor array, the system was tested for its dynamic response qualities and showed excellent damping characteristics to an impulsive perturbation. In addition, the array was tested against three (3) simple gases, CO, CO2 and O2 in order to assess its capabilities in detection. Results from the tests indicated very unique and noticeable effects from the gravimetric responses.

Subject Area

Mechanical engineering|Systems design

Recommended Citation

Candelaria, Donald M, "Experimental investigations on gas detection using QCM sensor array and phase locked loop" (2006). ETD Collection for University of Texas, El Paso. AAI1439484.