Next Article in Journal
A Study on Rational Function Model Generation for TerraSAR-X Imagery
Previous Article in Journal
Proof of Concept of Impact Detection in Composites Using Fiber Bragg Grating Arrays
Article

Practical Strategies for Stable Operation of HFF-QCM in Continuous Air Flow

1
Chemische Institute, Abteilung Elektronik, Rheinische Friedrich-Wilhelm-Universität Bonn, Gerhard-Domagk-Str. 1, Bonn D-55121, Germany
2
Institut für Organische Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, Mainz D-55128, Germany
*
Author to whom correspondence should be addressed.
Sensors 2013, 13(9), 12012-12029; https://doi.org/10.3390/s130912012
Received: 23 July 2013 / Revised: 1 September 2013 / Accepted: 1 September 2013 / Published: 9 September 2013
(This article belongs to the Section Chemical Sensors)
Currently there are a few fields of application using quartz crystal microbalances (QCM). Because of environmental conditions and insufficient resolution of the microbalance, chemical sensing of volatile organic compounds in an open system was as yet not possible. In this study we present strategies on how to use 195 MHz fundamental quartz resonators for a mobile sensor platform to detect airborne analytes. Commonly the use of devices with a resonant frequency of about 10 MHz is standard. By increasing the frequency to 195 MHz the frequency shift increases by a factor of almost 400. Unfortunately, such kinds of quartz crystals tend to exhibit some challenges to obtain a reasonable signal-to-noise ratio. It was possible to reduce the noise in frequency in a continuous air flow of 7.5 m/s to 0.4 Hz [i.e., σ(τ) = 2 × 10−9] by elucidating the major source of noise. The air flow in the vicinity of the quartz was analyzed to reduce turbulences. Furthermore, we found a dependency between the acceleration sensitivity and mechanical stress induced by an internal thermal gradient. By reducing this gradient, we achieved reduction of the sensitivity to acceleration by more than one decade. Hence, the resulting sensor is more robust to environmental conditions such as temperature, acceleration and air flow. View Full-Text
Keywords: quartz crystal microbalance; high fundamental frequency; allan deviation; turbulences; laminar flow element; acceleration sensitivity; temperature gradient quartz crystal microbalance; high fundamental frequency; allan deviation; turbulences; laminar flow element; acceleration sensitivity; temperature gradient
Show Figures

MDPI and ACS Style

Wessels, A.; Klöckner, B.; Siering, C.; Waldvogel, S.R. Practical Strategies for Stable Operation of HFF-QCM in Continuous Air Flow. Sensors 2013, 13, 12012-12029. https://doi.org/10.3390/s130912012

AMA Style

Wessels A, Klöckner B, Siering C, Waldvogel SR. Practical Strategies for Stable Operation of HFF-QCM in Continuous Air Flow. Sensors. 2013; 13(9):12012-12029. https://doi.org/10.3390/s130912012

Chicago/Turabian Style

Wessels, Alexander, Bernhard Klöckner, Carsten Siering, and Siegfried R. Waldvogel. 2013. "Practical Strategies for Stable Operation of HFF-QCM in Continuous Air Flow" Sensors 13, no. 9: 12012-12029. https://doi.org/10.3390/s130912012

Find Other Styles

Article Access Map by Country/Region

1
Only visits after 24 November 2015 are recorded.
Back to TopTop