Detection of ppb ozone using a dispersive surface acoustic wave reflective delay line with integrated reference signal

Abstract We report the characterization of a dispersive surface acoustic wave (SAW) delay line for the detection of ozone in air at parts-per-billion (ppb) concentrations. Augmenting recent developments in wireless SAW tag technology, we fabricated 435 MHz SAW devices and prepared them with polybutadiene coatings to serve as ozone-specific gas sensors. We measured the frequency dependent one-port electromagnetic scattering parameter, S 11 ( f ), at regular time intervals as the gas stream was adjusted using an EPA primary standard ozone calibrator. The temperature and relative humidity were also recorded using an independent commercial sensor. The data allowed us to estimate the sensitivity to ozone and to temperature, and we estimated other parameters useful in personal dosimetry: saturation dose, shelf life, and limit of detection. Finally, the built-in time multiplexed response provided reference data for first order temperature compensation, yielding a chemical limit of detection of 63 ppb-min ozone.

[1]  Mark R. Stolzenburg,et al.  A New, Portable, Real-Time Ozone Monitor , 2000 .

[2]  D. Neuberg,et al.  Outdoor/Indoor/Personal Ozone Exposures of Children in Nashville, Tennessee , 2004, Journal of the Air & Waste Management Association.

[3]  B. Rietz,et al.  Piezoelectric crystal detector for the monitoring of ozone in working environments. , 1985, Analytical chemistry.

[4]  Ikmo Park,et al.  A novel wireless, passive CO2 sensor incorporating a surface acoustic wave reflective delay line , 2007 .

[5]  Wolf-Eckhart Bulst,et al.  Mechanical sensors based on surface acoustic waves , 1994 .

[6]  Wen Wang,et al.  A novel 440 MHz wireless SAW microsensor integrated with pressure–temperature sensors and ID tag , 2007 .

[7]  Colin Campbell,et al.  Surface Acoustic Wave Devices for Mobile and Wireless Communications , 1998 .

[8]  Michael Brauer,et al.  Ozone personal exposures and health effects for selected groups residing in the Fraser Valley , 1997 .

[9]  A. Pohl.  A review of wireless SAW sensors , 2000, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[10]  A. Hearn.  The Absorption of Ozone in the Ultra-violet and Visible Regions of the Spectrum , 1961 .

[11]  P. Koutrakis,et al.  Evaluation of the harvard ozone passive sampler on human subjects indoors. , 1994, Environmental science & technology.

[12]  M. Thompson,et al.  The Potential of the Bulk Acoustic Wave Device as a Liquid-Phase Immunosensor , 1987, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.