DocumentCode :
3456052
Title :
An acoustic plate mode sensor for aqueous mercury
Author :
Schweyer, M.G. ; Andle, J.C. ; McAllister, D.J. ; French, L.A. ; Vetelino, J.F.
Author_Institution :
BIODE Inc., Bangor, ME, USA
Volume :
1
fYear :
1996
fDate :
3-6 Nov 1996
Firstpage :
355
Abstract :
Many industrial processes have resulted in mercury contamination of soils and potentially of the surrounding groundwater. The remediation efforts for these sites requires a method of long-term verification. Sensors with lifetimes of months to years of operation without operator intervention are required to monitor these sites. One sensor geometry which is capable of detecting relevant concentrations of aqueous mercury while withstanding typical environmental conditions is the acoustic plate mode (APM) microsensor. This piezoelectric sensor protects the electronics from the potentially corrosive aqueous fluid environment while providing a significant interaction with the fluid. Gold films are employed to accumulate the mercury via surface amalgamation. The added mass is measured as a change in the resonant frequency of the piezoelectric element. A reference device helps compensate environmental factors, such as temperature drift, solution effects (viscosity, density and conductivity changes) and pressure fluctuations. Initial results indicate a sensitivity of approximately 10 ng/ml (10 μg/L) which is approximately five times the limit imposed by the safe drinking water act (SDWA). Research is currently underway to lower this detection limit to allow the sensor to meet the requirements of environmental sensing, wastewater monitoring and drinking water testing
Keywords :
chemical sensors; compensation; environmental factors; mercury (metal); microsensors; monitoring; piezoelectric transducers; Au; Au films; Hg; acoustic plate mode sensor; aqueous Hg; corrosive aqueous fluid environment; drinking water testing; environmental conditions; environmental sensing; microsensor; piezoelectric sensor; pressure fluctuations; resonant frequency; sensitivity; shear horizontal type; surface amalgamation; temperature drift; wastewater monitoring; Acoustic measurements; Acoustic sensors; Acoustic signal detection; Contamination; Geometry; Gold; Microsensors; Piezoelectric films; Protection; Soil;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Ultrasonics Symposium, 1996. Proceedings., 1996 IEEE
Conference_Location :
San Antonio, TX
ISSN :
1051-0117
Print_ISBN :
0-7803-3615-1
Type :
conf
DOI :
10.1109/ULTSYM.1996.583991
Filename :
583991
Link To Document :
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