Persistent Link:
http://hdl.handle.net/10150/290608
Title:
Development of a photoacoustic gas detector
Author:
Angeli, Gyorgy Zsolt, 1954-
Issue Date:
1996
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The work detailed in the dissertation has resulted in a photoacoustic gas detector chamber that has been proved to be applicable for measuring very low concentration gas traces in ambient air. Calculation tools were developed for photoacoustic cell design, namely (i) a method estimating the acoustic quality factor of a cavity even for open configurations; and (ii) a technique calculating the effectiveness of light-sound energy conversion. An open, windowless resonant photoacoustic chamber was designed, that has high acoustic quality factor and good noise suppression. In such a chamber neither the window material nor the contamination adsorbed on the window surface can contribute to the generation of unwanted coherent background signal. The most important factor limiting the applications of high quality factor resonant photoacoustic cells is the resonant frequency shift due to the possible temperature and gas density variations in the chamber. To compensate this drift, a unique electronic resonance tracking system was constructed. A calibration experiment applying a grating tuned CO₂ laser was performed. The achieved detection limits were 8 ppb for ethylene, 50 ppt for sulphur-hexafluoride, and 11 ppm for carbon-dioxide. The reliability of the system was determined by three repeated measurement campaigns over a month, and it was found outstanding. The photoacoustic detector system was also tested against a conventional analytical technique and good agreement was found with the colorimetric ammonia detection method recommended by the NIOH.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Chemistry, Analytical.; Engineering, Electronics and Electrical.; Physics, Optics.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Electrical and Computer Engineering
Degree Grantor:
University of Arizona
Advisor:
Szilagyi, Mike N.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleDevelopment of a photoacoustic gas detectoren_US
dc.creatorAngeli, Gyorgy Zsolt, 1954-en_US
dc.contributor.authorAngeli, Gyorgy Zsolt, 1954-en_US
dc.date.issued1996en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe work detailed in the dissertation has resulted in a photoacoustic gas detector chamber that has been proved to be applicable for measuring very low concentration gas traces in ambient air. Calculation tools were developed for photoacoustic cell design, namely (i) a method estimating the acoustic quality factor of a cavity even for open configurations; and (ii) a technique calculating the effectiveness of light-sound energy conversion. An open, windowless resonant photoacoustic chamber was designed, that has high acoustic quality factor and good noise suppression. In such a chamber neither the window material nor the contamination adsorbed on the window surface can contribute to the generation of unwanted coherent background signal. The most important factor limiting the applications of high quality factor resonant photoacoustic cells is the resonant frequency shift due to the possible temperature and gas density variations in the chamber. To compensate this drift, a unique electronic resonance tracking system was constructed. A calibration experiment applying a grating tuned CO₂ laser was performed. The achieved detection limits were 8 ppb for ethylene, 50 ppt for sulphur-hexafluoride, and 11 ppm for carbon-dioxide. The reliability of the system was determined by three repeated measurement campaigns over a month, and it was found outstanding. The photoacoustic detector system was also tested against a conventional analytical technique and good agreement was found with the colorimetric ammonia detection method recommended by the NIOH.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectChemistry, Analytical.en_US
dc.subjectEngineering, Electronics and Electrical.en_US
dc.subjectPhysics, Optics.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineElectrical and Computer Engineeringen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorSzilagyi, Mike N.en_US
dc.identifier.proquest9713365en_US
dc.identifier.bibrecord.b34357725en_US
All Items in UA Campus Repository are protected by copyright, with all rights reserved, unless otherwise indicated.