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dc.contributor.advisorBaker, Steven R.
dc.contributor.authorO'Malley, Sean P.
dc.dateJune 2001
dc.date.accessioned2012-08-22T15:34:23Z
dc.date.available2012-08-22T15:34:23Z
dc.date.issued2001-06
dc.identifier.urihttp://hdl.handle.net/10945/10940
dc.description.abstractThe acoustic impedance of a material describes its reflective and absorptive properties. Acoustic impedance may be measured in a wide variety of ways. This thesis describes the construction and testing of an acoustic impedance measurement tube which employs modem Fourier Transform techniques. Two methods are employed for acoustic impedance measurement using this apparatus. One technique uses a two-microphone continuous excitation method and the other uses a single microphone transient excitation method. Simple acoustic theory is used to derive equations for both methods. MATLAB computer programs are developed using these equations, to provide graphical results of acoustic impedance measurements over a frequency range for a given material, from raw data. A procedure is subsequently developed for using this apparatus using to make acoustic impedance measurements. The performance of this device is evaluated by making measurements utilizing both methods on three sample materials and also with the end of the tube open to the atmosphere (referred to as an open tube measurement). The open tube measurements are compared with theoretical values. The results using both approaches compared favorably with the open tube theoretical values. Additionally both approaches agreed reasonably well with each other for the three sample materials. Performance at frequencies below 500 Hz, however, yielded deficient results, indicating a need for development of a filter for better accuracy.en_US
dc.description.urihttp://archive.org/details/constructionndte1094510940
dc.format.extentxvi, 135 p. ; 28 cm.en_US
dc.rightsThis publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. As such, it is in the public domain, and under the provisions of Title 17, United States Code, Section 105, may not be copyrighted.en_US
dc.titleConstruction and testing of a modern acoustic impedance tubeen_US
dc.typeThesisen_US
dc.contributor.departmentApplied Physics
etd.thesisdegree.nameM.S. in Applied Physicsen_US
etd.thesisdegree.levelMastersen_US
etd.thesisdegree.disciplineApplied Physicsen_US
etd.thesisdegree.grantorNaval Postgraduate School (U.S.)en_US


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