Fimiani, Fosca
(2016)

*Study of the calibration method of pressure-velocity probes and its application in a field of progressive plane waves.*
[Laurea magistrale], Università di Bologna, Corso di Studio in

Fisica [LM-DM270]

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## Abstract

This dissertation presents a calibration procedure for a pressure velocity probe.
The dissertation is divided into four main chapters. The first chapter is divided into six
main sections. In the firsts two, the wave equation in fluids and the velocity of sound in gases
are calculated, the third section contains a general solution of the wave equation in the case
of plane acoustic waves. Section four and five report the definition of the acoustic impedance
and admittance, and the practical units the sound level is measured with, i.e. the decibel scale.
Finally, the last section of the chapter is about the theory linked to the frequency analysis of a
sound wave and includes the analysis of sound in bands and the discrete Fourier analysis, with
the definition of some important functions.
The second chapter describes different reference field calibration procedures that are used to
calibrate the P-V probes, between them the progressive plane wave method, which is that
has been used in this work. Finally, the last section of the chapter contains a description of the
working principles of the two transducers that have been used, with a focus on the velocity one.
The third chapter of the dissertation is devoted to the explanation of the calibration set up and
the instruments used for the data acquisition and analysis. Since software routines were extremely
important, this chapter includes a dedicated section on them and the proprietary routines most
used are thoroughly explained. Finally, there is the description of the work that has been done,
which is identified with three different phases, where the data acquired and the results obtained
are presented. All the graphs and data reported were obtained through the Matlab® routine.
As for the last chapter, it briefly presents all the work that has been done as well as an
excursus on a new probe and on the way the procedure implemented in this dissertation could
be applied in the case of a general field.

Abstract

This dissertation presents a calibration procedure for a pressure velocity probe.
The dissertation is divided into four main chapters. The first chapter is divided into six
main sections. In the firsts two, the wave equation in fluids and the velocity of sound in gases
are calculated, the third section contains a general solution of the wave equation in the case
of plane acoustic waves. Section four and five report the definition of the acoustic impedance
and admittance, and the practical units the sound level is measured with, i.e. the decibel scale.
Finally, the last section of the chapter is about the theory linked to the frequency analysis of a
sound wave and includes the analysis of sound in bands and the discrete Fourier analysis, with
the definition of some important functions.
The second chapter describes different reference field calibration procedures that are used to
calibrate the P-V probes, between them the progressive plane wave method, which is that
has been used in this work. Finally, the last section of the chapter contains a description of the
working principles of the two transducers that have been used, with a focus on the velocity one.
The third chapter of the dissertation is devoted to the explanation of the calibration set up and
the instruments used for the data acquisition and analysis. Since software routines were extremely
important, this chapter includes a dedicated section on them and the proprietary routines most
used are thoroughly explained. Finally, there is the description of the work that has been done,
which is identified with three different phases, where the data acquired and the results obtained
are presented. All the graphs and data reported were obtained through the Matlab® routine.
As for the last chapter, it briefly presents all the work that has been done as well as an
excursus on a new probe and on the way the procedure implemented in this dissertation could
be applied in the case of a general field.

Tipologia del documento

Tesi di laurea
(Laurea magistrale)

Autore della tesi

Fimiani, Fosca

Relatore della tesi

Correlatore della tesi

Scuola

Corso di studio

Indirizzo

Curriculum E: Fisica applicata

Ordinamento Cds

DM270

Parole chiave

calibration, pressure-velocity probes, calibration method, acoustic, matlab

Data di discussione della Tesi

22 Luglio 2016

URI

## Altri metadati

Tipologia del documento

Tesi di laurea
(NON SPECIFICATO)

Autore della tesi

Fimiani, Fosca

Relatore della tesi

Correlatore della tesi

Scuola

Corso di studio

Indirizzo

Curriculum E: Fisica applicata

Ordinamento Cds

DM270

Parole chiave

calibration, pressure-velocity probes, calibration method, acoustic, matlab

Data di discussione della Tesi

22 Luglio 2016

URI

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