title: A comparison measurement of nonlinear ultrasonic waves in tubes by a microphone and by an optical interferometric probe.
abstract: This paper deals with the analysis of ultrasonic fields inside waveguides generated by ultrasonic waves of high amplitude. These waves behave nonlinearly, so it is not possible to use standard linear equations to describe their behaviour. Therefore, we started with an experimental determination of the acoustic pressure of air in glass tubes. We chose two methods of measurement--by a microphone and by an optical interferometric probe. The conventional method by a microphone creates numerous problems, which can be avoided by using an optical method, a heterodyne laser interferometer.
authors.affiliation: Faculty of Electrical Engineering, Department of Physics, Czech Technical University in Prague, 166 27 Prague 6, Technicka 2, Czech Republic. slegroz@feld.cvut.cz
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Slegrová
authors.forename: Rudolf
authors.initials: R
authors.lastname: Bálek