TITLE:
Detecting Photoacoustic Signals of Sulfur Hexafluoride at Varying Microphone Positions
AUTHORS:
Wittmann S. Murphy, Han Jung Park
KEYWORDS:
Photoacoustic Effect, Sulfur Hexafluoride, Gas Detection, Microphone Placement, Acoustic Wave Formation
JOURNAL NAME:
Open Journal of Physical Chemistry,
Vol.6 No.3,
June
27,
2016
ABSTRACT: Photoacoustic spectroscopy was used to test the photoacoustic properties
of sulfur hexafluoride, an optically thick and potent greenhouse gas. While
exploring the photoacoustic effect of sulfur hexafluoride, the effects of the
position of the microphone within a gas cell were determined. Using a 35 cm gas
cell, microphones were positioned at 17.5 cm, the middle of the gas cell, 12.5
cm, 7.5 cm, and 2.5 cm from the window of the cell. From the photoacoustic
signal produced for each resonance frequency at each microphone position, the effects
of acoustic pressure produced at each position on the signal recorded were
observed. This is the first study done by experimentation with the
photoacoustic effect to show that standing waves have different amplitudes at
different microphone positions.