The acoustic modes of a gaseous system in a cylindrical resonant cavit
y were excited with a tunable CO2 laser. The experimental setup is com
pletely controlled by a personal computer and virtualized as an applic
ation-oriented system by employing a so-called virtual instrumentation
software through a GPIB interface. A detailed description of the hard
ware arrangement. software virtualization, and the measured resonant p
rofile of the spectrophone is presented. (C) 1995 American Institute o
f Physics.