The applicability of laser photoacoustic spectroscopy to the analysis of complex gas mixtures.
The quantitative analysis of complex gas mixtures, such as
the hydrazines and their air oxidation products, is of
paramount importance in closed cycle systems used, for
example, in submarines. A laser optoacoustic
(photoacoustic) spectrometer which is capable of detecting
these species at parts per billion levels has been developed
and a system for field use is described.
Laser optoacoustic measurements have been made on a range
of other species which absorb in the CO2 laser region of
9 - 11.3~m, including many atmospheric pollutants such as
the chlorofluorocarbons, perfluorocarbons, and some of the
new 'ozone friendly' propellant and refrigerant species.
Absorption coefficient data and limits of detection have
been established for many gaseous molecules, and a series of
optoacoustic cells has been designed, together with a novel
method for the generation of gaseous species at low
A CO2 laser based optoacoustic spectrometer is compared
favourably with a range of other current methods used to
detect low levels of atmospheric contaminants, and has been
shown to be a most suitable technique for the quantitative
detection of a wide range of substances at the parts per