Instrumentation and Measurement Physics(DIMP)
Physique des instruments et mesures (DPIM)
Kirk H. MICHAELIAN
Natural Resources Canada
Dispersive Photoacoustic Spectroscopy of Hydrocarbons
A dispersive photoacoustic (PA) spectroscopy system was constructed from a 450-W Xe lamp, a 0.19-m monochromator fitted with three interchangeable gratings, a mechanical chopper, and a commercial PA cell. After preamplification, signals were detected with a lock-in amplifier.
Magnitude and phase spectra of a series of opaque, viscous hydrocarbon liquids revealed the existence of near-ultraviolet absorption edges. The wavelengths of these features depended on sample boiling point and were consistent with data from conventional transmission spectroscopy. Dispersive visible and near-infrared PA spectra contained additional bands of interest.