REAL-TIME PHOTOACOUSTIC SIGNAL ANALYSIS IN A GAS-PHASE SPECTROPHONE -A FEASIBILITY STUDY

A digital signal processing (DSP) system has been constructed for the acquisition of intracavity dye laser photoacoustic spectra (ICL-PAS), The DSP system permits observation of the real-time PA pulse, an arran gement which facilitates the adjustment of all spectral acquisition pa rameters as well as signal processing for noise reduction, Sample spec tra of the real-time PA pulse illustrate the improvements possible wit h Fourier filtering and time-averaging. Spectra of the region of the f ifth CH stretching overtone of ethene, benzene, and propane in the gas phase are presented, The system offers significant potential advantag es in signal quality. signal processing, and construction cost over th e more conventional lock-in amplifier detection method.