Application Of Piezoelectric Transducers In Photoacoustic Spectroscopy For Trace Gas Analysis

Photoacoustic spectroscopy (PAS) is a boomingly developed spectroscopic method for trace gas analysis in the past decades. Unlike traditional laser absorption spectroscopy, an acoustic transducer is employed to detect the acoustic waves instead of optical waves. Microphone is a commonly used transducer to convert the acoustic signal into electrical signal, which is related to the gas concentration. In recent years, piezoelectric materials are playing important roles in the acoustic-to-electrical conversion process of photoacoustic system. In this article, recently used transducers in PAS such as quartz tuning fork, polyvinylidene fluoride, lead zirconate titanate, electromechanical film and LiNbO3, BiB3O6, NbCOB crystals are summarized and discussed in detail. The different spectrophone configuration, schematic diagram, and experimental system are reported. Side by side comparison is carried out to show the gas sensing performance of these piezoelectric transducers.