In quartz-enhanced photoacoustic spectroscopy (QEPAS) a quartz tuning fork (QTF) is utilized as resonator, as well as a transducer for a photoacoustic signal. QTFs are smaller than 5 mm in the longest dimension. Therefore, a QEPAS sensor enables significant potential for miniaturization, in contrast to conventional photoacoustic instruments.
In this work, a prototype for sensing particles with QEPAS is presented for the first time. Specifically, measurements of mass concentrations of soot from a miniCAST soot generator are compared with those from an AVL Micro Soot Sensor. The results show excellent linearity with the reference equipment over a wide range of mass concentrations of soot.