The custom designed 2.8 kHz I-shape QTF is the optimal solution for dual gas detection employing quartz-enhanced photoacoustic spectroscopy (QEPAS).

Due to its geometrical properties, the 2.8 kHz QTF allows an efficient access to both the fundamental resonance mode and the first overtone. In this way, by means of simultaneous excitation of both the QTF resonance modes, it is possible to perform simultaneous gas detection.

Geometrical parameters as well as resonance properties of the custom QTF are reported in the following table. Additional information about the QTF and dual gas detection can be found here.