Design framework for a gas sensor based on an open photoacoustic resonator

Photoacoustic spectroscopy (PAS) is a well-established methodology for selectively sensing gaseous components. We present a design framework for a PAS sensor concept based on an open path detection geometry. The main purpose of the framework is the optimization of the open sensor geometry in harsh environments regarding flow speed and external noise. A first design study of a NO
₂
sensor including the technical realization was carried out. Good qualitative agreement of simulation and experiment was achieved, resulting in a theoretical limit of detection for NO
₂
as low as 5 ppm and providing a valid basis for future design optimizations for a multitude of analytes.