Open photoacoustic cell for concentration measurements in rapidly flowing gas

János Fekete; Péter Torma; Anna Szabó; Miklós Balogh; Csaba Horváth; Tamás Weidinger; Gábor Szabó; Zoltán Bozóki

doi:10.1016/j.pacs.2023.100469

Open photoacoustic cell for concentration measurements in rapidly flowing gas

Photoacoustics. 2023 Feb 26:30:100469. doi: 10.1016/j.pacs.2023.100469. eCollection 2023 Apr.

Authors

János Fekete¹, Péter Torma^{2

3}, Anna Szabó^{1

2}, Miklós Balogh⁴, Csaba Horváth⁴, Tamás Weidinger⁵, Gábor Szabó¹, Zoltán Bozóki^{1

2}

Affiliations

¹ Department of Optics and Quantum Electronics, University of Szeged, H-6720 Szeged, Hungary.
² ELKH-SZTE Research Group for Photoacoustic Monitoring of Environmental Processes, H-6720 Szeged, Hungary.
³ National Laboratory for Water Science and Water Security, Budapest University of Technology and Economics, Faculty of Civil Engineering, Department of Hydraulic and Water Resources Engineering, H-1111 Budapest, Hungary.
⁴ Department of Fluid Mechanics, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, H-1111 Budapest, Hungary.
⁵ Department of Meteorology, Eötvös Loránd University, H-1117 Budapest, Hungary.

Abstract

High temporal resolution concentration measurements in rapid gas flows pose a serious challenge for most analytical instruments. The interaction of such flows with solid surfaces can generate excessive aero-acoustic noise making the application of the photoacoustic detection method seemingly impossible. Yet, the fully open photoacoustic cell (OC) has proven to be operable even when the measured gas flows through it at a velocity of several m/s. The OC is a slightly modified version of a previously introduced OC based on the excitation of a combined acoustic mode of a cylindrical resonator. The noise characteristics and analytical performance of the OC are tested in an anechoic room and under field conditions. Here we present the first successful application of a sampling-free OC for water vapor flux measurements.