Differential photoacoustic spectroscopy for flow gas detection based on single microphone

Lujun Fu; Jiangshan Zhang; Yufeng Pan; Ping Lu

Photoacoustics (Aug 2024)

Differential photoacoustic spectroscopy for flow gas detection based on single microphone

Lujun Fu,
Jiangshan Zhang,
Yufeng Pan,
Ping Lu

Affiliations

Lujun Fu: Wuhan National Laboratory for Optoelectronics (WNLO) and National Engineering Research Center for Next Generation Internet Access System, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
Jiangshan Zhang: School of Electronic Information and Communications, Huazhong University of Science and Technology, Wuhan 430074, China; Corresponding author.
Yufeng Pan: Wuhan National Laboratory for Optoelectronics (WNLO) and National Engineering Research Center for Next Generation Internet Access System, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
Ping Lu: Wuhan National Laboratory for Optoelectronics (WNLO) and National Engineering Research Center for Next Generation Internet Access System, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China; Wuhan OV Optical Networking Technology Co., Ltd., Wuhan 430074, China; Corresponding author at: Wuhan National Laboratory for Optoelectronics (WNLO) and National Engineering Research Center for Next Generation Internet Access System, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China.

Journal volume & issue: Vol. 38
p. 100624

Abstract

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Differential photoacoustic spectroscopy (PAS) for flow gas detection based on single microphone is innovatively proposed and experimentally demonstrated. Unlike the traditional systems, only one microphone is used to suppress flowing gas noise. Wavelength modulation spectroscopy and second harmonic detection technique are applied in this PAS system with Q-point demodulation for acetylene (C2H2) gas detection. The experiment is conducted at 1 atm and 300 K. Different concentrations and flow rates of C2H2 from 0 sccm to 225 sccm are detected by using nitrogen (N2) as the carrier gas, which indicates that the system can respond well to flowing gases while maintaining the noise at the same level. The system response time decreases to 3.58 s while the gas velocity is 225 sccm. The detection limit of 43.97 ppb with 1 s integration time and normalized noise equivalent absorption (NNEA) coefficient of 4.0 × 10-9 cm-1 W Hz-1/2 is achieved at the flow rate of 225 sccm. The firstly proposed differential PAS based on single microphone greatly simplifies the system structure for flow gas detection, which provides a novel route for development of PAS with significant practical implementation prospects.

Published in Photoacoustics

ISSN: 2213-5979 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Science: Physics: Acoustics. Sound; Science: Physics: Optics. Light
Website: http://www.journals.elsevier.com/photoacoustics/

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