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Indexed by:会议论文

Date of Publication:2020-01-01

Included Journals:CPCI-S

Volume:11438

Key Words:photoacoustic spectroscopy; gas detection; Fabry-Perot; Parylene-C diaphragm

Abstract:A low-frequency photoacoustic (PA) sensor based on Parylene-C diaphragm for micro-leakage gas detection is presented. The overall structure of the sensor head includes a cylindrical brass shell, a Parylene-C diaphragm, and a PA cavity regarded as a Fabry-Perot (F-P) cavity as well. The volume of the PA cavity is only 74 mu L. A distributed feedback (DFB) laser is used as an acoustic excitation source. The PA pressure signal is obtained by measuring the deflection of the Parylene-C diaphragm using fiber-optic white-light interference (WLI) method. The PA sensor head is used for acetylene (C2H2) detection. A detection limit of 36 parts-per-billion (ppb) is achieved when the lock-in integration time is 1 s.