Modeling of a cylindrical resonant photoacoustic cell for high sensitive gas detection

Abstract

Photoacoustic spectroscopy (PAS) is a sensitive spectroscopic technique for trace gas sensing. As a key component of a PA sensor system, the cell constant of the cylindrical PA cell has been simulated for optimizing geometric design, and the acoustic pressure distribution and frequency response of the first longitudinal and radial modes are analyzed by using a self‐established algorithm model. According to the theoretical simulation, a resonant PAS sensor system was finally designed and evaluated at the first longitudinal mode for trace water vapor detection. Highly sensitive wavelength modulation spectroscopy and second harmonic detection technique was combined with PAS detection method for enhancing sensitivity. Allan deviation analysis indicates that a detection limit of 2 ppm for H2O could be achieved at an optimal integration time of 200 s, corresponding to a normalized noise equivalent absorption coefficient of 2.59×10−9W⋅cm−1Hz−1/2.

Advances in differential photoacoustic spectroscopy for trace gas detection

“…By means of the FDM technique, the DME-PA method avoids the use of two matched PACs and microphones, which can pursue more compact devices. Especially, it can be assumed that the use of quartz tuning forks in conjunction with novel light sources in DME-PA gas sensing systems [58][59][60][61][62][63][64][65][66] will lead to further…”

Recent advances and applications of off‐axis integrated cavity output spectroscopy

“…Laser-based spectroscopy has been demonstrated as an impressive tool in gas detection for its unique advantages of high sensitivity due to the species and internal-state selectivity, the nonintrusive and the quantitative character, as well as the fast time response. [1][2][3][4][5][6] Therefore, different approaches have been developed including laser direct absorption spectroscopy, 7,8 laser photoacoustic spectroscopy, [9][10][11][12] laser heterodyne spectroscopy, 13,14 and so forth. Since long interacting optical paths can effectively enhance the absorption signal according to the Beer-Lambert absorption law, multipass cells and resonant optical cavities-based technologies have been reported.…”

Mid‐infrared dissolved CO2 measurement system using the ultra‐compact multipass cell

“…2 The instrument based on Raman spectrum can be used in sea dissolved gas measurement, but the precision level of the instrument is only several parts per thousand. 3 Infrared absorption spectroscopy has been widely used in the field of trace gas detection, [4][5][6] which has advantage of the high precision and low cost and fast response time, and so on. [7][8][9][10][11][12] Tunable diode laser absorption spectroscopy (TDLAS) combines gas-liquid separation technology and deep-sea pressure resistance technology can be used in ocean dissolved CO 2 and carbon isotope detection to investigate natural gas hydrate.…”