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 $2.59\times {10}^{-9}W\cdot {\mathit{cm}}^{-1}{\mathit{Hz}}^{-1/2}$.

中文翻译：

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用于高灵敏度气体检测的圆柱形谐振光声电池的建模

光声光谱 (PAS) 是一种用于痕量气体传感的灵敏光谱技术。作为PA传感器系统的关键部件，对圆柱形PA单元的单元常数进行了优化几何设计的模拟，并使用自建算法分析了第一纵模和径向模的声压分布和频率响应模型。根据理论模拟，最终设计并评估了共振PAS传感器系统，用于痕量水汽检测的第一纵模。高灵敏度波长调制光谱和二次谐波检测技术与PAS检测方法相结合，提高了灵敏度。Allan 偏差分析表明 H ₂的检测限为 2 ppmO 可以在 200 s 的最佳积分时间实现，对应于归一化噪声等效吸收系数为 $2.59\times {10}^{-9}宽\cdot {\mathit{厘米}}^{-1}{\mathit{赫兹}}^{-1/2}$.