Key Laboratory of Intelligent Manufacturing Technology, Ministry of Education, College of Engineering, Shantou University, 243 Daxue Road, Shantou 515063, China.
State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2023 Jan 15;285:121908. doi: 10.1016/j.saa.2022.121908. Epub 2022 Sep 22.
Highly sensitive and stable measurement of methane (CH) and acetylene (CH) based on a novel dual-channel off-beam quartz-enhanced photoacoustic spectroscopy and time-division multiplexing technique was realized by a compact 3D-printed gas cell with a size of 3 × 2 × 1 cm. Two near-infrared distributed feedback diode lasers were employed to target the CH absorption line at 6046.9 cm and the CH absorption line at 6521.2 cm, respectively. Second-harmonic wavelength modulation spectroscopy method was used for photoacoustic signal recovery. A minimum detection level of ∼ 7.63 parts-per-million in volume (ppmv) for CH and a level of ∼ 17.47 ppmv for CH were achieved with a 1 s lock-in integration time, leading to a normalized noise equivalent absorption (NNEA) coefficient of 7.24 × 10 cm·W·Hz and 3.73 × 10 cm·W·Hz for CH and CH, respectively. Allan-Werle deviation analysis was employed to evaluate the stability and the minimum detection limit (MDL) of the developed photoacoustic CH/CH dual-gas photoacoustic sensor. Owing to the high stability of the developed sensor system, an MDL of ∼ 0.73 ppmv and an MDL of ∼ 1.60 ppmv with a 100 s averaging time were achieved for CH and CH, respectively.
基于新型双通道离轴石英增强光声光谱和时分复用技术，通过尺寸为 3×2×1 cm 的紧凑型 3D 打印气体池，实现了对甲烷（CH）和乙炔（CH）的高灵敏度和稳定测量。该系统采用了两个近红外分布式反馈二极管激光器，分别针对 6046.9 cm 的 CH 吸收线和 6521.2 cm 的 CH 吸收线。采用二次谐波波长调制光谱法进行光声信号恢复。在 1 s 的锁定积分时间下，CH 的最小检测水平达到约 7.63 体积ppm（ppmv），CH 的水平达到约 17.47 ppmv，归一化噪声等效吸收（NNEA）系数分别为 7.24×10 cm·W·Hz 和 3.73×10 cm·W·Hz。采用 Allan-Werle 偏差分析评估了所开发的光声 CH/CH 双气体光声传感器的稳定性和最小检测限（MDL）。由于开发的传感器系统具有高稳定性，在 100 s 的平均时间下，CH 和 CH 的 MDL 分别达到约 0.73 ppmv 和约 1.60 ppmv。
