Detection of SF6 gas decomposition component H2S based on fiber-optic photoacoustic sensing
Detection of SF6 gas decomposition component H2S based on fiber-optic photoacoustic sensing
复制标题
基于光纤光声传感的SF6气体分解成分H2S检测
DOI：
10.1016/j.snb.2022.133174
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发表时间：
2022-12-20
影响因子：
8.4
通讯作者：
Xu, Lin
中科院分区：
文献类型：
--
作者：
Chen, Ke;Wang, Nan;Xu, Lin
提出了一种抗电磁干扰、本质安全的高灵敏度光纤法布里-珀罗(F-P)光声气体检测系统，用于SF6分解组分H2S的定量分析。掺铒光纤放大与声共振放大相结合以增强光声信号。光纤悬臂梁声传感器（FOCAS）用于感测微弱的光声信号。为了提高光声信号检测的灵敏度和稳定性，研究了SF6气体对FOCAS和光声池（PAC）响应的影响。当SF6为背景气体时，PAC的共振频率会大大降低，FOCAS的灵敏度会提高。激发光功率为1 W，平均时间为200 s，SF6背景中H2S气体的最低检测限（MDL）达到14 ppb，归一化噪声等效吸收（NNEA）计算为3.14 x 10(-9) cm(-1)中心点W中心点Hz（-1/2）。光声信号的激发增强和检测增强相结合，解决了传统传感器因H2S气体在近红外区域吸收系数低而难以提高检测灵敏度的问题。
A high-sensitivity fiber-optic Fabry-Perot (F-P) photoacoustic gas detection system with properties of antielectromagnetic interference and intrinsically safe was presented for quantitative analysis of SF6 decomposition component H2S. Erbium-doped fiber amplification was combined with acoustic resonance amplification to enhance the photoacoustic signal. A fiber-optic cantilever acoustic sensor (FOCAS) was used to sense weak photoacoustic signals. To enhance the sensitivity and stability of photoacoustic signals detection, the effect of SF6 gas on the responses of FOCAS and photoacoustic cell (PAC) was investigated. When SF6 is the background gas, the resonance frequency of the PAC will be greatly reduced and the sensitivity of the FOCAS will be improved. With the excitation light power of 1 W and an averaging time was 200 s, the minimum detection limit (MDL) of H2S gas in the SF6 background reached 14 ppb, and the normalized noise equivalence absorption (NNEA) was calculated to be 3.14 x 10(-9) cm(-1)center dot W center dot Hz (-1/2). The combination of excitation enhancement and detection enhancement of the photoacoustic signal solves the problem that the traditional sensor is difficult to improve the detection sensitivity due to the low absorption coefficient of H2S gas in the near-infrared region.