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乙炔常伴随变压器内放电性故障的出现而产生,为了检测乙炔气体,通过研究乙炔在近红外波段的红外吸收特性及深入分析光声池的设计,构建了用以检测乙炔的光声光谱气体检测装置。利用该装置,对分布反馈半导体激光器的辐射特性进行了实验分析,结果表明,激光器的辐射波长随工作温度或注入电流的升高以近似线性升高,且在工作温度下的变化梯度大于注入电流下的变化梯度;利用分布反馈半导体激光器的窄线宽和可调谐特性,测得乙炔分子在近红外区第一泛音带的R(4)、R(5)支光声光谱;对光声信号受气体体积分数、激光功率影响的实验分析表明,在低气体体积分数、低激光功率条件下,光声信号与气体体积分数、激光功率间具有良好的线性依赖关系,该装置对乙炔的最低体积分数检测限约为1.4×10-6。
In order to detect acetylene gas, the acetylene is often accompanied by the appearance of discharge fault in the transformer. In order to detect the acetylene gas, the infrared absorption characteristics of acetylene in the near infrared band and the design of the photoacoustic tank are analyzed in depth. Device. The experimental results show that the wavelength of the laser rises approximately linearly with the increase of the working temperature or the injection current, and the variation gradient of the laser diode at operating temperature is larger than the injection current The R (4) and R (5) photoacoustic spectra of acetylene molecules in the first overtone band in the near infrared region were measured by using the narrow linewidth and tunable characteristics of the distributed feedback semiconductor laser. Experimental analysis of the gas volume fraction and laser power shows that there is a good linear dependence between photoacoustic signal and gas volume fraction and laser power at low gas volume fraction and low laser power. The fractional detection limit is about 1.4 × 10-6.