基于煤矿瓦斯浓度的窄带光源谐波检测技术研究

Research on Methane Concentration Harmonic Detection Technology in Coal Mines Based on Narrow-band Light Source

在对煤矿瓦斯气体浓度的检测中,由于噪声、气体的吸收峰很窄、光源波长随温度的漂移等原因将引起测量的不稳定,通过采用对激光器的中心波长和气体吸收峰中心波长对准,测量光经过气体时的损耗就可以检测气体的浓度,利用一次谐波作为误差信号,可将光源精确地锁定在气体吸收峰上,并给出了窄带光源谐波检测的理论依据。实验结果表明,该方法可应用于甲烷气体浓度的光谱测量,它具有高精度、强选择性、快速响应等特点。

In detection of methane concentration in coal mines, absorption peak of noise and gas is narrow, and wavelength of light source drifts with temperature change and so on, result in instability of measurement value. By aligning central wavelength of laser and central wavelength of gas absorption peak, methane concentration can be detected by measuring light loss after it goes through gas, light source can be accurately locked at gas absorption peak by using a first harmonic as error signal. In the paper the theoretical basis of source harmonic detection based on narrow-band light source was given. The experimental results show that the detection method can be applied to spectra measurement of methane concentration. It has characteristics of high accuracy, strong selectivity and fast response.