天然气管道泄漏检测对人员安全、 环境保护以及国家财产安全等具有重要的意义, 但是, 由于管线跨越地域广阔, 操作工况以及环境情况复杂, 致使管线的泄漏检测存在困难。 文章介绍了一种基于波长扫描差分吸收光谱技术的移动式遥测天然气泄漏检测仪。 针对遥测回波吸收光谱特性, 提出了基于小波变换的改进型软阈值小波去噪方法, 实验分析能够提高系统信噪比3倍多, 同时在遥测光强为530 nA时, 可达到的最小遥测灵敏度为80 ppm·m, 系统采用波长扫描差分吸收光谱技术成功实现天然气泄漏的定量遥测与准确定位, 具有快速、 准确、 智能及安全等特点。

The detection of natural gas pipeline leak becomes a significant issue for body security, environmental protection and security of state property. However, the leak detection is difficult, because of the pipeline’s covering many areas, operating conditions and complicated environment. A mobile sensor for remote detection of natural gas leakage based on scanning wavelength differential absorption spectroscopy (SWDAS) is introduced. The improved soft threshold wavelet denoising was proposed by analyzing the characteristics of reflection spectrum. And the results showed that the signal to noise ratio (SNR) was increased three times. When light intensity is 530 nA, the minimum remote sensitivity will be 80 ppm*m. A widely used SWDAS can make quantitative remote sensing of natural gas leak and locate the leak source precisely in a faster, safer and more intelligent way.