Acoustic microfiber sensor for gas pipeline leakage detection

Gas pipeline leakage can have significant environmental and industrial consequences, making it crucial to safely and efficiently detect such leaks. This study introduces a novel microfiber sensor based on the Mach-Zehnder structure, designed specifically for detecting small gas pipeline leaks. Initially, simulations were conducted to analyze the electric field distribution of the microfiber and the changes in sound pressure caused by pipeline leakage. Subsequently, the sensor was developed by encasing the microfiber in a double layer of polydimethylsiloxane (PDMS) and utilizing a nut with a hole as an external fixation device. To ensure accurate measurement of low-frequency acoustic pressure changes, the sensor's installation structure was integrated into the pipeline branch pipe. Experimental results demonstrate sensor's capability to detect acoustic signals generated by small leakage apertures measuring 0.1 mm in diameter. The received voltage signal exhibited a strong linear relationship with the size of the leakage aperture within the range of 0.1-6 mm, with a correlation coefficient exceeding 0.97. In addition, the sensor has reliable electrical safety and anti-electromagnetic interference capability.