Detection of water leakage location by utilizing optical time domain reflectometery (OTDR) technique

Abstract

Over the past few decades, much research has been done on distributed sensors as well as on the fabrication of an optical fiber sensor to detect vibration, cracks on buildings and other environmental parameters. This project investigated the ability of optical fiber sensor and Optical Time Domain Reflectometer (OTDR) to detect the location of water leakage. The sensor was constructed using a medium density fibreboard (MDF) wood, steel water pipeline and helicoidal steel wire to produce microbending on an optical fiber. The constructed sensor was evaluated using Optical Time Domain Reflectometer (OTDR) with different types of fiber (50/125 multi mode optical fibre (MMOF), a 62.5/125 multi mode optical fiber (MMOF) and a 8/125 single mode optical fibre (SMOF). When water was absorbed, the MDF wood became swollen and introduced microbending on the optical fiber resulting in transmission loss. This permits the detection of the water leakage location. OTDR trace was obtained for sensor at different location along different fibers. For each sensor location the losses with immersion time in water was recorded. The sensor constructed was able to detect two leakage points simultaneously. The minimum distance between two leakage points at the early stage of immersion time was 8 m but at longer immersion time this distance increases to 20 m. The sensor was able to detect the leakage points as early as 10 min