Novel Fiber Optic Sensor Probe with a Pair of Highly Reflected Connectors and a Vessel of Water Absorption Material for Water Leak Detection

Abstract

The use of a fiber optic quasi-distributed sensing technique for detecting the location and severity of water leakage is suggested. A novel fiber optic sensor probe is devised with a vessel of water absorption material called as water combination soil (WCS) located between two highly reflected connectors: one is a reference connector and the other is a sensing connector. In this study, the sensing output is calculated from the reflected light signals of the two connectors. The first reflected light signal is a reference and the second is a sensing signal which is attenuated by the optical fiber bending loss due to the WCS expansion absorbing water. Also, the bending loss of each sensor probe is determined by referring to the total number of sensor probes and the total power budget of an entire system. We have investigated several probe characteristics to show the design feasibility of the novel fiber sensor probe. The effects of vessel sizes of the probes on the water detection sensitivity are studied. The largest vessel probe provides the highest sensitivity of 0.267 dB/mL, while the smallest shows relatively low sensitivity of 0.067 dB/mL, and unstable response. The sensor probe with a high output value provides a high sensitivity with various detection levels while the number of total installable sensor probes decreases.

Fiber-Optic Chemical Sensors and Biosensors (2013–2015)

“…Sensing the fraction of water in industrial solvents is critical not only to quality control and for safety reasons but also because water inhibits certain large-scale chemical reactions such as the Grignard reactions. A fiber-optic quasi-distributed sensor was developed for detecting the location and severity of water leakage . A vessel of water absorbing material called water combination soil (WCS) is deposited between two highly reflected connectors.…”

Distributed Humidity Sensing in PMMA Optical Fibers at 500 nm and 650 nm Wavelengths

“…One way of spatial multiplexing can be achieved by using the optical time domain reflectometry (OTDR) technique. The majority of OTDR-based humidity sensor implementations only allow for quasi-distributed measurement, for example involving induced macrobend loss [ 15 , 16 ] or recoating of silica fiber sections with a humidity-sensitive film [ 6 ]. Michie et al proposed a distributed water detection sensor design based on a water-swellable polymer provoking microbend optical loss along a silica optical fiber [ 17 ].…”

A Pipe-Embeddable Impedance Sensor for Monitoring Water Leaks in Distribution Networks: Design and Validation

“…In order to situate the results here reported with respect to the state of the art, we compare them with other techniques sensitive to small leaks (i.e., below 10 L), namely optical fibers [ 23 ], smart flow meters [ 24 ], and pressure sensing [ 25 ]. As summarized in Table 6 , impedance allows for monitoring of a long segment of pipe (up to 6 m), with a volume resolution of 0.5 L and a fast response time (~1 s).…”