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Novel fiber optic sensor probe with a pair of highly reflected connectors and a vessel of water absorption material for water leak detection.

Cho TS, Choi KS, Seo DC, Kwon IB, Lee JR - Sensors (Basel) (2012)

Bottom Line: 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 sensor probe with a high output value provides a high sensitivity with various detection levels while the number of total installable sensor probes decreases.

View Article: PubMed Central - PubMed

Affiliation: Center for Safety Measurement, Korea Research Institute of Standards and Science, 1 Doryong-dong Yuseong-gu, Daejeon 305-340, Korea. tscho@kriss.re.kr

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.

No MeSH data available.


Related in: MedlinePlus

Initial state and received signal of a sensor probe.
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f7-sensors-12-10906: Initial state and received signal of a sensor probe.

Mentions: We investigate, first, the tension effect of the metal wire because it may influence the bending loss before the response test of the sensor probes. Fortunately, the force of the WCS expansion is not enough to bend the metal wire because the wire is strongly tightened and very stiff. Thus, we neglect the wire tension effect on the bending loss due to the WCS expansion in this study. In addition, the single mode fiber (SMF) is tightly jacketed with 1 mm-diameter plastic tube. If we assume that bare fibers are employed, the bending loss will be much larger than that of the 1 mm-loose tube SMF because 1 mm plastic jacketed SMF is stiffer than bare fibers. In order to study the response of a sensor probe, at first, we test a single sensor probe with the sensor system. In the result of this test, the reflected signals from the reference connector and the sensing connector are −25.8 and −25.2 dB, respectively, at the initial state of no-water absorption shown in Figure 7. We can know that these two reflections are located 2 m apart from each other.


Novel fiber optic sensor probe with a pair of highly reflected connectors and a vessel of water absorption material for water leak detection.

Cho TS, Choi KS, Seo DC, Kwon IB, Lee JR - Sensors (Basel) (2012)

Initial state and received signal of a sensor probe.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3472865&req=5

f7-sensors-12-10906: Initial state and received signal of a sensor probe.
Mentions: We investigate, first, the tension effect of the metal wire because it may influence the bending loss before the response test of the sensor probes. Fortunately, the force of the WCS expansion is not enough to bend the metal wire because the wire is strongly tightened and very stiff. Thus, we neglect the wire tension effect on the bending loss due to the WCS expansion in this study. In addition, the single mode fiber (SMF) is tightly jacketed with 1 mm-diameter plastic tube. If we assume that bare fibers are employed, the bending loss will be much larger than that of the 1 mm-loose tube SMF because 1 mm plastic jacketed SMF is stiffer than bare fibers. In order to study the response of a sensor probe, at first, we test a single sensor probe with the sensor system. In the result of this test, the reflected signals from the reference connector and the sensing connector are −25.8 and −25.2 dB, respectively, at the initial state of no-water absorption shown in Figure 7. We can know that these two reflections are located 2 m apart from each other.

Bottom Line: 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 sensor probe with a high output value provides a high sensitivity with various detection levels while the number of total installable sensor probes decreases.

View Article: PubMed Central - PubMed

Affiliation: Center for Safety Measurement, Korea Research Institute of Standards and Science, 1 Doryong-dong Yuseong-gu, Daejeon 305-340, Korea. tscho@kriss.re.kr

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.

No MeSH data available.


Related in: MedlinePlus