Next Article in Journal
Detection of Cracks on Tomatoes Using a Hyperspectral Near-Infrared Reflectance Imaging System
Previous Article in Journal
Toward Real-Time Automated Detection of Turns during Gait Using Wearable Inertial Measurement Units
Article Menu

Export Article

Open AccessArticle
Sensors 2014, 14(10), 18823-18836;

A Fiber-Optic Sensor Using an Aqueous Solution of Sodium Chloride to Measure Temperature and Water Level Simultaneously

School of Biomedical Engineering, College of Biomedical & Health Science, BK21 Plus Research Institute of Biomedical Engineering, Konkuk University, 268 Chungwon-daero, Chungju-si, Chungcheongbuk-do 380-701, Korea
Department of Organic Materials & Fiber Engineering, College of Engineering, Soongsil University, 369 Sangdo-ro, Dongjak-gu, Seoul-si 156-743, Korea
Department of Nuclear & Energy System Engineering, College of Natural Science, Dongguk University-Gyeongju, 123 Dongdae-ro, Gyeongju-si, Gyeongsangbuk-do 780-714, Korea
Author to whom correspondence should be addressed.
Received: 1 August 2014 / Revised: 19 September 2014 / Accepted: 29 September 2014 / Published: 10 October 2014
(This article belongs to the Section Physical Sensors)
Full-Text   |   PDF [1815 KB, uploaded 10 October 2014]


A fiber-optic sensor system using a multiplexed array of sensing probes based on an aqueous solution of sodium chloride (NaCl solution) and an optical time-domain reflectometer (OTDR) for simultaneous measurement of temperature and water level is proposed. By changing the temperature, the refractive index of the NaCl solution is varied and Fresnel reflection arising at the interface between the distal end of optical fiber and the NaCl solution is then also changed. We measured the modified optical power of the light reflected from the sensing probe using a portable OTDR device and also obtained the relationship between the temperature of water and the optical power. In this study, the water level was simply determined by measuring the signal difference of the optical power due to the temperature difference of individual sensing probes placed inside and outside of the water. In conclusion, we demonstrate that the temperature and water level can be obtained simultaneously by measuring optical powers of light reflected from sensing probes based on the NaCl solution. It is anticipated that the proposed fiber-optic sensor system makes it possible to remotely monitor the real-time change of temperature and water level of the spent fuel pool during a loss of power accident. View Full-Text
Keywords: fiber-optic sensor; NaCl solution; OTDR; temperature; water level fiber-optic sensor; NaCl solution; OTDR; temperature; water level
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Yoo, W.J.; Sim, H.I.; Shin, S.H.; Jang, K.W.; Cho, S.; Moon, J.H.; Lee, B. A Fiber-Optic Sensor Using an Aqueous Solution of Sodium Chloride to Measure Temperature and Water Level Simultaneously. Sensors 2014, 14, 18823-18836.

Show more citation formats Show less citations formats

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Sensors EISSN 1424-8220 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top