title: A fiber-optic sensor using an aqueous solution of sodium chloride to measure temperature and water level simultaneously.
abstract: 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.
authors.affiliation: 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. wonzip@kku.ac.kr.
authors.forename: Wook Jae
authors.initials: WJ
authors.lastname: Yoo
authors.affiliation: 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. saucony9116@gmail.com.
authors.forename: Hyeok In
authors.initials: HI
authors.lastname: Sim
authors.affiliation: 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. shshin9431@gmail.com.
authors.forename: Sang Hun
authors.initials: SH
authors.lastname: Shin
authors.affiliation: 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. kko988@kku.ac.kr.
authors.forename: Kyoung Won
authors.initials: KW
authors.lastname: Jang
authors.affiliation: Department of Organic Materials & Fiber Engineering, College of Engineering, Soongsil University, 369 Sangdo-ro, Dongjak-gu, Seoul-si 156-743, Korea. scho@ssu.ac.kr.
authors.forename: Seunghyun
authors.initials: S
authors.lastname: Cho
authors.affiliation: Department of Nuclear & Energy System Engineering, College of Natural Science, Dongguk University-Gyeongju, 123 Dongdae-ro, Gyeongju-si, Gyeongsangbuk-do 780-714, Korea. jhmoon86@dongguk.ac.kr.
authors.forename: Joo Hyun
authors.initials: JH
authors.lastname: Moon
authors.affiliation: 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. bslee@kku.ac.kr.
authors.forename: Bongsoo
authors.initials: B
authors.lastname: Lee