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Extended study of fiber optic-based humidity sensing system performance for sewer network condition monitoring

Rente, B., Fabian, M., Vidakovic, M. , Vorreiter, L., Bustamante, H., Sun, T. ORCID: 0000-0003-3861-8933 & Grattan, K. T. V. ORCID: 0000-0003-2250-3832 (2021). Extended study of fiber optic-based humidity sensing system performance for sewer network condition monitoring. IEEE Sensors Journal, 21(6), pp. 7665-7671. doi: 10.1109/jsen.2021.3050341


This paper reports on an extended (20-month) period of monitoring of humidity in situ at two locations in the sewer network operated by Sydney Water using a fibre optic network into which a series of Bragg Grating-based sensors had been installed. The locations (Eustace Street in Manly, Sydney and Old Toongabbie at Oakes Reserve, western Sydney, Australia) both had different operating environments and thus conditions for evaluating the sensor system. It was designed to provide a solution to enable long term, low cost and more reliable monitoring in the harsh conditions of the sewer environments in terms of high relative humidity > 95% and a broad range of hydrogen sulfide levels. The results of the study show that even after ~20 months of use, the same sensor is reliably recording humidity and temperature in the sewer environment – overcoming the problems seen with conventional electrical sensors, which typically fail within a couple of weeks of use in this continuous high acid/high humidity environment. The data, recorded constantly from the sensor system, were stable throughout the full monitoring period and further, a comparison with the changing weather conditions was made over the different seasons during the study. The sensor system developed was battery operated and had 4G connectivity for data transfer and debugging. These features have enabled the system to be installed in situations where power is not available and operate successfully with minimal human operation, thus allowing for additional systems to be integrated to the measurement system in the future.

Publication Type: Article
Additional Information: © 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
Publisher Keywords: Fibre Bragg grating, humidity sensor, sewer corrosion, aggressive biofouling environment
Subjects: T Technology > TD Environmental technology. Sanitary engineering
T Technology > TK Electrical engineering. Electronics Nuclear engineering
Departments: School of Science & Technology > Engineering
SWORD Depositor:
[thumbnail of 0105ZZ 1117 1024 Eustace st plus old toongab paper hb lv (00000002).pdf]
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