| 1. |
- Franciscangelis, Carolina, et al.
(author)
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On-field validation of real-Time phase-OTDR for roller bearing monitoring
- 2019
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In: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 9781510631236
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Conference paper (peer-reviewed)abstract
- This work presents an on-field validation of an in-house built real-Time phase-OTDR for monitoring the status of roller bearings. The acoustic sensor prototype was designed and assembled at RISE and evaluated on a 1 m diameter bearing at SKF AB facilities in Göteborg, Sweden. A 0.24 numerical aperture single-mode optical fiber was installed in the bearing lubrication groove, which is 50 mm large and 5 mm deep. Tests were performed to verify the response of the phaseOTDR to acoustic emissions in the bearing such as hammer hits and running the rollers at different loads. The fiber optic sensor results agree with the measurements performed by a standard industrial high sensitivity electronic accelerometer used for comparison. Moreover, as opposed to the reference electronic sensor, the phase-OTDR proved to be insensitive to electrical disturbances present on the environment.
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| 2. |
- Hey Tow, Kenny, et al.
(author)
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Carbon dioxide and carbon monoxide concentration monitoring for improved carbon capture and storage : From laboratory to a field test in a cement plant
- 2019
-
In: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 9781510631236
-
Conference paper (peer-reviewed)abstract
- The cement industry is facing pressure to find technological solutions in reducing greenhouse gas emissions owing to the large amount of process emissions originating from the calcination of limestone. In this communication, an all-fibre gas monitoring system based on anti-resonant hollow-core fibres is proposed. An on-field test was performed in the harsh environment of a cement factory and it demonstrated the feasibility of using this system for low-concentration carbon dioxide and carbon monoxide monitoring in exhaust fumes
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| 3. |
- Neves, Tiago, et al.
(author)
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A kilometre-range distributed relative humidity sensor
- 2019
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In: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 9781510631236
-
Conference paper (peer-reviewed)abstract
- Fibre optics sensors have been identified as very good candidates for environmental monitoring inside the silicon detectors operated at CERN's Large Hadron Collider. In this study, we present the results from the first highly sensitive relative humidity distributed sensor with kilometres sensing range. The setup is a 70 cm spatial resolution phase-sensitive Optical Time Domain Reflectometry (OTDR) and is able to monitor fibre lengths up to 10 km. The coating effect is also evaluated, analysing different coating thicknesses, number of coating layers, different manufacturing and different materials. Relative humidity tests were performed at two different temperatures (25°C and 42°C). Polyimide coated fibres show in general a higher humidity sensitivity then a standard acrylate coated fibre, while acrylate fibres offer the fastest response and settling time. The system is able to resolve 0.1% RH and all tested fibres proved to be good candidates to be employed in a distributed relative humidity sensor. If the requirements are a fast time response and short settling time at room temperature, the standard acrylate coated fibres are the best candidates. However, if the requirements are high sensitivity and measurement stability at different temperatures, the polyimide-coated fibres offer advantages on several aspects.
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