摘要 :
A fiber-optic temperature sensor system has been developed and implemented in the monitoring of the cooking process in pulp production. The sensor system is based on intensity modulation in mechanical multimode fiber connections c...
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A fiber-optic temperature sensor system has been developed and implemented in the monitoring of the cooking process in pulp production. The sensor system is based on intensity modulation in mechanical multimode fiber connections caused by the temperature dependent deflection of a bimetal strip. OTDR technology is used for monitoring the changes in optical power at the sensor points in the network, and a computer system takes care of calibration curves and the power-to-temperature conversion. Fiber segments between the sensor points and the control unit are realized with blown fiber.In this paper, the development and testing of the temperature monitoring system is reported on. Sensor performance, data readout, installation issues and measurement results are discussed. The system is shown to meet the requirements on precision and response time and to be a useful tool for the monitoring of the cooking process.
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摘要 :
A fiber-optic temperature sensor system has been developed and implemented in the monitoring of the cooking process in pulp production. The sensor system is based on intensity modulation in mechanical multimode fiber connections c...
展开
A fiber-optic temperature sensor system has been developed and implemented in the monitoring of the cooking process in pulp production. The sensor system is based on intensity modulation in mechanical multimode fiber connections caused by the temperature dependent deflection of a bimetal strip. OTDR technology is used for monitoring the changes in optical power at the sensor points in the network, and a computer system takes care of calibration curves and the power-to-temperature conversion. Fiber segments between the sensor points and the control unit are realized with blown fiber.In this paper, the development and testing of the temperature monitoring system is reported on. Sensor performance, data readout, installation issues and measurement results are discussed. The system is shown to meet the requirements on precision and response time and to be a useful tool for the monitoring of the cooking process.
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Distributed Optical Fiber Sensing is a mature technology given its strong record of over 20 years. Nevertheless, underground utilities are yet to embrace it as an everyday tool despite its enormous capability. One dimensional long...
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Distributed Optical Fiber Sensing is a mature technology given its strong record of over 20 years. Nevertheless, underground utilities are yet to embrace it as an everyday tool despite its enormous capability. One dimensional long buried utilities and tunnels offer the best application for the use of this technology. Research studies around the world offer the promise of this technology in monitoring the impact of ground movements on underground utilities and tunnels. No application standards existed that governed the use of this technology within any jurisdiction in the world in September 2012. A global task group on optical fiber sensing systems (OFSS) was born to become a unique pool of talent and experience on the subject with over 40 leading experts from 17 countries, which went on to author two companion standards American Society for Testing and Materials (ASTM) F3079-14 and F3092-14, within ASTM Technical Committee F36. This paper provides a brief overview of how OFSS work, what is in these standards, why OFSS is poised to become the most versatile innovation among all measurement tools for field monitoring, what problems the task group faced during the development of the standards and how the members of the task group resolved these problems, what the benefits are of such global standards and the future plans for the global OFSS task group. The most paramount goal of the authors is to share the lessons they learned during the development of the standards with the delegates of this conference.
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摘要 :
Distributed Optical Fiber Sensing is a mature technology given its strong record of over 20 years. Nevertheless, underground utilities are yet to embrace it as an everyday tool despite its enormous capability. One dimensional long...
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Distributed Optical Fiber Sensing is a mature technology given its strong record of over 20 years. Nevertheless, underground utilities are yet to embrace it as an everyday tool despite its enormous capability. One dimensional long buried utilities and tunnels offer the best application for the use of this technology. Research studies around the world offer the promise of this technology in monitoring the impact of ground movements on underground utilities and tunnels. No application standards existed that governed the use of this technology within any jurisdiction in the world in September 2012. A global task group on optical fiber sensing systems (OFSS) was born to become a unique pool of talent and experience on the subject with over 40 leading experts from 17 countries, which went on to author two companion standards American Society for Testing and Materials (ASTM) F3079-14 and F3092-14, within ASTM Technical Committee F36. This paper provides a brief overview of how OFSS work, what is in these standards, why OFSS is poised to become the most versatile innovation among all measurement tools for field monitoring, what problems the task group faced during the development of the standards and how the members of the task group resolved these problems, what the benefits are of such global standards and the future plans for the global OFSS task group. The most paramount goal of the authors is to share the lessons they learned during the development of the standards with the delegates of this conference.
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Distributed acoustic/vibration sensing schemes based on phase-OTDR are naturally sensitive to environmental perturbation. Nevertheless, further sensitivity enhancement is possible by using specialty fibers. In this paper, a nitrog...
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Distributed acoustic/vibration sensing schemes based on phase-OTDR are naturally sensitive to environmental perturbation. Nevertheless, further sensitivity enhancement is possible by using specialty fibers. In this paper, a nitrogen doped single-mode fiber with increased Rayleigh scattering properties is tested alongside a standard telecommunications single-mode fiber (SMF) for comparative phase-OTDR measurements. The high Rayleigh scattering fiber (HRF) does not only benefit from a higher numerical aperture, but also from a higher non-homogeneity of material density resulting in an enhanced scattering coefficient. For perturbations caused by shaker-induced vibration applied on a fiber section or by an acoustic signal emitted from a loudspeaker, the ability of localizing the perturbation and determining the frequency is studied simultaneously for the HRF and the SMF, using a direct detection phase-OTDR setup. Vibration frequencies in the range 100-7000 Hz with accelerations of up to 0.1g and acoustic signals in the frequency range 100-10000 Hz at sound pressure levels up to 115 dBC are tested. The signal-to-noise ratios (SNRs) for the differential phase-OTDR traces are calculated as the maximum difference signal level in the perturbation zone and a noise reference level outside the zone. Moving average methods are also employed for further enhancement. As expected, the HRF has superior performance for the localization and the frequency characterization, and it allows detection of signal levels that are undetectable with an SMF without using of denoising methods. On average, a 7 dB and a 3 dB improvement can be achieved for vibration detection and acoustic detection, respectively.
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摘要 :
Distributed acoustic/vibration sensing schemes based on phase-OTDR are naturally sensitive to environmental perturbation. Nevertheless, further sensitivity enhancement is possible by using specialty fibers. In this paper, a nitrog...
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Distributed acoustic/vibration sensing schemes based on phase-OTDR are naturally sensitive to environmental perturbation. Nevertheless, further sensitivity enhancement is possible by using specialty fibers. In this paper, a nitrogen doped single-mode fiber with increased Rayleigh scattering properties is tested alongside a standard telecommunications single-mode fiber (SMF) for comparative phase-OTDR measurements. The high Rayleigh scattering fiber (HRF) does not only benefit from a higher numerical aperture, but also from a higher non-homogeneity of material density resulting in an enhanced scattering coefficient. For perturbations caused by shaker-induced vibration applied on a fiber section or by an acoustic signal emitted from a loudspeaker, the ability of localizing the perturbation and determining the frequency is studied simultaneously for the HRF and the SMF, using a direct detection phase-OTDR setup. Vibration frequencies in the range 100-7000 Hz with accelerations of up to 0.1g and acoustic signals in the frequency range 100-10000 Hz at sound pressure levels up to 115 dBC are tested. The signal-to-noise ratios (SNRs) for the differential phase-OTDR traces are calculated as the maximum difference signal level in the perturbation zone and a noise reference level outside the zone. Moving average methods are also employed for further enhancement. As expected, the HRF has superior performance for the localization and the frequency characterization, and it allows detection of signal levels that are undetectable with an SMF without using of denoising methods. On average, a 7 dB and a 3 dB improvement can be achieved for vibration detection and acoustic detection, respectively.
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摘要 :
A fiber-optic temperature sensor system has been developed and implemented in the monitoring of the cooking process in pulp production. The sensor system is based on intensity modulation in mechanical multimode fiber connections c...
展开
A fiber-optic temperature sensor system has been developed and implemented in the monitoring of the cooking process in pulp production. The sensor system is based on intensity modulation in mechanical multimode fiber connections caused by the temperature dependent deflection of a bimetal strip. OTDR technology is used for monitoring the changes in optical power at the sensor points in the network, and a computer system takes care of calibration curves and the power-to-temperature conversion. Fiber segments between the sensor points and the control unit are realized with blown fiber. In this paper, the development and testing of the temperature monitoring system is reported on. Sensor performance, data readout, installation issues and measurement results are discussed. The system is shown to meet the requirements on precision and response time and to be a useful tool for the monitoring of the cooking process.
收起
摘要 :
A fiber-optic temperature sensor system has been developed and implemented in the monitoring of the cooking process in pulp production. The sensor system is based on intensity modulation in mechanical multimode fiber connections c...
展开
A fiber-optic temperature sensor system has been developed and implemented in the monitoring of the cooking process in pulp production. The sensor system is based on intensity modulation in mechanical multimode fiber connections caused by the temperature dependent deflection of a bimetal strip. OTDR technology is used for monitoring the changes in optical power at the sensor points in the network, and a computer system takes care of calibration curves and the power-to-temperature conversion. Fiber segments between the sensor points and the control unit are realized with blown fiber. In this paper, the development and testing of the temperature monitoring system is reported on. Sensor performance, data readout, installation issues and measurement results are discussed. The system is shown to meet the requirements on precision and response time and to be a useful tool for the monitoring of the cooking process.
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In this paper, we discuss the operation principles, sensing mechanism, challenges and application areas of FBG-assisted phase-sensitive optical time-domain reflectometry. A special emphasis is given to the interrogation of fiber B...
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In this paper, we discuss the operation principles, sensing mechanism, challenges and application areas of FBG-assisted phase-sensitive optical time-domain reflectometry. A special emphasis is given to the interrogation of fiber Bragg grating arrays for vibration sensing application. Results obtained by different research groups are compared in terms of performance characteristics and future perspectives. Recent progress obtained through our research collaboration are also presented. In particular, the detrimental spectral shadowing effect and multiple reflection crosstalk are analysed and mitigation techniques are proposed.
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摘要 :
In this paper, we discuss the operation principles, sensing mechanism, challenges and application areas of FBG-assisted phase-sensitive optical time-domain reflectometry. A special emphasis is given to the interrogation of fiber B...
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In this paper, we discuss the operation principles, sensing mechanism, challenges and application areas of FBG-assisted phase-sensitive optical time-domain reflectometry. A special emphasis is given to the interrogation of fiber Bragg grating arrays for vibration sensing application. Results obtained by different research groups are compared in terms of performance characteristics and future perspectives. Recent progress obtained through our research collaboration are also presented. In particular, the detrimental spectral shadowing effect and multiple reflection crosstalk are analysed and mitigation techniques are proposed.
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