Hubert Braendle | ABB Inc (original) (raw)
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Papers by Hubert Braendle
IEEE/OSA Journal of Lightwave Technology, 2002
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IEEE/OSA Journal of Lightwave Technology, 2007
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A fiber-optic current sensor for direct currents up to 500 kA is presented. Applications include ... more A fiber-optic current sensor for direct currents up to 500 kA is presented. Applications include the control of the electrolysis process for the production of metals such as aluminum, copper, magnesium, etc. The sensor offers significant advantages with regard to performance and ease of installation compared to state-of-the-art Hall effect based current transducers. A novel scheme of a polarization-rotated reflection interferometer and fiber gyroscope technology is used to measure the magneto-optic phase shift. A new technique has been developed for packaging the sensing fiber in a flexible strip of fiber re-enforced epoxy for coil diameters up to several meters. The sensor can be installed without opening the current-carrying bus bars. Subsequent re-calibration is not necessary. Accuracy is within +/-0.1% over a wide range of currents and temperatures.
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IEEE Photonics Technology Letters, 2010
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The focus of this paper are performance and mechanical and optical reliability of fiber Bragg gra... more The focus of this paper are performance and mechanical and optical reliability of fiber Bragg gratings as stress/strain and temperature sensors in high temperature applications for extended periods of time. However, not a particular sensor application will be considered but functionality and reliability of fiber Bragg gratings under this condition will be investigated.
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IEEE Sensors Journal, 2012
Distributed temperature sensors (DTS) measure temperatures by means of optical fibers. Those opto... more Distributed temperature sensors (DTS) measure temperatures by means of optical fibers. Those optoelectronic devices provide a continuous profile of the temperature distribution along the cable. Initiated in the 1980s, DTS systems have undergone significant improvements in the technology and the application scenario over the last decades. The main measuring principles are based on detecting the back-scattering of light, e.g., detecting via Rayleigh, Raman, and Brillouin principles. The application domains span from traditional applications in the distributed temperature or strain sensing in the cables, to the latest “smart grid” initiative in the power systems, etc. In this paper, we present comparative reviews of the different DTS technologies, different applications, standard, and upcoming, different manufacturers.
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IEEE Sensors Journal, 2010
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Ammonia plays an important role in the NOx removal in combustion processes. However, a too high c... more Ammonia plays an important role in the NOx removal in combustion processes. However, a too high concentration of NH3 results in unconverted ammonia that pollutes the environment and damages the combustion plant. Today's available ammonia sensors are either not suitable for high temperature applications that are common in combustion processes or do not have the needed accuracy to control the ammonia concentration. The authors present a robust and cost-efficient extractive gas sensor suitable for detection of NH3 with a precision of 50 ppb.
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IEEE/OSA Journal of Lightwave Technology, 2002
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IEEE/OSA Journal of Lightwave Technology, 2007
Bookmarks Related papers MentionsView impact
A fiber-optic current sensor for direct currents up to 500 kA is presented. Applications include ... more A fiber-optic current sensor for direct currents up to 500 kA is presented. Applications include the control of the electrolysis process for the production of metals such as aluminum, copper, magnesium, etc. The sensor offers significant advantages with regard to performance and ease of installation compared to state-of-the-art Hall effect based current transducers. A novel scheme of a polarization-rotated reflection interferometer and fiber gyroscope technology is used to measure the magneto-optic phase shift. A new technique has been developed for packaging the sensing fiber in a flexible strip of fiber re-enforced epoxy for coil diameters up to several meters. The sensor can be installed without opening the current-carrying bus bars. Subsequent re-calibration is not necessary. Accuracy is within +/-0.1% over a wide range of currents and temperatures.
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IEEE Photonics Technology Letters, 2010
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Bookmarks Related papers MentionsView impact
The focus of this paper are performance and mechanical and optical reliability of fiber Bragg gra... more The focus of this paper are performance and mechanical and optical reliability of fiber Bragg gratings as stress/strain and temperature sensors in high temperature applications for extended periods of time. However, not a particular sensor application will be considered but functionality and reliability of fiber Bragg gratings under this condition will be investigated.
Bookmarks Related papers MentionsView impact
IEEE Sensors Journal, 2012
Distributed temperature sensors (DTS) measure temperatures by means of optical fibers. Those opto... more Distributed temperature sensors (DTS) measure temperatures by means of optical fibers. Those optoelectronic devices provide a continuous profile of the temperature distribution along the cable. Initiated in the 1980s, DTS systems have undergone significant improvements in the technology and the application scenario over the last decades. The main measuring principles are based on detecting the back-scattering of light, e.g., detecting via Rayleigh, Raman, and Brillouin principles. The application domains span from traditional applications in the distributed temperature or strain sensing in the cables, to the latest “smart grid” initiative in the power systems, etc. In this paper, we present comparative reviews of the different DTS technologies, different applications, standard, and upcoming, different manufacturers.
Bookmarks Related papers MentionsView impact
IEEE Sensors Journal, 2010
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Ammonia plays an important role in the NOx removal in combustion processes. However, a too high c... more Ammonia plays an important role in the NOx removal in combustion processes. However, a too high concentration of NH3 results in unconverted ammonia that pollutes the environment and damages the combustion plant. Today's available ammonia sensors are either not suitable for high temperature applications that are common in combustion processes or do not have the needed accuracy to control the ammonia concentration. The authors present a robust and cost-efficient extractive gas sensor suitable for detection of NH3 with a precision of 50 ppb.
Bookmarks Related papers MentionsView impact