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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 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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The major requirement of telecommunications outside network products is to satisfy the performance requisites concerning the various environments in which they are applied. Countries such as Brazil, with large extensions located i...
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The major requirement of telecommunications outside network products is to satisfy the performance requisites concerning the various environments in which they are applied. Countries such as Brazil, with large extensions located in tropical regions, have demanded products designed to specific needs, adjusted technologically to the diverse environments, in order to provide telecommunications network reliability and optimized durability in terms of the cost-benefit ratio. Considering climatic factors such as temperature, relative humidity and atmospheric pollutants, three localities from the five described by Koeppen [1] were selected: Manaus, Fortaleza and Sorocaba. The cables were exposed for 18 months in field. Every three months the samples were removed and submitted to laboratory tests for electric resistivity, tensile test, and visual examination. Salt spray, sulphur dioxide and temperature and humidity assays were carried out in order to simulate the field conditions. In these accelerated ageing assays, the visual and mechanical performance was evaluated. For the environmental characterization, there was a follow-up of parameters of temperature, humidity and pollutants derived from chlorine and sulfur.
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Microsoft, Intel, and Google report that the cost of civil works in FTTX deployment is as high as 90% of the total capex and this is the primary reason why the deployment of FTTX has been painfully slow. It is ironic that cable ma...
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Microsoft, Intel, and Google report that the cost of civil works in FTTX deployment is as high as 90% of the total capex and this is the primary reason why the deployment of FTTX has been painfully slow. It is ironic that cable manufacturers for power, voice, video, and data, and their buyers are all interested in saving a few percent while having no desire at all to find ways to cut the cost of civil works. It is like spending most of the R&D budget to slim down a monkey using genetic engineering on a ferry that carries many Indian elephants. This industry asserts at conferences "we do not want to be like the airline industry," but the irony is that the cable and the telecom industry are like the airline industry with little change of direction due to little new blood coming into this industry. This industry is marked by continuous consolidation and manufacturing plants being taken off line. In order to provide engineering guidance to solve the above, ASTM formed F36 in 2001 and has written many standards. Cigre' formed a working group Bl-08 to survey worldwide experience of using multipurpose structures and shared rights of way among power cables, optical cables, and other utilities. Similarly, within IEEE, working group C27 of PES/ICC was formed to document the pros and cons of installing and operating cables in pipelines, tunnels, and rights of way toward producing some useful results. The primary function of this paper is to document the results of the above efforts and to report on the overall track record in this field from the global experience surveyed to encourage the cable industry to consider such innovative cost savings initiatives toward new growth opportunities.
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The present paper focuses on the heat transfer problem that describes the heat conduction effects in an OPGW submitted to short-circuit. An analytical solution is proposed which accounts for the effect of the temperature gradients...
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The present paper focuses on the heat transfer problem that describes the heat conduction effects in an OPGW submitted to short-circuit. An analytical solution is proposed which accounts for the effect of the temperature gradients in the aluminum covered steel wires, and the contact thermal resistance in the effective contact surface between the fiber extruded aluminum tube and the aluminum covered steel wires. The numerical results are compared with results previously obtained and reported in the 54th IWCS Conference, for an OPGW with armored steel wires with the same dimensions. The analytical solution is expressed in terms of integral equations, which can be numerically solved in terms of the heat flux, as well as the temperature of the tube and the wires. The present approach is appropriate and effective to make design parameter sensibility analysis as well as for parameter estimation of the thermal contact resistance. The numerical results reported here show that the aluminum layer of the steel wires are very effective in reducing the electrical resistance of the cable and therefore, the temperature gradients in the steel wire as well as the temperature increase in the aluminum tube.
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The high productivity of optical fibers is one of the strong demands in optical fiber manufacturing. One of the solutions to obtain the high productivity is to increase the speed of fiber drawing. However, our previous investigati...
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The high productivity of optical fibers is one of the strong demands in optical fiber manufacturing. One of the solutions to obtain the high productivity is to increase the speed of fiber drawing. However, our previous investigation indicated that the speed of fiber drawing affected mechanical properties of UV curable polyurethane acrylate coatings for optical fiber [1], [2]. The speed of fiber drawing, temperature of fiber glass and coating properties of primary coatings during fiber drawing, and mechanical properties of primary coatings after curing were measured and investigated in this report to design the primary coatings for high speed fiber drawing.
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Deep-sea research equipment such as Water Sampler and Remotely Operated Vehicle (ROV) use long torque balance cable for power supply and signal transmission between the under water equipment and its support vessel.However, cable r...
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Deep-sea research equipment such as Water Sampler and Remotely Operated Vehicle (ROV) use long torque balance cable for power supply and signal transmission between the under water equipment and its support vessel.However, cable rotation occurs in almost all these equipment while paying in/out works of the cable, even if the torque balance of the cable is perfect. Moreover, there have been many accidents on these tether cables, such as kink or disconnection caused by rotation of the cable. In this research, calculation method of strand track of a torque balance cable over sheave was established. Applying this calculation method, the mechanism of this cable rotation was found to be the uneven change of track length between layers caused by bending of the tether cable over a sheave. In addition to the theoretical studies, a doubly layered torque balance cable with 17.4mm O.D. was fabricated, and its rotational characteristic was measured in the sea.
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As fiber is pushed closer to the home in FTTx networks, new requirements are being placed on the robustness of fiber in deployment and field handling conditions. In particular, improvements in macro and microbending sensitivities ...
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As fiber is pushed closer to the home in FTTx networks, new requirements are being placed on the robustness of fiber in deployment and field handling conditions. In particular, improvements in macro and microbending sensitivities are critical for an optical fiber designed for use in access applications. These demanding specifications have led to development of a new bend insensitive (BI) optical fiber optimized for access networks. This new fiber provides low bending loss at tight bends with full spectrum, zero water peak (ZWP) performance. All properties are near the center of the ITU G.652D specification for seamless interoperability with existing networks. The new fiber offers the first industry specification at 20mm bending diameter, with values less than 0.2/0.5 dB per turn at 1550/1625 nm. Typical 20mm bending diameter values are less than 0.05/0.1 dB/turn at 1550/1625 nm. Microbending sensitivity is reduced by half compared to standard G.652D fiber.
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Cables can be installed into ducts by pushing, pulling, blowing and floating, or a combination of those techniques. The distances reached per installation unit depend on the installation technique, on the cable and duct parameters...
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Cables can be installed into ducts by pushing, pulling, blowing and floating, or a combination of those techniques. The distances reached per installation unit depend on the installation technique, on the cable and duct parameters and on the duct trajectory. Installers need test methods, theory and software to estimate the installation distances for the different situations. In this paper a review is given of the different cable in duct installation techniques, their typical applications and their typical installation lengths and installation forces. Also a review is given of the theory for the different installation techniques. Furthermore the existing test methods are reviewed, with their shortcomings. The possibilities of the software, based on the presented theory, with which the distances per installation unit can be estimated for the practical situations, are discussed. The software is illustrated by a typical installation example.
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FTTH demand is growing rapidly, which requires new fiber connection technologies in order to enable efficient deployment. Last year our company developed a field-installable optical connector that can be directly installed on the ...
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FTTH demand is growing rapidly, which requires new fiber connection technologies in order to enable efficient deployment. Last year our company developed a field-installable optical connector that can be directly installed on the outer jacket of a drop cable. The assembly process is very simple, as once the cleaved field fiber is inserted into the connector, the fiber coating is gripped, securing the fiber inside the connector. Additionally, every step in the connector assembly process is confirmed with an audible sound to mark that the step was completed properly. Using the same technology, we have developed a field-installable optical connector that can be used inside an aerial splice closure. The average insertion loss is a low 0.27dB (λ=1.31um), and the connector has good mechanical and environmental properties.
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Two direct buried FTTH cables have been developed for two different applications. One for soft soil in the Amsterdam Citynet network project and one for arctic soil for installation by ploughing in rural and suburban areas in Finl...
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Two direct buried FTTH cables have been developed for two different applications. One for soft soil in the Amsterdam Citynet network project and one for arctic soil for installation by ploughing in rural and suburban areas in Finland. Direct buried cable types are particularly cost-effective compared to ducting systems when the initial connection rate is very high. In this paper low fibre count (max 24 fibres) constructions for drop cable application will be presented. Both cable types can be extended up to a fibre count of 96. Both cables have to be very easy to terminate and resistant to all aspects of the soil they will be installed in and their installation method compared to ducting systems. The Soft Soil Cable is a non-metallic cable and easy to strip. These cables will be installed directly in the soil under the pavements. The pavements are mostly made with loose bricks and are therefore easily accessible. The Arctic Cable for Ploughing is designed to withstand the same installation method as for backbone cables, including rough handling during ploughing installation or soil movement during the winter.
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