Search results for "Fiber"
showing 10 items of 2343 documents
<title>Fiber optical intensity-ratio refractometer with digital display</title>
1994
Simplicity, cost efficiency, and higher fidelity compared to the single-channel design are the main advantages stimulating the recent interest on fiber optic intensity-ratio sensors. Optical and electronic designs of refractometric sensors of this kind are discussed here. Two optical schemes of retroreflective probes with one input and two output fibers are proposed. The probe sensitivity to liquid refractivity changes in the interval 1.33 < n < 1.41 is studied by computer simulation. An originally developed one-ADC-based signal processing circuit providing digital display of the intensity-ratio determined n-values is described as well.
<title>Optical power and irradiance microprocessor meter for fiber optic sensors and networks testing</title>
1999
In this paper are presented the optical power and irradiance meter with `an intelligent opto sensor' and the microprocessor measurement system. A designed and programmed microprocessor unit allows to measure a light power from 1 nW to 2 mW and an irradiance of light from 50 nW/cm2 to 150 mW/cm2 (with accuracy 0.2%) including sensor's and spectral responsively characteristic. It's built for measuring fiber optic systems, mainly for examination and testing of the optoelectronic sensor's structure (relatively small surface of the light detectors comparing to the partition of measured value) and it's an ideal detector for the fiber optic sensors and networks.© (1999) COPYRIGHT SPIE--The Interna…
<title>Control and measuring buses with amplitude fiber optical sensors</title>
2004
This paper presents controlling-measuring buses (linear and quasi-linear) using amplitude properties of fiber-optics and fiber-optical sensors of typical and/or special construction. It refers to linear sensors and commonly used measuring OTDR method, as wel as to realizations with linear binary sensors in transmission networks. Presented advantages and parameters of such measuring structures. Presented main area of application buses and practical realizations, regarding typical needs in industrial measurements, points out technical and economical advantages, in opposition to difficult and expensive (but more accurate) technology of measuring networks based on polarization and interfering m…
Optical Fibre Control-Measurement Systems Of Compound HV/HP Electrical Equipment
1988
Responsible electrical equipment should be controlled during the work in care of their high reliability. Traditional control measurement systems cannot fulfil the task because of the hard conditions in which the equipment may operate (various electrical potentials, electromagnetic interferences, changes of temperature, etc.). The development of fibre optic transmission media and fibre optic sensors allows the construction of new control measurement systems for cooperation with such electrical equipment as: converters, generators, treLnsforniens, switch bays, busbards, etc. Those optical fibre structures, composed of bu-ses and sensors are subject of this paper. The main attention is paid to…
<title>Fiber optic monitoring buses with binary on-off sensors</title>
1999
This paper presents general theoretical considerations of complex-structure optical fiber networks (buses) with binary `on-off' fiber optic sensors and fiber optic transmission lines for monitoring, diagnostic or measurement systems. The principles of fiber optic serial and parallel buses and various types of intensity fiber optic binary sensors are described as well as the advantages and disadvantages of the individual types of networks. The choice of the use of fiber optic technology rather than other techniques is discussed. Special emphasis was put on the role and function of optoelectronic and optical fiber devices in harsh environments. Theoretical considerations are illustrated by th…
Connection Of System Measuring Voltages And Currents Of High Voltage Power Line To A Microcomputer By Optical Fibre Link
1986
The prototype of equipment for service of the measuring units of power high voltage line is presented. That system is composed of the transmitter /with A/D conversion/, optical fibre data link and receiver feeding the output into the microcomputer. The application of this equipment in the automatic protection system protecting the power network against short-circuit is described.
Combined Analysis of OFDM-UWB Transmission in Hybrid Wireless-Optical Access Networks
2009
[EN] The hybrid wireless-optical transmission of ultra-wideband signals employing orthogonal frequency-division multiplexing modulation (OFDM) ultra-wideband (UWB) as defined in the ECMA-368 standard is experimentally analyzed in this letter. The OFDM-UWB signals provide 400 Mb/s per user at optical distances from 5 to 50 km on standard single-mode fiber (SSMF). The analysis includes the wireless radiation from 0 to 3 m after optical transmission. The results indicate a maximum error-vector-magnitude degradation of 2.5 dB measured at 1.5-m radio after 50-km SSMF optical transmission for the first two UWB channels. This degradation translates to 1-m maximum wireless-reach penalty.
Analytical model for high-strength concrete columns with square cross-section
2008
In the present paper a mechanical model to predict the compressive response of high strength short concrete columns with square cross-section confined by transverse steel is presented. The model allows one to estimate the equivalent confinement pressures exercised by transverse steel during the loading process taking into account of the interaction of the stirrups with the inner core both in the plane of the stirrups and in the space between two successive stirrups. The lateral pressure distributions at hoop levels are obtained by using a simple model of elastic beam on elastic medium simulating the interaction between stirrups and concrete core, including yielding of steel stirrups and dam…
A mobile robot for vigilance tasks improved with a new robust and low cost communications system immune to attacks with EMI noise
2006
This work pretends to develop a robot for vigilance tasks that are able to tolerate diverse kinds of attacks and be able to operate in environments with elevated electromagnetic noise, being even immune to sabotage provoked by means of high electromagnetic fields. A new CAN based communications system that interconnects the different devices that compose the mobile robot has been developed to achieve this goal. The system is based on a shielded communications hub, that interconnects diverse nodes by means of CAN. On the other hand, the point to point communication between each node and the hub is carried out by means of economic optical fiber. With this approach all robot devices are connec…
Analyses of Dual Polarization WDM and SCM Radio over Fiber and Radio over FSO for C-RAN Architecture
2016
En este trabajo se simulan y verifican experimentalmente los esquemas de transmisión para una Arquitectura de Red de Acceso Radio Centralizada (C-RAN) basados en la combinación de dos tecnologías: Radio sobre Fibra (RoF) y Radio sobre FSO (RoFSO). Las configuraciones propuestas se optimizan para la evolución a largo plazo (LTE) con un ancho de banda de 20 MHz utilizando una modulación de amplitud en cuadratura de 64-QAM en términos de magnitud de vector de error (EVM). En primer lugar, se comparan las mediciones de la multiplexación por división de polarización mediante la combinación de RoF y RoFSO (PDM-RoF/FSO) con los modelos de simulación. Esto se amplía con la combinación de PDM-Multip…