Optical fibre cables

Electricity, electrical household appliances electrical cables, optical fibres, flexible telephone cables, inlet and outlet cable channels... 

Wire and cable insulation and jacketing, telecommunication wires and cables, optical fibre coating, extruded coatings... 

Optical fibre cables Optical fibre cables are communication cables made from... 

The running of telephone lines through power lines is long discontinued. They are now run on separate structures within a city and nearby areas at audio frequency (— 0.3-3.4 kHz), and maintain enough distance from HT power distribution lines. They are therefore almost unaffected from such disturbances. Nevertheless, interferences must be kept in mind when installing these lines so that they are out of the inductive interference zone of the power lines. The latest method in the field of communications to avoid disturbances is to use underground optical fibre cables, where possible, as discussed later. Optical fibre cables are totally immune to such disturbances. 

All ctfecis caused by electrostatic or electromagnetic inductions are termed Inductive Interferences. With the use t)f glass optical fibre cables in new installaiioiis. this effect is overcome automatically. Optical fibre cables, as discussed later, have no metal content and cany no electrical signals. Therefore the above discussion is more appropriate for existing installations and also to provide a theoretical aspect and moi c clarity on the phenomena of inductive interferences. These can also be applied to other fields rather than communications alone. 

Telephone cable Pneumatic Optical fibre Optical - infrared Radio... 

Wire and cable or fibre optic applications, optical fibre tubing. .. 

Figure 5.8 — Probe-type sensor based on continuous circulation of a stream containing an acid-base indicator for the batch determination of COj in sea water, (a) Reagent delivery capillary, (d) Reagent exit capillary, (c) Optical fibre from source, (d) Optical fibre to detector, (e) White silicone rubber membrane. (/) White silicone sealant, (g) Epoxy resin, (/i) 0-ring. (/) Sensor housing. (/) Optical cable. (Reproduced from [12] with permission of the American Chemical Society).

Optical sensors display several advantages over electronic sensors. Since photons rather than electrons carry the information, they are almost immune to electrical interference. Usually the optical components are made from glass chips or fibre-optic cable fibres, giving them excellent mechanical and thermal stability and often, moreover, a high chemical resistivity. Finally the use of glass, especially fibre-optic, fibres helps to minimise the size and weight of these sensors. Optical sensors, especially fibre-optic sensors have been the subject of several recent reviews [116-120]. 

IEC 60332-1 Tests on electric and optical fibre cables under fire conditions Test for vertical flame propagation for a single insulated wire or cable, IEC, Geneva, Switzerland, 2004. 

Transmission of information between switchboards and to other locations such as a control room can be achieved by either optical fibre or hard wire cables. Suitable interfaces are placed at each end of the cables. As with many aspects of computing the speed of data transmission, method of porting, the protocols available, memory capacity and speed of calculation are upgraded, improved and superseded almost on a yearly basis. It is therefore necessary to be well aware of the state of the art in these subjects so that a system that is about to be superseded is not pmchased. 

Besides these functions, safety aspects are vital in developing these types of MRl compatible devices. One should avoid electric cables, metallic parts and prevention of bacteriologic and viral cross-patient contamination. One of the main advantages of optical fibre sensors is their immunity to electromagnetic radiations. 

Rgure 3.42 Digital pulses of laser light down an optical fibre cable. 

Optical fibre cables are communication cables made from optical-quality plastic, the same material from which spectacle lenses are manufactured. The energy Is transferred down the cable as digital pulses of laser light, as against current flowing down a copper conductor In electrical Installation terms. 

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