Archived 2016 Lapp Group International Catalog

Appendix Glossary

ÖLFLEX ® ACCESSORIES FLEXIMARK ® SILVYN ® SKINTOP ® EPIC ® HITRONIC ® ETHERLINE ® UNITRONIC ® APPENDIX Specific volume resistance The specific volume resistance [Ohm m] results from the measured volume resistance [Ohm] multiplied by the measuring area [m²] divided by the sample length [m]. VDE 0207, Part 4 and VDE 0303, Part 30. Speed of signal propagation Signals propagate in all cables at a speed that is always lower than the speed of light. The NVP value specifies the ratio of this speed to the propagation speed of light. Spiral cable Flexible cables that are formed into a “spiral spring”. The cable is wound onto a mandrel. The addition of heat (tempering) reduces the tensions in the plastic caused by the winding process, which means that the cable retains the spiral shape in a stress free condition after cooling. When expanded, the spiral extends and, when the force is no longer acting upon it, returns to its original condition. Splice Connection of two light waveguides created by melting their ends. Fixed connection between two light waveguides. A distinction is made between bonded and welded splices (→ Welded light waveguide con- nection). Stabiliser a) A component used in some plastics to obtain certain physical and chemical properties during processing and the usage time. b) Additives (e. g. lead, tin or cadmium salts) for plastics. They delay or counteract the decomposition and aging process that occurs when exposed to thermal loads. Step index fibre Light waveguide with a stepped profile, i. e. with a refraction index profile that is characterised by a constant refraction index within the core and a sharp decline in the refraction index at the boundary of the core and the sheath. STP In twisted pair cables with foil screening of the individual pairs and an overall braided screening (STP = Individually Screened Foil and Braid Twisted Pair), the cores are twisted in pairs and individually screened with a metallic foil, to achieve exceptionally low near end crosstalk. An additional overall screen is then added. Strain relief of cable glands The ability of a cable gland to limit the movement of a secured cable under a dynamic and torsional load. Strand The individual wires in a conductor combined into a bundle; the number and individual wire thickness varies according to the desired cross-sec- tion. The individual wires are either bundled by stranding or by twisting. Individual cores, e. g. LiY, H05V-K, H07V-K Stranding The individual elements of cables are wound parallel around a central element. The elements can be the individual wires in a conductor or the cores or groups of cores themselves. Depending on requirements, the elements are twisted or stranded with different twist lengths. This is done in concentric layers, one on top of another, according to the number of elements. If the subsequent layer of the element is stranded in the same direction as the preceding layer, this is known as parallel

lay stranding, as opposed to cross lay (reversed lay) stranding, where each subsequent layer is stranded in the opposite direction to the previous one. The stranding has an “S” lay if the stranding direction runs to the left as an observer looks at it, or a “Z” lay if the stranding runs to the right: A distinction is also made between stranding tech- niques with and without back twist. Stranding machine, twister Stranding machines are used to strand the components of a cable. Different types of stranding machines include single twist, double twist, multiple twist, high-speed, basket, SZ and universal stranding machines. Strip line Strip lines are used as fixed signal transmission cables in control and steering technology, measurement and data processing technology. They can contain up to 40 cores which lie parallel to each as a result of the welded insulating cover. Single cores can be separated from the strip line, without causing any damage to the insulating cover. Their flat arrangement means they can be guided through narrow slots or open- ings. They are fixed in place using brackets or adhesive. Styrol Is used as an insulating material for telecommunication cables (→ Die- lectric). It has a good strength value, however is not resistant to sol- vents. Super conduction The property of metals and oxides to lose their electrical resistance due to cooling when a so-called transition temperature is reached. Supporting cable Because of their small dimensions, they are used for installation in small and miniature equipment. Supporting core Strands of hemp, steel or plastic are incorporated into the construction as supporting elements or to absorb tensile forces. In most cases, the carrier organ is positioned next to the core, i. e. in the middle of cables. However, there are also constructions in which one or two steel strands are positioned outside the bunch of cores but below a shared outer sheath. Surface mount base Lower housing sections with an enclosed base are referred to as sur- face-mounted. Surface mounted bases are available with a cable outlet on the right-hand side or on both sides of the housing. Synthetic india rubber Butyl synthetic rubber has a high resistance to ageing and lower gas permeability. It is highly resistant to chemicals.

T T-Coupler

Optical component for combining the light from two light waveguides (see also → Coupler). Conversely, it can also be used to split the light output in one light waveguide into two outgoing light waveguides. Take-up system Sheathed cables are generally wrapped around wooden or process drums. The most common types of winding devices are bottom roller

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