Archived 2016 Lapp Group International Catalog

Appendix Glossary

ÖLFLEX ® ACCESSORIES FLEXIMARK ® SILVYN ® SKINTOP ® EPIC ® HITRONIC ® ETHERLINE ® UNITRONIC ® APPENDIX

winders, axial winders and barrel winders. Depending on their flexural loading, tensile strain, torsional strain, design, storage, mechanical load and transport, cables are individually wrapped and delivered on drums, bobbins, in coils or barrels. Talcum Talcum is a mineral, slightly fatty natural product. It is used in powder form as a separating agent or lubricant. It is also used when mixed with mica. When sheathing a strand of cores, to prevent the sheathing material that is applied when hot from sticking to the core insulation, the strand is dusted with talcum first. As well as the separating effect, this greatly reduces the friction between the individual elements of the cable and thus promotes flexibility and stripping. Tape The stranded assembly, comprising several cores, is surrounded by the tape. Generally, the tape is made from one or several synthetic or paper band layers. Tape wrapping Cables can be wrapped in a variety of different insulating materials. The tape is always helically wrapped around the cable as the taping machine operates in a rotary motion and the pull-off movement is always in a longitudinal direction. Several layers of paper or plastic tape are wrapped around the cable stranding or the cable core. TDR The Time Domain Reflectometry measuring method is used to locate faults in copper cables. The running time and shape of a reflected pulse enables the possible location of the fault to be determined relatively accurately. For PVC insulated cores, this value is approx. 0.541. Telephone cord Cables to or in telecommunication devices which have a high flexural loading or flexibility. Temperature range If the specified minimum temperature range is not reached, no mechanical forces may act on the cable as otherwise the insulation will break (rigidity of polymer chains). If the maximum temperature is exceeded, the insulation begins to melt (decomposition of polymer chains). Important! With every change of temperature, the resistance of the conductor also changes. Tensile load The maximum force with which a cable can be loaded under defined conditions. Test voltage The voltage applied to a test specimen to demonstrate a particular electrical strength. Tex The fineness of fibres is determined using the “fineness in Tex” system. This is a physical variable. 1 Tex = a fibre that has a mass of 1g at a length of 1000 m. Example: Polyester silk has a rating of 7 Tex = 1000 m of silk weighs 7 g. Thermal splice A thermal splice is a connection between light waveguides created by fusing the ends of the conductors.

Thermoplastics, thermoplastic materials Thermoplastics are non-cross linked macromolecular compounds. By heating, it is possible to transfer them repeatedly to a plastic condi- tion. They are primarily used for sheathing and insulation of cables. Thomson measuring bridge for resistance measurement Primarily used to measure very low resistances. The measuring range is between 10-6 and one Ohm. It is independent of voltage changes. The measured result is not falsified by the resistance of the measuring lead and other transition resistances (see also → Electrical resistance). Tight buffer tube Fibre type used in light waveguides, with a solid plastic layer attached directly to the outer glass. Torsion Twisting of the cable about the longitudinal axis. VDE0298, Part 300, Section 5.4.4: Flexible cables are not generally intended for torsional loads. In cases where this kind of torsional load cannot be avoided, the construction of the cable and the type of installation must be agreed between the user and the cable manufacturer. Tracer thread A thread whose structure, colour or colour combination is registered and protected as a trademark by a cable manufacturer. It provides informa- tion about the manufacturer of the relevant cables (at Lapp, the colour is ochre yellow). Train signal cable Designed for voltages up to 600 V. Depending on their purpose, the cores are twisted in fours or layers. They are PE insulated. Because of the strong electromagnetic fields on railways, an effective copper screen and steel tape armouring must be fitted under the outer sheath. Transceiver This is the active component of an Ethernet LAN for connection of termi- nals to the electrical bus cable with collision detection and signal adap- tation functions. Transceiver is a combination of the words transmitter and receiver. The transceiver performs transmitting, monitoring, recep- tion and interference functions. Transfer impedance Measure for the quality of the screening, defined as the ratio of the voltage along the screening in the system subject to interference to the current of the system causing the interference. The transfer imped- ance (coupling resistance) is the key variable for the quality of the screen and depends on the frequency. It is the ratio of the voltage drop along a screen on the side with interference (outside) to the interfer- ence current on the other side (inside) of the screen. The coupling resistance is determined by the construction of the screen, the skin effect and the capacitive coupling. Transfer rate The frequency at which the level of the transmission function of a light waveguide has reduced to half of its value at a frequency of zero, i. e. at which the signal attenuation has increased by 3 dB. As the transmis- sion bandwidth of a light waveguide is approximately the reciprocal of its length (mode mixing), the bandwidth/length product is often specified as a quality feature. Tin Tin is used for tin plating copper wires.

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