Archive: Institute of Measurement Technology

The shielding of conductors and cables represents one of the most important preparatives against interferences caused by external electromagnetic influences. Shielded cables often consist of braided wire shields. Studies in the past have shown, that damages of braided shields due to fabrication tolerances and particularly mechanical stress change the properties of the conductors. This results in shield inhomogeneities and leakage locations where electromagnetic energy can be coupled into the conductors. Interfering currents are the consequence which e.g. can affect the reliability of transfer signals in networks. Since most of the cables are enclosed by synthetic strand insulation and frequently hard to access, it is difficult to find the location of an aperture by means of an optical measure procedure. Hence, the aim of this research project is the development of a measurement system which detects the location and degree of a leakage on the cable shield. In order to characterize single shield inhomogeneities the tranfer impedances and transfer admittances have to be measured. Besides the measurements, computer simulations are planned to expand the recorded results for other cables with different conductor arrangements and geometries.