Should light scanners or light barriers be intended to be used under extremely narrow space conditions, at very high temperatures or e. g. in hazardous areas, the application of optical fibres combined with corresponding amplifier electronic systems is recommended. According to the type of application, it is decided whether a plastics optical fibre is sufficient or fibre optics are required to be used (e.g. in case of increased temperature). Welotec offers e.g. standard plastics optical wave guides that can be shortened by the user himself and be combined with amplifiers of different type series.