Fiber optic tube diagnostic by using reflectograms

The water propagation into solid dielectric (water treeing) has been considered as one of the most important, causes of the failure in power cables with polymeric insulation. Since the discovery of these phenomena in underground cables in 1968, many researches have been devoted to understanding of moisture migration mechanisms. To detect, whether the moisturizing of the fiber optic underground cables may be diagnosed by the optical time-domain reflectometer (OTDR) measurement, we made a measurement of a 8-tube British cable (BICC) after one years propagation in a University local area network (LAN).