Time domain reflectometry testing of a transmission line in a group of similar lines

摘要

A transmission line of interest within a group of transmission lines is tested for anomalies using Time Domain Reflectometry by applying the same pulse to all lines in the group simultaneously. A time domain reflectometer comprises a pulse generator 44 and a splitter 46 which creates pulses of equal magnitude and form to apply to several cables simultaneously via TDR probes 42. Only one cable within the group is tested for faults at a time, but identical pulses are applied to all neighbouring cables within the group. This reduces attenuation in the cable under test because all adjacent cables also carry a similar pulse. The transmission lines may be the three cables of a three phase power transmission system or alternatively groups of twisted pair wires or coaxial cables. Multiple reflection paths are also eliminated by the method.