Enhancement of Leak Detection in Pipelines Through TDR/GPR Measurements

Leakage localization is crucial in the water distribution sector, where the percentage of water lost due to leaks often exceeds 30-40 %. In this regard, the authors have recently developed a time-domain reflectometry (TDR)-based system which, being based on an electromagnetic technique, overcomes the well-known downsides (such as sensitivity to environmental noise, to pipe material and geometry, etc) of traditional, electro-acoustic leak-localization techniques. Starting from the positive results obtained so far, in this work, the authors investigate the possibility of implementing an integrated TDR/GPR approach: the TDR would allow the preliminary leak localization, while the GPR technique would be used to have a countercheck for possible false positives. Also, GPR would allow to assess the entity of the leak (thus scheduling a priority order for repair) and to obtain a three-dimensional view of the subsurface soil around the pipes, so as to assess their health status. In this work, the combined TDR/GPR approach is tested on a pipe section in presence of two leaks. In addition to this, in this paper, also a different configuration of the TDR sensing element (SE) is experimented. As described in the following, this new SE configuration is expected to expedite considerably the implementation and the use of the TDR-based leak detection system.