Politecnico di Milano experimenting with fibre optics against water wastage

Milan, 20 July 2023 - Using fibre optic sensors to monitor water networks against wastage: the international journal Sensors published the results of an experiment carried out at Politecnico di Milano aimed at optimising the water network.

Researchers from the Department of Civil and Environmental Engineering pioneered the use of distributed fibre optic sensing (DFOS) based on Stimulated Brillouin Scattering (SBS) technology for monitoring water pipeline networks over long distances. At the heart of this technology is the common and inexpensive optical fibre used for telecommunications (which brings the internet into our homes) capable of measuring deformations to a hundredth of a millimetre.

The scholars worked on High Density Polyethylene (HDPE) piping, today the most commonly used material for distribution systems. By wrapping and fixing the fibre optic sensor cable on the outer surface of the pipe, they tested the ability to detect deformations related to pressure anomalies along a pipe, such as those caused by water leaks.

The experiment consisted of two phases. "In the first one," the researchers explain, "we assessed the sensitivity of the sensor layout on an HDPE pipe stressed with static pressure. This first stage was successful, so we then concentrated on detecting the pressure anomaly produced by a leak in a piping circuit with flowing water. Overall, the results returned positive feedback on the use of DFOS, confirming the possibility of identifying and localising even very small water leaks.

In the future, the tested technology will be further developed towards industrial-scale production of 'natively smart' HDPE pipes, where DFOS are integrated into the pipe surface during the extrusion process.

The study, signed by Manuel Bertulessi, Daniele Fabrizio Bignami, Ilaria Boschini, Marina Longoni, Giovanni Menduni and Jacopo Morosi, is available at this link.

Water resource wastage is a global issue, increasingly exacerbated by the impact of climate change on the hydrological chain. In Italy, more than one third of the water fed into the national distribution network is wasted, according to ISTAT data from 2022. Widespread monitoring and efficient maintenance of the infrastructure are therefore two strategic and urgent actions.