Laboratory experiments on the water meters performarce under intermittent and continuous water supply

Accurate water measurement is essential for the effective management of urban water distribution networks, particularly in systems characterized by intermittent supply. This study investigates the performance of volumetric water meters under both steady and transient flow conditions, with specific attention to pipeline refilling phases and the presence of air within the pipes. Experimental tests were conducted on a full-scale laboratory network, built at the Environmental Hydraulic Laboratory of the University of Enna (Italy). Flow rate, pressure and water volumes through the water meters were measured with high precision, using an innovative ad hoc measurement system, based on a wireless data transmission between the sensors and the acquisition system, representing a scalable and cost-effective solution. Furthermore, the water volume was estimated using the water weight and density. Single-jet and multi-jet meters were investigated. The results show for both meters, good accuracy, under steady-state flow conditions; however, significant measurement errors arise during transient events, with huge overestimation of the water volume flowing through the meters. The experimental campaign demonstrated how apparent losses are deeply affected by the management of the network, with errors ±100% in function of the specific operating conditions. In intermittent water supply, in fact, the water volume is clearly overestimated, whereas in continuous supply systems it can be deeply underestimated. These findings highlight the importance of testing water meters and monitoring devices under more realistic operational scenarios to ensure reliable billing, accurate water loss assessment, and improved overall water network management.