Sotto® Vibration Sensors: Listening for Network Leaks at South East Water
Sotto® is a key innovation in South East Water’s (SEW) critical work to reduce non-revenue water losses due to hidden leaks on SEW’s network.
SEW’s Sotto® program involves the development of high-performance vibration sensors that are small enough and cost effective enough to be packaged within a digital water meter installed on commercial and residential properties. While digital meters will identify leaks on the consumer’s property Sotto® is instead tuned to detect water leaks on SEW’s infrastructure before the leak reaches the surface where it invariably is reported by the public or potentially develops into a mains burst emergency.
The Sotto® sensor has been in development and testing for over three years and is currently at a commercial level quality and undergoing trials installed within digital water meters. The trials are on actual in-field leaks and are focused on determining Sotto®’s ability to detect and report those leaks. In addition, the trials are studying the impact of pipe materials, understanding the likely sensor distribution density of any large-scale network deployment and interpreting the generated data and how it may be used to increase Sotto®’s effectiveness.
The Sotto® device takes multiple vibration readings during the quietest part of the night and assesses them against a pre-determined threshold before sending alerts to operations teams via the digital meter’s reporting payload. Various actions and algorithms are applied to mitigate against false positive signals. Leak vibration signals depend on several variables including distance, pipe material and leak size among others.
Sotto® has detected vibration signals at 80m and, when leaks are detected on multiple sensors simultaneously, can support triangulation to approximate the leak location. Where there is no leak a very low noise floor on the sensor ensures a leak signal is not lost within the noise and minimizes the chance for false positives.
Trials to date have exceeded expectations with Sotto®’s performance similar to or better than benchmark commercial leak detection ‘listening sticks’. Sotto® has shown the capability to detect a majority of SEW’s network leaks. Further development work is underway to improve Sotto®’s sensitivity on challenging small leaks and pipe materials such as UPVC that attenuates vibrations
A patent has been submitted and is pending.
The program is now approaching final trials with the deployment of 1,000 Sotto® embedded digital meters in mid-2020 and another 4,500 in late 2020.
To read the full paper, you can download it HERE.