Image Processing Technique for Improving the Sensitivity of Mechanical Register Water Meters to Very Small Leaks.

Marco Carratù,Antonio Pietrosanto,Giuseppe Di Leo,Salvatore Dello Iacono,Consolatina Liguori

doi:10.3390/s21217251

Abstract

Discovering very small water leaks at the household level is one of the most challenging goals of smart metering. While many solutions for sudden leakage detection have been proposed to date, the small leaks are still giving researchers a hard time. Even if some devices can be found on the market, their capability to detect a water leakage barely reaches the sensitivity of the employed mechanical water meter, which was not designed for detecting small water leakages. This paper proposes a technique for improving the sensitivity of the mechanical register water meters. By implementing this technique in a suitable electronic add-on device, the improved sensitivity could detect very small leaks. This add-on device continuously acquires the mechanical register’s digital images and, thanks to suitable image processing techniques and metrics, allows very small flows to be detected even if lower than the meter starting flow rate. Experimental tests were performed on two types of mechanical water meters, multijet and piston, whose starting flow rates are 8 L/h and 1 L/h, respectively. Results were very interesting in the leakage range of [1.0, 10.0] L/h for the multijet and even in the range [0.25, 1.00] L/h for the piston meter.

Highlights

The European Metrology Program for Innovation and Research (EMPIR), according to the European Association of National Metrology Institutes (EURAMET), funded, in 2018, the Joint Research Project (JRP), named 17IND13 Metrowamet—“Metrology for real-world domestic water metering”
The well-known importance of water for human life is a large reason why water leakage is today considered a severe problem even in small quantities [1,2]. For this reason, much research about the issues regarding the development of leakage detection techniques have been recently proposed: in [3] it has been reported feedbacks about the use of Automated Meter Reading (AMR) system to detect leakage in a large-scale demonstration site, which is conducted at the Scientific Campus of the University of Lille; in [4] the water management system based on Wireless Sensor Networks (WSN) has been analyzed; while in [5,6] novel leak detection techniques are proposed
While some practical solutions exist in the distribution networks for leakage detection, the latter appears to be more challenging at the household level

Summary

Introduction

The European Metrology Program for Innovation and Research (EMPIR), according to the European Association of National Metrology Institutes (EURAMET), funded, in 2018, the Joint Research Project (JRP), named 17IND13 Metrowamet—“Metrology for real-world domestic water metering”. Mechanical water sensors are based on pistons or turbines, providing starting flow rates ranging from 1 L/h to 12 L/h This aspect has a significant impact on the performance of small leakage detection aims. Good sensitivities (ranging from 0.5 to 5 L/h), but any response time are indicated in datasheets Due to these characteristics, only solutions that implement suitable small detection algorithms in domestic water meters would spread to the customer as wide as requested by the problem’s importance. The continuous offtake and the Period with Null Consumption (PWNC) monitoring represent a practical approach to developing a robust method for detecting small leakages In more detail, both quantities are time interval values characterized, respectively, by the Sensors 2021, 21, 7251 meter, several PWNCs should appear for an entire day. The microcontroller has been suitably programmed in C language, using the Keil uVision software, which allows the compile, program, and debug the C-code for these devices’ typologies

Image Processing Techniques and Metrics

Dynamic Profile

Conclusions