A Non-Intrusive Ultrasonic Sensor System for Water Flow Rate Measurement

Ultrasonic technologies have established themselvesas optimal solutions for water flow rate measurement thanksto the high reliability and efficiency they offer. However, theexisting applications often require ultrasonic sensors to be embeddedin pipes, i.e., intrusive, which significantly increases initialdeployment and maintenance costs. Considering the volume ofemployment, one to each house, the water meters have to bedesigned in a way that the consumers can deploy and maintainthem without any skilled labourer. Hence, this paper proposes adelta time-of-flight (ToF)-based non-intrusive sensor systemfor plug-and-play ultrasonic water flow rate metering. Afterintroducing the measurement theory and our proposed design,we experimentally evaluated the performance of three differentToF calculation methods in terms of memory and computationrequirements through a dedicated testbed consisting of a closedloopmulti-pipe layout. The results helped us to determine theoptimal ToF method for the employed platform, which isthen used to select the best sensor and housing setting thatis operable even under the worst deployment conditions (pipematerial, diameter). Compared to its intrusive counterparts, theproposed system achieved a sufficient level of precision (\ub15.7%),and hence provided the possibility of replacing the conventionalmethods of intrusive water metering at the household level