Performance Analysis of Ageing Single-Jet Water Meters for Measuring Residential Water Consumption

Abstract

Single-jet meters are one of the most frequently used domestic meters that can be found in water distribution systems. Like any other water meter technology, they have significant metrological limitations that prevent them, even if recently installed, from measuring all water consumption of a domestic customer. After installation, their metrological characteristics evolve depending on the particular design of the meters and their actual working conditions in the field. This work presents a comprehensive set of tests to determine the initial and after installation weighted error of two types of domestic single-jet water meters. Three non-linear degradation models have been derived from the tests results. These models consider age, totalised volume, or both parameters simultaneously as drivers of the weighted error. The results show that even though the construction of the two examined meters is similar, they have been working under comparable operational conditions and measuring water of the same quality, there is a significant difference in the performance between both types. This result highlights the need to conduct individual analyses for each meter type and the impossibility of generalizing conclusions on how the weighted error could evolve over time.

Advances in the Economic Analysis of Residential Water Use: An Introduction

“…These papers cover a large number of countries (Spain, France, Jordan, Australia, Bangladesh, Brazil, Lithuania, Peru, Poland, Russia, Serbia, Tanzania, Zambia, Zimbabwe, Colombia, India and Unites States of America). Some papers deal with the impact of water metering on residential water use (i.e., [46][47][48]), while others consider pricing policies (i.e., [49,50]), non-price policies (i.e., [51,52]) or the performance of water services (i.e., [53,54]). All selected papers contribute to a better understanding of residential water use, and they provide relevant results for policy-makers in charge of water management.…”

Systematic oversizing of service lines and water meters

“…Figure presents two sets of solutions to quantify potential improvements in accuracy from using a downsized meters. Consistent with observations from Barfuss et al () and Arregui et al (), here, it is assumed the meter underregisters when the flow occurs outside the specified accuracy limits. The lower line in Figure shows the potential benefits of using a meter one size smaller at site 116, and the upper line shows potential benefits of using a meter two sizes smaller at site 116.…”

“…A key observation of the study was that “most manufacturers that publicize AWWA standard compliancy do not consistently meet AWWA metering standards” (Barfuss et al, ). A similar study on in situ water meters in Spain did not compare meters to AWWA standards but instead chose to directly model the degradation of meter accuracy with time (Arregui, Gavara, Soriano, & Pastor Jabaloyes, ). A practical conclusion from these researchers is that care is needed when designing near either endpoint of a meter accuracy curve.…”

Calculation Proposal for the Economic Level of Apparent Losses (ELAL) in a Water Supply System

“…There is always a technically minimal volume of unmeasured water, defined as the Unavoidable Annual Unmeasured Volume (U AUV), that cannot be completely removed, even in well-maintained and properly managed systems. The reason is simple: water meters have an intrinsic error even at the time of installation (Table 1) [23]. This initial and minimum achievable error mainly depends on the working principle of the meter.…”

“…The reason is that even in a best-case scenario when meters have been recently installed, there is an unavoidable measuring error intrinsic to the meter technology used. Furthermore, as meters age and their mechanical parts wear out, their metrological characteristics degrade and measuring inaccuracies increase [23]. The resulting apparent losses (meters under-registration) will depend on the working conditions of the meter and also on the customers' consumption profile [24].…”