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Fluctuations in the network pressure of water supply systems affect hydraulic performance and water meter accuracy. The development of metering error curves requires steady-state conditions which are extremely rare in water distribution systems characterized by intermittent supply. Simple deterministic models are suggested and developed from monthly data collected over a 4-year period (2010–2014) for three most dominant meter models (Models 1–3) in the Kampala Water Distribution System (KWDS), Uganda. This study combines pressure and billing information at the same time to understand metering accuracy. Results showed that metering accuracy increased by 4.2% for Model 1, 8.4% for Model 2 and 2.9% for Model 3, when the pressure was increased from 10 to 50 meters head. Age did not influence the impact of pressure on meter accuracy. The most sensitive parameter in the model was the meter age. Metering accuracy was relatively constant after a period of 5 years. The least sensitive parameter was the working pressure which caused a slight change to the annual billed volume. The ability of the model to accurately predict the meter registration degenerated with an increasing annual billed volume. Model 2 meters were the best performing and probably the most suitable meters in the KWDS. HIGHLIGHTS Working pressure showed a positive effect on meter registration which degraded with aging.; Low median working pressure caused an increase in meter under-registration.; Meter age was the most sensitive parameter.; The ability of the model to accurately predict the meter registration degenerated with an increasing annual billed volume.; Model 2 meters were the most suitable meters in the KWDS.

Intermittent supply is common worldwide. It triggers households with piped connection to adjust the supply scheme by the use of a water tank with a float valve (FV) at the entrance, which has a major influence on the water meter accuracy. This study investigated the impact of the water tank with a FV on the performance of water meters under intermittent and continuous supply conditions, using laboratory experiments, field measurements, and hydraulic modeling. Results revealed that the inflow rates into the water tank are consistently lower than the outflow rates of the tank. This will always be the case owing to the balancing mechanism of the tank. The flows that pass through the water meter represent the inflows into the tank. Therefore, higher metering errors and more apparent losses are expected for a combination of a water tank, FV, and continuous supply. Besides, different FV types have different hydraulic characteristics. Larger FVs with higher discharge rates tend to maintain the water level close to the full level in the tank and conferred longer periods of low flows, worse meter performance, and more apparent losses. For intermittent supply, results confirmed that higher intermittency levels lead to improved performance of water meters and reduce the apparent losses. This points to the complication in transformation from intermittent to continuous supply worldwide. In this case, water utilities should expect higher meter errors and more revenue losses unless the meter replacement policy recognises lower flows passing through the meter.

Water utilities worldwide lose 128 billion cubic meters annually, causing annual monetary losses estimated at USD 40 billion. Most of these losses occur in developing countries (74%). This calls for a rethinking of the challenges facing water utilities in developing countries, foremost of which is the assessment of water losses in intermittent supply networks. Water loss assessment methods were originally developed in continuous supply systems, and their application in intermittently operated networks (in developing countries) is hindered by the widespread use of household water tanks and unauthorised consumption. This study provides an extensive review of existing methods and (software) tools for water loss assessment. In addition, several new methods providing improved water loss assessment in the case of intermittent supply are discussed. As the volume of water loss varies monthly and annually according to the amount of water supplied, this study proposes procedures to normalise the volume of water loss in order to enable water utilities to monitor and benchmark their performance in water loss management. The study also develops a novel method for estimating apparent losses using routine data of WWTP inflows, enabling future real-time monitoring of losses in networks. Different methods have been suggested to estimate unauthorised consumption in networks. This study found that minimum night flow analysis can still be applied in the case of intermittent supply if an area of the network is supplied for several days. Furthermore, the study concluded that water meter performance is enhanced under intermittent supply conditions. However, continuous supply in the presence of float valves significantly reduces the accuracy of water meters. Finally, this study provides guidance and highlights several knowledge gaps to improve the accuracy of water loss assessment in intermittent supply networks. Accurate assessment of water loss is a prerequisite for reliable leakage modelling and minimisation, as well as planning for, and monitoring of water loss management in distribution networks.

Water utilities worldwide lose 128 billion cubic meters annually, causing annual monetary losses estimated at USD 40 billion. Most of these losses occur in developing countries (74%). This calls for a rethinking of the challenges facing water utilities in developing countries, foremost of which is the assessment of water losses in intermittent supply networks. Water loss assessment methods were originally developed in continuous supply systems, and their application in intermittently operated networks (in developing countries) is hindered by the widespread use of household water tanks and unauthorised consumption. This study provides an extensive review of existing methods and (software) tools for water loss assessment. In addition, several new methods providing improved water loss assessment in the case of intermittent supply are discussed. As the volume of water loss varies monthly and annually according to the amount of water supplied, this study proposes procedures to normalise the volume of water loss in order to enable water utilities to monitor and benchmark their performance in water loss management. The study also develops a novel method for estimating apparent losses using routine data of WWTP inflows, enabling future real-time monitoring of losses in networks. Different methods have been suggested to estimate unauthorised consumption in networks. This study found that minimum night flow analysis can still be applied in the case of intermittent supply if an area of the network is supplied for several days. Furthermore, the study concluded that water meter performance is enhanced under intermittent supply conditions. However, continuous supply in the presence of float valves significantly reduces the accuracy of water meters. Finally, this study provides guidance and highlights several knowledge gaps to improve the accuracy of water loss assessment in intermittent supply networks. Accurate assessment of water loss is a prerequisite for reliable leakage modelling and minimisation, as well as planning for, and monitoring of water loss management in distribution networks.

All residential water meters have published flow rates for which they will operate as designed. These specifications include a maximum operating flow rate, which is recommended not to exceed. However, there are situations which may cause a meter to flow above the maximum flow rate. This thesis explores what effect these surge flows have on residential water meters. Twenty-one 5/8���x3/4��� meters were tested in this study: three oscillating pistons, six nutating disks, nine ultrasonic, and three electromagnetic. Testing was done at the Utah Water Research Laboratory using a gravimetric test bench specifically designed for residential water meter testing. The results of this study showed that the ultrasonic meters decreased significantly in accuracy for tests above 35 gallons per minute. The nutating disk and oscillating piston meters were found to be accurate through nearly all surge flow rates tested. The electromagnetic meters were found to be accurate up to 55gallons per minute. Accuracy tests that were performed after surge flows showed that some nutating disk and oscillating piston meters decreased in accuracy at flow rates below two gallons per minute. The electronic meters had similar accuracy before and after surge flows.

This paper presents a water meter substitution plan based on a composite "Replacement indicator" which was defined and compared with common substitution strategies based on meter age and on run-to-fail approaches. The methodology was applied to one of the 17 sub-networks in which the Palermo city water distribution network (Italy) is divided. The analysis was carried out considering a substitution budget limitation and the results showed that the use of "Replacement indicator" outperform the classical substitution strategies based on meter age because it takes into account some other variables that may affect meter precision and wearing. (C) 2013 The Authors. Published by Elsevier Ltd.

March 3, 2016 – The water meter buried in your front yard isn’t exactly the most cutting-edge piece of technology. While they are accurate, most residential water meters are read only once per month, resulting in rough usage data – often rounded to the nearest 1,000 gallons. With the limited data, water utility managers can’t distinguish individual uses, such as sprinklers versus toilets, or determine usage by time of day. This limits their ability to spot costly leaks or see opportunities for water conservation. And it gives water users no useful information about how and when they use water., https://digitalcommons.usu.edu/engineering_news/1082/thumbnail.jpg

Köçkar, Hakan (Balikesir Author), Co-Fe films were electrodeposited on polycrystalline Titanium substrates from the electrolytes with different pH levels. X-ray diffraction (XRD) was used to study the crystal structure of the films. The XRD patterns showed that the films grown at the pH levels of 3.70 and 3.30 have a mixed phase consisting of face-centred cubic (fcc) and body-centred cubic, while those grown at pH=2.90 have only fcc structure. It was observed that the film composition, by energy dispersive x-ray spectroscopy, contain around 88 at% Co and 12 at% Fe for all films investigated in this study. Morphological observations indicated that all films have grainy structure with the slight change of grain size depending on the electrolyte pH. Magnetoresistance measurements, made at room temperature, showed that all films exhibited anisotropic magnetoresistance, which is affected by the electrolyte pH. From the magnetic measurements made by vibrating sample magnetometer, the saturation magnetization increases as the electrolyte pH decreases. Furthermore, all films have in-plane easy-axis direction of magnetization.

We demonstrate that a micro Coriolis mass flow sensor can be excited in its torsional movement by applying parametric excitation. Using AC-bias voltages for periodic electrostatic spring softening, the flow-filled tube exhibits a steady vibration at suitable voltage settings. Measurements show that the sensor for this type of excitation can be used to measure water flow rates within a range of 0±500 ul/h with an accuracy of 1% full scale error.