Substituição racional de hidrômetros em sistemas de abastecimento de água

Abstract

This study evaluated the effect of under-metering in 862 water meters in a countryside city of São Paulo State, with 75,000 active water connections. It was evaluated metrological class A and B water meters, separated by manufacturer, year and totalized volume. All water meters were subjected to bench tests in three flows, 15 L/ h (class B) or 30 L/ h (class A), 75 L/ h (class A and B) and 750L/ h (A and B class). The results showed that 37.1% were disapproved by registering reading lower than the reference, with sub-metering ranging from -0.7 to 31.1%. It was observed that some older water meters had better metrological performances than the newest ones, and if a replacement without criteria be held, it may result increase in an apparent losses with a reduction of incoming rather than benefits. This study enabled the creation of a sequence of groups of lowest water meter metrological performance, and its replacement will result in an increase in micromeasured volume, reducing the rate of apparent losses and, consequently, increasing the amount billed.