Effect of elevated temperature on water meter accuracy: An investigative study using three positive displacement mechanical meters

In certain parts of Australia, summer temperatures can exceed 40 C. Domestic water meter performance under these extreme conditions is not well understood. The internationally adopted standard for pattern approval and verification (OIML R49-2 2006) does not require determination of the influence of both elevated water and ambient temperature on the error of measurement of the meter. A study was therefore undertaken to investigate these aspects using three positive displacement mechanical meters: two new 20mm nominal diameter (DN20) meters and one used 32mm nominal diameter (DN32) meter. A combination of temperature conditions was varied from 20 degreesC to 50 degreesC and the meter accuracy was determined. There was increased under-reading with the increase in water and ambient temperature. However, the measurement error largely remained within the limits of the maximum permissible error (MPE). It is concluded that, based on the results of this study, periodic elevated temperatures do not significantly affect the performance of domestic water meters and, therefore, do not adversely affect the water suppliers or consumers.