During the EMPIR project MetroWaMet – Metrology for real-world domestic water metering metrology and measurements were developed for domestic water meters under real-life conditions and especially for dynamic measurements.
The overall aim of the MetroWaMet project was to provide European manufacturers of water meters and water suppliers with needed trusted measurement capabilities to assess the measurement performance of domestic water meters close to real world conditions such as dynamic changes and fluctuations in water quality. Test profiles reflecting water consumption characteristics were derived for dynamic flow changes. All partners implemented an infrastructure to evaluate the performance of household water meters under dynamic load changes. The capabilities and quality of the newly developed metrological infrastructure were demonstrated in an inter-comparison. Moreover, the impact of water quality on the performance of domestic water meters and the intelligent detection of small flows and leaks were examined in the project.
VTT MIKES built a test facility that can perform both static and dynamic flow measurements for different types of flow meters with pipe size DN15–25 and a flow range from 50 kg/h up to 3000 kg/h. The test rig is based on a scale as the reference device, and it imitates a household system: the local water supply network is used to feed the inlet and an additional pressure vessel is used to stabilize the inlet water pressure. The meter under test is installed to measurement section and after that are the valves to control the flow rate. The maximum mass of the scale is 800 kg with a step value of 10 g, the inlet pressure ca. 4 bar and water temperature between 4–10 degrees. The lowest measurement uncertainty of the device is 0.40 % (k = 2) for dynamic flows and 0.16 % (k = 2) for static flows.
The new test equipment expands VTT MIKES liquid flow measurement range for smaller flows, as previously the smallest measurable flow rate was ca. 3600 kg/h. The possibility of dynamic measurements also brings new dimensions to the study of flow meters, and the equipment is already being used in a new research project.
VTT MIKES maintains the national standards for water flow. The northernmost national standards laboratory in the world, located in Kajaani, has three water flow calibration rigs. The gravimetric calibration rig (D200) serves as the national measurement standard for water flow, and it has 6000 kg and 800 kg scales as reference device. Measurable pipe size is up to DN200, mass flow up to 720 kg/h and the measurement uncertainty of the rig is 0.05 % (k = 2). Two other calibration rigs (D500, D100) are based on reference meters. The pipe size is up to DN500, volume flow up to 2700 m3/h and the measurement uncertainty of these rigs is 0.3 % (k = 2).