1. All-Russia D.I. Mendeleyev Scientific and Research Institute for Metrology (Vniim) (FGUP "D.I.Mendeleyev VNIIM") Konstantin Popov Constv.popov@gmail.com

2. National standards VNIIM VNIIM have 53 Primary Standards of Russian Federation, including: Mass Length Force Density Viscosity Pressure Velocity of air flow Velocity of water flow

3. Building water meters and gas meters Departments of Weights and Measures Built in1902 г.

4. The pump of waters meters Department

5. Primary Standard of velocity of water flow Range, m/s0.05 – 20.0 SD, %0.2

6. Primary Standard of velocity of Air flow Range, m/s0.1 – 100.0 SD, %0.2

7. 7 Laser Dopler Anemometr grid step of velocity field12.5 mkm

8. Water Flow Calibration Facility The VNIIM WFCF is a closed loop flow system that consists of a flow source (3 centrifugal pumps), flow conditioners, pipe lines, test section for the meters installation, valves for changing the flow, a diverters with collection/bypass unit, water reservoir, collection tanks, weigh scales, measured tanks, 5 master-meter ( electromagnetic flowmeters KROHNE ).

9. Water Flow Calibration Facility 2 separate pipelines EP-50 Pipe Size, 10-50 mm, flow range 0.012-50.0 m 3 /h Expanded Uncertainty 0.05-0.3 % EP-150 Pipe Size, 50-200 mm, flow range 2-320.0 m 3 /h Expanded Uncertainty 0.05-0.3 %

10. EP-50 Pipe Size, mm 10-50 Flow Range, m 3 /h0.012-50 Scale TypeWeight Scale Scale Capacity, kg150 Scale Resolution, kg0.05 Tank MaterialStainless Steel Tank Volume, m 3 4 Measured Tanks, m 3 100, 500 Temperature of water, o C15-90 Expanded Uncertainty, %0.05-0.3

11. EP-150 Pipe Size, mm 50-200 Flow Range, m 3 /h2.0-320 Scale TypeWeight Scale Scale Capacity, kg3000 Scale Resolution, kg0.1 Tank MaterialStainless Steel Expanded Uncertainty, %0.05-0.3

12. Flow generation system Pumps Water Reservoir Measured tanks Weight Scale Flow diverting device

13. Water Reservoir The facility is located near a water reservoir that has a capacity of approximately 600 m 3.

14. Flow Diverting Device Typedouble-wing Flow Range, m 3 /h2 – 320 Switch time, s0.15 Timer calibration, s0.0001 Min Test Time, s30 Time error, s0.003 According to ISO 4185:1980 “Measurement of Liquid Flow in Closed Conduits – Weighing Method” Appendix A1.1.1 Uncertainty, %0.01

15. Uncertainty Budget of Measurement

16. Thank you for your attention

17. In 2009, during carrying out of the APMP Water Flow Key Comparison (APMP.FF-K1 KC) problems with stability of a flow and diverting device have been found out. For the decision of these problems the hydraulic scheme of flow facility has been changed, water reservoir (600 м 3 ), additional damper and circular pump are included in an loop flow system. Also new adjustment and error definition for flow diverter is spent on ISO 4185:1980. Now VNIIM WFCF has a more stabilisated flow and optimised flow diverter, and Expanded Uncertainty is 0.05 % (K=2).