1. Ultrasonic Flowmeter Technology

2. Ultrasonic Flowmeter - UFM
Measurement Principle: Transit Time
(or time-of-flight principle)
Theory:
Signal in the direction of flow travels faster compared
to signal against the flow direction
The difference in transit time is a measure for the flow velocity
A swimmer swims faster with the flow as
compared to against the flow
The sonic signal does the same
… external measurement of internal flow

3. Clamp-on Ultrasound Flow Meter
The average velocity of the entire pipe is measured directly

4. Shear wave principle – for liquids
Pipe wall penetration
Multi reflection

5. Shear Wave Transducer No pipe frequency dependency
4 size transducers covers full pipe range
… external measurement of internal flow

6. Flow profile disturbance
Bends, valves, elbows, diffusers, reducers, pumps etc. change the profile of the flow.
Certain distances to such flow elements are necessary for an undisturbed flow profile.

7. Multiple Beams – less straight run
Direct Mount 10-5
Reflect Mount 5-2
2 Path – 3-1

8. Monitoring water networks with ultrasound flow meters
Costs of installing inline flow meters
Calculating the effects of the water supply interruption:
Are there other pipes that lead into the affected area?
Are these pipes sufficient to supply the affected area?
Or is a bypass required?
Planning effort: at least ½ man-day

9. Monitoring water networks with ultrasound flow meters
Costs of installing inline flow meters
Informing of the supply interruption
Identifying which streets / households are affected
Printing the notifications
Distributing the notifications

10. Monitoring water networks with ultrasound flow meters
Costs of installing inline flow meters
Installation of the flow meter:
Shutting off the pipe
Cutting the pipe
Welding the flanges
Installing the flow meter
Effort: starting with 6 man-days (3 staff members x 2 days)

11. Monitoring water networks with ultrasound flow meters
Costs of installing inline flow meters
Restarting the water supply:
Reopening the pipe
Flushing the pipe
Effort: 1-2 hours

12. Monitoring water networks with ultrasound flow meters
What do the IWA and EPA guidelines mean for a water supplier?
Example Richmond (Virginia)
If every DMA requires just 2 flow meters (for inflow and outflow) then Richmond would require about 60 flow meters
Inline flow meter installation costs (excluding earth works) if IWA and EPA guidelines are followed:

13. USFM Monitoring water networks with ultrasound flow meters
Costs of installing ultrasound flow meters
Calculating the effects of the supply interruption:
Not necessary
Informing of the supply interruption:
Not necessary
USFM
Restarting the water supply:
Not necessary

14. Monitoring water networks with ultrasound flow meters
Costs of installing ultrasound flow meters
Installation of the flow meter:
Shutting of the pipe
Cutting the pipe
Welding the flanges
Determining pipe parameters
Installing transducers
Connecting the transducers and parameterizing the transmitter
Effort: about ½ man-day

15. Monitoring water networks with ultrasound flow meters
Comparison of man-days
Work step
Minimum man-days inline flow meter
Minimum man-days ultrasound flow meter
Calculating the effects of the supply interruption
½ day
not necessary
Informing of the supply interruption
¼ day
Installation of the flow meter
6 days
Restarting the water supply
Summ:
7 days

16. Monitoring water networks with ultrasound flow meters
What do the IWA and EPA guidelines mean for a water supplier?
Example Richmond (Virginia)
If every DMA requires just 2 flow meters (for inflow and outflow) then Richmond would require about 60 flow meters
Inline flow meter installation costs (excluding earth works) if IWA and EPA guidelines are followed:
Ultrasound flow meter installation costs (excluding earth works) if IWA and EPA guidelines are followed:

17. Purchase of flow meters Installation of flow meters
Monitoring water networks with ultrasound flow meters
Possible bottlenecks in the implementation of the IWA and EPA guidelines
Planning of zones
Purchase of flow meters
Installation of flow meters
Staff bottleneck
Capital expenditure bottleneck
Staff and operational expenditure bottleneck

18. Monitoring water networks with ultrasound flow meters
What is required of a DMA flow meter?
Measuring very low flow velocities
The flow velocity in pipes DN200 – DN400 is seldom above 1 m/s
The minimum night flow velocity is nearly always below 0.2 m/s
Nightly changes of flow direction are not seldom

19. Monitoring water networks with ultrasound flow meters
What is required of a DMA flow meter?
Extremely robust
Must be permanently resistant to groundwater and rainwater
Have to withstand the possible strain of being stepped on (during chamber inspections) and the strain during the cleaning of chambers
Must withstand the mechanical stress during the burial of the transducers

20. Monitoring water networks with ultrasound flow meters
What is required of a DMA flow meter?
Completely maintenance-free
No consumable material
No wear parts

21. Monitoring water networks with ultrasound flow meters
Extreme low flow measurements with ultrasound
Measures extremely low flow rates (down to 0.01 m/s) and is therefore ideally suited for DMA monitoring
Cable length of up to 300 m (Transmitter to Transducer)
Integrated temperature compensation

22. Monitoring water networks with ultrasound flow meters
Extremely robust design
Massive stainless steel mounting
Transducers are not directly visible
Transducer mounting can only be opened with tools
No connections on the IP68 transducer heads

23. Monitoring water networks with ultrasound flow meters
Coupling pads – maintenance free
Maintenance-free due to coupling pads
No use of coupling paste
Instead the high signal strength and the excellent signal evaluation software enable us the use of permanent coupling pads
No more Gel fixed units

24. Thank you