Marsh McBirney Flo-Dar Accurate Flow Measurement Flo-Dar TM provides the user with highly accurate flow measurements under a wide range of flows and site conditions. By measuring the velocity of the fluid from above, Flo-Dar TM eliminates problems inherent with submerged sensors including sensor disturbances, high solids content, and distribution of acoustic reflectors. KEY ADVANTAGES OF FLO-DAR As the Flo-Dar uses radar sensing it will work on clean water as well as raw sewage, the system has no contact with the flow which means no ragging, leading to maintenance free operation, Ease of use Site set-up via keypad or software supplied. No site work or flow shutdown is usually required as the sensor fits into the existing site. No entry to confined space after initial installation, sensor can be removed without manhole entry. Low flowrates can be measured typically flows with depths less than 5 mm. Level is detected by ultrasonic pulse echo. Flow is then calculated based on the continuity equation Q=V*A, where Q = Flow, V = average Velocity and A = Area.
Flo-Dar TM Model 460 (Portable System) Flo-Dar TM Model 464 (Fixed System) Model 460 Portable System The temporary (portable) monitor model 460 is a battery powered data logging system housed in a sealed watertight (IP68) polyurethane enclosure. The monitor is able to resist submersion in surcharge conditions. The monitor has a 64K memory to store 16000 cycles of velocity and level data from the Flo-Dar TM sensor. Two sixvolt batteries can provide up to 10 weeks of data collection on 15 minute data interval. Stored data are retained when batteries are removed or depleted. The monitor has a RS232C connection for easy set-up and data retrieval with a laptop computer. Model 464 Fixed System The Model 464 is a fixed control unit designed for outside installation. The enclosure is rated IP 65. The unit can be powered 220 or 110 VAC/50 Hr or 12 VDC. The Model 464 interfaces directly with the Flo-Dar TM sensor and the site set-up is made via RS232C connected to a laptop or PC and a menu driven Windows based set-up software. The Model 464 provides three 4-20 ma outputs, for flowrate, velocity and level and has an integral data logger Options: Digital output board with 1 alarm and 2 flow proportional contact closures fully adjustable. GSM and PSTN modems, Solar Power packages ATEX Zone 1 option Surcharge Sensor: Allows full pipe flow measurement
Flo-Dar Data Reporting The portable Flo-Dar (Model 460) and the fixed Flo-Dar (Model 464) are equipped with builtin data loggers as standard. Data is downloaded from the Flo-Dar via Flo-Ware, this software is supplied free of charge with each system. Flo-Ware is a powerful reporting package that enables users to produce professional reports quickly and easily, examples of graphical and tabular reports are shown below. Screen print showing graphical display of inlet flows at a treatment works. Min, Max and Average values are shown in blue, flow is shown in red, level is shown in green. Screen print showing one of the many reports that are generated by clicking a single button on the report manager look-up table
Examples of Flo-Dar TM Installations Installation above 2m rectangular flow to treatment inlet channel Installation in enclosed channel. Note: Channel shape, flow in any channel shape can be measured Sensor installed in a 2m wide rectangular inlet channel
Examples of Flo-Dar TM Installations Installation inside chamber measuring turbulent flows in a 900mm pipe Typical chamber installation with 460 logger. Note flow velocity is over 4 m/s Flo-Dar measuring incoming flow to a treatment works
Flo-Dar TM Comparison Data Test results comparing Flo-Dar (non-contact) and an Electromagnetic (wetted sensor) To prove the Flo-Dar to a Water Authority a test was set to compare the Flo-Dar against an electromagnetic type open channel flowmeter. The electromagnetic system uses a wetted sensor to measure velocity, this sensor is mounted in the bottom of the channel. Both systems were installed into a 1.2 metre wide trapezoidal flow to works channel for a 2 week period, the flows from both meters were logged. The following graph shows the results produced, both meters worked well but the electromagnetic system was occasionally effected by ragging and would require maintenance in a fixed system. The graph below shows how Flo-Dar can never rag up even in raw sewage flows 600.00 500.00 Flo-Dar Magnetic System Flo-Dar used in 1.2 m wide flow to works channel Storm events, Flo-Dar continues to measure flow wetted sensor is effected by "ragging" 400.00 Flow to Works l/sec 300.00 200.00 Normal daily flow patterns 100.00 0.00-100.00 Time Period - 2nd July 1999 to 16th July 1999
Results comparing Flo-Dar and Full bore Electromagnetic Flowmeter To verify the accuracy of the Flo-Dar in a waste water treatment works a comparison was made between flows measured by Mag meters at the inlet to the works and the same flows measured by the Flo-Dar in an open channel located after the primary screens. Flow data from both systems was logged, these are shown on the chart below, Inlet Flow is measured with Mag meters, Bypass Flow is measured with the Flo-Dar. In this particular application the Flo-Dar is being used to control flows and chemical dosing to a primary treatment process, the Flo-Dar is a vital element in the correct operation of the works.
Results comparing Flo-Dar and Full bore Electromagnetic Flowmeter To verify the accuracy of the Flo-Dar in an actual sewer flow installation a comparison was made between flows measured by a temporary installation of an Electromagnetic Flowmeter at located downstream of the Flo-Dar installation. Data was logged for each flowmeter and is charted below. 60 50 Flow (l/sec) Test site Infiltration/Inflow Date: 24-26.03.03 40 30 20 10 Modified full pipe EM meter MMI, Radar 0 11:15:00 12:30:00 13:45:00 15:00:00 16:15:00 17:30:00 18:45:00 20:00:00 21:15:00 22:30:00 23:45:00 01:00:00 02:15:00 03:30:00 04:45:00 06:00:00 07:15:00 08:30:00 09:45:00 11:00:00 12:15:00 13:30:00 14:45:00 16:00:00 17:15:00 18:30:00 19:45:00 21:00:00 22:15:00 23:30:00 00:45:00 02:00:00 03:15:00 04:30:00 05:45:00 07:00:00 08:15:00 09:30:00 10:45:00 12:00:00 Time
Flo-Dar TM General Specifications Flow Measurement Volumetric flow partially filled round, rectangular and odd shaped conduits DN100 upwards. Velocity Measurement Method: Non Contact Doppler Radar Zero Stability: +/- 0.001 m/s Accuracy: +/- 0.5% of reading, depths >5 mm Range: 0.2 m/s to + 6 m/s W.T. Licence exempt under MPT 1349 Level Measurement Method: Ultrasonic pulse echo Maximum range to flow surface: 1625 mm Minimum range to flow surface: 100 mm Operating range: 0 to 1524 mm Temperature compensated Accuracy: > +/- 2mm Flow Calculation Method: Conversion of water level and pipe size to fluid area. Multiplication of fluid area by mean velocity to equal flowrate. Flow measurement accuracy: +/- 5% reading typical ( up to 90% full pipe) * * Proper site selection, sensor placement are recommended to achieve accuracy Sensor unit Field interchangeable with Control units Sensor housing: IP 68. Impact Resistant Polystyrene Sensor cable: 9m polyurethane outer jacket 8.25 mm o/d, special cables to order. Max Sensor cable length: 120 m, Sensor mounting hardware: Stainless Steel frame Temperature Limits: Max Ambient temperature +50 Deg C Sensor can be installed and removed from the pre-installed mounting frame without manhole entry. Controller/Display Unit Field interchangeable with Sensor units Model 460 Portable IP 67. Enclosure, Built-in data logger 16000 flow readings, control unit programmable with software supplied, report generating software supplied FOC, battery powered 2x6volt lantern cells Model 464 Fixed IP 65. Enclosure, IP66 option, Built-in data logger 16000 flow readings, control unit programmable with software supplied, Display: Flowrate/Total, report generating software supplied FOC 3 off Programmable 4-20 ma output for Flowrate, level and velocity. Certification CE marked Radio licence exempt under MPT 1349 Optional ATEX Zone 1 approval