General Information
Measurement system and application

• Ultra Sonic Sensors
• Transducer-electronics
• Intelligent processing units

Additional modules for special functions open up an exceptionally wide field of application:

• Flow measurement in storage and run-of-river power stations
• Pipe rupture monitoring of penstocks
• Flow measurements in open channels
• Flow measurement in water distribution networks of public water supplies
• Inflow and outlet measurements for sewage treatment plants

Transit-Time Measurement Principle

The sensors work alternately as transmitter or receiver. A piezo-ceramic oscillator is excited with a transducer voltage surge. The resulting ultrasonic sound pulse is propagated through the medium to be measured and is received at the opposite side where it is transformed back into an electrical signal. The transducer-electronics calculates the flow rate from the travel time difference of the ultrasonic pulses which are transmitted alternately with and against the flow.

Advantages:

Microprocessor controlled digital technology

• Sophisticated processing units
• Short measurement time
• High accuracy
• No moving parts
• High electromagnetic compatibility
• No impairment of the pipe or channel cross-section and therefore no pressure or head loss
• Large nominal diameter range
• Independent of liquid conductivity
• Multi-path measurements possible including cross flow correction
• Extremely flexible arrangement of transducer electronics and processing unit
• Proven operating concept in the languages English, German, French, Italian or Spanish
• Various additional modules, e.g., for pipe rupture monitoring

Multi Path measurement: Proven technology

Several tests were carried out at the IMHEF hydraulic laboratory of the Swiss Federal Institute Of Technology Lausanne. The test conduit had a diameter of 444,6mm. Florets from 80l/s to 930l/s have been produced, which corresponds to velocities from 0,5m/s to 6m/s. It can be shown that multiple path technology extremely shortens the straight-run requirements for ultrasonic transit-time flowmeters.
 

Single Path (1 Plane)  Two Paths (2 Planes)

Two Paths Crossed (1 Plane)  Four Paths Crossed (2 Planes)

Application

Accessories

Plastic field housing large for wall mounting and more accessories are available.

Technical Data of the Transducer-Electronics MFUMUN

Transducer Electronics

Flow rate 0 ... 0.7 to 0 ... 20 m/s (0 ... 2 to 0 ... 60 ft/s) Accuracy in pipe: single path ± 6 mm/s at v < 0.6 m/s ± 1% at v > 0.6 m/s Accuracy in pipe: Multi-path ± 3 mm/s at v < 0.6 m/s ± 0.5% at v > 0.5 m/s Accuracy in channel 1...5%, depending on measurement arrangement Resolution 0.8 mm/s Temperature dependence 0.01 mm/s per ºC

Pipe Measurement

The RISONIC sensors used for pipe measurement comprise a transducer insert, pressure insert and welding neck. Measurement takes place without restricting the pipe cross-section and therefore causes no pressure loss. The transducer insert can be removed under pressure. Complete measurement pipes are also available as an option.

The fully digitized transducer-electronics calculates the flow rate and communicates with the intelligent processing unit via the two-wire leads of the SENSORbus. In parallel, the transducer-electronics also provides the acquired flow as an analog signal.

The user friendly processing unit enables the application-specific parameterization of the entire measuring installation. The processing unit has:

• 2 analog outputs 0/4 ... 20 mA
• 2 pulse outputs
• 1 flow direction output
• 1 OK output
• 1 DUAL PORT RAM connection

Technical Data of Ultra Sonic Pipe Measurement Sensors "RISONIC"

Ultrasonic sensors

Pipe diameter 150 mm up to 8000 mm (6” up to 320”) Pipe wall strength 4 ... 60 mm (0.15 ... 2.36”) Material (pressure insert and welding neck) corrosion-resistant steel 1.4301 (316) Maximum allowable pressure 150 bar (2250 psi) Protection class IP67 (NEMA - 4X) Operating temperature -30ºC ... +70ºC (-20ºF ... 158ºF) Humidity 100% relative humidity Max. line length to transducer-electronics 150 m (450 ft), triaxial cable

Open Channel Measurement

The Ultra Sonic open channel measurement system offers the same functionality as the pipe measurement. The processing unit is equipped with the same outputs: 2 analog outputs 0/4 ... 20 mA 2 pulse outputs 1 flow direction output 1 OK output 1 DUAL PORT RAM connection

For the flow measurement in an open channel, level H must also be taken into consideration. The processing unit therefore additionally provides 2 analog inputs 0/4 ... 20 mA.

With one or two pressure sensors (4-20 mA) or with an intelligent level measurement system (SDI-12) a single level or a level average is acquired. Measuring a level average, the accuracy of the flow calculation is further increased.

The processing unit can likewise communicate over the SENSORbus with several transducer-electronics. A multi-path measurement is thereby optimally supported.

Technical Data of Ultra Sonic Channel Measurement Sensors "Risonic"

Ultrasonic Sensor for submersible mounting

Channel forms rectangle, trapezoid, etc. Assembly sensors adjustable, surface of buried type Max. channel width 15 m (600”) Max. allowable pressure 15 bar (225 psi) Protection class IP68 (submersible)

[ Pressure & Level ] [Flow ][Position]

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Advanced Measurements & Controls, Inc.