Clamp-on Doppler Ultrasonic Flowmeter
Insertion Doppler Ultrasonic Flowmeter
DMDF1 Enhanced Ultrasonic Doppler Flowmeters measure solids-bearing or aerated liquids in metal or plastic pipe. Proprietary circuitry allows this instrument to operate with lower concentrations of suspended solids than any competitive Doppler flowmeter expanding the instrument's range of applications and reliability. Clamp-on, or Insertion transducers permit the instrument to be installed in minutes without interrupting system pressure or flow. In addition, no pressure head-loss is created; therefore system pump horsepower requirements are reduced. The DMDF1 transmitter has a full keypad designed for simple field setup and application versatility. The two-line, backlit, alphanumeric display shows instantaneous flow rate and totalized flows in a variety of user selectable engineering units.
Features:
■ The system can be field configured to pipe sizes ranging from 1 to 120inches [25 to 3050 mm].
■ Non-fouling transducer is immune to build-up of grease, paraffin and
other coating materials.
■ Solid-state measurement never requires re-calibration and is virtually maintenance-free.
■ Operates with relatively clean liquids as well as liquids with
concentrations of suspended solids or aeration.
■ Does not require long straight runs of pipe.
■ Rugged NEMA 4X design permits extended outdoor and rough service use.
■ Industry standard outputs allow direct interface to loggers and controls systems.
Principles of Operation:
Ultrasonic Doppler flowmeters operate by transmitting and receiving ultrasonic sound signals in liquids. An instrument, such as the DMDF1, incorporates dual transducers that are clamped on opposite sides of a liquid filled pipe. Each transducer contains a piezoelectric crystal . Referring to the above illustration, the Г1 transducer transmits an ultrasonic signal through the pipe wall into the liquid. A portion of this signal is reflected by suspended solids, entrained gases or flow turbulence moving with the fluid, back toward the second transducer, Г2, Electronic circuitry compares the transmitted frequency with the received frequency. The difference, or frequency shift, is proportional to fluid velocity, in accordance with principles developed by Christian Johann Doppler. If the liquid is not moving (a zero flow condition) the transmitted and received frequencies are identical. The Series 901 features advanced signal processing and an exclusive auto-adapting digital filter to produce accurate and stable indications of flow rate and totalized flows. A full function keypad allows field configuration of pipe size, engineering units, the 4-20mA output and all operating parameters.
Applications:
■ Raw sewage
■ Return activated sludge
■ Pulp and paper slurries
■ Chemical slurries
■ Waste activated sludge
■ Ground water
■ Mining recirculate
■ Animal renderings
Specifications:
| TRANSMITTER |
DESCRIPTION |
SPECIFICATION |
POWER REQUIREMENTS |
115/230 VAC 50/60 Hz ±10% and 12VDC. Power consumption less than 12VA |
VELOCITY |
Clamp on, 1 - 20 FPS [0.3 - 6.08 MPS]; Insertion: 0.5 - 20 FPS [0.15 - 6.08 MPS]; |
OUTPUTS |
4-20 mA, 600 Ohms max., isolated. 12VDC pulse, 50 mS duration, 0-1 Hz to 0-10 Hz, user adjustable for driving electro mechanical totalizer.(Opt) Relay, 3A@250VAC resistive, SPDT |
INDICATORS |
Power, Signal Strength, Flow Analyzer, Fault, Over-range,
Read |
DISPLAY
|
2 line x20 character alphanumeric LCD (backlit). Digit height 0.2
inches [5 mm], 6 digit rate, 6 digit totalizer (resettable) |
UNITS: |
User configured |
RATE U.S. [METRIC] |
FPS, GPM, MGD [MPS, LPM, M3/hr] |
TOTALIZER U.S. [METRIC] |
Gallons [liters, M3] |
AMBIENT CONDITIONS |
-22 to 160°F [-30 to 70℃], 0-95% relative
humidity, non-condensing. |
ENCLOSURE |
NEMA 4X, [IP-65] ABS with SS hardware. 11W x 17L x 8D inches [279W x 432L x 203D mm] |
NON-LINEARITY (ACCURACY) |
±2% Full Scale |
SENSITIVITY |
0.4% of Full Scale |
REPEATABILITY |
±0.4% of Full Scale |
RESPONSE TIME |
5-50 seconds, user configured, to 90% of value,
step change in flow. |
| TRANSDUCER |
DESCRIPTION |
SPECIFICATION |
LIQUID REQUIREMENTS |
25 ppm of 30 micron size* suspended solids or entrained gases (air).
*Less than this minimum will re q u i re transducer mount downstream of a 90°elbow. |
TRANSDUCER TO
TRANSMITTER DISTANCE |
20 feet [6.08 meters], flexible armored conduit.
Lengths to 300 feet [100 meters] |
PIPE SIZES |
1 - 120 inches [25 - 3050 mm] Pipe I.D.
0.25 - 1 inch [6 - 25 mm], Small Pipe Transducer |
TEMPERATURE |
(Std) -40°to 180°F [-40° to 82°C].
(Opt) -40°to 300°F [-40° to 150°C] |
HOUSING MATERIAL |
(Std) Aluminum, Ultem™ w/epoxy encapsulation |
(High Temp) Vesped™, w/SS |
AGENCY APPROVAL |
(Opt)Fm approval I.S., Class 1, Groups A-G. |
Cable lengths to 100 feet [30 meters] |
Download DMDF1 Catalogue (1,196KB)