Dynasonics DFX Specifications

Doppler Ultrasonic Flow Meter

Series DFX

DESCRIPTION

The DFX ultrasonic Doppler flow meter measures flows of liquids
containing suspended particles or aerated liquids. Used with the
DT9 clamp-on, non-intrusive transducers, the meter is suitable
for sewage and mud slurries and can be used on most pipes
constructed from metal or plastic.

The DT9 transducer for the DFX meter is rated to Type 6 (IP67) and
has the ability to work with temperatures up to 194° F (90° C).

APPLICATIONS

Successful application of Doppler ultrasonic flow meters relies on
three physical constraints:

• The liquid flowing within the pipe must contain 100 ppm of
useful sonic suspended reflectors. Dissolved solids do not
generate reflections and are not relevant.

• A significant portion of the ultrasound energy generated by
the transducer must reach the sonic reflectors. The ultrasonic
transducer must be acoustically coupled to the outside of a
pipe (using grease or RTV couplant) and the pipe must permit
ultrasound to pass without significant attenuation. Most
pipes constructed of solid, homogenous materials meet this
qualification. Pipes that cause application difficulty include
concrete pressure pipes, woodstave pipes, Teflon®-lined pipes
and fiberglass reinforced pipes.

• The pipe must be completely filled with liquid when
measurements are made. The DFX microprocessor assumes that
the pipe is completely full when it calculates flow rate. Use on
partially-filled pipes may result in inaccurate readings.

BENEFITS

• Minimal installation time: the DFX may be installed and fully
operational within minutes. For most homogeneous pipe
materials, there is no need to break into pipelines.

• Minimal material costs: clamp-on sensor eliminates the need
for in-line flanges, pipe fittings, strainers or filters.

• Reduced down-time: installation may be performed on full pipes
and active systems. There is no need to shut down the process
for installation or maintenance.

• Lower maintenance costs: with no moving parts, there is nothing
on the DFX to wear down.

OPERATION

The DFX flow meter operates by transmitting ultrasonic sound from
its transmitting transducer through the pipe wall into the flowing
liquid. Each transducer contains piezoelectric crystals to transmit
this signal. The sound will be reflected by useful sonic reflectors
suspended within the liquid and recorded by the receiving
transducer (see Figure 1). If the reflectors are moving within the
sound transmission path, sound waves will be reflected at a
frequency shifted (Doppler shift) from the transmitted frequency.
The difference between the reflected frequencies and transmitted
frequencies is directly proportional to the speed of the sonic
reflectors, resulting in a liquid flow rate that is converted to various
user defined measuring units.

Figure 1: DFX operation

FEATURES

• Non-intrusive, clamp-on transducers for most pipes from

0.25 in. (6 mm) and above.

• Wide velocity range: 0.15…30 fps (0.0…9 mps).

• Flexibility: with automatic gain control and in-field linearization,
the DFX will adapt to a wide variety of applications.

DPP-DS-01296-EN-05 (August 2019)

Product Data Sheet

Doppler Ultrasonic Flow Meter, Series DFX

CLAMPON TRANSDUCER OPTIONS

Standard temperature

Standard pipe system (DT94)

FLOW

Top view of pipe

Standard temperature

Small pipe system (DT95)

FLOW

Top view of pipe

SPECIFICATIONS

Velocity Range 0.15…30 fps (0.05…9 mps)
Accuracy ±2% full scale, over calibrated span

Liquid Types

Monitor Enclosure

Power Supply 115/100/230V AC 50/60 Hz ±15% @ 17V A max; 12…28V DC @ 7V A max
Display 2-line × 8 character LCD; LED backlighting; 8-digit rate, 8-digit total (resettable)

Units

Rate Interval Second, minute, hour, day. Totalizer exponent: E-2 to E+6 (x ¹/100 to x 1,000,000)
Response Time User selectable: 6…60 seconds

Output Options

Multiple Meters

Keypad 4-key, tactile
Ambient Conditions –40…185º F (–40…85º C); 0…95% relative humidity (non-condensing)
Approvals (Std.) General Safety US and Canada. Certified to UL 61010-1 and CSA C22.2 No. 61010-1
Transducer Type Compression-mode Ultrasonic; 625 kHz

Construction

Pipe Sizes

Liquids containing a minimum of 100 ppm of useful sonic suspended reflectors greater than 35 micron size, and at least 25%
of the overall particle volume is larger than 100 microns

NEMA 4X (IP 66), polycarbonate, stainless steel, brass,
plated-steel mounting brackets 7.00 in. H × 5.75 in. W × 3.88 in. D (178 mm × 146 mm × 99 mm)

User configured: Feet, US gallons, ft³, Mil-gal, meters, liters, Mil-ft³, m³, Mil-liters, acre-feet, oil barrels (42 US gallons),
liquid barrel (32.5 US gallons), lb, Kg

4…20 mA 800 ohms max, internal or external power supply, 12-bit resolution

Optically Isolated Dual Relay

Rate Pulse

Synchronization provision included—utilized for multiple meter, single pipe/manifold system. Up to four meters may be
interconnected, up to 100 feet (30 meters) apart

Standard Clamp-On

Optional Flexible Armored Conduit Zinc-plated steel, PVC
Standard Clamp-On Transducers 1 inch (25 mm) and above
Small Pipe Clamp-On Transducers 0.25…1 inch (6…25 mm)
Standard Lengths 20, 50 and 100 foot (6.1, 15 and 30 meter), 78 Ohm twinax cable
Optional Lengths To 990 feet (297 meters), 75 Ohm RG59 cable

500 mV AC 2500 Hz max, 12-bit resolution, 500 mV AC into 2 K Ohm minimum;
Open collector 2500 Hz max, 1 A at 100 V max

Independently configured; Form C, 200V AC @ 0.5 A resistive; rate alarm, totalizer
pulse, error

Type 6* (IP 67) –40…194º F (–40…90º C) CPVC, Ultem®, Nylon, PVC (Cable Jacket),
Aluminum (small pipe) *Depth of 1 meter for 30 minutes

Page 2 August 2019DPP-DS-01296-EN-05