Open channel & partially filled pipe
Ultrasonic flow meters
SUITABLE FOR PARTIALLY FILLED PIPES AND OPEN CHANNEL
FAMOUS PROFESIONAL ULTRASONIC FLOWMETERS MANUFACTURER, ADVANCED
TECHNOLOGY, SERIES PARTIALLY FILLED PIPE ＆ OPEN CHANNEL ULTRASONIC
FLOWMETERS ARE SUITABLE TO MEASURE THE FLOW OF PARTIALLY FILLED PIPE OR
OPEN CHANNEL.
Applications
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Open channel flow
Partially filled pipes
Water treatment
Sewage treatment
Irrigation
Industrial waste
Environmental monitoring
DMDF-OP-A Partially Filled Pipe Flow meters
PRINCIPAL
DMDF-OP-A Partially Filled Pipe Ultrasonic flowmeter is designed for partially filled pipe applications.
It has the same measurement as doppler ultrasonic flowmeter of full filled pipe on the fluid velocity
measurement. When calculating the flow rate, DMDF-OP-A needs the cross-sectional area of actual flow,
so DMDF-OP-A flowmeter also has to measure the level of fluid, then calculate the flow rate.
When measuring liquid velocity, the flow meter operates by transmitting an ultrasonic sound from its
transmitting transducer, the sound will be reflected by useful sonic reflectors suspended within the liquid
and recorded by the receiving transducer. If the sonic reflectors are moving within the sound
transmission path, sound waves will be reflected at a frequency shifted (Doppler frequency) from the
transmitted frequency. The shift in frequency will be directly related to the speed of the moving particle
or bubble. This shift in frequency is interpreted by the instrument and converted to various user defined
measuring units.
The liquid level measurement principle: the level transducer uses ultrasonic level meter of special
small-scale and low dead zone to measure the level. When installing the level meter, user needs to fix a
welding base, the height welding base is usually 80～100mm, so it can ensure a high measurement
accuracy.
The flow formula of partially filled pipe: Q=V·A
Where
V——Fluid velocity in pipe
A——Cross-sectional area of liquid in pipe
A is the function of liquid level and inner diameter, A=f（D·h）
Where
D——Inner diameter of pipe
h——Liquid level
Features
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Excellent low flow rate measurement ability, low to 0.05 m/s
Automatically signal gain adjustment
Complete in specifications, and can provide a variety of applications
4-20mA and RS485/MODBUS output, GPRS is optional
Very suitable for large pipe sewage measurement
International explosion proof certificate
DMDF-OP-A flow meter includes flow calculator, transmitter, velocity transducer and
level transducer.
DMDF-OP-A Fixed Partially Filled Pipe Flow meters
(If installation environment requires explosion-proof, please contact manufacturer to order DMDF-OP-A
Explosion-proof partially Filled Pipe Flow meters.)
Measuring Diagram
Velocity and Level
Measurement
Velocity and Level
Measurement
Flow Calculator
The flow calculator can set the cross-sectional area calculation of partially
filled pipe or open channel, for circular pipe, it only need to input the inner
diameter; for open channel, it only need to input the width; users also can input
up to 20 point coordinates of channel to calculate the cross-sectional area. The
flow calculator can display the velocity, level, flow rate and flow totalizer, and
is configured with 4-20mA and, RS485/MODBUS output, GPRS is optional.
Fixed Flow Calculator
Transmitter
The transmitter and level transducer output 4-20mA analog signal of the
velocity and level, which are connected to the two external 4-20mA input of
flow calculator.
Transmitter
Velocity Transducer
The velocity transducer includes two types: Clamp-on and Insertion, both of them are hot-tapped
installation and demounted online.
Clamp-on Velocity Transducer
Installation Drawing of Insertion Velocity Transducer
When installing the insertion velocity transducer, the pipe can’t be welded directly, such as cement pipe,
ductile iron or other unweldable material, please notify manufacturer for extended velocity transducers
(wall thickness of pipe can be up to 110mm) shown as below. In this case, it also need to install a
weldable (usually carbon steel) hoop shown as below.
Extended Velocity Transducers
Installation Drawing of Weldable Hoop
Level Transducer
The measurement principle of level transducer: the level transducer uses
ultrasonic level meter of special small-scale and low dead zone to measure the
level. When installing the level meter, user needs to fix a welding base, the
height welding base is usually 80 ～ 100mm, so it can ensure a high
measurement accuracy.
TECHNICAL SPECIFICATIONS
Accuracy
1.0～2.0%F.S.
Pipe Sizes
DN100～3000
Liquid Types
Liquids containing 100 ppm of reflectors and at least
20% of the reflectors are larger than 100 micron.
Flow Calculator
Enclosure
NEMA 4X [IP65], cast aluminum
260L×193W×80H (mm), 10.2L×7.6W×3.2H(inch)
Power Supply
Standard: 100~240VAC, 50/60HZ ±5%, 5VA Max
Optional: 12~28VDC, 2.5VA Max
4-20mA, RS485/Modbus, GPRS (optional)
Outputs
Temperature
-40 to +70℃
Transmitter
Enclosure
NEMA 4X [IP65], cast aluminum
260L×193W×80H (mm), 10.2L×7.6W×3.2H(inch)
Power Supply
Standard: 100~240VAC, 50/60HZ ±5%, 5VA Max
Optional: 12~28VDC, 2.5VA Max
4-20mA
Outputs
Temperature
-40 to +70℃
Velocity Transducer
Measuring Range
Type
0.05m/s ～12m/s
Clamp-on and Insertion
Liquid
Temperature
Standard: -40℃～+121℃
High temp: -40℃～+250℃
-40℃～+150℃(Stainless Steel)
Cable Length
Standard Lengths: 20Feet [6m]
Optional Lengths: to 990 Feet [300m]
Housing Material
Standard Transducer: Aluminum
High Temp Transducer: Engineering plastic
Stainless Steel Transducer: Stainless Steel
Insertion Transducer: Stainless Steel
Protection Class
Standard
IP65
Optional
IP68, can work under water
Level Transducer
Measuring Range
0.5 to 18 feet (0.15m to 5.4m)
Temperature
-40 to +60℃
Power Supply
12-36 VDC
Outputs
Housing Material
4-20mA
Engineering plastic, NEMA 4X [IP65]
Model Selection Table of DMDF-OP-A Fixed Flow meters
MODEL: DMDF-OP-A -X -X -X -X
-DOPF -X
-X
-X
-X
-X
-X
Flow Calculator
F-Fixed
Transmitter
F-Fixed
Power Supply
A-110VAC
B-220VAC
E-24VDC
S-Solar Supply
Output
N- None
R-RS485
M-Modbus
G-GPRS
Velocity Transducer
1-Standard Clamp-on (DN40～4000)
2-Standard Insertion (DN65～4000)
3-Extended Insertion (DN65～4000)
Velocity Transducer Material
N-Standard material
S-Stainless Steel (Only for Standard Clamp-on)
Velocity Transducer Protction Class
N- IP65
O- IP68, can work under water
Liquid Temperature
N- -40～121℃
H1- -40～250℃
H2- -40～150℃（high temperature for stainless steel transducer material）
Cable Length of Velocity Transducer
020-20Feet (6m)
XXX-Optional, up to 990 Feet (300m)
Level Transducer
N-Standard
D1-DynaProbe level meter (Compact type)
D2-DynaProbe level meter (Remote type)
Example: DMDF-OP-A-F-F-B-G-DOPP-1-N-N-N-020-N means fixed flow meters; 220VAC power
supply; Need GPRS output; velocity transducer is standard clamp-on, Aluminum material, protection
class: IP65; Liquid Temperature is -40 to 121℃; the cable length of velocity transducer is 20 Feet; Level
transducer is standard.
DMDF-OP-A Portable Partially Filled Pipe Flow meters
Flow Calculator
Measuring diagram
Portable Flow Calculator
The flow calculator can set the cross-sectional area calculation of partially filled pipe or open channel,
for circular pipe, it only need to input the inner diameter; for open channel, it only need to input the
width; users also can input up to 20 point coordinates of channel to calculate the cross-sectional area.
The flow calculator can display the velocity, level, flow rate and flow totalizer, and is configured with
4-20mA and RS485/MODBUS output, GPRS is optional.
Transmitter
Portable Transmitter
Velocity Transducer
Clamp-on Velocity Transducer
Level Transducer
The measurement principle of level transducer: the level transducer uses
ultrasonic level meter of special small-scale and low dead zone to measure
the level. When installing the level meter, user needs to fix a welding base, the
height welding base is usually 80 ～ 100mm, so it can ensure a high
measurement accuracy.
The transmitter and level transducer output 4-20mA analog signal of the
velocity and level, which are connected to the two external 4-20mA input of flow calculator.
TECHNICAL SPECIFICATIONS
Accuracy
1.0～2.0%F.S.
Pipe Sizes
DN100～3000
Liquid Types
Liquids containing 100 ppm of reflectors and at least
20% of the reflectors are larger than 100 micron.
Flow Calculator
Enclosure
Power Supply
Outputs
Temperature
NEMA 4X [IP65], ABS
358L×250W×150H (mm), 14.1L×9.8W×5.9H(inch)
rechargeable lithium battery, 12VDC, 14.4Ah
Over 50 hours working time on a full-charge
Charger: 100~240VAC, 50/60 HZ ±5%, 3A Max
4-20mA, RS485/Modbus, GPRS (optional)
-40 to +70℃
Transmitter
Enclosure
Power Supply
Outputs
Temperature
NEMA 4X [IP65], ABS
358L×250W×150H (mm), 14.1L×9.8W×5.9H(inch)
rechargeable lithium battery, 12VDC, 14.4Ah
Over 50 hours working time on a full-charge
Charger: 100~240VAC, 50/60 HZ ±5%, 3A Max
4-20mA
-40 to +70℃
Velocity Transducer
Measuring Range
Type
0.05m/s ～12m/s
Clamp-on
Liquid
Temperature
Standard: -40℃～+121℃
High temp: -40℃～+250℃
-40℃～+150℃(Stainless Steel)
Cable Length
Standard Lengths: 20Feet [6m]
Optional Lengths: to 990 Feet [300m]
Housing Material
Standard Transducer: Aluminum
High Temp Transducer: Engineering plastic
Stainless Steel Transducer: Stainless Steel
Protection Class
Standard
IP65
Optional
IP68, can work under water
Level Transducer
Measuring Range
0.5 to 18 feet (0.15m to 5.4m)
Temperature
-40 to +60℃
Power Supply
12-36 VDC
Outputs
Housing Material
4-20mA
Engineering plastic, NEMA 4X [IP65]
Model Selection Table of DMDF-OP-A Portable Flow meters
MODEL DMDF-OP-A -X -X -X -X -X –DOPP -X -X -X -X -X -X
Flow Calculator
P- Portable
Transmitter
P- Portable
Power Supply
A—115VAC (Two round terminals)
B—230VAC (Two round terminals)
C—110VAC (Two rectangular terminals)
D—230VAC (Two rectangular terminals)
Output
N-None
R-RS485
M-Modbus
G-GPRS
Extend operation time
N- Normal
E- Extend the operation time to 120 hours
Velocity Transducer
1-Standard Clamp-on (DN40～4000)
Velocity Transducer Material
N-Standard material
S-Stainless Steel
Velocity Transducer Protction Class
N- IP65
O- IP68, can work under water
Liquid Temperature
N- -40～121℃
H1- -40～250℃
H2- -40～150℃（high temperature for stainless steel transducer material）
Cable Length of Velocity Transducer
020-20Feet (6m)
XXX-Optional, up to 990 Feet (300m)
Level Transducer
N-Standard
D1-DynaProbe level meter (Compact type)
D2-DynaProbe level meter (Remote type)
Example: DMDF-OP-A-P-P-A-G-N-DOPP-1-S-N-020-N means portable flow meters; 115VAC
power supply; Need GPRS output; Normal battery; velocity transducer is standard clamp-on, Stainless
Steel; Liquid Temperature is -40 to 121℃; the cable length of velocity transducer is 20 Feet; Standard
level meter.
DMDF-OP-B Partially Filled Pipe Flow meters
PRINCIPAL
DMDF-OP-B Ultrasonic flowmeter is designed for partially filled pipe and open channel applications. It
has the same measurement as doppler ultrasonic flowmeter of full filled pipe on the fluid velocity
measurement. When calculating the flow rate, DMDF-OP-B needs the cross-sectional area of actual flow,
so DMDF-OP-B flowmeter also has to measure the level of fluid, then calculate the flow rate.
When measuring liquid velocity, the flow meter operates by transmitting an ultrasonic sound from its
transmitting transducer, the sound will be reflected by useful sonic reflectors suspended within the liquid
and recorded by the receiving transducer. If the sonic reflectors are moving within the sound
transmission path, sound waves will be reflected at a frequency shifted (Doppler frequency) from the
transmitted frequency. The shift in frequency will be directly related to the speed of the moving particle
or bubble. This shift in frequency is interpreted by the instrument and converted to various user defined
measuring units.
When measuring liquid level, place the DYNAMETERS
transducer on or near the bottom watershed, through water
static pressure sensor which is in transducer, and the power
supply signal cable has ventilation effect, water static
pressure sensor sets Atmospheric pressure on the water
surface as reference pressure to measure the fluid pressure,
then calculates liquid level.
The flow formula of partially filled pipe: Q=V·A
Where
V——Fluid velocity in pipe
A——Cross-sectional area of liquid in pipe
A is the function of liquid level and inner diameter, A=f（D·h）
Where
D——Inner diameter of pipe
h——Liquid level
Features






Excellent low flow rate measurement ability, low to 0.021 m/s
Superior measurement accuracy
4-20mA and RS485/MODBUS output, GPRS is optional
Very suitable for sewage measurement
User-friendly configurations
Complete in specifications, and can provide a variety of applications
DMDF-OP -B Flow Meter includes flow calculator, DYNAMETERS velocity and level transducer. It is
suitable for the flow measurement of pipe outlet and open channel.
DMDF-OP-B Fixed Partially Filled Pipe Flow meters
Flow Calculator
Series DMDF-OP -B Fixed Flow meters
Fixed Flow Calculator
The flow calculator can set the calculate the cross-sectional area of partially filled pipe or open channel,
for circular pipe, it only need to input the inner diameter; for open channel, it only need to input the
width; users also can input up to 20 point coordinates of channel to calculate the cross-sectional area.
The flow calculator can display the velocity, level, flow rate and flow totalizer, and is configured with
4-20mA and RS485/MODBUS output, GPRS is optional.
DYNAMETERS Velocity and Level Transducer
By using digital signal processing techniques, DYNAMETERS velocity and level transducer is able to
perform in a wide range of environments. It is used to record flows in pipes, channels and small streams
and operates in a wide range of water qualities from fresh streams to primary sewage channels.
DYNAMETERS velocity and level transducer combines water velocity and water depth measurement
with a powerful data logger. Its systems have been tested in small streams and pipes, and the calibration
has been verified in a tow tank.
DYNAMETERS velocity and level transducer is mounted on (or near to) the bottom of the
stream/pipe/culvert and measures the velocity and depth of the water flowing above it.
DYNAMETERS Velocity and Level Transducer
Installation Drawing of Transducer
When installing transducer, a hoop as shown above is needed, at first, fix the transducer on the hoop,
then fix the component in the pipe, and connect the cable to flow calculator.
TECHNICAL SPECIFICATIONS
Pipe Sizes
DN300～2000
Flow Calculator
Enclosure
Power Supply
Outputs
Temperature
NEMA 4X [IP65], cast aluminum
260L×193W×80H (mm), 10.2L×7.6W×3.2H(inch)
100~240VAC, 50/60 HZ ±5%, 5VA Max
Or 12~28VDC, 2.5VA Max.
4-20mA, RS485/Modbus, GPRS(optional)
-40 to +70℃
DYNAMETERS Velocity and Level Transducer
Enclosure
290L×70W×25H(mm); 11.4L×2.8W×1H(inch)
Material
PVC body, Stainless steel mounting plate
Accuracy
Velocity
2% of measured
Level
±0.25% of calibrated lower range
Velocity
0.021m/s to 4.5m/s bidirectional
Level
0 to 2m（021） 0 to 5m（051）
Measuring
Range
Temperature
0°C to 60°C water temperature
Cable Length
15 meters, 9 way vented cable «SQL» Compatible
Power Supply
Battery
External 12VDC
Voltage
11.5V to 15VDC
Model Selection Table of DMDF-OP -B fixed flow meters
MODEL
DMDF-OP -B
-X
-X
-X
-X
Flow Calculator
F-Fixed
Power Supply
A-110VAC
B-220VAC
E-24VDC
S-Solar Supply
Output
N-None
R-RS485
M-Modbus
G-GPRS
Level Range
21-0 to 2m（021）
51-0 to 5m（051）
Example: DMDF-OP -B-F-B-G-21 means fixed flowmeters, 220VAC power supply; GPRS output,
and the level range is 0 to 2m.
DMDF-OP-B Portable Partially Filled Pipe Flow meters
Flow Calculator
Series DMDF-OP -B Portable Flow meters
Portable Flow Calculator
The flow calculator can set the calculate the cross-sectional area of partially filled pipe or open channel,
for circular pipe, it only need to input the inner diameter; for open channel, it only need to input the
width; users also can input up to 20 point coordinates of channel to calculate the cross-sectional area.
The flow calculator can display the velocity, level, flow rate and flow totalizer, and is configured with
4-20mA and RS485/MODBUS output, GPRS is optional.
DYNAMETERS Velocity and Level Transducer
By using digital signal processing techniques, DYNAMETERS velocity and level transducer is able to
perform in a wide range of environments. It is used to record flows in pipes, channels and small streams
and operates in a wide range of water qualities from fresh streams to primary sewage channels.
DYNAMETERS velocity and level transducer combines water velocity and water depth measurement
with a powerful data logger. Its systems have been tested in small streams and pipes, and the calibration
has been verified in a tow tank.
DYNAMETERS velocity and level transducer is mounted on (or near to) the bottom of the
stream/pipe/culvert and measures the velocity and depth of the water flowing above it.
DYNAMETERS Velocity and Level Transducer
Installation Drawing of Transducer
When installing transducer, a hoop as shown above is needed, at first, fix the transducer on the hoop,
then fix the component in the pipe, and connect the cable to flow calculator.
TECHNICAL SPECIFICATIONS
Pipe Sizes
DN300～2000
Flow Calculator
Enclosure
Power Supply
Outputs
Temperature
NEMA 4X [IP65], ABS
358L×250W×150H (mm), 14.1L×9.8W×5.9H(inch)
rechargeable lithium battery, 12VDC, 14.4Ah, Over 50
hours working time on a full-charge Charger:
100~240VAC, 50/60 HZ ±5%, 3A Max
4-20mA, RS485/Modbus, GPRS (optional)
-40 to +70℃
DYNAMETERS Velocity and Level Transducer
Enclosure
290L×70W×25H(mm); 11.4L×2.8W×1H(inch)
Material
PVC body, Stainless steel mounting plate
Accuracy
Velocity
Measuring
Range
2% of measured
Level
±0.25% of calibrated lower range
Velocity
0.021m/s to 4.5m/s bidirectional
Level
0 to 2m（021） 0 to 5m（051）
Temperature
0°C to 60°C water temperature
Cable Length
15 meters, 9 way vented cable «SQL» Compatible
Power Supply
Battery
External 12VDC
Voltage
11.5V to 15VDC
Model Selection Table of DMDF-OP -B Portable flowmeters
MODEL
DMDF-OP -B
-X
-X
-X
-X
-X
Flow Calculator
P-Portable
Power Supply
A—115VAC (Two round terminals)
B—230VAC (Two round terminals)
C—110VAC (Two rectangular terminals)
D—230VAC (Two rectangular terminals)
Output
N-None
R-RS485
M-Modbus
G-GPRS
Level Range
21-0 to 2m（021）
51-0 to 5m（051）
Extend operation time
N- Normal
E- Extend the operation time to 120 hours
Example: DMDF-OP -B-P-A-G-21-E means portable flowmeters, 115VAC power supply; GPRS
output, and the level range is 0 to 2m, Extend the operation time to 120 hours.