Large Channels
ADFM Pro 20

ADFM Pro 20 Inside the ADFM Pro20 flow sensor are four piezoelectric ceramics which emit short pulses along narrow acoustic beams pointing in different directions to measure velocity. A fifth ceramic is mounted in the centre of the sensor, and aimed vertically, is used to measure depth. Each acoustic beam measures velocity at multiple points in the water column. Each measured velocity data point is very precise to within 0.01ft/s. This distribution of accurate velocity measurements is then used to determine the flow pattern over the entire cross-section of flow. Since the flow pattern and measured velocity distribution are dependent on each other, the ADFM's advanced flow algorithms automatically adapt to changing hydraulic conditions within the pipe. This insures accurate flow rate measurement over a host of different measurement environments and hydraulic conditions. This also removes the need for in-situ calibration.

The data logging, signal processing and data output electronics are all housed in the ADFM enclosure. The enclosure is available as a NEMA 4X Box housing which is suitable for wall or console mounting in permanent applications, or a NEMA 6P cylindrical housing for use in manholes or other "wet" environments.

Standard Features:

  • Pulse-Doppler velocity profiling technology
  • Upward looking sensor mounts on a stainless steel band and is positioned in the channel invert
  • Rugged, long lasting construction
  • Real-time data output
  • Data quality verification information (signal strength and correlation)
  • In-situ calibration never required
  • Quad-redundant velocity sensors and depth sensor combined in a single housing

ADFM Pro 20
Pulse-Doppler velocity profiling technology
In-situ calibration never required
Quad-redundant velocity sensors and depth sensor
Highly Accurate +/- 1 to 2% of reading.

ADFM Pro20 Measurement Performance - Flow Rate
Flow Accuracy
1-2% of reading
Measurement Performance - Velocity
Velocity Range
±30.0 ft/s (±9 m/s)
Velocity Bin Size
2 to 12 inches (50 to 300 mm) - user selectable
Vertical Profiling Range
9 inches to 20 feet (230 mm to 6 m) nominal, for particle concentrations of 50-1000 ppm
0.5% of reading ± 0.01 ft/sec (3.0 mm/s)
Measurement Performance - Water Level
Measurement Range
4.5 inches to 20 feet (110 mm to 6 m)
0.5% of reading ± 0.2 in (5 mm)
ADFM Pro20 Acoustic Frequency
1.23 MHz
Physical - ADFM Pro20 Electronics Unit
Electronic Unit Configurations
Cylindrical canister or wall-mount box

Operating Temperature
-15 to 125°F (-26 to 52°C)
Storage Temperature
-65 to 160°F (-54 to 71°C)
NEMA 6P (IP 68) for canister; NEMA 4X for box
Canister - 28.5x10 in. (724 x 254 mm); Box - 17.5x14.8x6.7 in (445x375x170 mm)
Canister Housing 36 lbs (16 kg); Box Housing 24 lbs (11 kg)
Physical - ADFM Pro20 Sensor
Operating Temperature
23 to 95°F (-5 to 35°C)
Housing Material
Static Pressure
250 psi Nominal
8 x 3 x 1.5 inches (200 x 75 x 40 mm)
3.2 lbs (1.5 kg)


The H-ADFM is a revolutionary flow meter that has set new standards for flow measurement accuracy in wide channels and has made pulse doppler technology available for open channel applications with a width of 10ft or greater. The H-ADFM mounts on the side of a channel which allows easy access for maintenance. It measures the horizontal distribution of velocity within the flow, across the channel, using pulse doppler velocity profiling technology. Horizontal profiling increased information on the flow conditions and velocity structure that can not be provided from a single point surface measurement

The H-ADFM is the most versatile and most accurate flow meter available for metering sites in open channels and very large pipes including chlorine contact basins and other applications with rapidly changing, non-uniform, near zero, zero , reversed or backwatered flow conditions.The H-ADFM sensors can also be 'stacked' to provide horizontal profiles at multiple depths in the flow, providing superior data quality and increased accuracy eve in difficult hydraulic conditions.

Standard Features:
  • Submersible sensor (to 100ft)
  • Pulse doppler velocity profiling technology
  • Real-time data output
  • Upward looking depth sensor and redundant cross-channel velocity sensors combined in one housing
  • Processing and sensor electronics in a single module
  • Data quality verification information (correlation and signal strength)
  • Stainless steel mounting bracket for installation on side of channel.
  • Rugged construction

Advanced Flow Measurement Performance
The most precise and accurate choice for metering sites in very large pipes and open channels
Revolutionary Flow Meter
Has set new standards for flow measurement in wide channels and enabled Doppler technology for open channels in applications of 10ft or greater including bubbler and ultrasonic

H-ADFM Measurement Performance - Flow Rate
Flow Rate Accuracy
2-5% of reading
Measurement Performance - Velocity
Velocity of Range
±15 ft/s (±5 m/sec)
Number of Cells
Velocity Bin Size
0.8 to 12 ft (250 mm to 4 m)
Maximum Profiling Range
65 ft (20 m) at 1200 kHz (Maximum range depends on a number of factors, including temperature, salinity, suspended materials)
Minimum Recommended Channel Width
10 ft (3 m) at 1200 kHz

Velocity Accuracy
±0.5% ±0.01ft/s (3mm/s)
Measurement Performance - Water Level
0.3 to 30 feet (100 mm to 9 m)
H-ADFM Transducer Assembly
Beam Geometry
2 beams, ±20°
Beam Width
Temperature Sensor
-25° to 105°F (-4° to 40°)
±0.4°F (±0.2°C)
Tilt Sensor (2 axes)
±0.2° at 0°, ±0.5° at 10°
Physical - H-ADFM Sensor
7.5lb (3.4kg)
7.2 x 7.2 x 7.4 inches (183 x 183 x 189 mm)
(H x W x D mounted horizontally)
Cast polyurethane with titanium hardware, mounting plate included.