​2150 Area Velocity Module ​

Continuous wave Doppler flow meter is ideal for portable flow surveys and permanent installations.

2150 Area Velocity ModuleThe 2150 Flow Module uses continuous wave Doppler technology to measure mean velocity. The sensor transmits a continuous ultrasonic wave, then measures the frequency shift of returned echoes reflected by air bubbles or particles in the flow. 

The 2150’s “smart” area velocit​y probe is built on digital electronics, so the analog level is digitized in the sensor itself to overcome electromagnetic interference. The probe is also factory-calibrated for 10-foot (3 meter) span at different temperatures. This built-in calibration eliminates drift in the level signal, providing long-term level stability that reduces recalibration frequency and completely eliminates span recalibration. 

In field use, the 2150 is typically powered either by two alkaline, or Teledyne ISCO Rechargeable Lead-acid batteries, within a 2191 Battery Module. Highly efficient power management extends battery life up to 15 months at 15-mi​nute data storage intervals. Other power options (including solar) are available.


When you purchase instruments from Teledyne ISCO, you not only receive innovative, high quality products, you also receive excellent customer service and product support. Your initial purchase is only the beginning of Teledyne ISCO's ongoing commitment to their customers.


2100 Series Flow Modules BrochureBrochure
2100_Diagnostics_White_PaperCase Study
ISCO 2150 Area Velocity Flow Module DatasheetDatasheet
2150 Area Velocity Flow Module and Sensor Safety and Certification SheetSafety and Certification Sheet
2150 Flow Module User ManualUser Manual


​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​2150 Flow Module

Size (HxWxD): 2.9 x 11.3 x 7.5 in (74 x 287 x 191 mm)
Weight: 2.0 lb (0.9 kg)
Materials of construction: High-impact polystyrene, stainless steel
Enclosure (self-certified): NEMA 4X, 6P (IP68)
Temperature Range: -40° to 140° F (-40° to 60° C) operating and storage
Power Required: 12 VDC nominal (7.0 to 16.6 VDC), 100 mA typical, 1 mA standby
Power Source: Typically, a Teledyne Isco 2191 Battery Module, containing 2 alkaline or 2 rechargeable lead-acid batteries. (Other power options are available; ask for details.)
Typical Battery Life: (using 15-minute data storage interval) Energizer® Model 529 alkaline - 15 months; Teledyne Isco rechargeable lead-acid - 2.5 months
Program Memory: Non-volatile programmable flash; can be updated using PC without opening enclosure; retains user program after updating.

Built-in Conversions

Flow Rate Conversions: Up to 2 independent level-to-area conversions and/or level-to-flow rate conversions.
Level-to-Area Conversions: Channel Shapes - round, U-shaped, rectangular, trapezoidal, elliptical, with silt correction; Data Points - Up to 50 level-area points.
Level-to-Flow Conversions: Most common weirs and flumes; Manning Formula; Data Points (up to 50 level-flow points); 2-term polynomial equation
Total Flow Calculations: Up to 2 independent, net, positive or negative, based on either flow rate conversion

Data Handling and Communications

Data Storage: Non-volatile flash; retains stored data during program updates. Capacity 395,000 bytes (up to 79,000 readings, equal to over 270 days of level and velocity readings at 15-minute intervals, plus total flow and input voltage readings at 24-hour intervals)
Data Types: Level, velocity, flow rate 1, flow rate 2, total flow 1, total flow 2, input voltage, temperature
Storage Mode: Rollover; 5 bytes per reading.
Storage Interval: 15 or 30 seconds; 1, 2, 5, 15, or 30 minutes; or 1, 2, 4, 12, or 24 hours; Storage rate variable based on level, velocity, flow rate, total flow, or input voltage
Data Retrieval: Serial connection to PC or optional 2101 Field Wizard module; optional modules for spread spectrum radio; land-line or cellular modem; 1xRTT. Modbus and 4-20 mA analog available.
Software: Teledyne Isco Flowlink for setup, data retrieval, editing, analysis, and reporting
Multi-module networking: Up to four 2100 Series Flow Modules, stacked and/or remotely connected. Max distance between modules 3300 ft (1000 m).
Serial Communication Speed: 38,400 bps

2150 Area Velocity Sensor

Size (HxWxD): 0.75 x 1.3 x 6.0 in (19 x 33 x 152 mm)
Cable (Length x Diameter): 33 ft x 0.37 in (10 m x 9 mm) standard. Custom lengths available on request.
Weight (including cable): 2.2 lbs (1 kg)
Materials of construction: Sensor - Epoxy, chlorinated polyvinyl chloride (CPVC), stainless steel; Cable - Polyvinyl chloride (PVC), chlorinated polyvinyl chloride (CPVC)
Operating Temperature: 32° to 140° F (0° to 60° C)

Level Measurement

Method: Submerged pressure transducer mounted in the flow stream
Transducer Type: Differential linear integrated circuit pressure transducer
Range: Standard: 0.033 to 10 ft (0.010 to 3.05 m)
Optional: up to 30 ft (9.15 m)
Maximum Allowable Level: 34 ft (10.5 m)
Accuracy: ±0.01 ft from 0.033 to 10 ft (±0.003 m from 0.01 to 3.05 m)
Long-Term Stability: ±0.023 ft/yr (±0.007 m/yr)
Compensated Range: 32° to 122°F (0° to 50°C)

Velocity Measurement

Method: Doppler ultrasonic, frequency 500 kHz
Typical Minimum Depth: 0.08 ft (25 mm)
Range: -5 to +20 ft/s (-1.5 to +6.1 m/s)
Accuracy: (in water with uniform velocity profile, speed of sound = 4,850 ft/s, for indicated velocity range); ±0.1 ft/s from -5 to 5 ft/s (±0.03 m/s from -1.5 to +1.5 m/s); ±2% of reading from 5 to 20 ft/s (1.5 to 6.1 m/s)

Temperature Measurement

Accuracy: ±3.6° F (±2° C)

2191 Battery Module

Size (HxWxD): 6.0 x 9.6 x 7.6 in (152 x 244 x 193 mm)
Weight (without batteries): 3.2 lb (1.4 kg)
Materials of construction: High-impact polystyrene, stainless steel
Enclosure (self certified): NEMA 4X, 6P, (IP68)
Batteries: Two 6-volt Energizer Model 529* alkaline (25 Ahrs capacity) or Teledyne Isco Rechargeable Lead-acid (5 Ahrs capacity) recommended. *Note - Energizer 529 ER does not give specified life.

​For a full list of product specifications, see the datasheet.



Standard Features

  • Rugged, submersible enclosure meets NEMA 4X, 6P (IP68) environmental specs.
  • Chemically resistant epoxy-encapsulated sensor withstands abuse, resists oil and grease fouling, and eliminates the need for frequent cleaning.
  • Replaceable high-capacity internal desiccant cartridge and hydrophobic filter protect sensor reference from water entry and internal moisture.
  • Pressure transducer vent system automatically compensates for atmospheric pressure changes to maintain accuracy.
  • The quick-connect sensor can be easily removed and interchanged in the field without requiring recalibration.
  • Up to four 2100 Series flow modules can be networked by stacking and/or extension cables.
  • Software features:
    • Secure data storage. All data are continuously stored in flash memory to protect against loss in case of power failure
    • Easy to upgrade. New operating software can be downloaded into non-volatile flash memory, without affecting stored program and data.
    • Records and stores input voltage and temperature data.
    • Variable rate data storage lets you change the data storage interval when programmed conditions occur. This feature assures maximum information about an exceptional event – such as an overflow – while conserving power and data capacity during normal conditions.
    • 38,400 bps communication provides speedy setup and data retrieval.


  • Portable and permanent-site AV flow monitoring for inflow and infiltration, capacity assessment, sewer overflow, and sewer studies.
  • Measures shallow flow is small pipes. Low-profile velocity sensor minimizes flow stream obstruction, and senses velocity in flows down to 1 inch (25 mm) in depth.
  • Stack modules you need to build a compact, integrated system.
  • Monitor multiple flow streams at the same time.
  • Obtain redundant measurements to guarantee integrity.
  • Remotely locate modules and connect them via cable.
  • Expand your monitoring system as your requirements evolve.

Options and Accessories

  • 2101 Field Wizard - ruggedized keyboard and display stacks on 2100 system
  • 2102 Wireless Module - adds 2-way spread spectrum radio communication for remote data retrieval without manhole entry
  • 2103 Modem Module - adds telephone (land line) communication for remote data retrieval
  • 2103Ci CDMA Cellular Modem Module - adds cellular communication using Serial Over IP technology (with Flowlink Pro software)
  • 2103Gi GSM/GPRS Cellular Modem Module - supports 3G GSM "pushed data" (with Flowlink Pro software)
  • 2108 Analog Output Module allows easy interface with SCADA/DCS or other secondary instrument systems