Flow Sensors

POA Correlation Wedge Sensor

Part No. POA-V2XXK

Medium measurement range for levels up to ca. 1m

Ultrasonic sensors for flow measurement with very high accuracy in slight to heavily polluted media. For installation on channel wall or channel bottom

  • For high-accurate flow measurement by means of ultrasonic cross correlation method
  • Interference-free connection over long distances through digital signal transmission
  • Cables can be extended without any problems using standard cables
  • Absolutely stable zero point and drift-free
  • Measurement in heavily polluted and abrasive media
  • Easy installation without additional constructions and perfectly matched mounting accessories
  • Installation under process conditions possible
  • Suitable for all channel cross sections
  • The tailored selection of sensor constructions ensures the best possible solution for each application


POA flow velocity sensors are suitable for continuous measurement of slight to heavily polluted media.
The wedge-shaped sensors are designed for installation on either the channel wall or the channel bottom. Combined with transmitter types such as NivuFlow 750 and an external level measurement the result is a complete flow measurement system.

Typical applications for POA wedge sensors

  • Wastewater treatment plants: intake, discharge, activated sludge tank intakes, return sludge, recirculation, surplus sludge, digester discharge and flocculant dosage
  • Permanent measurements on stormwater treatment facilities such as stormwater overflow tanks, rainwater sedimentation and retention tanks
  • Direct discharge control, infiltration (extraneous water) or leakage detection
  • Industrial wastewater networks
  • Measurement campaigns in channel networks
  • and many more



Measurement principle Ultrasonic Cross Correlation with digital pattern detection (flow velocity)

Ultrasonic transit time (level measurement)
Piezo-resistive pressure measurement (level measurement)

Sensor types v-sensor with T-compensation

v-sensor with T-compensation and h measurement (water-ultrasound)

v-sensor with T-compensation and h measurement (hydrostatic)

v-sensor with T-compensation and 2 x h measurement (water-ultrasound + hydrostatic)
Protection IP 68
Ex-Approval II 2 G Ex ib T4 Gb (ATEX)
Ex ib IIB T4 gb (IECEX)
Operating temperature -20 °C to +50 °C
-20 °C to +40 °C if using the sensors in Ex Zone 1
Storage temperature -30 °C to +70 °C
Operating pressure max. 4 bar (combi sensor with pressure cell max. 1 bar)
Cable lengths 10/15/20/30/50/100 m pre-configured, can be extended upon request;
a pressure compensation element is required if cables longer than 30 m are used with sensors featuring an integrated pressure measurement cell. The compensation element can be used also to connect the extension.
Cable types Combi sensor with pressure measurement: LiYC11Y 2x1.5 + 1 x 2 x 0.34 + PA 1.5/2.5
Sensors without pressure measurement: LiYC11Y 2x1.5 + 1 x 2 x 0.34
Outside cable diameter Combi sensor with pressure measurement: 9.75 mm ±0.25 mm
Sensors without pressure measurement: 8.4 mm ±0.25 mm
Sensor connection Cable end pre-configured for connection to OCM CF
Cable end with plug for connection to PCM 4 and PCM Pro
Cable end with plug and pressure compensation element (sensors with pressure measurement cell only) for connection to PCM 4 and PCM Pro
Medium-contacting materials Polyurethane, stainless steel 1.4571, PPO GF30, PA Optional: sensor resistant to chemicals made of PEEK, mounting plate made of Hastelloy C-276; mounting plate made of titanium; cable with FEP coating
Types of construction - Wedge sensor for installation on channel bottom or channel wall
- Pipe sensor for installation in pipes with sensor screw joint and retaining element
Flow velocity measurement
Measurement range -100 cm/s to +600 cm/s
Number of scan layers max. 16
Measurement uncertainty for 0.05≤|V|≤0.5 m/s: E_v=0.5/|V| [%]
for |V|>0,5 m/s: E_v=1 %
Zero point drift absolutely stable zero point
Beam angle ±5 degrees
Level measurement water-ultrasonic sensor
Measurement range 0.05 to 200 cm
Measurement uncertainty +/- 2.0 mm or 0.2% of measured range (whichever is greater)
Level measurement – Pressure
Measurement range 0 to 500 cm
Zero point drift max. 0.75 % of final value (0 – 50 °C)
Measurement uncertainty standing medium:
+/- 0.5 of final value (within a range of 0.05 – 5 m)
Temperature measurement
Measurement range -20 °C to +60 °C
Measurement uncertainty ±0.5 K

Specifications subject to change.

Technical Instructions Correlation Sensors

Technical instructions for correlation sensors and external electronic box

Installation Instruction for Correlation and Doppler Sensors

Installation instruction for save installation 

EC type examination certificate sensor type POA

EC type examination certificate sensor type POA incl. supplement

IECEx Certificate of Conformity

Declaration of Conformity Ultrasonic Active Sensors POA / OCL / CS2

Ultraschall-Aktivsensoren POA / OCL / CS2

Declaration of Conformity "Ex" - Ultrasonic Active Sensors POA / OCL / CS2

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