Flow Sensors

KDA Doppler Wedge Sensor

Part No. KDA-K/KDS-K

Wedge-shaped flow velocity sensor for channels

Ultrasonic sensors for flow measurement in slight to heavily polluted media. Wedge shape for installation on channel wall or channel bottom

  • Latest fourth-generation intelligent <link https: www.nivus.com en service-download know-how doppler external-link-new-window>Doppler technology
  • Cost-effective pricing
  • Suitable for all channel cross sections
  • Easy to install without the need for additional constructions
  • Cables can be extended without any problems
  • Measurement in heavily polluted and abrasive media
  • Built-in pressure cell mechanically protected


KDA 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 PCM F and OCM F the result is a complete flow measurement system.

Typical applications for KDA 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






Technical Data
Measurement principle
  • Doppler (flow velocity)
  • Piezo-resistive pressure measurement (level measurement)

IP 68

  • ATEX: IBExU 07 ATEX 1082 Edition 1 
  • II 2G Ex ib IIB T4 Gb
Operating temperature

-40 °C to +50 °C (also for use in Ex zone 1)

Storage temperature

-40 °C to +70 °C

Operating pressure

max. 4 bar (combi sensor with pressure cell max. 1 bar)

Cable lengths

10 / 15 / 20 / 30 / 40 / 50 / 60 / 70 / 80 / 90 / 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 2 x 1.5 + 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 F / FR, cable types "K" or "L"

Sensor types
  • v-sensor with T-compensation
  • v-sensor with T-compensation and h measurement (hydrostatic)
Medium-contacting materials
  • PVDF (wedge sensor body); stainless steel 1.4571 (ground plate); Polyurethane (cable sheath, screw joint and pipe sensor head)
  • Additionally for sensors with pressure measurement cell: Stainless steel 1.4404 (AlSl 316L), V4A (pressure measuring cell); Viton® Shore A (O-ring)
  • Optional: cable with FEP coating (sensors without pressure measurement only)

Flow velocity measurement

Measurement range

-600 cm/s to +600 cm/s

Measurement uncertainty

±1 % of measurement range end value

Zero point drift

absolutely stable zero point

Beam angle

±5 degrees

Level measurement – Pressure

Measurement range

0,005 to 5 m

Zero point drift

max. 0.75 % of final value (0 – 50 °C)

Measurement uncertainty

standing medium: +/- 0.5 of final value

Temperature measurement

Measurement range

-20 °C to +50 °C

Measurement uncertainty

±0.5 K

Specifications subject to change.


Datasheet KDA Sensors

Datasheet for KDA pipe and wedge sensors

Technical Instruction | Doppler Sensors (Rev. 04)

Installation Instruction | Correlation and Doppler Sensors (Rev. 07)

Installation instruction for save installation 

EC-Type Examination Certificate Compact Doppler

for  KDA-K.. / KDA-R.. / incl. supplements

Declaration of Conformity Compact Doppler Active Sensors

Compact Doppler Active Sensors KDA-K.. / KDA-R.. / KDS-K.. / KDS-R..

Declaration of Conformity "Ex" Compact Doppler Active Sensors

System Products
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