SVS Non-Contact Surface Velocity Sensor

HyQuest Solutions’ SVS is a contact-free surface velocity sensor for open channels and rivers. The sensor uses innovative radar technology and enables reliable, non-contact measurement without the need for structural work in the water.

With its very low power consumption, its high reliability and low maintenance SVS enables the permanent recording of the flow velocity of open channels for long periods of time. It is the ideal sensor for 24/7 monitoring surface water velocity especially in unattended areas. Because contact-free water velocity measurements are unaffected by sediments, mud and floating refuse, the SVS provides accurate results even in flooding situations.

SVS is easily mounted on bridges, ceilings of closed channels or any superstructures of the channel. Depending on the condition of the water surface, the device can be installed in a height of 0.5 to 130 m.

Measuring principle

The SVS transmits a a radar signal to the water surface (at a 60° angle) and receives the reflected signal. By analyzing and comparing both signals the water surface velocity can be derived (principle of Doppler frequency shift). To provide reliable data, a minimum wave height of at least 3 mm is required.

Setting and configuration of the SVS can be easily and conveniently done on a PC or laptop via standard terminal programs


  • Surface Water Velocity Measurement
  • Natural Open Waters
  • Open Channels
  • Water Flow


  • Non-contact, maintenance-free
  • No structural constructions in the water needed
  • Simple integration into existing system
  • Remains operational in flooding situations
  • Low power, optionally solar powered
  • Detection of flow direction
  • Measurement range from +/- 0.10 to +/- 15 m/s (depending on flow conditions)
  • Near blanking zone 0.5 m
  • Set measurement frequency or external trigger
  • Independent of environmental influences
Dimensions and Weight
241 x 246 x 154 mm, 2.7 kg
Aluminum housing, powder coated
Protection Class
IP 67
  • Supply: 6 to 30 V
  • Consumption at 12 V: standby approx. 1 mA, during active operation approx. 110 mA
  • Lightning protection
  • Operating temperature: -35 to 60 °C
  • Storage temperature: -40 to 60 °C
Velocity Measurement
  • Measurement range: 0.10 to 15 m/s (depending on flow conditions)
  • Accuracy: +/- 0.01 m/s; +/- 1 % FS
  • Resolution: 1 mm/s
  • Direction recognition: +/-
  • Measurement duration: 5 to 240 s, measurement interval: 8 s to 5 h
  • Radar: frequency 24 GHz (K-Band), opening angle 12°
  • Distance to water surface: 0.50 to 130 m
  • Necessary minimum wave height: 3 mm
Automatic Vertical Angle Compensation
Accuracy +/- 1°, resolution +/- 0.1°
  • 1 x RS485 or Modbus
  • 1 x SDI-12
  • Optional analog version: velocity 4 to 20 mA, 0 to 10 m/s configurable
Digital Input
  • 1 x Trigger input
  • Low: 0 to 0.6 V; High: 2 to 30 V

Radar sensor connecting cable:

LiYCY, 12 x 0.25 mm² , all solder joints protected with shrink tubing, shielded cable with tinned copper braiding, PVC outer sheath, configured and tested.


iRIS dataloggers and data modems:

  • Robust housing
  • IP over one or two channels of your choice: 4G with 3G fallback / GPRS, satellite, IoT
  • I/O: analog, digital, SDI-12, Modbus
  • iLink software
  • Telemetry or cloud app

Please ask for details