High-precision Surface Velocity Radar Sensor For Flow Velocity Monitoring.

Geolux RSS-2-300 W surface velocity radar sensor is a revolutionary flow speed sensor.Geolux RSS-2-300 W provides precise contactless measurement of surface flow velocity. Contactless radar technology enables quick and simple sensor installation above the water surface, and requires minimum maintenance.

RSS-2-300 W flow meter is used to monitor flow velocity of open channels such as rivers, irrigation channels or sewer systems, and for monitoring and control of hydropower plants and wastewater treatment plants. The flow meter is also suitable for various mass flow metering applications in mining processing plants, industrial installations, and, due to operation without moving parts and robust mechanical design, is ideal for measurement of flammable fluids and harsh chemical applications.

The radar operates in K-band (at 24.125 or 24.200 GHz), and provides flow speed readings 20 times per second over serial (RS-232, RS-485) and CAN interfaces. Variety of supported communication interfaces and protocols enable easy integration with existing telemetry equipment and SCADA systems. Integrated tilt sensor measures inclination angle of the sensor and the flow velocity measurement is automatically cosine-corrected according to the measured mounting tilt angle.

Geolux RSS-2-300 W radar sensor is certified according to both European and American standards, and is being used worldwide.

HydroSpan Ltd is the exclusive distributor and service partner of Geolux RSS-2-300W in Asia & Russian Federation.HydroSpan is also authorised by Geolux.d.o.o to sell RSS-2-300W globally.


Outstanding Low Speed Performance 0.172m/s




 Outstanding Low Speed Performance 0.134m/s


Typical Veolcity of Irrigration Channel 1.23m/s

Made in Europe


  • Features
  • Applications
  • Specifications
  • Download
  • HydroLab
  • Scientific Papers
  • Approval
  • Movie
  • Success Stories
  • Contactless flowsurface velocity speed measurement
  • Operates in K-band (24.125 GHz or 24.200 GHz)
  • Automatic identification incoming & outgoing flow directions
  • Wide measurement range from 0,10 m/s to 15 m/s
  • Long range operation up to 50 m
  • Low power consumption 
  • 9 to 27 VDC input voltage range
  • Operating temperature range from -40℃to +85℃
  • IP67/IP68 aluminum casing
  • RS-232, RS-485 and CAN communication interface support
  • ASCII-S and GLX-NMEA protocols support; more protocols can be supported on customer request
  • Automatic mounting tilt angle compensation
  • Easy pole, wall or enclosure mounting
  • Low cost

Open Channel Flow Measuremen

RSS-2-300 W radar provides precise contactless measurement of surface flow velocity. Unlike ultrasound-based flow velocity sensors, the radar sensor is immune to air temperature / air density changes. Since the radar is packed inside IP66-rated waterproof enclosure, it is perfectly suitable for measuring open channel flow. The radar can be mounted either above the stream or sideways. The radar supports multiple communication interfaces and protocols, which makes it easy to integrate in an existing SCADA system.

Industrial Flow Measurement

RSS-2-300 W radar can be used for precise flow measurement in all kinds of outdoor and indoor industrial facilities. Since the radar waves propagate through plastic materials, the radar can be used to measure flow speed inside plastic pipes/tubes within an industrial facility. Geolux RSS-2-300 W radar is also perfectly suited for use in various water/sewage processing facilities, hydro power plants etc.


  • River monitoring
  • Storm water supervision
  • Sewer networks
  • Irrigation channels
  • Hydropower plants
  • Wastewater management plants

Radar Type K-band 24.125GHz/24.200GHz Doppler radar,
27 dBm EIRP
Beam Angle 12° Azimuth
24° Elevation
Detection Distance 50 m
Speed Range 0,1 m/s to 15.0 m/s
IP Rating IP67/IP68


Power Input 9 to 27 VDC
Power Consumption < 1,35W (typical 1,0W)
Maximal Current < 150 mA
Temperature Range -40°C to +85°C
(without heating or coolers)
Device Outer Dimensions 110mm x 90mm x 50mm

Serial Interface 1 x serial RS-485 half-duplex
1 x serial RS-232 (two wire interface)
Baud Rate 1200 bps to 115200 bps
Serial Protocols ASCII-S, GLX-NMEA,
Modbus RTU
Analog Interface 4-20mA through RS-485
Alarm Outputs 2 x open collector, max 50V 200mA
Connector M12 circular 12-pin

EN 50293:2000
EN 61000-6-2, EN 61000-6-4:2007
EN 61000-3-2:2006+A1:2009+A2:2009, EN 61000-3-3:2008
EN 300 440-1, EN 300 440-2
FCC Part 15 Subpart C



Trapezoidal and U shape channel hydroLab & 164 meters calibration channel,  0.1-6.0 m/s 


164m calibration channel


EN Test Report Summary

Test performed by: SIQ – Slovenian Institute of Quality and Metrology

Test report No.: T251-0760/11

Date: 2011-09-22

Standards: EN 50293:2000

EN 61000-6-2:2005

EN 61000-6-4:2007

EN 61000-3-2:2006+A1:2009+A2:2009

EN 61000-3-3:2008


FCC Test Report Summary

Test performed by: SIQ – Slovenian Institute of Quality and Metrology

Test report No.: T251-0864/11

Date: 2011-09-22

Standards: FCC Part 15, Subpart C