RSS-2-300W-QXC is a revolutionary radar type flow meter based on surface velocity and level measurement. RSS-2-300W-QX radar flow meter uses state of the art non-contact radar measuring technology to provide precise contactless measurement of flow discharge above the water surface. Contactless radar & ultrasonic technology enables quick and easy instrument installation above the water surface, and requires almost no maintenance.

RSS-2-300W-QXC flow meter is used to monitor flow discharge of open channels such as rivers, irrigation channels or sewer systems, and for monitoring and control of hydro-power 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 flow meter is combined with a radar based velocity sensor and an ultrasonic/radar based water level sensor .The flow velocity radar Geolux RSS-2-300W 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.Water depth is measured by a ultrasonic/radar based water level sensor with the best accuracy of 3mm.(radar type)

RSS-2-300W-QXC flow meter is certified according to both European and American standards.

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

  • Features
  • Applications
  • Specifications
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  • Combined contactless flow surface velocity & water level measurement
  • Automatic identification incoming & outgoing flow directions
  • Operates in K-band (24.125 GHz or 24.200 GHz)
  • Wide measurement range from 0.1 m/s to 15.0 m/s
  • Long range operation up to 50 m
  • Low power consumption (max 1,35 W, typically 1 W)
  • 9 to 27 VDC input voltage range
  • Operating temperature range from -40℃to +85℃
  • IP66 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 0,10 m/s to 15 m/s
IP Rating IP66


Power Input 9 to 27 VDC
Power Consumption < 1,35W (typical 1,0W)
Maximal Current < 250 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,
other available on request
CAN Interface Up to 1Mbps CAN2.0
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


Method Non-Contact Ultrasonic Pulsed Echo


l  0,00 to 1.0m (HS-100)

l  0,06 to 3.0 m (HS-300)

l  0,30 to 6.0 m (HS-600)

Accuracy l  ± 0,2% of reading (HS-100)

l  ± 0,3% of reading(HS-300&HS-600)

Temp. Error Max. 0,04%/K
Resolution 1 mm


Method Non-Contact Pulsed Radar
Range 0,01 to 25 m
Accuracy ±3 mm of reading
Resolution 1 mm