RSS-2-300W-QX 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-QX 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 water level sensor .

By introducing the superior dual radar technologies , measurement accuracy of radar flow meter is not influenced by air humidity (including fog), precipitation, air temperature ,fluctuations driftwood ,debris & Sediment concentration etc. Further advantages include the low energy consumption, short measuring cycle, minor dead angles and the short mounting distance.Possible false echoes caused by nearby supports etc, are removed by internal configuration of the software.RSS-2-300W-QX radar operates in K-band (at 24.125 or 24.200 GHz), and provides flow speed & level readings 20 times per second over serial (RS-232, RS-485) interfaces. Variety of supported communication interfaces and protocols enable easy integration with existing telemetry equipment and SCADA systems.

Installation is easy with minimum construction work.RSS-2-300W-QX is excellent where driftwood, debris, water traffic, or ice could damage stilling wells or other structures. The device can easily be relocated in the event of a storm changing the flow pattern, or if the river bed is sandy.

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.

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  • Applications
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▪Non-contact measurement of water velocity, level & discharge

▪Velocity measuring range up to 15 m/s ,accuracy up to ±0.02m/s

▪Water level Measuring range up to 20 m,accuracy up to ±3mm

▪Insensitive to fog, precipitation and temperature

▪Installation with minimal construction work

▪Maintenance free

▪Dual direction flow measurement

▪RS-232 &RS-485 interface

▪Compact,Low power consumption

▪Easy pole, wall or enclosure mounting

▪Low cost

Open Channel Flow Measuremen

RSS-2-300W-QX radar flow meter provides precise contactless measurement of surface flow velocity and water level.  The radar sensors are 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-2-300W-QX radar flow metercan 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. RSS-2-300W-QX radar flow meter 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 24VDC
Power Consumption < 150mA @12V DC
Maximal Current < 180 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  0,10 to 20 m(RSS-2-300W-QX)

l  0,10 to 30 m(RSS-2-300W-QX-30)

Accuracy l  ± 3mm  (RSS-2-300W-QX)

l ±  5mm  (RSS-2-300W-QX-30)

Resolution 1 mm