
DISCHARGE RADAR SENSOR RQ-30D
DISCHARGE MEASUREMENT FOR WIDE RIVERS WITH INHOMOGENEOUS DISTRIBUTION OF FLOW VELOCITY
With the system of one master-radar sensor and several slave-radar sensors the velocity is measured at several spots throughout the whole water cross-section. Therefore a very high accuracy of the discharge measurement is guaranteed also for very wide water bodies.
- Discharge measurement with high accuracy – ideal use for very wide rivers with inhomogeneous velocity distribution
- One water level measurement and multiple, individual velocity measurements
- Well-proven RQ-radar technique: non-contact measurement, maintenance-free system, flood-proof
- No structural work is necessary for the water
- Recognition of flow direction and hysteresis effects
- Measurement in tidal waters
- Measurement in backwater situations
- Measures even where weed growth prevails and the sensor is not affected by turbidity
- Measuring range 0.08 … 16 m/s (depending on the flow conditions)
- Analog outputs from 4 to 20 mA (optional)
MEASURING PRINCIPLE
For the RQ-30d (in comparison to the RQ-30) the measuring principle was enhanced: Here the river is split into multiple sections and from each one a partial velocity measurement is taken. One sensor, the master device, additionally measures the water level and distributes this information to all the other devices (= slaves) in the system. Now they are able to calculate the partial discharge rate per section. Summing up all partial amounts of discharge results in the total discharge at the actual site – continuously, with non-contact to the water, and with increased accuracy. The RQ-30d system can be operated with up to seven slave devices at the maximum.
- Wide River Discharge: Measures multiple velocities across the river width for accurate flow in large rivers.
- Complex Flow Conditions: Suitable for river bends, confluences, or near watergates with irregular flow profiles.
- High Weed Environments: Non-contact radar is unaffected by weed growth, ensuring reliable measurements.
- Tidal & Backwater Areas: Accurately measures flow in tidal or backwater-affected regions.
- Flood Monitoring: Flood-proof design allows continuous velocity measurement during flood events.
- Turbid Water: Performance unaffected by water turbidity.
TECHNICAL DETAILS
GENERAL
- Dimensions master: 338 mm x 333 mm x 154 mm | slave: 175 mm x 154 mm x 246 mm
- Total weight master: 5.4 kg | slave: 2.7 kg
- Protection class IP 67
- Power supply 6 … 30 V
- Power consumption at 12V standby approx. 1mA; active operation approx. 140mA
- operating temperature – 35 … 60°C
- Miscellaneous over-voltage protection, reverse power protection, lightning protection
WATER LEVEL MEASUREMENT
- Measuring range 0 … 15 m standard version / 0 … 35 m extended version
- Resolution 1 mm
- Radar frequency 26 GHz (K-Band)
- Radar opening angle 10°
VELOCITY MEASUREMENT
- Measuring range 0.08 … 16 m/s (depending on flow conditions)
- Accuracy +/- 0.01 m/s; +/- 1 % FS
- Resolution 1 mm/s
- Direction recognition +/-
- Measuring duration 5 … 240 sec.
- Measuring interval 8 sec. … 5h
- Measuring frequency 24 GHz (K-Band)
- Radar opening anlge 12°
- Distance to water surface 0.50 … 35 m
- Minimum swell needed 3 mm
AUTOMATIC VERTICAL ANGLE COMPENSATION
- Accuracy +/- 1°
- Resolution +/- 0.1°
INTERFACE
- Interface 1x SDI-12 1 x RS 485 or Modbus
- Transfer rate 1.2 to 115.2 kBd
- Protocol diverse ASCII-protocols
- Output discharge rate, flow velocity, water level, quality parameters



