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.

FEATURES AND ADVANTAGES

• 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 in the water
• Recognition of flow direction and hysteresis effects
• Measurement in tidal waters
• Measurement in backwater situations
• Measures even where weed growth prevails and sensor is not affected by turbidity
• Measuring range 0.08 … 16 m/s (depending on the flow conditions)
• Analogue outputs from 4 to 20 mA (optional)

FIELDS OF APPLICATION

The main advantage of the RQ-30d is that the discharge can be measured more precisely, especially in rivers and streams where the flow velocity is distributed inhomogeneously over the cross-section. Varying velocities can be observed particularly in very broad streams as well as in situations, where the measuring site is located close to a river bend, an incoming river or watergates. In order to capture the complete flow-profile even more accurately, the RQ-30d system measures multiple individual flow velocities dispersed over the width of the body of water.

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 dicharge 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.

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

WATERLEVEL 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, waterlevel, quality parameters