RQ-30a Non-Contact Discharge Radar Sensor

The RQ-30a, RQ-30a-35 and the RQ-30a-75 are sensors for continuous discharge measurement of rivers, open channels and canals with known cross-section profile. The sensors use innovative radar technology to measure velocity, water level and discharge. They enable reliable, non-contact measurement without the need for structural work in the water.

Thanks to the non-contact radar technology the RQ-30a is not susceptible to contamination, debris or driftwood in the water. Furthermore, the non-contact measurement ensures very low maintenance and fail-safe operation especially during high water or flooding.

The RQ-30a can be simply mounted on bridges, on the roofs of closed canals or channel superstructures. Depending on the properties of the water surface the device can be installed in a height of 0.5 to 35 m. The RQ-30a is available in three versions: 

• RQ-30a: water levels from 0 to 15 meters (0 to 49.21 ft)
• RQ-30a-35m: water levels from 0 to 35 meters (0 to 114.83 ft)
• RQ-30a-75m: water levels from 0 to 75 meters (0 to 246 ft)

The measurable velocity range is between 0.10 and 15 m/s. Additionally the direction of flow is detected, enabling the operation in tide influenced rivers.

Measuring principle

The non-contact radar technology determines the water surface flow velocity using the Doppler frequency shift method and furthermore the water level is established by a travel time measurement. With known cross section profile the discharge Q of the water is calculated.