Flow measurement

I1-DOPPLER SL Side-Looking Doppler Flow Meter

The I1-DOPPLER SL side-looking Doppler flow meter by Tecnopenta is designed for continuous monitoring of water velocity and level in rivers, open channels and hydraulic infrastructure.

The system calculates flow rate and totalized volume, providing useful data for water resource management, plant control and hydrometric monitoring.

The sensor is installed submerged and laterally to the measurement section, on channel walls, riverbanks or existing structures. This configuration allows flow measurement along horizontal acoustic paths while keeping the instrument readily accessible for inspection and maintenance.

Operating principle

The sensor uses acoustic Doppler technology to measure water velocity. The transducers emit ultrasonic pulses and analyse the signal reflected by particles suspended in the flow; the frequency shift of the returned signal is used to determine their velocity.

The measurement is divided into multiple cells distributed along the acoustic path, allowing the system to detect how velocity varies with distance from the sensor rather than measuring at a single point.

Open channel flow measurement is calculated by combining velocity data with water level and the geometry of the measurement section.

Continuous measurement in rivers and channels

The I1-DOPPLER SL is suitable for fixed river and channel monitoring stations in both natural and artificial waterways. The available versions allow the measurement range to be selected according to the size of the section and the operating conditions.

The system measures both positive and negative velocities, allowing monitoring even in the presence of reverse flows, backflow or changes in flow direction.

The combined measurement of water velocity and level makes it possible to track hydraulic conditions over time and calculate both instantaneous flow rate and totalized volume.

Multi-cell velocity profiling

Multi-cell velocity profiling makes it possible to analyse the distribution of flow velocities along the portion of the section covered by the acoustic beams. The number, size and position of the cells can be configured according to the application.

Depending on the version, the system can manage up to 128 cells and provide horizontal measurement ranges of up to 120 metres, allowing use in channels of different sizes.

Level measurement and flow calculation

The system integrates level measurement using a vertical acoustic beam and a pressure sensor, depending on the selected configuration. Level data are combined with velocity measurements and section geometry for automatic flow calculation.

The instrument also provides totalized volume measurement, making useful data available for continuous monitoring and water resource management.

Main features

The I1-DOPPLER SL family includes instruments with velocity measurement ranges up to ±7 m/s and an accuracy of ±1% of the measured value, with an additional term of ±0.005 m/s.

Depending on the selected version, the acoustic level measurement range can reach 18 metres and the horizontal measurement range can extend up to 120 metres.

The different configurations allow the system to be adapted to site conditions, hydraulic section dimensions and data acquisition and transmission requirements.

Side installation and maintenance

The sensor can be installed on channel walls, riverbanks, bridge piers or other suitable structures, with the acoustic beams directed towards the section to be monitored.

To simplify maintenance operations, Tecnopenta can provide a sliding rail support specifically designed for the application. This solution allows the sensor to be removed from its operating position and returned to the same position in a stable and repeatable manner.

Data acquisition and remote monitoring

The I1-DOPPLER SL can be integrated with data loggers, supervisory systems and remote monitoring systems for continuous monitoring and remote access to measurement data.

Available interfaces include RS232, SDI-12 and, depending on the configuration, Modbus communication and analogue outputs. Dedicated software allows measurement configuration, acquired data management and report generation.

Applications

The Doppler flow meter is suitable for river flow measurement, channel flow monitoring, irrigation networks, hydropower plants, stormwater systems and hydraulic infrastructure.

It can also be used in port and marine applications, subject to verification of site conditions and the required configuration.

Request a flow measurement solution

Contact Tecnopenta to identify the I1-DOPPLER SL configuration best suited to the measurement section, expected water levels and velocities, communication requirements and maintenance needs of the installation.