The sensor employs the acoustic Doppler principle to reliably measure flow velocity in a variety of naturally occurring conditions, including during most flood events.
Usage Type: Fixed installation
Measurement technology: Acoustic
Parameters measured: Flow velocity
Product Highlights: Side-Looking-Doppler for continuous discharge measurement in rivers and open channels. Discharge calculation based on velocity – index – method. Integrated vessel filter algorithm, Modbus interface and output of total volume of flow (max. interval 1 day).
Measurement range: ± 10 m/s
Accuracy: ± 1 % of measured value ± 0.5 cm/s
- Equipped with two horizontal ultrasonic transducers “looking sideways” into the flow (Side Looking Doppler) to measure water velocity.
- An optional vertical transducer and integrated pressure cell measures the water level.
- All measurement values are analyzed, verified and processed by an integrated signal processor, before being used in the calculation of discharge.
- Velocity measurements from up to nine cells are used, along with measured water level, to calculate discharge either internally in the OTT SLD or externally in a data logger.
- All measurements can be retrieved using SDI-12, RS485 , RS232 or Modbus RTU protocols and are available for storing in a data collection platform, such as the OTT netDL station manager.
Flow velocity measurement Measuring range ± 10 m/s Accuracy 1% of measured value ± 5 mm/s Number of measuring cells 9
Cell size / Blanking 600 kHz 2 … 10 m / 0.5 … 30 m 1.0 MHz 1 … 4 m / 0.3 … 15 m 2.0 MHz 0.2 … 2 m / 0.1 … 8 m
Beam angle / Max. profiling range* 600 kHz 2.4° / 80 m 1.0 MHz 2.4° / 25 m 2.0 MHz 2.1° / 10 m Minimum coverage 0.15 m (water level option)
Electrical data Supply voltage 12 … 16 V DC, typ. 12 V Power consumption 50 … 500 mW, depending on measurement cycle
Water level measurement Measuring range (optional) 0.15 … 10 m Accuracy ±3 mm, depending on stratification Measuring principle Piezo-resistive Measuring range 0 … 10 m Accuracy ±0.25 % FS Interfaces RS-232, SDI-12 or SDI-12 via RS-485, Modbus (optional)
Environmental conditions Operating temperature -5 … + 35 °C Storage temperature -20 … +70 °C Length x Ø 45 … 52.2 cm x 7.5 cm Housing material POM
Wall bracket (accessory) Components Bracket, protective cover, and C rail mount Material Stainless steel Details On request Discharge calculation Within the unit or externally on a datalogger, e.g. OTT netDL OTT SLD EasyUse Installation and service software System setup, commissioning, reviewing and optimizing OTT Prodis 2 (accessory) Calibration software Determining correction factors, (velocity-index method and others), optimizing discharge calculation, managing stations
*The beam angle is understood to be the measured angle with regard to the main axis. The maximum profiling range depends on the water profile, salinity, suspended matter content etc.