UB-Flow AV : the average flow velocity monitoring sensor

The UB-Flow AV is a Doppler sensor which aims to monitor average velocity in sewer networks.


  • compact and hydrodynamic
  • low power consumption
  • quality indicators
  • high accuracy
  • fast measurement

The UB-Flow AV is a Doppler sensor which aims to monitor average velocity in sewer networks (between -1 and 4m/s). This sensor measures precisely very low velocities and starting from 30mm water depth, including in low particle laden water. In addition to the average velocity, other information are given to guide the user in the flow rate estimation, such as standard deviation, minimal and maximal measured velocities, and to estimate the measurement quality, such as Doppler quality and echo quality indicators.

The fast booting time and fast measurement acquisition time allows to reach an autonomy on battery of more than a year.

An accelerometer gives pitch and roll angles to check the right orientation of the device (+/-1°). A temperature sensor gives a value in °C (+/- 1°C) of the environment temperature around the sensor.

Measurement Performances
Measurement principle Acoustic, pulsed Doppler
Velocity range between -1 and 4m/s
Velocity measurement resolution ± 0.001 m/s
Operating temperature 5°C to 60°C
Pitch / Roll ±1°
Temperature sensor ±1°C
Single measurement duration 1.2s
Emitting frequencies 1MHz
Number of transducers 1
Dimensions 161 x 28.4 x 26.6 mm
Weight sensor head about 160g (670g with 10m cable)
Cable 10m long (5.6mm section)
Fixation Screws through 3 inserts beneath
Data Management
Communication Modbus RTU protocol, RS-485
Communication speed 57600 Baud (custom on request)
Internal data logger NA
Velocity data Average velocity, Standard deviation, Maximal velocity, Minimal velocity
Data quality Doppler quality indicator, Echo quality indicator, Number of good values, Statistical velocity distribution
System data Serial number, Firmware version, Pitch/Roll angles, Temperature
Input 8V to 28V, Inverted voltage protection
Consumption 1 W
Power up 0.9 s
Norms and security
RoHS compliant
CE Yes
Emissions Class B (EN 61326-1 and EN 55011)
  • technical datasheet, user manual and modbus communication protocol on request)