Ultrasonic Flowmeter

SeFlow 400

The SeFlow 400 is Sewerin’s single channel portable flowmeter for applications in the municipal water and wastewater sector offering long term stable and precise bidirectional flow measurements in remote areas outdoor.

Thanks to its matched transducer pairs, sophisticated internal signal processing and  highly stable  zero  point, the SeFlow 400 can identify even the lowest flow rates, making it the ideal measurement tool for all leak detection, service and maintenance activities, for long and short term monitoring, data logging and meter verification.

Measurement are made from the outside of the pipe without any need for contact with the water column; there is no need to cut into the piping system or to interrupt the water supply.


  • Water loss balancing / Leak detection / Measurement of night flows.
  • Measurement of consumption profiles on drinking water distribution networks.
  • Verifying existing meter accuracy.
  • Control of network elements and storage facilities.
  • Monitoring during pumping tests or when carrying out step tests.



  • Non-invasive flow measurement : no process shutdowns or supply interruption.
  • Easy & intuitive to use – tailored to the needs of the water market.

  • Suitable for a wide range of nominal diameters (DN 40 to 4700 mm) and pipe materials.

  • Very precise bidirectional measurements with very high dynamics (flow velocity range from 0.01 to 25 m/s) and detection of very low flow velocities (from 0.01 m/s).

  • The digital signal processing unit (DSP) and its noise reduction algorithms guarantees stable and reliable results even under difficult measurement conditions (up to 1000 measurements per second analyzed).

  • Very robust housing with IP67 protection index.

  • Very high battery autonomy thanks to the integrated "Low power" and "Night flow" modes (autonomy >1 month with 1 meas. every 10 minutes; > 6 months with additional battery pack).

  • Flow profile correction functionality (non-ideal inflow conditions).

  • Integrated datalogger allowing the recording of more than  100,000 measurements and diagnostic data.

  • Equipped with one 0/4-20mA current output (passive) and one binary output (opto-relay) with simplified configuration  for  data  transmission  on  remote  management  station/logger  or

    process/control applications (fully customizable alarm scenarios).

  • Ultra-powerful and matched IP68 transducers with reinforced cables (measurement possible in harsh conditions). No Zero adjustment necessary.

  • Stainless steel fastening sets and installation in minutes.

  • Reading of the internal memory via serial interface and full data analysis with the FluxDiag Reader Software (free).

  • No drift over time, no recalibration necessary.

  • Easily transportable, the measuring sets are delivered in a transport case.