The FlowMaid is a small monitoring device used to record level, flow, volume and discrete events. It calculates the volume lost in a SSO event using the Manning equation. As an open channel flow meter, the user can select from 11 flow formulas.

The only requirement is to enter the level of the overflow pipe, its diameter, material and angle. Years of data can be recorded before filling its memory. Every event shows start and end time, duration, average flow and volume lost.

The relay output can be remotely activated or based on events such as high level. For an optimum operation time on batteries, the relay output can be used to interrupt the power supply of the level sensor or other accessories like a cellular modem.

Level Monitor and open channel flow meter

The user can use one of the following formulas (pictures are in same order) : Manning, Manning for open channel, California pipe, Rectangular weir with end contractions, Rectangular weir without end contractions, V-notch (or triangular) weir and Trapezoidal (or Cipolletti) weir or use a standard or polynomial flow formula or a lookup table.


  • Instantaneous readout of flow and level
  • Available with a Plug and Play pressure sensor kit with fast setup.
  • Easy installation
  • High levels of accuracy in most condition
  • Level and flow history on the Web
  • Cellular Wireless or Non-Wireless models available
  • Access your level and flow data from the internet 24/7
  • Economical, compact solution for level and flow monitoring
  • 10 years data storage capacity
  • Dynamic logging intervals ensures data is collected as conditions change
  • Disconnectable sensor for quick and easy field replacement
  • Less Maintenance and Troubleshooting
  • On-site sensor operation verification prior to leaving the site


  • Information Program
  • Billing / Custody Transfer
  • Level and flow Studies
  • Real time flow analysis
  • Low and high level and flow warning system

Select the formula for your application:

  • Manning
  • Manning for open channel
  • California pipe
  • Rectangular weir with end contractions
  • Rectangular weir without end contractions
  • V-notch (or triangular) weir
  • Trapezoidal (or Cipolletti) weir
  • Standard or polynomial flow formula
  • Lookup table

Accessories of the