MJ-Series Flow Sensor

Choose Affordable Protection Over Costly Leaks

With cost-effective flow-sensing technology from Rain Bird, you can help homeowners avoid small leaks and big issues—building more trust and a stronger reputation for your business. And it all starts with our MJ100B Flow Sensor.

This durable product delivers precise flow monitoring, so homeowners can capitalize on the advanced functionalities that Rain Bird offers. When combined with the ESP-ME3 Controller, MJ-Series Flow Sensors allow homeowners to take system protection to a whole new level:

  • Flo-Watch™: Flo-Watch functionality in the ESP-ME3 controller uses information from the MJ100B to constantly monitor for low-flow and excess-flow conditions caused by broken lines or heads. When a problem is detected, it automatically shuts the area down, while continuing to irrigate non-affected areas. This saves water, protects plants and prevents flooding and property damage.
  • Learned Flow: The MJ100B Flow Sensor works with ESP-ME3 Controllers to automatically learn appropriate station flow rates, resulting in greater accuracy. This automatic collection prevents you from having to manually enter data or physically visit each valve to collect flow data.
  • LNK™ WiFi: When the LNK WiFi Module is used, homeowners are given total control of their system from any smartphone or tablet.
  • Rain Bird App: Control your irrigation system from anywhere. Available in the App Store or Google Play.


  • Higher value brass flow sensor compared to competitors.
  • Active management of irrigation when paired with the ESP-ME3 Controller.
  • The included brass NPT threaded unions allow for fast installation and removal.
  • Delivers precise accuracy with flow ranges from 1.2 gpm to 50 gpm.


  • Multi-Jet Totalizing Landscape Flow Sensor with analog register dial readout and wired connection for ESP-ME3 Controller.
  • Brass body and glass-filled nylon construction provide maximum protection against high pressure surges, physical damage, and corrosion.
  • Not to be used with an unfiltered water source containing potential debris (lakes, ponds, wells, or other unfiltered sources).
  • Exposing the Flow Sensor, full of water, to temperatures below freezing can lead to permanent damage. To winterize the meter, allow it to drain through a downstream drain valve.


Rain Bird MJ-Series Flow Sensor Suggested Operating Range (MJ100B)

Flow Sensor Table

Related Documents