NEW! The FT-3500 Series Flow Meter and Thermal Energy Measurement System

New from ONICON: The FT-3500 Series Insertion Electromagnetic Flow Meter / Thermal Energy Measurement System combines the convenience of an insertion style design with the reliability of electromagnetic flow measurement. They are ideal for measuring flow in a wide variety of applications. When provided with the thermal energy (BTU) meter option, the FT-3500 becomes a complete hydronic energy measurement system.

ONICON’s FT-3500 Series Thermal Energy Measurement System is a versatile insertion electromagnetic flow meter and thermal energy measurement system. It is designed to measure electrically conductive liquids in a variety of applications. The FT-3500 features a remote touch screen display that allows users to interact intuitively with measurement values, application details, and configuration settings. The advanced FT-3500 transmitter features a native BACnet and MODBUS communication protocol via IP or RS485. It also features a dual analog output for flow or energy rate. Additionally, the FT-3500 boasts a high-resolution frequency and three scalable pulse outputs for totalization or alarm signals.

The standard configuration of the FT-3500 is ideal for volume rate and totals. The thermal energy configuration integrates ONICON’s high-precision temperature sensors to provide a complete hydronic energy measurement system. Whether you need to measure flow rate or energy consumption, the FT-3500 series is a reliable and accurate choice.


  • Chilled water
  • Heating hot water
  • Condenser water
  • Domestic/municipal water
  • Water/glycol


  • Simple Installation and Commissioning – Factory configured and ready for use upon delivery.
  • Exceptional Performance & Value – Insertion style design provides cost-effective solution for accurate and reliable flow measurement in larger pipe sizes.
  • Excellent Long-Term Reliability – Low maintenance, no-moving-parts flow sensing technology works well in difficult flow measurement applications such as open loop condenser water flow.
  • Highly Accurate Over a Wide Flow Range – Highly efficient sensor design with high accuracy and sensitivity, particularly at low flow rates.
  • Simplified Hot Tap Insertion Design – Standard on every insertion flow meter, this feature allows for insertion and removal by hand without a system shutdown.
  • Ideal Solution for Retrofits – The innovative hot tap adapter design allows for wet tapping pipes without interrupting flow.
  • Touch Screen Remote Display – All process data and programming functions are accessible via user friendly display. Advanced diagnostics are available to confirm wiring connections, noise detection via waveforms, and built-in verification for accurate system performance. Color coded interconnecting cabling and installation instructions are provided to ensure error-free installation.
  • Network Communication and Output – All data is reported via BACnet or MODBUS directly to the BMS/BAS via IP or RS485 connection. The FT-3500 is provided with three (3) pulse outputs for totalization, alarm, and system status; two (2) analog outputs for energy, flow, and temperature; and one (1) frequency output for flow rate.
  • BTU (Energy) Meter Option – When ordered with the thermal energy (BTU) meter option, the FT-3500 becomes a complete thermal energy measurement system providing accurate flow, energy, and temperature data.


Every ONICON FT-3500 flow meter is wet calibrated in a flow laboratory against standards that are directly traceable to National Institute of Standards and Technology (N.I.S.T.). A certificate of calibration accompanies every meter.


The FT-3500 provides the user with a single point of communication for BACnet MS/TP, BACnet IP, MODBUS RTU, or MODBUS TCP/IP. Interval data for energy and volume are provided along with operating status and diagnostic data.

FT-3500 alarms can be configured to the upper and lower limits of specific BACnet objects and provide custom alarm states at the meter display. The new BACnet stack includes:

  • Stack Modularity: Traditional polling methods of data acquisition are supported and Change-of-Value (COV) notifications report changes to the network on an interrupt basis (without polling)
  • Intrinsic Reporting: Provides detailed control for customers to specify when notifications should occur, and additional metrics that can be used for quick diagnosis.
  • Foreign Server Registration: Allows a unit to be remotely routed to another BACnet network over IP, relieving the need for the customer to install multiple BACnet clients or routers.
  • Advance Network Diagnostics: Network time synchronization for troubleshooting and isolating meters from other facility issues. Network-accessible event logs provide a record of changes and power events for further aid in troubleshooting.



  1. Provide a Class II Input Power 20-28V AC/DC, 60 Hz.
  3. Active Analog outputs do not provide power.
  4. Digital Outputs are available for flow totals, operating modes, and alarms.
  5. Remote wall mount aluminum cast NEMA 4 Touch screen display.
  6. Optional ½” FNPT waterproof conduit connectors.
  7. ONICON provided cable up to 200ft. Direct burial rated.
  8. Order ONICON Installation kits separately. Installation kits vary based on pipe material and application. For installations in pressurized (live) systems, use “Hot Tap Installation Kit” and drill hole using a 1” wet tap drill.
  9. Allow enough slack in the flexible conduit to permit the meter to be removed from the valve.

When ordered as a thermal energy (BTU) meter:

  • 10. ONICON temperature sensors and thermowell kits ordered separately.
  • 11. Analog outputs are available for energy rate, flow rate, supply, return, or delta temperature.
  • 12. Digital outputs are available for energy totals, flow totals, operating modes, and alarms.

    Interested in learning more about this unique Flow Meter? Download the documents below:

    Or call us today: 763-777-9525 You can also fill out the form below and we will reach out to you.

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