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A completed FT3 application data form is required to purchase this meter. We will contact you about your order.


  • Field selectable units SCFM, NM3H, Kg/Hr and more
  • Turndown range typically 100:1
  • Measures process gas and temperature
  • 4 to 20 mA outputs for flow and temperature; pulse output for flow
  • 316 stainless steel sensor; Hastelloy C276 optional
  • USB connection standard (free FT3 View Software); Optional HART and RS485 Modbus
  • Optional display, LCD 2 line, 16 character, backlit, Infrared (IR) buttons
  • CAL-V in pipe calibration validation
  • Zero CAL-CHECK calibration validation feature
  • Power input 24 VDC or optional 85 to 264 VAC in local or remote enclosures
  • FM and FMc approvals
  • ATEX and IECEx approvals, Zone 1 and 2
  • Class I, Div 1, Groups B,C,D
  • Class I, Div 2, Groups A,B,C,D
  • Class II & III, Div 1, Groups E,F,G
  • Indoor/outdoor NEMA 4X and CE approved

The Fox Thermal FT3 mass flow meter and temperature transmitter measures two important process variables with a single instrument, providing isolated 4 to 20 mA and pulse outputs for flow rate, and a 4 to 20 mA pulse output for process gas temperature or a second flow rate output.

Direct mass flow measurement, exceptional low-flow sensitivity, fast response, and low maintenance requirements distinguish the Fox Model FT3. Virtually immune to changes in temperature and pressure, the flow meter delivers repeatable, accurate mass flow measurement under varying loads. It's rugged, no-moving-parts design is also ideal for high-vibration industrial environments, and enhanced EMI immunity makes it suitable for environments where electric motors, igniters or dirty power may affect instrument performance.

CAL-V Performs Calibration Validation in your Pipe

The Model FT3's CAL-V feature is an in-situ calibration routine that validates the flow meter's calibration accuracy by testing the functionality of the sensor and its associated signal processing circuitry. This innovative approach lets you validate instrument calibration in your pipe, at your process conditions, with just a push of a button. At the conclusion of the test, the meter will display a pass/fail message and the CAL-V data is saved in the meter for look-up at any time.

Zero CAL-CHECK Calibration Validation Feature

  • Checks for build-up on sensor that could affect calibration
  • Further validates the zero stability of the meter
  • Checks thermal conductivity (heat transfer) repeatability of the sensor

Unlike CAL-V, which may be performed in the pipe and at process conditions, Zero CAL-CHECK must be performed at zero flow to ensure a valid test result. Depending on the test selected (insitu or out of pipe), zero flow will either be compared to a customer-established field baseline or factory baseline.

View the FT3 calibration validation flyer for more information about the CAL-V and Zero CAL-CHECK features.

Required Components

These additional components are required for the operation of your product. We strongly advise you to purchase these components unless you already own them or own a suitable alternative.

Fox Thermal 101570 Remote Sensor Cable
5 conductor, 18 AWG PVC shielded cable for FT2 and FT3 remote sensors
Fox Thermal Oxygen Service Prep
Have FT1, FT2 or FT3 cleaned and bagged for oxygen service


Fox Thermal FT3 View Software Download
Application software program that runs on a PC and communicates with a Fox FT3 Thermal Mass Flow Meter


Please consider these optional accessories.

Fox Thermal 102878 Teflon Ferrule Kit
For FT2 and FT3 insertion mass flow meter
Fox Thermal Certificate of Origin
Chamber of Commerce proof of origin


This product can be used in the following applications:

Application Notes

Here's how some of our customers used this product.

Natural Gas Flow

The Background: Our customer is a natural gas power plant seeking to replace the flow meters they use to measure the amount of natural gas used by the plant.

The Problem: The customer needs a highly accurate flow meter with hazardous area approvals. The don’t want to have to rework piping in order to install the new meter.

The Solution: We recommended the Fox Thermal FT3 mass flow meter which provides ±0.2% full scale accuracy and is available with a wide range of hazardous area approvals for use with natural gas. The FTY3 also includes built-in flow conditioners that eliminate the need for long, straight pipe runs making installation easy and reducing installation costs.