Fox Thermal Instruments FT2A Specifications

Model

Thermal Mass
Flow Meter &
Temperature
Transmitter

Precision Mass Flow Measurement

Model FT2A Gas Mass Flow Meter
For Industrial & Wastewater
Applications

• Measures gas flow rate in SCFM,
NM3/HR, LBS/HR, KG/HR, & many

more

• Wide measurement range; 100:1
turndown typical

• Measures process gas temperature

• 4-20mA for flow rate & temperature;
pulse output for flow/total

• USB port to connect to a PC standard;
Modbus RTU (RS485), BACnet MS/
TP (RS485), Profibus-DP, DeviceNet or
Ethernet Modbus TCP

• Insertion and Inline models

• Welded, 316 SS sensor construction;
Hastelloy C276 optional

• Microprocessor based, field
programmable electronics

• On-board 2 line x 16 character, backlit
display with configuration panel to
view/set readings and parameters

• Free FT2A View ™ Software available

• NIST traceable calibration

• Low-end sensitivity for leak detection

• Negligible pressure drop

• No moving parts design

• FM (U.S.) & FMc (CANADIAN)
approved for Class I, II, III, Division
2, Groups A, B, C, D, E, F, G T4A
hazardous locations. NEMA 4X and CE
approved.

• EMC Certification to: EN 61326­1:2013

• LVD Certification to: EN 61010-1:2010

• EU Directive: 2014/68/EU

• Weld Testing: EN ISO 15614-1 and EN
ISO 9606-1, ASME B31.3

FOX THERMAL

399 RESERVATION ROAD
MARINA, CA 93933
PHONE: [phone]
FAX: [phone]
[e-mail]
www.foxthermal.com

An ON

I

CON Brand

FT2A

Fox Model FT2A Gas Mass Flow Meter & Temperature
Transmitter

The Fox Model FT2A measures gas ow rate in standard units without

the need for temperature or pressure compensation. It provides isolated

4-20mA and pulse outputs for ow rate, and a 4-20mA output for process

gas temperature. The pulse output is normally used for totalization.

With an on-board 2 line x 16 character, backlit display, operators can view

ow rate, total, elapsed time, process gas temperature, and alarms. The
display is also used in conjunction with the Conguration Panel to congure
ow meter settings, pulse output frequency scaling, pipe area, zero ow
cutoff, ow ltering (damping), display congurations, diagnostics and high

or low alarm limits.

The Model FT2A is available in both insertion and inline models. The insertion
meter is easily installed by drilling a ¾” hole in the pipe and welding on a

¾” NPT coupling. A Fox-supplied compression tting secures the probe in

place. The inline model is available in ¼-inch to 6-inch sizes and includes

built-in ow conditioners that eliminate the need for long, straight pipe runs.
The meter can be ordered with ange or NPT end connections.

Both models are supplied with 316 stainless steel wetted materials standard

or Hastelloy C-276 as an option (inline ow bodies also available in carbon

steel). A USB port to connect to a computer or laptop is standard; interface
options include Modbus RTU (RS485), BACnet MS/TP (RS485), Probus-DP,

DeviceNet or Ethernet Modbus TCP.

Fox has certied cleaning and bagging procedures for ow meters to be

used in oxygen applications.

100

10

1

110 100 1000 10,000

6"

.25"

.5"

.75"

1"

1.5"

2"

3"

4"

1.25"

2.5"

6"

4"4"

1000

100

10

1

110 100 1000 10,000

6"

.25"

.5"

.75"

1"

1.5"

2"

3"

4"

1.25"

2.5"

6"

3.3

THERMAL MASS TECHNOLOGY

Theory of Operation

Fox Thermal Flow Meters use a constant temperature

differential (constant Δ T) technology to measure mass flow

rate of air and gases. The thermal mass flow sensor consists
of two Resistance Temperature Detectors (RTD’s). The sensor
elements are constructed of a reference grade platinum

NIST Traceable Factory Calibration

Fox calibrations are performed with NIST traceable ow
standards. Whether you require a straightforward air

calibration or a complex mixed gas calibration, our goal is
to achieve the highest accuracy and the fastest turnaround
time.

wire wound around ceramic mandrels that are inserted into
stainless steel or Hastelloy tubes.

The Fox Calibration Lab employs a wide range of gases,
gas mixtures, temperatures, pressures and line sizes to

The Reference RTD measures the gas temperature. The
instrument electronics heat the mass flow sensor, or heated

element, to a constant temperature differential (constant Δ T)

simulate actual uid and process conditions. This real-

world approach improves installed accuracy and minimizes
measurement uncertainty.

above the gas temperature and measures the cooling effect

of the gas flow. The electrical power required to maintain a

constant temperature differential is directly proportional to
the gas mass flow rate. The microprocessor linearizes this
signal to deliver a linear 4-20mA signal.

PRESSURE DROP DIMENSIONS

Pressure Drop Charts for Inline Flow Meters

As seen in the charts below, pressure drop is negligible and energy
losses are minimal.

Meter Dimensional Drawings

The FT2A is available in many different
configurations. An example of the
local insertion and remote inline flange
configurations are shown below. To see more
configurations, visit our website at www.

foxthermal.com/literature/

Inches of Water

millibars

Local Insertion

(84)

1.50
(38.0)

1.40
(35)

7.12

(181)

SCFM

2x 3/4 inch NPT Female

FLOW

5.35
(136)

Input
Power

MODEL FT2A

Gas Mass Flowmeter & Temperature Transmitter

C
L

Signal
Wiring

“HH”

“LL”

Remote Insertion

3.3

2X 3/4” NPT,

FEMALE

SHIELDED, 100ft (30.48m) MAX

(84)

1.50
(38)

1.4
(35)

7.12
(181)

4.4

“HH”

(112)

2.0
(51)

4.5

(114)

“LL”

FLOW

CONDUIT,
3/4”, METAL

C
L

5.35
(136)

MODEL FT2A

Gas Mass Flowmeter & Temperature Transmitter

REMOTE CABLE, 5 CONDUCTOR,

NM3/hr