Technical Specifications

Fox Thermal Model FT4A Thermal Mass Flow Meter & Temperature Transmitter

Performance Specs

Flow Accuracy:

Air: ± 1% of reading ± 0.2% of full scale.
Other Gases: ± 1.5% of reading ± 0.5% of full scale.
Accuracy specification applies to customer's selected flow range

Straight, unobstructed pipe requirement:

15 diameters upstream; 10 downstream.

8 diameters upstream; 4 downstream.

Flow Repeatability:

± 0.2% of full scale

Flow Response Time:

0.8 seconds (one time constant)

Temperature Accuracy:

± 1° F (± 0.6° C)

Calibration:

Factory Calibration to NIST-traceable standards
CAL-V™: In situ, operator-initiated calibration validation

Operating Specs

Flow Units (field selectable):

SCFM, SCFH, NMPS, NM3/M, NM3/H, NM3/D, NLPS, NLPM, NLPH, MCFD, MSCFD, SCFD, MMSCFD, MMSCFM, SM3/M, SM3/D, SM3/H, LB/S, LB/M, LB/H, LB/D, KG/S, KG/M, KG/H, SLPM, SFPM, MT/H

Flow Rates:

15 to 60,000 SFPM (0.07 to 283 NMPS)

Turndown:

up to 1000:1; 100:1 typical

Flow Ranges:

Pipe Size	SCFM	MSCFD	NM³/HR
1.5" (40mm)	0 - 840	0 - 1,220	0 - 1,325
2" (50mm)	0 - 1,400	0 - 2,020	0 - 2,210
2.5" (63mm)	0 - 2,000	0 - 2,880	0 - 3,150
3" (80mm)	0 - 3,100	0 - 4,440	0 - 4,890
4" (100mm)	0 - 5,300	0 - 7,650	0 - 8,360
6" (150mm)	0 - 12,000	0 - 17,340	0 - 18,930
8" (200mm)	0 - 20,840	0 - 30,020	0 - 32,870
10" (250mm)	0 - 32,800	0 - 47,250	0 - 51,740
12" (300mm)	0 - 46,600	0 - 67,180	0 - 73,500

Pipe Diameter	SCFM	MSCFD	NM³/HR
0.75" (20mm)	0 - 220	0 - 320	0 - 350
1" (25mm)	0 - 360	0 - 520	0 - 570
1.25" (32mm)	0 - 625	0 - 900	0 - 990
1.5" (40mm)	0 - 840	0 - 1,220	0 - 1,325
2" (50mm)	0 - 1,400	0 - 2,020	0 - 2,210
2.5" (63mm)	0 - 2,000	0 - 2,880	0 - 3,150
3" (80mm)	0 - 3,100	0 - 4,440	0 - 4,890
4" (100mm)	0 - 5,300	0 - 7,650	0 - 8,360
6" (150mm)	0 - 12,000	0 - 17,340	0 - 18,930

Note: To determine if the FT4A will operate accurately in other pipe sizes, divide maximum flow rate by the pipe area. The application is acceptable if the resulting velocity is within the velocity range above.

Note: Consult factory for flow ranges above those listed. Inline meters above 5,000 SCFM (7,900 NM3/H) air may require third party calibration.

Gas Pressure (max):

w/o Retractor: 740 psig (51.02 barg)
with Retractor: 150 psig (10.3 barg)

316 SS inline w/NPT ends: 300 psig (20 barg)
316 SS inline w/150lb flanges: 230 psig (16 barg)
CS inline w/NPT ends: 300 psig (20 barg)
CS inline w/150lb flanges: 285 psig (20 barg)

Check with factory for higher pressure options.
NOTE: When teflon ferrule option ordered, gas pressure is 60psig (4.1 barg) maximum.

Relative Humidity:

90% RH maximum; non-condensing

Temperature:

DDC-Sensor™: -40 to 250°F (-40 to 121°C)
Enclosure: -40 to 158°F (-40 to 70°C)
*Note: Display dims below -4°F (-20°C); function returns once temperature rises again.

Input Power:

Input power: 12 to 28VDC, 6 watts max. (CE requirement)
Full input power input range: 10 to 30VDC, 6 watts maximum.

Inputs/Outputs

• All outputs and communication circuits are galvanically isolated.
• Standard 4-20mA output proportional to the flow rate; fault indication per NAMUR NE43; HART communication option.
• The second output can be ordered for pulse/alarm or Modbus RTU (RS485).
• Isolated pulse output: 5 to 24VDC, 10mA max, 0 to 100Hz for flow.
• The pulse output can be used as an isolated solid state output for alarms.

Port:

Mini USB communication port is standard.

Software:

The free PC-based software tool - FT4A View™ - provides complete configuration, remote process monitoring, and data logging functions.

Optional serial communication:

Modbus RTU (RS485) (when no pulse output has been ordered).

4-20mA and Pulse Verification:

Simulation mode used to align 4-20mA output and pulse output (if ordered) with the input to customer’s PLC/DCS.