Sonic FEx-100 Ultrasonic Gas Flow Meter Flame-proof


Gas flow monitoring with FEx-100 intelligent function in a hazardous area. Sonic's wide variety of ultrasonic flow meters meet customer's needs for flow monitoring in any situation.


  • Flame-proof Exd II BT6 compliant
  • Wider measurement range
  • No pressure loss
  • Faster response and better reproductivity
  • Wide-screen LCB and various display function
  • Various output port (analog x2, digital x1, contact x4)

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Applicable fluid: gas (*1, *2)
Applicable pipe: Nominal diameter: 50mm ∼ 4000mm (*3)
Spool piece: Flange rating: JIS 10k standard (*4)
Material : SGP, STPG, SUS304, SUS316, STPY (*5)


Flame-proof standard / ExdIIBT4
Sensor :

Standard (screw type) temperature : -30 ∼ 180ºC
Pressure : -0.05 ∼ 1MPa
Large (flange type) temperature : -30 ∼ 180ºC
Pressure : -0.05 ∼ 1MPa
Measurement method: Ultrasonic transit time

Seal: Gas seal unit
Installation requirement: Straight pipe: Wider than 15D
at upstream
wider than 5D at downstream (D is inner diameter)
Cable length: Sensor to convertor: Standard 6m or 10m


Flame-proof standard: ExdIIBT6
Measurement method: Ultrasonic transit time method
Measure line: 1 line or 2 lines (option)
Traverse: Z o V
Accuracy : ±1.0% FS (flow velocity 5 ∼ 60 m/s)
Reproductivity : 0.2%
Flow velocity resolution: less than 0.5mm per second
Averaging : Default 10 sec (0.5 ∼ 180 sec variable)
Ultrasonic thermometer: Measure temperature
(in case of air) by ultrasound transit time

Ambient temperature: -10 ∼ +50ºC
Material: AC4A (aluminum cast)
Power supply :

AC100V±10%, 50/60Hz
AC115V, 220V (option)

Surge protection: Built-in surge absorber (VDD line, signal line)
Power dissipation: Max.27W

Analog x2

Range: DC4∼20mA
Over range: DC0∼24mA
Load resistance: Less than 450Ω
Output mode: Flow rate, temperature, pressure

Contact Output x4

Open collector: Rated voltage and current 30V, 0.25A
Output mode: Integrated flow rate, alarming, normal,
reverse output, upper limit alarming, lower limit alarming
Integrated pulse width : 1.6msec or 50msec
Power supply for pressure and temperature :
DC24V±0.5V, 0.2A
Digital output: RS232C, RS422

Input / Temperature : DC4∼20mA, Pressure : DC4∼20mA
Display : LCD 128 dot x 240 dot, backlight
Measurement View: Nominal diameter, temperature, pressure,
flow rate range etc.
Adjustment view: Zero adjustments, averaging time, low-cut etc.

Data Sheet: Sonic FEx-100 Ultrasonic Gas Flow Meter