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Gas Detector
  • Pre-calibrated, user-replaceable Smart Sensors
  • Suitable for hazardous environments
  • Onboard LCD for standalone real-time monitoring of concentrations
  • 4 to 20 mA, optional Modbus RTU® and wireless interface
  • Non-intrusive configuration


The GDX-350 transmitter with Smart Sensor technology provides accurate and continuous detection of toxic, combustible and asphyxiate gases using infrared, catalytic bead and electrochemical sensors. The full-featured design of the GDX-350 includes a large LCD display, a 4 to 20 mA interface, programmable alarms, optional relays and a Modbus interface. Exclusive, pre-calibrated replacement sensor technology simplifies maintenance requirements.

Its rugged construction, intrinsic safety capability (in two-wire mode with barrier) and an explosion-proof housing allow the GDX-350 to function in extreme temperature conditions like blast chillers and deep freezers. The GDX-350 can be placed directly in many classified or hazardous industrial environments to deliver reliable, superior sensing performance that protects personnel, equipment and property.



Gas detector using infrared, catalytic bead or electrochemical sensors


Ammonia (NH3), Carbon Dioxide (CO2), Carbon Monoxide (CO), Hydrocarbons, Hydrogen (H2), Hydrogen Sulfide (H2S), Methane (CH4), Nitrogen Dioxide (NO2), Oxygen (O2), Pentane (C5H12), Propane (C3H8), Sulfur Dioxide (SO2)

Measuring Range*

ppm, %LEL or Vol% depending on the sensor

Power Supply

10 to 30 VDC


Graphic LCD 64 x 128 pixel; status indicators

Analog Output

4 to 20 mA, 3-wire

Alarm Relays

3 SPDT, rating 5 A @ 30 VDC or 240, resistive load

Digital Output (Optional)

Modbus RTU via RS 485, optional


-40 to 140 °F (-40 to 60 °C)


5 to 90 %RH, non-condensing

Size (w x h x d)

Approx. 5.5" x 8.0" x 4.6" (140 x 205 x 120 mm)


Powder-coated aluminum


CSA: Class 1, Division 1, Groups B, C, D (not for NH3)

* See datasheet for details