GX-3R 4 Gas Monitor LEL/O2/H2S & COGX-3R 4 Gas Monitor LEL/O2/H2S & CO

GX-3R 4 Gas Monitor LEL/O2/H2S & CO

  • Smallest & lightest 4 gas monitor
  • 2.2″ W x 2.55″ H x 1.02″ D, 3.52 ounces
  • Simultaneous detection of 4 gases
  • LEL, O2, H2S & CO
  • H2 Compensated CO sensor available
  • Simple 2-button operation

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The GX-3R is the worlds smallest 4 gas monitor weighing only 3.52 ounces and can comfortably be clipped within a worker’s breathing zone (2.2” W x 2.55” H x 1.02” D).

It simultaneously monitors and displays LEL combustibles, O2, CO (Hydrogen compensated CO also available),and H2S.

The GX-3R represents the latest evolution of gas detection technology utilizing a new generation of micro sensors. The LEL sensor has a unique design with two active filaments in one sensor to increase it’s resistance to silicone poisoning. If one filament gets poisoned the second filament takes over. The new O2 sensor is electrochemical with a 3 to 5 year life span.  H2S and CO are now available in a combo micro sensor. 

Gas Detected

(CO) H2 Compensated

Carbon Monoxide(CO)Hydrogen Sulfide(H2S)H2S Only

Combustible Gases (Methane as standard)

Dual Sensor

Sensor Slot



Detection Principle


Catalytic combustion

Detection Range (Increments)

0 ~ 2,000 ppm (1 ppm)

0 ~ 200.0 ppm (0.1 ppm)

0 ~ 100% LEL (1% LEL)

Accuracy Statement

± 5% of reading or ± 2 ppm CO

± 5% of reading or ± 5 ppm CO (whichever is greater)± 5% of reading or ± 2 ppm H2S (whichever is greater)

± 5% of reading or ± 2% LEL (whichever is greater)

Sampling Method

Diffusion sampling standard (hand aspirator or clip-on motorized pump optional)


Digital LCD displays with 7 segment plus 14 segment plus icon

Preset Alarms (User Adjustable) Overscale alarm (Non-adjustable)1st alarm: 25.0 ppm 2nd alarm: 50.0 ppm 3rd alarm: 1200.0 ppm TWA alarm: 25.0 ppm STEL alarm: 200.0 ppm Over alarm: 2000.0 ppm1st alarm: 5.0 ppm 2nd alarm: 30.0 ppm 3rd alarm: 100.0 ppm TWA alarm: 1.0 ppm STEL alarm: 5.0 ppm Over alarm: 200.0 ppm1st alarm: 10% LEL 2nd alarm: 25% LEL 3rd alarm: 50% LEL Over alarm: 100% LEL
Types of AlarmsGas Alarm: 3 Increasing alarms, STEL, TWA, overscale alarm. O2 decreasing/increasing. Trouble alarm: Sensor disconnection, low battery, circuit error, calibration range error
Display of AlarmGas Alarm: Flashing LEDs, continuous buzzer (100 db @ 30 cm),flashing gas value, vibration Trouble alarm: Flashing LEDs, intermittent buzzer (95 db @ 30 cm),display of error message
Operating Temp. & Humidity-20°C ~ +50°C [ -4°F ~ +122°F ], 10 to 90% RH, non-condensing (continuous environment) -40°C ~ +60°C [ -40°F ~ +140°F ], 0 to 95% RH, non-condensing (temporary environment, 15 minutes)
Response TimeWithin 30 seconds (T90)
Power SourceLithium-ion battery, Approx. 25 hours after a 3 hour full charge
ApprovalsATEX, CSA (Pending)
Dimension & Weight2.2” W x 2.55” H x 1.02” D (Approx. 58 W x 65 H x 26 D mm),3.52 ounces (approx. 100 g) without rubber booth 2.4” W x 2.63” H x 1.06” D (Approx. 61 W x 67 H x 27 D mm),3.70 ounces (approx. 105 g) with rubber booth
Case MaterialExplosion proof, dust and water resistant to IP-66/68 (2m,1h) approval. Drop height 23 ft
ControlsTwo buttons: POWER / MODE, AIR
DataloggingLogs user ID, station ID, Calibration & Bump Test history, Alarm Events & Alarm Interval Trends
Standard AccessoriesAlligator clip, protective rubber boot, charger, and calibration adapter
Optional AccessoriesSDM-3R calibration station RP-3R Clip-on sampling pump with 4” rubber nipple, 10’ hose and probe (up to 40’ hose available) Padded carrying case for GX-3R and accessories USB to IrDA downloading cable for datalogger