RKI GX-3R Personal Gas Monitor
RKI GX-3R Personal Gas Monitor
RKI GX-3R Personal Gas Monitor

RKI GX-3R Personal Gas Monitor

Pine Item #56185

OSHA defines the breathing zone as a ten-inch radius around the worker’s nose and mouth and requires that worker exposure monitoring air samples be collected in the breathing zone. Air sampling filters may be attached to the collar or lapel.  Traditionally this means only a single gas monitor would be small enough for a worker to practically wear a gas monitor ‘In the breathing zone’. Now there is a 4 gas monitor smaller than many single gas monitors.

The GX-3R is the world's 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.


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

Non-Compliance Indicator

Alarms: audible, visual, & vibration

3 user adjustable alarm levels

25 hours of operation (Lithium-ion battery)

Water and dust resistant design, IP66/68


Personal monitoring

Confined spaces



Oil and Gas


Fire Services


Quantity must be 1 or more
Equipment available for both rental and purchase
Request a Quote

Gas Detected(CO)
H2 Compensated
Carbon Monoxide(CO)Hydrogen Sulfide(H2S)H2S
Combustible Gases
(Methane as standard)
Dual Sensor    
Sensor Slot123    
ECDual ECECCatalytic combustionEC    
Detection Range
0 ~ 2,000 ppm
(1 ppm)
0 ~ 200.0 ppm
(0.1 ppm)
0 ~ 100% LEL
(1% LEL)
0 ~ 40% Vol. (0.1%)    
± 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)
± 5% of reading O2    
Sampling MethodDiffusion sampling standard (hand aspirator or clip-on motorized pump optional)
DisplayDigital LCD displays with 7 segment plus 14 segment plus icon
Preset Alarms
(User Adjustable)
Overscale alarm
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 ppm
1st 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 ppm
1st 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
& Weight
2.2” 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
Manuals, Data Sheets & Software