RKI Instruments

RKI GX-3R 4 Gas Confined Space Monitor (TIIS) 72-RA-C-T

Bulk discount rates

Below are the available bulk discount rates for each individual item when you purchase a certain amount

Buy 5 or above and pay only $459.00 each
On Sale
  • RKI01-72-RA-C-T-Product_Image_1
  • RKI01-72-RA-C-T-Product_Image_2
Now: $476.00
Was: $595.00


Please Note: Unfortunately, RKI has reported that the GX-3R and GX-3R Pro CSA certification is in a pending status causing the long lead time you see displayed on our website. Due to this pending status, RKI will not be able to ship instruments with the CSA & ATEX labels for several months (Possibly March 2024).

RKI has offered this alternative to fulfill orders in the interim - GX-3R and GX-3R Pro units with the TIIS intrinsically safe labels.

  • Both the CSA and TIIS labeled products are certified as intrinsically safe explosion proof instruments suitable for Class 1, Division 1 environments.
  • The only difference between the CSA and TIIS instruments is the certification label.
  • The packaging, menu system, pricing, and 3-year warranty are all the same.
  • RKI GX-3R 4 Gas Confined Space Monitor (TIIS approved) is the smallest, and lightest CS Gas Monitor and includes a 3-year warranty on the monitor and sensors. Weighing only 3.52 ounces, it clips comfortably within a worker's breathing zone. It simultaneously monitors and displays LEL combustibles, O2, CO, and H2S. The GX-3R utilizes 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.

    Safety supervisors will appreciate the non-compliance indicator. The instrument flashes it’s 3 LED lights every 30 seconds in the following conditions; if the instrument has not been bump tested, or if calibration is due, or if there was a gas alarm event. The 3 LED lights will continue to flash once every 30 seconds until the non-compliance condition has been resolved. The 30 second interval is adjustable.

    Applications: Personal monitoring, Confined spaces, Refineries/petrochemical, Utilities, Oil and Gas, Water/wastewater, Fire services, Construction

    Key Features:

    • 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
    • Impact resistant body with removable rubber boot
    • Large LCD Auto-backlit display
    • 25 hours of operation (Lithium-ion battery)
    • Field replaceable sensors & filters
    • Water and dust resistant design, IP66/68
    • Stealth mode for law enforcement
    • 3-Year warranty on the monitor and sensors
    • TIIS Safety Approval
    • Updated version of the GX-2009 (Unlike the GX-2009, the GX-3R uses a 0.25 Regulator.)

    Sensor Specifications:(Warranty is renewed for each sensor replaced.)

    • Carbon Monoxide (CO)
      • Detection Range: 0 ~ 2,000 ppm (1 ppm)
      • ± 5% of reading or ± 2 ppm CO
      • Preset Alarms:
        • 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
    • Hydrogen Sulfide(H2S)
      • Detection Range: 0 ~ 200.0 ppm (0.1 ppm)
      • Accuracy Statement: ± 5% of reading or ± 2 ppm H2S (whichever is greater)
      • Preset Alarms:
        • 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
    • Combustible Gases (Methane as standard)
      • Detection Range: 0 ~ 100% LEL (1% LEL)
      • Accuracy Statement: ± 5% of reading or ±; 2% LEL (whichever is greater)
      • Preset Alarms:
        • 1st alarm: 10% LEL
        • 2nd alarm: 25% LEL
        • 3rd alarm: 50% LEL
        • Over alarm: 100% LEL
    • Oxygen (O2)
      • Detection Range: 0 ~ 40.0% Vol. (0.1%)
      • Accuracy Statement: ± 0.5% O2
      • Preset Alarms:
        • Low 1 alarm: 19.5% Low
        • 2 alarm: 18.0%
        • High alarm: 23.5%
        • Over alarm: 40.0%

    Remember to calibrate every three months and regularly perform bump tests.

    TIIS vs ATEX/CSA certification: 

    TIIS Certificate: 

    Specification Sheet: 

    Quick Reference Guide: 


    Datalogging Software: 

    IRDA Reprograming Instructions (step by step procedure): 

    Optional Accessory: Downloading cable,  USB / IrDA adapter, 0.25 Regulator

    Part Numbers:
    72-RA-C-T - Gas Monitor with 100-240 VAC charger

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    Additional Information

    Gas Type:
    %LEL, O2, H2S, CO
    Top Rated
    Country of Origin:
    0.25 LBS
    2.50 (in)
    3.00 (in)
    1.50 (in)
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