RKI GX-Force 4-Gas Monitor

Manufacturer: RKI Instruments
Part Number: GX-Force
Order / Quote

The GX-Force is RKI’s smallest personal 1-4 gas monitor with a strong internal sample pump capable of a 100’ sampling range. Weighing only 9.8 ounces, the GX-Force can monitor the standard confined space gases (LEL combustibles, Oxygen, Carbon Monoxide, and Hydrogen Sulfide).  Built around high-quality micro-sensor technology, which are compatible with the GX-3R, GX-3R Pro, 04 Series, and Gaswatch 3 instruments.

With the GX-Force, you have multiple tools in one instrument. Having 2 operating modes, the GX-Force can be used for confined space, safety monitoring in its Normal Operating mode. A Leak Check mode (firmware available Q4) is the solution for all leak investigations.

The GX-Force operates 30 hours on a Li-ion battery, and has a large LCD display showing all gas readings, battery level, current time and automatically backlights in alarm conditions. Standard alarm types include vibration, visual, and audible alarms, which can be set to latching or non-latching. Controlled by a microprocessor, the GX-Force continuously checks itself for sensor connections, low battery, circuit trouble, low flow, and calibration errors.

Calibration and bump test intervals and reminders are user adjustable and can be set to either go into alarm or to lock the user out of normal measurement mode once a calibration period has expired. Calibration can be done individually or in a group.

In Leak Check Mode, the GX-Force, can monitor for combustibles in the ppm range.


Sampling Method Internal sample pump, flow rate nominal 0.5 LPM, includes hydrophobic filter
Suction Flow Rate Minimum 0.35 L/min (open flow rate)
Gas Alarm Pattern Lamp flashing, continuous modulating buzzer sounding, gas concentration display flashing, vibration
Gas Alarm Reset Operation Self-resetting or latching
Fault Alarm/Self-Diagnosis System, clock, or sensor abnormality; battery voltage drop; calibration failure; pump abnormality; low flow rate
Fault Alarm Pattern Lamp flashing, intermittent buzzer sounding, detail display
Fault alarm reset operation Self-resetting
Display LCD digital (7-segment + 14-segment + icons) with backlight
Individual Operations Operational status, clock, battery level, peak reading, pump status, calibration notification
Sound Pressure Approx. 90 dB (30 cm)
Data Logger Function Maximum storage capacity: 3,600 items Interval: 5 minutes (adjustable)
Communication Specifications USB, 2.0 (for data logger) Connector: Type-C
Power Source Rechargeable lithium ion battery, USB Type-C power cord
Continuous Operating Time Approx. 30 hours (25 °C, fully charged, no alarm, no backlight)
Operating Ambient Temperature /Humidity Range -20 °C to +50 °C (no sudden changes), 0 – 95 % RH (no condensation) (-4 °F to +122 °F)
Approvals Intrinsically safe construction

IECEx (Ex da ia IIC T4 Ga/Ex ia IIC T4 Ga)

ATEX (II1G Ex da ia IIC T4 Ga/II1G Ex ia IIC T4 Ga)

Certifications ATEX / IECEx, QPS (pending)
Protection Level IP67 equivalent
External Dimensions / Weight Approx. 2.52 (W) × 6.81 (H) × 1.85 (D) (excluding protrusions) / Approx. 9.87 oz.
Warranty Three years material and workmanship
Detection target gas

Combustible gas (CH4 or HC)

Oxygen (O2)

Carbon monoxide (CO)

Hydrogen sulfide (H2S)

Detection principle

Catalytic combustion

Electrochemical type

Detection range

0 – 100 % LEL

0.0 – 40.0 vol %

0 – 2,000 ppm

0.0 – 200.0 ppm


1 % LEL

0.1 vol %

1 ppm

0.1 ppm

Alarm setpoints

(User-defined setting)

1st alarm: 10 % LEL

2nd alarm: 25 % LEL

3rd alarm: 50 % LEL

OVER alarm: 100 % LEL

L alarm: 19.5 vol %

LL alarm: 18.0 vol %

H alarm: 23.5 vol %

OVER alarm: 40.0 vol %

1st alarm: 25 ppm

2nd alarm: 50 ppm

3rd alarm: 1200 ppm

TWA alarm: 25 ppm

STEL alarm: 200 ppm

OVER alarm: 2,000 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

Response time (T90)

CH4: Within 30 seconds,

HC: Within 40 seconds

Within 20 seconds

Within 30 seconds

Within 30 seconds

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