RKI GX-3R 4-Gas Detector

The RKI GX-3R is the world's smallest and lightest 4-gas personal monitor, weighing just 3.52 ounces (approximately 100g) and measuring a compact 2.2" W x 2.55" H x 1.02" D. This breakthrough design allows it to clip comfortably within a worker's OSHA-defined breathing zone — something traditionally only possible with single-gas detectors. Ideal for confined space entry, personal safety monitoring, and hazardous environments, the GX-3R simultaneously detects and displays four critical gases: LEL (combustible gases), O2 (oxygen), H2S (hydrogen sulfide), and CO (carbon monoxide) — with an optional H2-compensated CO sensor for enhanced accuracy in environments with hydrogen interference.

Engineered with next-generation micro sensors, the GX-3R delivers reliable performance in demanding conditions. Its innovative LEL sensor features dual active filaments to resist silicone poisoning — if one filament is compromised, the second takes over for continuous protection. The electrochemical O2 sensor offers a long 3–5 year lifespan, while the H2S/CO combo micro sensor keeps the unit ultra-compact without sacrificing detection quality.

Key Features of the RKI GX-3R 4-Gas Detector

• Ultra-portable design — Smaller than many single-gas monitors for true breathing-zone compliance
• Simultaneous 4-gas monitoring — LEL, O2, H2S, and CO (H2-compensated CO available)
• Simple 2-button operation — Easy to use even with gloves
• Non-Compliance Indicator — Flashes 3 LEDs every 30 seconds (adjustable) if bump test, calibration, or gas alarm is overdue — perfect for safety supervisors
• Robust alarms — Audible (100 dB), visual (flashing LEDs), vibration, plus 3 user-adjustable levels, STEL, TWA, and overscale alerts
• Long battery life — Up to 25 hours on a single lithium-ion charge
• Rugged & reliable — IP66/68 water/dust resistant, impact-resistant body with removable rubber boot, survives 23 ft drops
• Advanced datalogging — Tracks user ID, station ID, calibration history, bump tests, alarm events, and trends
• Field-serviceable — Easily replaceable sensors and filters
• 3-year warranty — Backed by RKI Instruments' reputation for quality

Ideal Applications

The RKI GX-3R excels in high-risk industries where portability and reliability matter most:

• Confined space entry
• Oil & gas operations
• Refineries and petrochemical plants
• Utilities and wastewater treatment
• Construction sites
• Fire services
• General industrial safety monitoring

At Ideal Calibrations, we specialize in RKI GX-3R sales, parts, sensors, and expert calibration services right here in Michigan. Pair your detector with our precision RKI-specific calibration gas blends (like our popular 50% LEL CH4 / 50 ppm CO / 25 ppm H2S / 12% O2 RKI 4-gas mix) for accurate, hassle-free bump tests and calibrations. We stock replacement sensors, including the H2S/CO combo, LEL, and O2, so your GX-3R stays in peak condition.

Ready to get the smallest, most advanced 4-gas monitor on the market? Shop the RKI GX-3R today or contact us for custom configurations, bulk pricing, or calibration support.