Quick Overview

Simultaneous and real-time detection of 4 gases LEL, O2, H2S & CO
Large simultaneous display for 4 gases
Water and dust resistant, IP67
Loud alarm buzzer 95dB at 30cm
3 bright LED alarm windows


The GX-2009 is the world’s smallest and lightest personal 4-gas monitor made by Riken Keiki, Japan. Weighing only 130 grams, it fits in the palm of your hand. The GX-2009 represents the latest evolution of gas detection technology. The GX-2009 simultaneously monitors and displays combustibles, Oxygen (O2), Carbon Monoxide (CO2), and Hydrogen Sulphide (H2S). All in a compact 70(H) x 75(L) x 25(D)mm (approx.) size.

Advancements include dual audible alarm ports and alarm LED’s on 3 sides of the instrument, so that alarm conditions are obvious from multiple perspectives especially in high noise environments. Other features include a water-resistant and dust-proof design with IP 67 rating, an impact resistant rubber over-mold body that is RFI resistant, and a large capacity data logging system included as standard.

GX-2009 FeaturesThe GX-2009 is designed around Riken Keiki’s compact and proven sensors, utilizing catalytic combustion, electrochemical and galvanic sensor technologies. Each miniaturized sensor is manufactured with the same high quality control that has made Riken Keiki’s sensors and instruments the most reliable and long lasting monitoring devices in the industry.

Optional five gang multi-charger available.GX-2009 Multiple Linked Chargers

GX-2009-calibration-stationThe SDM-2009 is a single module calibration station for the GX-2009 gas monitor that can calibrate, bump test, charge, and archive data. It can work either independently of a PC or can be directly connected and controlled from a PC. Up to ten units can be connected together.



Gas Detected Combustible Gases (Methane as standard) Oxygen (O2) Hydrogen Sulfide (H2S) Carbon Monoxide (CO)
Detection Principle Catalytic combustion Galvanic cell Electrochemical cell
Detection Range (Increments) 0 ~ 100% LEL (1% LEL) 0 ~ 40.0% Vol. 0 ~ 100.0 ppm (0.5 ppm) 0 ~ 500 ppm (1 ppm)
(0.1% Vol.)
Accuracy Statement ± 5% of reading or ± 2% LEL (whichever is greater) ± 0.5% O2 ± 5% of reading or ± 2 ppm H2S (whichever is greater) ± 5% of reading or ± 5 ppm CO
(whichever is greater)
Sampling Method Diffusion sampling standard / hand aspirator or motorized pump optional
Display Digital LCD displays all four gases simultaneously, with auto backlight
Preset Alarms 1st alarm 10% LEL Low alarm 19.5% 1st alarm 5 ppm 1st alarm 25 ppm
(User Adjustable) 2nd alarm 50% LEL High alarm 23.5% 2nd alarm 30 ppm 2nd alarm 50 ppm
Overscale alarm Over alarm 100% LEL Over alarm 40.0% TWA alarm 1 ppm TWA alarm 25 ppm
(Non-adjustable)     STEL alarm 5 ppm STEL alarm 200 ppm
      Over alarm 100 ppm Over alarm 500 ppm
Types of Alarms Gas Alarm: 2 Increasing alarms, STEL, TWA, overscale alarm. O2 decreasing/increasing.
Trouble alarm: Sensor disconnection, low battery, circuit error, calibration range error
Display of Alarm Gas Alarm: Flashing LEDs, intermittent buzzer (95 db @ 30 cm), flashing gas value, vibration
Trouble alarm: Flashing LEDs, intermittent buzzer (95 db @ 30 cm), display of error message
Operating Temp. & Humidity -4°F to 122°F (-20°C ~ +50°C), 0 to 95% RH, non-condensing (splash resistant)
Response Time Within 30 seconds (T90)
Continuous Operation 20 hours after a 3 hour full charge (14 hours after 90 min charge)
Power Source Direct charging NiMH batteries, set of 2
Safety Design / Approvals IECEx zone 0 Ex ia IIC T4; ATEX II 1G Ex ia IIC T4;
ATEX / CSA us classified, as intrinsically safe. Class I, Division 1, Groups A, B, C, D
Dimension & Weight 2.7″ H x 3″ W x 1″ D (Approx. 70 H x 75 W x 25 D mm), 4.6 ounces (approx. 130 g)
Case Material High impact over molded rubber. Dust and water resistant with IP-67 approval.
Controls Two glow in the dark buttons: POWER / MODE, AIR
Datalogging Standard with all instruments. Stores 8 alarm trend sessions where readings are recorded 30 minutes
before and after an alarm event. 3,600 data point capacity with a log time range of 10 to 300 hours
(based on programmable interval times); and stores up to 100 calibration records.
Required Accessories Battery charger
Standard Accessories Alligator clip
NiMH batteries (set of 2)
Charging station with 115/220 VAC power supply
Optional Accessories Belt Clip
Padded carrying case for GX-2009 and accessories
Charging station, 115/220 VAC powered for 2, 3, 4, or 5 instruments
Charging station with 12 VDC power supply and vehicle adapter plug
12 VDC adapter with vehicle plug (does not include charger base)
RP-2009 pump with 4″ rubber nipple, 10′ hose and probe (up to 40′ hose available)
Hand aspirated sample draw with 10′ hose and probe (up to 40′ hose available)
USB to IrDA downloading cable
SDM-2009 single calibration station
Configurations •4 gas, LEL / O2 / H2S / CO • 3 gas, LEL / O2 / H2S • 3 gas, LEL / O2 / CO
• 2 gas, LEL / O2 • 2 gas, O2 / H2S • 2 gas, O2 / CO
• Single gas LEL, O2, CO, H2S
Warranty Two years material and workmanship