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Portable Gas Detectors

RX-8500 Sample Drawing Portable Multi Gas Monitor for Cargo Monitoring on LNG Tankers

IR Sensor for Methane (CH4) and Carbon Dioxide (CO2) as well as an Electro-Chemical sensor for Carbon Monoxide (CO) and a Galvanic Sensor for Oxygen

The Riken Keiki RX-8500 Portable Multi Gas Monitor is designed for measuring multiple gases in inert or air atmospheres. Their main application is aboard LNG marine tankers. They replace and improve upon the very successful RX-515 family.

Users typically use them to measure gas concentrations in storage tanks or piping during inerting/purging and tank maintenance work. Their advanced sensor technology gives accurate gas measurement even in Nitrogen (N2) and other inert environments.

Product Features


The RX-8500 is designed specifically for Liquid Natural Gas (LNG) carriers. It has IR sensors for Methane (CH4) 0 – 100% LEL and 0 – 100% Volume(Autoranging). Carbon Dioxide (CO2) 0-20% Volume as well as an Electro-Chemical sensor for Carbon Monoxide (CO) 0-1000ppm.  A Galvanic Sensor for Oxygen with a 0-40% Volume range is also included.

Auto-ranging Technology

The RX-8500 has accurate measurement over the entire range of target hydrocarbons up to 100% by volume. Users benefit from dual auto-ranging technology that allows the instruments to automatically switch from a 0 – 100% LEL to a 0 – 100% volume range.

The RX-8500 Series has an internal pump that samples at 750ml per minute. The RX8500 has a clear and intuitive digital display. The Instruments are explosion and intrinsically safe and are ATEX as well as MED approved.

The RX-8500 has a compact and lightweight but very robust design. They are powered by a Lithium-Ion battery pack. This gives over 15 hours of continuous operation as well as being quick to charge.

The RX-8500 has additional features that include Pilot and pump driving indicator, activating confirmation beep (1 minute intervals) and Bump Test function. Users have IrDA communications and Password Protection also available. Data logger software is available as an option.



Target Gas Methane (CH4) Oxygen (O2) Carbon Monoxide (CO) Carbon Dioxide (CO2)
Detection Principal Non- Dispersive Infrared Ray Galvanic Cell Electro-Chemical Non-Dispersive Infrared Ray
Detection range 0-100.0%LEL/


0-40%.0vol% 0-1000ppm 0-20.0%vol
Increments 0.5%LEL(0-100.0%LEL)


0.1%vol 1ppm 0.01%vol(0-2%vol)


0.1%vol  (5-20%vol)

Samples Method  Sample Draw 
Sampling Rate  Minimum 0.75L/min
Display  Digital LCD (7 segment + sign + bar display)
Power Supply  Lithium-Ion Battery ( Standard )

Alkaline battery (AA battery x 3)( option)

Continous Supply  Li-ion battery : Longer than 15 hours ( full charge, no alarm, no light at 25 Deg C)

AA Battery Unit : Longer than 8 hours ( new battery , no alarm, no light at 25 Deg C)

Operating temp and Humidity  -20-+50 deg C , below 85% RH (Non-condensing )
Dimensions  Approx 154(W) x 81(H) x 163(D) mm
Weight  Approx 1.3kg ( Lithium battery type , 1.2kg Alkaline battery type)
Ingress Rating  IP-67
Explosion Proof  Intrinsically safe (Ex ia II CT4)(ATEX/IECEx)
Approvals  ATEX/IECDx . TIIS . MED 
Other Functions  LCD backlight , Datalogger , Log data , Peak Hold , Pump stop function
Transmission Method  IrDA for Datalogger

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