Water-Resistant Oxygen 0-25% and Carbon Dioxide 0-50,000 ppm Monitor

Water-Resistant Oxygen 0-25% and Carbon Dioxide 0-50,000 ppm Monitor

Item #: 99188


Product Summary

The Water-Resistant Sample Draw Dual O2/CO2 Monitor is a self-contained system that is designed for continuous monitoring of inert gases in confined spaces. The monitor can sample O2/CO2 levels from up to 100 feet away and is ideal for facilities that use inert gases including, but not limited to, nitrogen, helium, and argon. The NEMA 4X/IP66 dust and water-tight enclosure will protect the monitor against dust, water, and damage from external ice formation. The O2/CO2 monitor is perfect for environments such as breweries, bottling plants, food processing facilities, and laboratories. The monitor will remain accurate at temperatures as low as -40C. PureAire’s durable, zirconium oxide sensor cells, and NDIR cells, will last up to 10+ years in a normal environment, without needing to be replaced.

  • No calibration is required for oxygen
  • Self-calibrating CO2 sensor
  • Local backlit concentration display
  • Two 4-20mA output signals with dedicated circuits
  • Two alarm level set-points for both O2 and CO2
  • Two relays for both O2 and CO2
  • No drift due to environmental or temperature changes
  • No drift due to environmental or temperature changes
  • 3-year warranty
  • No scheduled maintenance zirconium oxide O2 cell and long-life CO2 sensor
  • Built-in flow sample pump for remote sampling up to 100 feet
  • NEMA 4X/IP66 Enclosure
  • Includes 24V 48W Power Supply

Long-Lasting Sensors

The PureAire Water-Resistant Combo O2/CO2 Monitor is a compact gas monitoring system that’s ideal for the continuous monitoring of both oxygen and carbon dioxide gases. The monitor is intended for use in nitrogen gas areas, CO2 food and beverage, confined spaces, and other locations where low oxygen levels and high levels of carbon dioxide may pose a hazard to personnel.

The PureAire Water-Resistant Combo O2/CO2 is made with a proprietary zirconium cell and patented NDIR cell, rather than a continuously depleting electrochemical sensor cell. The zirconium cell means the monitor can provide stable oxygen and carbon dioxide readings despite changes in temperature, barometric pressure, and humidity levels.

The PureAire Combo O2/CO2 oxygen sensor requires no quarterly calibration or annual maintenance and the CO2 sensor automatically adjusts to ambient levels. All you need to do is plug in the monitor and let it run in the background—no scheduled maintenance is required!


Sampling Method & Range Sample 0-25% O2 & 0-50,000ppm CO2
Accuracy  Delivers ± 0.2% O2 accuracy (± 1 % of Full Range) – O2
±300 ppm, ± 3% of measured value – CO2
Operating Temperature -40 to +122F   (-40 to +50C)
Display 3/4” backlit digital display
Sensor Type Zirconium oxide for O2, NDIR for CO2
Sensor Life 10+ years under normal conditions
Signal Outputs Two 4-20 mA analog outputs (Active)
Two user-adjustable Alarm relays for Oxygen and two user-adjustable Alarm relays for CO2. Relays are rated 2 amp 24VDC
Power Requirements 24VDC 300mA
Dimensions 7.0 (W) x 11.0 (H) x 6.0(D) inches; 177.8 mm x 279.4mm x 154.4mm
Weight 5.0 lbs (2.27 kg)
Enclosure  Polycarbonate
Calibration Calibration is not required for Oxygen. None for CO2 when Auto Cal function is activated. Periodic span adjustment as needed for Oxygen.
Country of Origin USA
Harmonized Tariff Code 8531.10.0045
Additional O2 Monitor Accessories List Price
8 Channel Controller $3,355.00 US (P/N # 99196)
Horn and Strobe  $190.00 US (P/N # 42002)
Remote Display $435.00 US (P/N # 99091-O2/99193-CO2)

Connects to Distributive Control Systems and Programmable Logic Controllers

The Water-Resistant Combo O2/CO2 can be used with PureAire’s proprietary controllers, or a commonly paired accessory, the remote display. Individuals can operate the oxygen monitors remotely by as much as 3,000 feet from fire panels or programmable logic controllers.

No Calibration Required

The Water-Resistant Combo O2/CO2 Monitor does not require quarterly calibration, unlike other types of gas monitors. Since the earth is a natural source of calibrated oxygen, PureAire’s combo monitor is continuously being challenged to 20.9%. Additionally, the earth’s ambient levels of CO2 are 400 ppm. On a weekly basis or on demand, the monitor automatically adjusts to ambient CO2 levels. Enjoy a safer workplace with no calibration, and no expensive scheduled maintenance. A simple, periodic span adjustment may be necessary.

Plug & Play Operation

The Water-Resistant Combo O2/CO2 Monitor is ready to go right out of the box. To begin using the combo monitor, remove it from the box and place it on a surface or mount it on the wall using the included brackets. Then plug the monitor into your facility’s power supply or a wall socket. After a brief startup sequence, the monitor begins to operate.

The Water-Resistant Combo O2/CO2 Monitor is designed to provide unattended 24/7 leak detection for years. Supplied with a full bumper-to-bumper warranty, the Combo O2/CO2 will be the last gas monitor you’ll need to purchase.

O2 Monitor System Features

PureAire uses a sophisticated built-in CPU that provides a local display, safety alarms, and control for both oxygen and carbon dioxide simultaneously.

The Water-Resistant Combo O2/CO2 Monitor comes with individual dedicated user-selectable relays designed to operate on-off valves for the control of CO2 injection in grow rooms while simultaneously activating alarms when oxygen levels drop.

Water-Resistant Sample Draw Dual O2/CO2 Monitor Product Literature 

Water-Resistant Sample Draw Dual O2 / CO2 Monitor Manual

Safety Risks of Oxygen Deficiency

Carbon Dioxide Safety

NIH – Protocol for Use & Maintenance of Oxygen Monitoring Devices 2021



Remote Digital Display 


Carbon Dioxide-99193

Horn/strobe 24VDC Red

horn and strobe


Replacement Filter with Drain 90179

8-Channel Controller for Oxygen, Carbon Dioxide, or Toxic/Combustible Gas Monitors