This dual-sensor monitor is designed for use in areas containing Nitrogen, Carbon Dioxide, Argon, and mixed cryogenic gases. It includes all of the top-of-the-line features of our air check oxygen deficiency monitor, though it monitors the level of CO2 in the room as well. It is ideal for use in environments such as breweries, laboratories, universities, bottling plants, pharmaceutical manufacturing facilities, or CO2 marijuana extraction. This monitor contains a 10+ year zirconium oxide sensor.
No scheduled maintenance zirconium O2 cell and long-life CO2 sensor
No calibration is required for oxygen
Self-calibrating CO2 sensor
Local backlit concentration display
Built-in audible horn
Built-in visual LED alarm indicators
Alarm level 1 for CO2 / Alarm level 2 for O2
No drift due to environmental or temperature changes
3-year warranty
24V DC Power Supply Included (99143)
International Power Supply Included (99144)
PureAire Monitoring System’s Dual O2/CO2 Monitor provides continuous monitoring of oxygen and carbon dioxide. This monitor is ideal for use in confined spaces where low oxygen concentrations could pose a health hazard, from nitrogen gas storage sites to carbon dioxide beverage gas distribution areas.
While many O2/CO2 meters rely on electrochemical sensor cells, PureAire developed its Dual O2/CO2 Monitor with a zirconium oxide and NDIR cell. This cell is impermeable to changing barometric pressure, storms, temperatures, and humidity, for reliable performance across a range of atmospheric conditions. While other units require quarterly calibration and periodic maintenance, PureAire’s Dual O2/CO2 Monitor needs no scheduled maintenance or calibration once installed. If you seek an O2/CO2 monitor that you can plug in, leave alone, and rely on to monitor oxygen and carbon dioxide levels, try PureAire.
Sampling Method & Range
Diffusion, 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
-0 to + 55 C
Display
¾” backlit LCD digital display
Sensor Type
Long-life zirconium oxide sensor for O2 and NDIR for CO2
Alarm indicators
Built-in Audible 90dB horn, Orange LED alarm indicator for CO2, Red LED alarm indicator for O2
Signal Outputs
One user-adjustable Alarm relay for Oxygen and one user-adjustable Alarm relay for CO2. Relays are rated 2 amp 24VDC / 24VAC
Analog Output
Analog 4-20mA output (Active), selectable for either Oxygen or CO2. Optional 0-5 VDC output for CO2.
Power Requirements
24VDC 350mA
Dimensions
6.5 (W) x 4.5 (H) x 3.25 (D) inches; (165.1 mm x 114.3 mm x 82.5 mm)
Weight
1.6 lbs. (.8 kg)
Enclosure
Polycarbonate
Calibration
Calibration is not required for Oxygen. None for CO2 when the Auto Cal function is activated. Periodic span adjustment as needed for Oxygen.
PureAire Oxygen Deficiency Monitors require occasional testing with nitrogen to validate the sensor’s response to low oxygen levels. While calibration is not necessary for our monitors to accurately measure oxygen depletion levels1, annual fine-tuning might be needed to ensure the sensor’s span accurately corresponds to the standard 20.9% oxygen concentrations.
PureAire’s Auto-Span not only simplifies the process of adjusting the span of the oxygen sensor but also provides a quick check of the sensor and the monitor’s response to an oxygen-deficient atmosphere. With a press of a button, this feature saves you time and money, protects your facilities and employees, and, most importantly, provides you with the reassurance of consistently reliable performance, making it a valuable addition to your safety measures.
On a weekly basis, the monitor automatically recalibrates to the ambient CO2 level for reliable performance.
1Please follow your facility’s safety guidelines and state and local regulations regarding calibration requirements for safety equipment.
Plug & Play Setup
PureAire’s Dual O2/CO2 Monitor is ready to work the moment you take it out of the box and mount it. All you need to do is remove the unit, mount it to a wall or another surface, and connect the power supply to a socket. The monitor takes four minutes to start up and then begins operating automatically. Once set up, the Dual O2/CO2 Monitor provides non-stop, leak detection for years. Our bumper-to-bumper warranty makes the Dual O2/CO2 Monitor the last monitor you’ll ever need to purchase.
PureAire’s Dual O2/CO2 Monitor Installations
PureAire’s Dual O2/CO2 Monitor is ideal for a range of installations. Place one in restaurants, fast food outlets, bars, and anywhere that N2 and CO2 are used to dispense carbonated beverages. Or use it in an agricultural grow room, laboratory, or other places where inert gases could pose a health hazard if a leak occurs. PureAire’s Dual O2/CO2 Monitor never drifts or loses sensitivity when weather, barometric pressure, or temperature changes, so you can rely on it to work properly at all times.
Dual O2/CO2 Monitor Control Features
PureAire’s Dual O2/CO2 Monitor comes with user-selectable relays that connect to on-off valves, which control CO2 injection and simultaneously activate alarms when oxygen levels fall below the OSHA threshold. Other sensor locations include incubators, food & beverage, research laboratories, and cryogenic storage areas. can also check carbon dioxide levels and control nitrogen generators in hypobaric rooms. PureAire’s Dual O2/CO2 Monitor features an inexpensive monitor that has a local display, separate controls for oxygen and carbon dioxide, safety alarms, and a built-in CPU.
Oxygen deprivation is a silent killer. Oxygen-depleting gases, such as nitrogen, argon, and helium, are odorless and colorless, making leaks impossible to detect, unless appropriate monitoring is in place.
What gases can be detected with an oxygen monitor?
PureAire oxygen deficiency monitors can be used to monitor nitrogen, argon, and helium. Carbon dioxide can also be monitored with PureAire’s dual oxygen/carbon dioxide monitor.
What is a 10+ year sensor? How does it compare to other types of sensors?
PureAire uses a proprietary, non-depleting, zirconium oxide sensor that will last up to 10 years in a normal environment without needing to be replaced.
PureAire’s sensors do not operate under partial pressure, meaning that a PureAire sensor will not need to be adjusted to account for different elevations. Additionally, the sensors will not drift due to changes in barometric pressure.
In contrast, other gas detection companies use depleting, electrochemical sensors. These sensors, because they are depleting, operate for 1-2 years before needing to be replaced. Electrochemical sensors do not offer long-term solutions to companies committed to safety.
How often do I need to replace sensors?
PureAire sensors are built to last 10 years. Often, the sensors work much longer. In fact, some of our first customers who started using PureAire products in 1997 report that the sensors are still in operation today.
On the other hand, an oxygen monitor that uses a depleting, electrochemical sensor is like a battery in that, as the sensor depletes, it begins to lose its power and responsiveness. In order to operate accurately, electrochemical sensors must be calibrated frequently.
How often do I need to calibrate O2 sensors? What maintenance is required?
PureAire sensors are made of non-depleting zirconium oxide, and calibration is typically not required.
However, a visual check of the monitor should be done once a year to verify that the sensor is functioning properly, and span adjustments should be done, as necessary. The sensor requires periodic testing with nitrogen to verify the sensor’s response to low oxygen levels.
In contrast, electrochemical sensors, because they deplete over time, will need to be calibrated every 2-3 months and totally replaced every 1-2 years.
Switching to a PureAire non-depleting, zirconium oxide sensor will save you time and money, while ensuring the safety of your workers and facility.
Why do some O2 sensors drift or read inaccurately?
Electrochemical sensors offered by other gas detection companies lose accuracy over time and must be calibrated. Calibration recharges and resets the monitor to get an accurate reading. It is important to note that an electrochemical sensor can only be calibrated a finite number of times before it must be discarded.
PureAire’s non-depleting zirconium oxide sensor will not experience drift. Oxygen sensors from PureAire will provide long-lasting, reliable, and accurate monitoring for an average of10+ years.
How many oxygen monitors do I need?
The oxygen monitor covers an area of approximately 692 square feet when mounted on a wall and should be placed no more than 21 feet from potential leak sources such as gas lines, gas cylinders, or any areas where a gas leak might be expected to occur.
To ensure safety, the maximum distance between two monitors mounted to the same wall, should not exceed 30 feet. However, since cryogenic gases, such as argon, helium, and nitrogen, are unpredictable, we encourage you to contact PureAire for additional guidance specific to your needs.
Where should I mount an oxygen monitor?
In most circumstances, PureAire recommends that oxygen monitors be installed 3-5 feet away from gas cylinders or cryogenic gas lines. To enable employees to see the monitor display and verify its performance, PureAire recommends mounting an oxygen monitor 3-5 feet off the ground.
There are other options for mounting an oxygen monitor. For instance, PureAire sensors can sample the air from up to 100 feet away, or be installed within a glovebox, freezer, sealed chamber, or even underground. PureAire monitors can also work in environments that require KF-25 flanges, as well as in nitrogen/argon enriched environments.
How to calculate response time when using sample tubing?
PureAire’s Sample Draw Monitors pull a sample flow at a rate of 250 ccs per minute. We recommend using 1/4” OD x 3/16” ID polypropylene sample tubing. Using this internal tubing dimension, to calculate transport (response) time, add 2 seconds per foot of sample tubing. For example, if the sample tube is 10 feet long, the initial response time would be 20 seconds (10ft x 2seconds=20seconds) at 15 feet the response time would be 30 seconds (15ft x 2seconds=30seconds), etc.
The response time when using the entire 100 feet of sample tube will take 3.5 minutes (100ft x 2seconds=200seconds or 3.5minutes) for the sample to reach the monitor.
