PureAire’s KF25 0-25% Oxygen Deficiency Monitor is ideal for facilities requiring continuous monitoring of gas lines, glove boxes, nitrogen compressors, and vacuum chambers, as well as any locations where low oxygen levels need to be supervised. The unit’s oxygen sensor mounts directly into the process chamber with the use of a KF-type vacuum fitting. The monitor is also well suited for semiconductor tools, OLED manufacturers, and, for any industrial applications where inert gases including, but not limited to, nitrogen, and argon are used. PureAire’s stable, long-life zirconium oxide sensor will last 10+ years in maintained environments without needing to be replaced.
No Drift due to Thunderstorms or barometric pressure changes
Wall mounting brackets and optional plug-in wall power supply
UL, C, UL, and CE Approvals
24V DC Power Supply Included (99035)
International Power Supply Included (99128)
PureAire’s KF25 Oxygen Monitor is for continuous monitoring of gas lines, 3D printers, glove boxes, nitrogen gas compressors, vacuum chambers, and locations where low oxygen levels need to be monitored. Unlike electrochemical sensor cells, PureAire’s O2 zirconium sensor cell provides stable oxygen readings even in areas where temperature and humidity levels are changing. PureAire’s KF25 Oxygen Monitor is well suited for monitoring directly in a vacuum.
The heart of the monitoring system is a long-lasting zirconium sensor, which detects low oxygen conditions within seconds and provides accurate measurements over a wide temperature and humidity range. The zirconium O2 sensor cell will operate continuously for 10 or more years and requires an absolute minimum of maintenance. There are no zero or span calibration pots to adjust and when compared to disposable type sensors, our long-life zirconium O2 sensor can save up to $475 annually and will pay for itself in just over 3 years!
The Monitor’s unique sensor mounts directly into chambers or load locks through the use of a KF-type vacuum fitting. Monitoring oxygen directly under a vacuum eliminates the need to change the environment back to ambient and can improve thru put. The Monitor also provides stable readings even in areas that contain high electromagnetic fields.
Diffusion (Supplied with KF 25 Vacuum Fitting)
0 – 25 % O2 & 0-1000ppm Analyzer, please inquire for more details
± 1 % of Reading
-40 to +50 ºC
3/4″ LCD Digital Display, Back Lit, 3 Alarms LED´s
Long-life zirconium oxide sensor cell
10+ years under Normal Conditions
4-20 mA Analog Output (Active)
Dual-Level Alarm Relay Contacts
Calibration is not required. Periodic span adjustment as needed.
Connects to DCS and PLC Controls
The AirCheck O2 Deficiency Monitor is 24 V DC powered and transmits continuous oxygen concentration levels to any distributive control system or programmable logic controller.
PureAire’s Oxygen Sensor Cell
The AirCheck O2 Deficiency Monitor uses an exclusive Current Limiting Zirconium Oxide Oxygen sensor that never requires a reference gas. Unlike concentration-type zirconium cells that must have a reference gas, PureAire’s O2 monitor can operate in 100 % nitrogen environments. Capable of detecting 0 % up to 95 % oxygen levels, the current limiting O2 sensor operates at a lower temperature than competitive concentration type cells. The average life of PureAire’s O2 sensor is over 8 years in most environments. The AirCheck O2 Deficiency Monitor never needs calibration. A simple, periodic span adjustment may be necessary. The earth is a wonderful source of calibrated oxygen and under ambient levels; PureAire’s O2 monitor is continuously being challenged to 20.9 %. The only optional response test required is to subject the O2 system to nitrogen periodically.
O2 Monitor System Features
The AirCheck O2 Deficiency Monitor is available in many different configurations perfect for OEM process tool installation. PureAire uses a sophisticated built-in CPU that is flexible to provide users with a low-cost basic display-only monitor or a full-featured monitor with dual-level, user-selectable alarm relays.
8-Channel Programmable Controller for Oxygen, Carbon Dioxide, or Toxic/Combustible Gas Monitors
Frequently Asked Questions
Why do I need an oxygen deficiency monitor?
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.
Do I need to purchase calibration gas?
Since PureAire monitors do not need to be calibrated, you do not need to purchase calibration gas.
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.