Oxygen Deficiency Monitor,  0-30%

Oxygen Deficiency Monitor, 0-30%

Item #: 99040


Product Summary

The PureAire Oxygen 0-30% Deficiency Monitor, model number 99040, is perfect for facilities that use inert gases such as nitrogen, CO2, helium, and argon among others. The monitor is well suited for use in confined spaces, cryogenic facilities, and freezers. The monitor will remain accurate at temperatures as low as -40C. PureAire’s durable, non-depleting, long-life zirconium oxide sensor will last for 10+ years in a normal environment without needing to be replaced.


We can ship next day with orders placed by Noon CST
Quantities less than 10 pieces ship next day. Estimated lead times do not include weekends or holidays. Transit time is determined by shipping method and destination. Orders requiring credit information might take additional time.
Two-Year Extended Warranty Available for this product in the US, Canada, and Mexico

O2 Monitor Features

  • Long life 10 + years average sensor life
  • Two, user-adjustable, alarm relay setpoints are available or alarm defaults are set to 19.5% and 18.0%
  • No Scheduled Maintenance Required
  • Built-in 90db audible alarm
  • 3 Year Warranty
  • Digital Display
  • 4-20mA Analog Output (Active)
  • Operates in Freezers at – 40 ºC
  • No Drift due to Thunderstorms or barometric pressure changes
  • Wall mounting brackets
  • UL, CUL, and CE Approvals
  • 24V DC Power Supply Included (99040)
  • International Power Supply Included (99149)

Long-Lasting O2 Zirconium Sensor

In-Stock. The PureAire Oxygen Deficiency Depletion Monitor features a long-lasting zirconium oxide sensor capable of providing accurate readings for 10+ years with no scheduled maintenance, and the Monitor comes with a full 3-year warranty.

PureAire’s O2 Deficiency Monitor is suitable for a wide range of uses. From bar and restaurant beverage stations, to tire repair centers, food processing plants, and hospitals, our Oxygen Monitors ensure that nitrogen and CO2 gas are safely used and that any leaks are detected before human safety is jeopardized.  Our zirconium O2 sensor performs reliably in temperatures ranging from -40 to 60° Celsius, so it’s ideal for environments including freezers, cryogenic facilities, and frozen food manufacturing plants. The low-maintenance and long-lasting sensor provides continuous monitoring in applications in which inert nitrogen gas and CO2 gas are stored.  Once set up, the O2 zirconium sensor will operate continuously. So long as everything is operating properly, the Monitor stays silent, but if oxygen levels fall to the OSHA action level, defined as 19.5%, the Monitor’s built-in horn will sound, alerting employees to danger.

Sampling Method Diffusion
Gases Detected Oxygen (O2)
Range 0 – 30 % O2
Accuracy Delivers±0.2% O2 accuracy (± 1 % of Full Range)
Operating Temperature -40° to 140ºF (-40° to 60°C)
Display 3/4″ LCD Digital Display, Back Lit
Sensor Type Long-life zirconium oxide sensor cell
Sensor Life > 10 years under Normal Conditions
Signal Outputs 4-20 mA Analog Output (Active)
Dual-Level Alarm Relay Contacts
Please contact PureAire for the available RS-485 option
Power Requirements 24 VDC
250 mA
Width  5.12 in
130.1 mm
Height 4.5 in
114.3 mm
Depth 3.25 in
82.1 mm
Weight 1.6 lb
0.8 kg
Enclosure  Polycarbonate
Calibration Calibration is not required.
Periodic span adjustment as needed.
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 # 99189)


No Calibration Required

While other oxygen deficiency monitors may require semi-annual (or even more frequent) tune-ups to work properly, PureAire’s O2 Deficiency Monitor provides constant monitoring,  with no calibration required. A simple, periodic span adjustment may be necessary.  This saves our customers time and money, protects their facilities and employees, and provides them the comfort that comes from consistently reliable performance.

Plug & Play Setup

PureAire’s O2 Deficiency Monitor mounts in minutes, and it is ready to go right out of the box. Simply mount the unit on the wall in a location where oxygen needs to be monitored, plug it into the power supply, and power on the unit. After four minutes, the Monitor will begin sampling oxygen levels, which are continuously displayed on the Monitor’s screen, ensuring readily available observation at all times. Our customers appreciate a reliable oxygen sensor that is easy to use and read, and that operates 24/7, with no oversight or scheduled maintenance necessary, for up to 10 years.

PureAire O2 Deficiency Monitor Features

To suit the needs of the user, the PureAire O2 Deficiency Depletion Monitor comes in a range of configurations. Every unit comes with a full-featured, dual-level monitor, options for alarm relays, and hysteresis to account for supply valves for CO2 and nitrogen. All units have a built-in CPU that houses the monitor, display, and alarm

Oxygen Deficiency Monitor 0-30% Literature

Oxygen Deficiency Monitor 0-30% Manual

Safety Risks of Oxygen Deficiency

NIH -Protocol for Use and Maintenance of Oxygen Monitoring Devices 2021

Oxygen Monitor Sales Presentation

DRA case drawing

Price Savings for PureAire Sensor vs Disposable Sensors

Comparison O2 Zirconium Oxide vs EC cell

Oxygen Monitor for horn/strobe or remote display

Connecting Multiple O2 Monitors to a Controller

Fire code Section 5309 Inert Gas Systems Used in Commercial

Remote Digital Display p/n 99189

Horn/strobe 24VDC Red 

horn and strobe


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