O2 Sensors for Rebreathers

Dive Gear Express stocks replacement oxygen sensors for rebreather applications branded by Analytical Industries, Poseidon, and rEvo.

For hand held gas analyzer replacement sensors please visit Analyzer Sensors.


  • The Analytical brand PSR-11-39-MD, is our most popular 'R-22D' type with Molex 3-pin connector, used in the Dive Rite O2ptima, Poseidon Se7en & Discovery VI, Hollis Prism2 & Explorer MK2, KISS Classic/GEM and upgraded KISS Sport, Hammerhead, Liberty, SubGravity and many other brands of rebreathers.
  • The Poseidon brand 6010-206 oxygen sensor, an R-22D type also manufactured in the US by Analytical, is used in both the MKVI, Se7en (and +) rebreathers and is the same as the PSR-11-39-MD except for the label.
  • The Mares rEvo brand CR22D oxygen sensor, an R-22D type manufactured in the UK by Vandagraph, is used in all the Mares rEvo & Horizon model rebreathers and is the only sensor offically approved by the Bruges factory for use in those models.

Replacement sensors manufactured in the US by Analytical Industries Inc for rebreathers include:

  • The PSR-11-15-2D is used in the Draeger Oxy Gauge and Dolphin rebreathers.
  • The PSR-11-33-NM1, depending on the revision level of the electronics, is used in Biomarine MK15/MK15.5/CCR-1000 rebreathers, and Steam Machines SM1000/SM1600 rebreathers.
  • The PSR-11-39-JD is used in the Hollis Explorer MK1 and VR Sentinel rebreathers.
  • The PSR-11-39-JJ is used in the JJ rebreather.
  • The PSR-11-39-MD is used in the Dive Rite O2ptima, Poseidon Se7en (and +) & Discovery VI, Hollis Prism2 & Explorer MK2, KISS Classic/GEM and upgraded KISS Sport, Hammerhead, Liberty, SubGravity and many other brands of rebreathers.
  • The PSR-11-39-MD1, depending on the revision level of the electronics, is used in Biomarine MK15/MK15.5/CCR-1000 rebreathers, and Steam Machines SM1000/SM1600 rebreathers.
  • The PSR-11-39-MDSX or PSR-11-39-MDSX1, depending on the revision level of the electronics is used in the Submatix SCR 100 rebreather.
  • The PSR-11-39-MEG is used in the ISC Megalodon rebreathers.
  • The PSR-11-39-MHD is a special version of the PSR-11-39-MD which provides a slightly higher mV range.
  • The PSR-11-39-REVO is used in the Mares rEvo and Mares Horizon rebreathers.
  • The PSR-11-39-SMB is used in the iQsub XCCR, APD Inspiration and APD Evolution rebreathers.
  • The PSR-11-39-TME is used in some homebuild rebreathers.
  • The PSR-11-39-XD is used in the SF2 rebreather.

Many rebreather manufacturers do not wish to deal with global retail sales of oxygen sensors and publish generic sensor specifications suitable for their units, allowing the market to determine supply and price. Some rebreather manufacturers prefer to tightly control sensor availability, stating only their own branded sensor is approved for use in their unit. Regardless, Dive Gear Express has not done any verification or validation of rebreather oxygen sensors and disclaims any responsibility and liability for the use of oxygen sensors in rebreather applications. Verification and validation of specific oxygen sensors for use in rebreather applications is the responsibility of the equipment user and/or original equipment manufacturer.

Oxygen sensors are one of the very few items on our website that are NON-RETURNABLE., because we can't know with absolute certainty how they were handled once delivered. Additional shipping and handling of the return can also degrade performance. They are critical to safety in diving, and our customers have a reasonable expectation of receiving as factory fresh a product as possible from Dive Gear Express. Your complete satisfaction is our goal, so please consider carefully before purchase.

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Dive Gear Express has not done any verification or validation of rebreather oxygen sensors and disclaims any responsibility and liability for the use of oxygen sensors in rebreather applications. Verification and validation of specific oxygen sensors for use in rebreather applications is the responsibility of the equipment user and/or original equipment manufacturer.

Oxygen sensors are one of the very few items on our website that are NON-RETURNABLE., because we can't know with absolute certainty how they were handled once delivered. Additional shipping and handling of the return can also degrade performance. They are critical to safety in diving, and our customers have a reasonable expectation of receiving as factory fresh a product as possible from Dive Gear Express. Your complete satisfaction is our goal, so please consider carefully before purchase.

Oxygen Sensor Life in Rebreathers

When any new oxygen sensor is removed from the sealed package, it can take anywhere from a few minutes to several hours for it to acclimate and the millivolt output to stabilize. We recommend waiting as long as practical before calibrating your rebreather with a freshly opened sensor.

Oxygen sensors are a consumable like a battery; their service life can vary considerably depending on usage, oxygen exposure and environmental factors. Three conditions are particularly notable for shortening the life of an oxygen sensor, regardless of brand.

  • Impact - Inside the oxygen sensor are tiny wires and seals that are very fragile. Sensors subjected to g-force shocks explains why a new sensor will come out of the package DOA; high, low or zero millivolt output; or with erratic behaviors.
  • Heat - The warmer the sensor, the shorter the life. That can happen during shipping or storage, especially in tropical climates. Their life can also be significantly shortened when the rebreather sits in the sun and gets very hot.
  • Prolonged Oxygen Exposure - Leaving elevated oxygen mixtures in the breathing loop, which often happens following a calibration, will substantially reduce the life of a sensor. Heavy use of your rebreather will also shorten the life of the sensor.

As oxygen sensors reach end-of-life they can become unpredictable, causing problems that are sometimes difficult to diagnose. The expiration date printed on some sensors is not a guarantee they can remain in-service until that date; it is a caution against use after that date. In our opinion, there is not ANY in-the-field test or dive procedure that will properly validate a oxygen sensor for use beyond it's expiration date or recommended service life.

Because oxygen sensors are so critical to the operational safety of rebreathers, we recommend discontinuing the use of oxygen sensors in rebreather diving applications that have been in-service over 12 months. While you might be tempted to 'extend' the service life of your sensors to continue to dive, please always follow the manufacturer's recommendations for sensor handling and replacement.

For more information, see our article on Oxygen Sensor Handling Best Practices.