Can you measure oxygen with a sensor inside a hyperbaric chamber?

Not reliably. Pressure changes oxygen's partial pressure, so a sensor inside a pressurised cabin reports a distorted value. The correct method is to draw a metered sample of cabin air out of the chamber and read it with an analyser outside at ambient atmospheric pressure.

What does NFPA 99 require of a hyperbaric chamber?

NFPA 99, the Health Care Facilities Code, sets a fire-safety limit on how much oxygen is allowed to accumulate inside the chamber during use. It is a fire-safety requirement rather than a therapeutic one, and meeting it is an engineering matter of managing the cabin atmosphere throughout a session.

Does an oxygen monitoring kit make a chamber NFPA 99 compliant?

No, and neither does any other single component. NFPA writes the code; it does not certify, list or approve products, so there is no such thing as an NFPA 99 certified part. Compliance is a property of the installed system and is determined by your Authority Having Jurisdiction. A monitoring kit supports ambient-pressure air quality monitoring, and the OxySafe Chamber Air Purge System is built to the NFPA 99 Chapter 14 requirements that govern chamber air, but the determination is the AHJ's to make.

How much does a hyperbaric chamber inspection cost?

Prestige Hyperbaric does not publish a separate inspection price. For a chamber you own, inspection work is carried out on the $850 a la carte service visit or under the $1,500 per year Preventative Maintenance Plan. For a chamber you are buying used, Pre-Owned Chamber Setup Training at $1,000 covers setup, testing, inspection and new owner training.

Should I inspect a used hyperbaric chamber before buying it?

It is the strongest case for an inspection. A private-sale chamber usually comes with no service history, and the difference between a well-maintained unit and a neglected one is not visible from the outside.

Hyperbaric Chamber Inspection and NFPA 99 Checks

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The one thing almost everybody measures wrong

If you take a single thing from this page, take this one. An oxygen sensor placed inside a pressurised chamber does not read what you think it reads. Pressure changes oxygen's partial pressure, so a sensor sitting in the cabin at 1.5 ATA reports a distorted value. The number looks like a reading and it is not one.

Measuring it properly means drawing a small, precisely metered sample of cabin air out of the chamber and reading it with an analyser outside, at ambient atmospheric pressure. That is the whole point of the Constant O2 Monitoring Kit — $500 for the sampling kit, or $950 with a factory-calibrated analyser included. Sampling only begins once the chamber passes 1.2 ATA so it cannot interfere with the door seal, and it is built for continuous use at 1.3 ATA and above.

Being straight about the limit of that: the kit supports ambient‑pressure air quality monitoring and does not, by itself, constitute NFPA 99 certification. Anyone telling you a sampling line alone makes a chamber compliant is selling you something.

What NFPA 99 actually asks of a chamber

NFPA 99, the Health Care Facilities Code, sets a fire‑safety limit on how much oxygen is allowed to accumulate inside a hyperbaric chamber while it is in use. It is a fire rule, not a therapy rule. Every session pushes exhaled gases and elevated oxygen into a closed cabin, and left unmanaged that atmosphere drifts toward the limit.

Meeting it is an engineering job rather than a paperwork one. The OxySafe chamber air purge and supply system is $4,000 plus $100 shipping, built to order for your specific chamber and configuration, with a 12‑month warranty on supplied components. It is built per chamber because port configurations and shell designs are not standard across brands, which is also the reason an inspection cannot be done from a photograph.

What gets looked at

An inspection is a set of comparisons, not a checklist of pass or fail boxes. What matters is how the chamber behaves now against how it behaved when it was commissioned.

What is being compared, and what a drift in it usually means
Area	What a change in it points at
Time to reach working pressure	Intake filtration first, then compressor output. A chamber that takes noticeably longer than it used to is telling you something before it strands anyone.
Cabin atmosphere at ambient pressure	Whether gas exchange is actually keeping the interior under the fire‑safety limit during a full session, rather than at the start of one.
Oxygen at the mask, measured separately	Concentrator and oxygen compressor condition. This is a different measurement from cabin air and needs its own reading.
Electrical service and switching	A browned or intermittent power switch is a known failure mode on these, and the fix is a rated replacement rather than any off‑the‑shelf part.
Sealing surfaces and relief hardware	On a hardshell, seals and relief valves on a service schedule. On a softshell, the flexible shell and its closure as wear items.
Placement and room conditions	Clearances, ventilation and heat. A chamber can be perfectly serviceable and still be badly sited.

When an inspection is worth paying for

Before you buy a used chamber. This is the strongest case on the list. A private-sale chamber comes with no service history, and the difference between a well-kept unit and a neglected one is not visible from outside.
After it has been moved. Freight, a house move or a room change all disturb connections and siting.
When an insurer or facility asks for NFPA 99 documentation. Then the question is specifically about how the chamber’s air supply is designed, and the honest answer involves that design rather than an inspection report. Whether it satisfies them is their determination to make, not ours.
After any component has been replaced. Particularly anything in the oxygen or pressurised path.

What this costs, said plainly

There is no separate published inspection price on this site, and rather than invent one, here is how it is actually sold. For a chamber you already own, inspection work is carried out on the $850 a la carte service visit, or as part of the $1,500 per year Preventative Maintenance Plan, which is where routine review, diagnostics and documentation live. For a chamber you are buying used, the right product is Pre‑Owned Chamber Setup Training at $1,000, which covers setup, testing, inspection and new owner training in one visit.

Scope of work is verified before any job is confirmed or scheduled. Payment is not a confirmed booking. Site conditions, chamber model, doorway and stair access, electrical service and travel distance all affect final scope and price, and nothing is dispatched until scope is confirmed in writing.

An inspection is not a repair

An inspection tells you the state of a chamber when nothing has obviously failed. If something has already failed and you know what it is, you do not need this page — you need a part, a diagnostic call or a service visit, and those have their own prices. Chamber repair and service →

Call 727-591-4268 Ask about an inspection NFPA 99 kit

Prestige Hyperbaric is not a medical facility and does not diagnose, treat, cure or prevent any disease or condition. Nothing on this page is a regulatory certification or a substitute for one. See our FDA disclosure for how these devices are classified, and our rules and industry practice chapter for the wider regulatory picture.

Page last updated 2026-08-31. Cited research, not medical advice. Prestige Hyperbaric is a wellness center, not a medical facility.

Hyperbaric Chamber Inspection