ATA Pressure Explained For Hyperbaric Chamber Buyers

ATA is total pressure, not added pressure

ATA stands for atmospheres absolute. It is the total pressure inside the chamber, including the atmosphere that is already around you at sea level. 1.0 ATA is normal air. A chamber running at 1.5 ATA holds one and a half times sea-level pressure, which is roughly 7 psi of gauge pressure - the number a pressure gauge on the chamber shows, because a gauge reads the difference rather than the total.

This is the first place buyers get confused. A supplier quoting 7 psi and a supplier quoting 1.5 ATA are quoting the same chamber. A supplier quoting 1.5 psi is quoting something very different.

The four bands Oxygen Times builds

Higher is not automatically better

Raising pressure increases how much oxygen dissolves into the body during a session. It also makes pressurisation and depressurisation more demanding, which matters when the same person sits several times a week. Home and studio buyers who start at 2.0 ATA because it is the biggest number often find their clients prefer the 1.5 ATA unit, and the higher-pressure chamber sits idle.

The more useful question is who uses the chamber and how often. A home user running daily sessions and a clinic running protocol-driven programmes are different purchases, and the honest answer for a mixed client base is often two chambers or a configurable one.

Configurable pressure

Two models avoid the decision entirely. The OTL15 is ordered as either a 1.3 ATA or a 1.5 ATA configuration. The OTL19 runs an adjustable 1.1 to 1.9 ATA under fully automatic control, so the operator sets the level for the session rather than for the life of the chamber.

What pressure does not tell you

Two chambers at the same ATA can be very different purchases. Interior diameter decides who fits. Build type decides whether it can be moved. Control type decides how much operator attention each session costs. Pressure is the first filter, not the specification.

A note on use

This page describes equipment. It is not medical advice. How a hyperbaric chamber may be used, and by whom, is set by the regulations of the country it is installed in, and meeting them is the buyer's responsibility.