Technical · updated 03 August 2026
Two numbers get muddled constantly: concentration and total ozone produced. They move in opposite directions, and understanding that is most of the battle.
Concentration: µg/ml
Micrograms of ozone per millilitre of gas. It describes how rich the gas is, not how much of it there is. Typical ranges on oxygen-fed units run from around 8 µg/ml at the low end to 120 µg/ml or more at the top.
Why flow rate changes everything
Here is the part that surprises people. Turning the oxygen flow up lowers the concentration.
The cell converts a roughly fixed amount of oxygen per second. Push gas through faster and each millilitre spends less time in the discharge, so each millilitre carries less ozone. You get more total ozone per minute, but at a lower concentration.
- Low flow = higher concentration, less total ozone per minute
- High flow = lower concentration, more total ozone per minute
This is why a dial position alone tells you nothing. Concentration depends on the dial and the flow rate together.
Reading an output chart
A proper chart is a grid: flow rate along one axis, dial position along the other, concentration in the cells. To hit a target concentration you set both.
A chart specific to your unit matters because cells vary slightly. A generic chart for a product line is an estimate; a chart produced from testing your actual serial number is a measurement.
Ozone does not keep
Ozone decays back to ordinary oxygen continuously. Roughly half of it is gone within about half an hour at room temperature, faster when warm, faster still in water.
Two consequences:
- You cannot make it in advance. It is produced at the point of use, every time.
- Anything you ozonate starts losing ozone the moment you stop.
Practical implications
If a result is not repeating, the usual causes are: flow rate drifted, the regulator is not holding steady, tubing has perished and is absorbing ozone, or the diffuser is partly blocked and back-pressure has changed the flow.
Our generators ship with a calibrated chart. See the range.
Equipment information only. Nothing here is medical advice.