What does µg/ml mean on an ozone generator?
Short answer: µg/ml (micrograms per milliliter, also written ug/ml or mcg/ml) is the concentration of ozone in the gas that leaves the generator. It tells you how much ozone is in every milliliter of gas. The higher the number, the stronger the ozone.
Why concentration is the number that matters
An oxygen-fed ozone generator takes in oxygen and turns part of it into ozone as it passes through the generator cell. What comes out is a mix of oxygen and ozone, and the µg/ml figure tells you how much of that mix is ozone.
This matters because different jobs need very different amounts of ozone. Ozonating one glass of water needs a lower level than ozonating a gallon, and some applications need higher concentrations still. A generator that only says “high output” tells you nothing you can work with. A stated range in µg/ml, with a chart to match, lets you choose the right machine and repeat the same result every time.
Micrograms, milligrams and percent
You will sometimes see ozone described in other units. A microgram (µg) is one thousandth of a milligram (mg), so 1,000 µg/ml is the same as 1 mg/ml. Large water treatment systems that run on air often describe their output as a percentage, or in mg/L, because they are measuring a much larger volume of gas. For oxygen-fed generators like ours, µg/ml is the practical number because it describes exactly what goes into your water or oil.
What changes the concentration
Two things decide the µg/ml you get:
- The output setting on the generator. Each Synergy generator has variable output settings on its control panel.
- The oxygen flow rate, set on your oxygen regulator in liters per minute. On oxygen-fed generators, the same setting gives a higher concentration at a slower flow, and a lower concentration at a faster flow, because the same amount of ozone is spread through more or less oxygen.
The oxygen itself matters too. Our generators are fed by an oxygen tank or an oxygen concentrator. Feeding them pure oxygen instead of room air is what makes higher concentrations possible, because air is only about 21% oxygen.
The ranges on our generators
- WPS-100: up to 80 µg/ml, with variable output positions and precise outputs. One chamber with its own on/off switch and regulator.
- WPS-400: two chambers that can be used independently for lower ozone levels, or together for higher levels of isotopes such as o8, o12 and o13. Each chamber has its own selector switch for an unlimited number of output settings.
- WPS-120: 8 µg/ml to 128 µg/ml, with absolute settings for accurate µg/ml and a calibrated output chart. Its quartz cell gives ultra pure and ultra stable ozone output.
How to read your output chart
- Set your oxygen flow on the regulator and note the liters per minute.
- Find that flow rate on the chart that came with your generator.
- Find the output setting you are using.
- Read across to the concentration in µg/ml.
- If you change the flow, check the chart again, because the concentration changes with it.
Write down the flow and setting you use for each job. Using the same pair every time is the simplest way to get consistent results.
Questions we get asked
Is a higher µg/ml always better?
No. The right concentration depends on what you are doing. Higher levels are for applications that need them; many everyday uses need much less. Choose the level for the job, then use your chart to hit it.
Why does my concentration drop when I turn up the oxygen?
Because the ozone the generator makes is spread through more oxygen. Turning the flow down raises the concentration; turning it up lowers it.
Does ozone stay at the same strength once it is made?
No. Ozone is unstable and turns back into oxygen. About half of it is gone within half an hour of being made, so it should be made at the time you need it.
A note on safety
Ozone is a strong oxidizer and it is harmful to breathe. Run your generator in a well ventilated room, keep the ozone inside tubing and closed containers, never breathe it directly, and follow the instructions that come with your unit.