Background:

The ozone meter measures the concentration of ozone in the air. These analyzers measure ozone in the air to provide parts per million (ppm) concentrations. As an unstable gas, ozone has unique properties that must be taken into account during detection. Ozone decays with temperature, humidity, time, and air agitation to form oxygen. Therefore, measuring ozone in a consistent manner can be tricky.

What is ozone gas?

Ozone is a simple gas composed of three oxygen molecules with the chemical formula O3. It has unique behavioral characteristics. It's an unstable gas that decays into oxygen, which means it's difficult to handle and measure.

Ozone is a strong oxidizing agent that has interesting disinfecting properties and is effective at killing fungi, bacteria and viruses. It is usually used in "clean" situations. For example, ozone is used in transportation applications to clean police cars, buses and commercial airliners.

Why is ozone a special gas?

Ozone is a special gas because it is unstable and breaks down into oxygen over time. It cannot be stored in cylinders. This unique property makes it tricky to obtain repeatable ozone measurements. Ozone gas also has oxidizing properties, making it a useful disinfectant for cleaning and emission reduction companies. Ozone is also used throughout medical treatments and applications due to its unique healing properties.

How is ozone gas measured?

Measure ozone in the air with a low-cost gas meter and ozone detector. Typically, low-cost detectors employ electrochemical sensors. These are primary cells that output a voltage proportional to the concentration of ozone. These cells are useful in the ppm ozone concentration range.

More expensive ozone meters use ultraviolet (UV) absorbing technology. Ozone molecules in the air absorb UV radiation. When a photodetector measures a change in light absorption, the detector outputs a proportional electronic signal. UV absorption is the best method for detecting low concentrations of ozone in the parts per billion (ppb) range.

Can I measure ozone concentration with my nose?

you can not. Although your nose can detect very low concentrations of ozone below 0.02 ppm, it adapts quickly and develops olfactory fatigue. Olfactory fatigue is used to describe loss of sensitivity to specific odors after exposure. When you keep sniffing the same smell, your nose and brain adapt over time and lose sensitivity to that smell. Eventually, you won't be able to identify smells, hence the name olfactory fatigue.

After the odor is removed, olfactory fatigue goes away, so your sensitivity returns to normal after a while. Everyone has different sensitivities to different smells, which also vary with age. All in all, don't bother trying to correlate the potency of ozone smells with a specific amount of ozone. It's not a reliable detection method at all.