Making Sense of Ozone Measurements

How much ozone is a particular machine making?

How concentrated is the ozone?

CONCENTRATION

One useful way to measure ozone concentration is to state how many parts of ozone are present per million parts of gas (normally air.) We can smell ozone when it is present in the air in as low as .01 parts per million (10 parts per billion). At .1 ppm levels in ambient air, ozone becomes uncomfortable. Industrial ozone generators can produce ozone in concentrations well over 100,000 parts per million. Usually these larger concentrations are expressed in % by weight. 100,000 ppm could be written as 100,000/1,000,000 which is 10/100 or 10%. Because the weight of an ozone molecule is heavier than the other gas molecules making up air, the actual measurement is 13.7 %wt. Parts per million is useful for many applications, but sometimes it is handy to use parts per billion for very low concentrations. The general principle is to reduce the number of zeros when communicating this information. We do the same thing when measuring distance with millimeters or kilometers etc. A good starting point to get a feel for ozone concentration is to become familiar with ppm and %wt. We provide definitions for other common units and links for conversions and calculators at our calculations page.

QUANTITY

A second dimension of ozone measurement is the actual quantity of ozone being produced or used. The production of smaller generators is measured in grams per hour. The production of the largest generators is measured in pounds per day. 1 lb/day ozone = 18.89 g/hr ozone. The smallest ozone generators we sell generate less than a half of a gram per hour. That would be about a hundredth of a pound per day which is an awkward figure to use. “Grams per hour” happens to be practical for describing the output of lower production machines. The larger ones we sell generate 1000 grams per hour or 50 pounds per day. Pounds per day happens to be practical for larger machines. A drinking water treatment plant in Texas uses up to 42,900 pounds of ozone per day (over 200 tons). One lightning storm can generate over 200 tons of ozone.

FLOW RATE

A third dimension of measurement for any gas application is flow rate. When generating ozone, flow rate will affect the ozone concentration. With a given ozone production rate (for example, 200 grams per hour), lower flow rates will result in higher ozone concentrations. Higher flow rates will result in lower concentrations. One useful calculator helps determine the amount of ozone needed to supply a particular concentration at a particular flow rate.  For example, if you need a concentration of 5% by weight and have an oxygen flow of 10 LPM, you will need a generator capable of 43 grams per hour. If the flow doubles to 20 LPM, the concentration is cut in half.

People working with municipal water treatment get used to working with larger units such as pounds per day and high ozone concentrations. People working with sanitation equipment and other mid-scale applications get used to thinking in terms of grams per hour and the whole spectrum of ozone concentration measurements. Those involved in small household applications and generators are more familiar with milligrams per hour and low concentrations. Our system integration experts need to be familiar with the whole spectrum of measurements. Familiarity and precision in application grows with years and diversity of experience. Our online calculator provides a powerful tool for an efficient and effective integration of ozone into your application.

Oxidation Technologies provides equipment, engineering expertise, and service to a wide range of applications and ozone demands. Our service requires flexibility in thinking and a familiarity with the full spectrum of ozone concentrations. We build ozone systems to integrate into your existing industrial process. Every situation has a multitude of variables that will affect the performance.

Give us a call. We’d love to help you harness the power of ozone for your application.  515-635-5854

Flow-Meter Quiz

Efficient and accurate ozone production requires accurate measurements of gas flow rates. The rota-meter style flow-meter is a simple, robust, and accurate way to measure the flow of gas or liquid.   The only moving part is a metal ball (float) within a tapered transparent tube.  As flow rate increases, the ball rises.  Try out this quick, one-question quiz to test your ability to read this instrument.

One limitation to this device is its inability to factor in gas pressure in a direct reading.  Gas under pressure is squeezed together so more gas is able to flow past the ball than it reads.  Some flow-meters are calibrated for a specific gas pressure.  Such meters are accurate only at that pressure.  This limitation is easily overcome with a simple calculation.   You can calculate an accurate flow rate at any pressure when you  know the gas pressure of the gas flowing through the meter.  How did you do on the quiz?  If you haven’t tried it yet, check out our calculator page for better chance of getting it right.

 

Measure ozone production rates real-time

Tracking performance of an ozone system real-time is valuable for pilot test and even full-scale ozone systems and may be easier than you think.

Ozone system output is measured in g/hr or lb/day.  These values indicate the production rate of an ozone system.  Knowing the production rate of your ozone system real-time can have value in tracking system performance and preventing system failures by spotting potential issues before they start.

To calculate ozone production both the oxygen flow-rate and ozone concentration must be measured.  Both of these values can be measured real-time with digital devices installed inline with your ozone system.

ozone pilot system example install with measuring devices
Ozone generation system example with a Mass Flow Meter, UV Ozone Analyzer, and Oxygen Purity Meter installed inline.

Mass Flow Meter:

Mass Flom Meter GFM
GFM Mass Flow Meter

The GFM Mass Flow Meter will measure and display oxygen flow through your system real-time with a pressure compensated flow rate.  A mass flow meter measures the overall mass of gas passing through the device using ultrasonic technology.  This ensures reliable and repeatable flow measurements that do not require any conversions for temperature or pressure changes to the gas stream.  An LCD display or digital output can be provided to record oxygen flow rate.

UV Ozone Analyzer:

UV-HCR High Concentration Ozone Analyzer
UV-HCR Ozone Analzyer

The UV-HCR Ozone Analyzer will measure ozone concentration real-time to indicate the actual concentration of ozone produced by your ozone generator.   The UV Analyzer uses UV absorption technology to measure ozone concentration.  This unit provides an LCD display or digital output to record ozone concentration.

A sidestream of ozone gas must flow through the UV ozone analyzer (1-2 LPM).  Some of the ozone will be destroyed in the UV lamp measurement tube, the remaining must be converted back to oxygen safely using an ozone destruct device.

Oxygen Purity Meter:

OXM-12L Oxygen Purity Meter
OXL-12L Oxygen Purity Meter

The OXM-12L Oxygen Purity meter will measure oxygen purity real-time to ensure the oxygen purity remains stable and sufficient for efficient ozone production.  Ultrasonic technology is used to measure the composition of gas and ensure oxygen purity remains consistent.  This unit provides indicator lights to display oxygen purity and a digital output, an LCD display is optional.

Data Logger:

DL-3 Ecosensors data logger
DL-3 Data Logger

Data from each of the devices can be input into a PLC for real-time calculation and reporting of ozone production in g/hr or lb/day.  Data can also be recorded with a simple datalogger that can record data from each device real-time to be recorded for later review.

When measuring ozone concentration in % by weight the feed-gas (air or oxygen) must be factored into the calculation as oxygen and air have different weights. When calculating a percentage of a weight, it is necessary to know the weight of carrier gas.

 

Ozone Calculations:

Ozone Calculations and online calculators can be found at the links below:

 

Ozone generator output

((LPM x 60) x 0.001) x g/m3 = g/hr

Example = ((10 LPM x 60) x 0.001) x 10 g/m3 = 6 g/hr ozone production

 

Ozone Concentration in air by weight

100 g/m3 = 7.8% O3

1% = 12.8 g/m3 O3

1% = 7,284 ppm O3

Ozone Concentration in oxygen by volume

100 g/m3 = 6.99% O3

1% = 14.3 g/m3 O3

1% = 6,520 ppm O3


Online calculators for ozone output conversions

Need to calculate the output of your ozone generator?  We now have online ozone calculators to calculate ozone output based on g/m3, or % by weight.  These calculators will work on your computer, tablet or even smartphone.  Bookmark our pages for easy to use and easy to find ozone calculators.

 

online ozone output calculator
Ozone output calculator for g/m3 ozone concentration values

 

online ozone output calculator
Calculate ozone generator output from % by weight

We have additional online ozone calculators on our website.  Click HERE for all our ozone calculators in one place.

If you are looking for instructions on how to test output from your ozone generator, we have that information on our website also.  Click the image below for full details on the process of obtaining the ozone concentration from your ozone generator.

 

Measure output of an industrial ozone generator
Test ozone concentration from ozone generator to calculate ozone production.

 

We also offer a full line of ozone analyzers and other ozone accessories.  Should you have any questions on using our calculators, or any ozone-related question, please contact our office.  We are happy to help.