The Best Oxygen Analyzers (for Concentrators)

Oxygen Analyzer, Oxygen Detector -

The Best Oxygen Analyzers (for Concentrators)

Oxygen analyzers measure oxygen levels that are produced from oxygen generators, oxygen concentrators, oxygen systems and oxygen machines. Typically, oxygen analyzers combine oxygen purity concentration (O2), flow (F) and pressure (P). Oxygen analyzers are made up of an oxygen ultrasonic sensor that detects oxygen and nitrogen. Oxygen analyzers range from $300 to $5,000.



  • O2 analyzers can be as low as $300.
  • Oxygen sensors last for over 5 years.
  • Oxygen is the gas of life and is abundant in air at 20.9%.Oxygen concentrators can further increase this concentration to elevated O2 levels.
  • Oxygen can be displaced and becomes dangerous to life when less than 19.5%.
  • Oxygen can become dangerous at enriched levels and low level - so precaution is needed.
  • Highly accurate and specialized oxygen sensors can be expensive.

What is Oxygen gas?

O2 is the chemical formula for oxygen. It is a common gas that occurs naturally in the air. There is 20.9% of oxygen in the air. O2 has many modern uses:

  • O2 is used in manufacturing processes
  • O2 is used for life support in spacecrafts, aircrafts, submarines and vet hospitals 
  • O2 is used in scuba diving
  • O2 is used to support human and animal health
  • O2 is used as a propellant in rockets
  • O2 is used in welding torches

Why is Oxygen gas so important?

Oxygen is one of the most important gases in our atmosphere. Our atmosphere has a level of 20.9% of oxygen. Oxygen helps sustain life on earth. Without oxygen our planet would be lifeless.

Oxygen also plays an important role in plant and animal life, including photosynthesis and respiration.

What does an Oxygen Analyzer do?

Oxygen analyzers are sometimes called oxygen detectors, oxygen meters, oxygen monitors, oxygen purity analyzers or oxygen purity testers. They all refer to an oxygen measuring instrument, that detects oxygen and provides the user with a quantitative concentration of the detected oxygen gas.

A Oxygen Analyzer tracks the oxygen concentration and provides the user with a unit value of % or part per million (ppm) reading.

More often, O2 analyzers present the user with a % concentration display. Some oxygen analyzers and monitors have an alarm that warms when O2 goes below 19.5%. 

How is Oxygen Gas Detected?

Oxygen is measured in air using O2 gas meters, monitors and analyzers. Within these gadgets, there are oxygen sensors that actually interact with oxygen molecules to produce a electronic signal that represents the oxygen concentration. These O2 sensors range from $10 up to $1000. 

How does an Oxygen Analyzer Work?

An oxygen analyzer works by using an ultrasonic oxygen sensor to detect oxygen concentrations.

These sensor works on the principle of sound wave speed, called ultrasonics. As sound travels through a gas, it propagates at different speeds and its intensity attenuates to different degrees depending upon the composition of the gas. This principle is also applicable for other gases beyond oxygen such as Nitrogen, Hydrogen, Nitrous Oxide, Carbon Dioxide, Argon, and Helium. 

For oxygen, the change in speed is proportional to the oxygen concentration in the gas being sampled. The sound speed is a function of the molecular composition of the gas.

The electronic components used for the ultrasonic sensor are ultrasonic transducers that are completely solid state in composition. This means they last a long time compared to other oxygen sensors such as electrochemical cells.

oxygen ultrasonic sensor

What is the difference between different oxygen sensors?

O2 Sensor Technology

Working Principle




Ultrasonic Sensors

The speed of sound is a function of the molecular composition of the gas. Detecting the speed and attenuation is proportional to the oxygen content.
  • Easy to integrate with electronics
  • Immediate ON
  • Long Life
  • Long calibration stability
  • Medium Expensive
  • More bulky than electrochemical cells



Gas reacts with a working electrode triggering a electrochemical redox reaction. Current is generated proportional to oxygen levels.
  • Small & Cheap
  • Easy to integrate with electronics
  • Immediate ON
  • Limited life from 24 to 36 months
  • Influenced by temperature and humidity



Zirconia allows  oxygen ions to travel so when exposed to gases at different concentrations an electrochemical voltage is generated.
  • Very accurate
  • Large Detection Range
  • Requires control hardware
  • Very Expensive
  • Requires heating and power

What are Safe Oxygen Levels?

Various government agencies and associations have recommended oxygen gas limits. Some examples are in the below table.


Recommendation / Requirement

Occupational Safety and Health (OSHA)

Air is considered oxygen-deficient below 19.5%

National Institute for Occupational Safety and Health (NIOSH)

Air is considered oxygen-deficient below 19.5%

American Conference of Governmental Industrial Hygienists (ACGIH)
<18% is minimum partial pressure without need for respiratory protection at normal atmospheric pressure

What are the Health Effects of High Oxygen?

When using enhanced oxygen or concentrated oxygen, sometimes it may be too much that may lead to hyperoxia causing oxygen toxicity or oxygen poisoning. Oxygen toxicity may damage the lungs, damage cell tissue and may induce coughing and trouble breathing. 

What are the Health Effects of Low Oxygen?

When we breath low oxygen levels, we are getting into serious health trouble. Depleted oxygen effects the body and hypoxia can occur. Per symptoms of hypoxia includes:

Hypoxia can also lead to a condition called hypercapnia. This occurs when the lungs retain too much carbon dioxide due to breathing difficulties.

What is an Oxygen Analyzer used for?

There is a plethora of applications that call for the use of an oxygen analyzer. A generic list that captures some of them is highlighted below.

  • Veterinary: Oxygen therapy is administered to animals under various situations. Hence the requirement for a oxygen analyzer to ensure the correct amount of concentration is being provided to the animal.
  • Headspace Analysis of Modified Atmosphere Packaging: Used in many food industries as a quality control check to ensure MAP equipment is operating to specification. Typical requirements includes O2 measurement range from 0 to 100%, with 0.01% resolution and built-in pump. 
  • Equipment Processing & Leakage: Many industrial systems and equipment incorporate N2 gas supply and monitoring of leaks is paramount using a O2 analyzer and probe. Typical requirements includes O2 measurement range from 0 to 100%, with 0.01% resolution and built-in pump.
  • Oxygen Concentrators and Oxygen Supply: Therapeutic oxygen is required to be administered to those that have health disorders. Typical requirements includes O2 analyzers to detect enhanced and concentrated oxygen ranging from 21 to 100% that are emitted from pressure swing absorption (PSA) oxygen generators.
  • Incubators: Used to grown and store biological samples, incubators require a constant CO2 and O2 levels. Oxygen detection requirements typically 20.9 to 0% with 0.1% resolution.
  • Combustion: Many combustion process from household to industrial requires the analysis of oxygen in the exhaust gas to ensure the upmost  combustion efficiency. Typical oxygen ranges required is 20.9 to 0% with 0.1% resolution. 

How can I Test my Oxygen Analyzer?

The best way to test your oxygen detector is to expose it to nitrogen. Since air has 20.9%, perturbing this concentration and bump testing it to pure nitrogen or reduced levels is a good check. Another approach is to bump test it to enhanced oxygen. 

If you analyzer or meter has alarms, verify they are operational. One simply sprays the gas onto the sensor to confirm sensor and LED and buzzer alarm operation. This type of testing is generally referred to as bump testing and is good practice to undertake especially in personal protection applications where safety is paramount.

Will my Oxygen Analyzer alarm if I breath on it?

If you breath onto your O2 detector, it will quickly decrease in O2 reading as breath exhalation has depleted oxygen levels, about 17%. Inhalation of oxygen depletion (and elevated CO2) has become a controversial issue with the mandatory wearing of facial masks.

    What is the Best Oxygen Analyzer brand?

    There are many oxygen analyzers on the market. The reputable brands used to detect elevated oxygen coming from oxygen sources and concentrators includes the following:

    How do I select an Oxygen Analyzer?

    To select the best oxygen analyzer that serves your purpose follow this guide. You need to first understand your application. To narrow down your selection answer these questions:

      • What oxygen detection range do I need?
      • What resolution do I need?
      • How often will I use it?
      • What is my budget and operating cost budget?
      • Does my application require any special product requirements? such as pump, such as accreditations?
      • Do I need advanced functions such as battery operation? Detection of flow or pressure?
    Based on these answers you can quickly narrow down a product for your purpose. You may need to compromise of features to adjust for your budget.

      How long do Oxygen Analyzers last for?

      O2 sensors that employ ultrasonic detection principle last well over 5 years. 

        What is Oxygen Analyzer Bump Testing?

        • Bump testing is a procedure when one exposes the gas detector to a small amount of “blast” target gas to ensure the detector operates as expected. 
        • The function of this test is to verify detection operation and build user confidence, particularly in hazardous and critical user applications.
        • It is recommended to bump test when first purchased. Weekly thereafter especially in LIFE THREATENING and/or DANGEROUS applications in order to verify detector operation. See video explanation here

        How do I take care of my Oxygen Analyzer?

        • Store your oxygen analyzer in normal room temperature - about 70F with 50%RH (well within operating specifications).
        • Store it away from electromagnetic or magnetic sources such as phones.
        • Store it in a clean environment where no dust or particles exist.
        • Store is away from any exhaust gas, concentrated vapors, harsh chemicals that may poison the sensor.
        • Clean the casing of your detector with a damp cloth.
        • Store it in a stable place where there are no vibrations or continuous shaking.

        How do I properly use an Oxygen Analyzer?

        When operating a oxygen analyzer, there are some important tips to consider. Obviously, be smart and read your product manual. But do keep these tips in mind:

        • Ensure the oxygen analyzer has been bump tested and validated operational.
        • When using a personal protection oxygen meter, turn it ON, and keep it on your man. Set your alarms as desired.
        • If undertaking analytical measurements, keep the unit stationary. Ensure humidity and temperature is also tracked and are as constant as possible.
        • Apply the oxygen source to the analyzer. Make sure the "pressure" of the source is within the acceptable range of the specifications - we have seen damage caused due to high pressure situations.
        • Allow the analyzer at least 60 second to come to a stable reading.
        • Once finished, proceed with your next measurement. 
        • Recovery time (i.e. time to come back to 20.9%) is typically longer than the response time of the oxygen sensor.

          What is the difference between a ppm and % Oxygen?

          The typical scale of concentration for O2 is ppm or %.

          In most cases, Oxygen % unit is used much more often since 20.9% concentration is in the air. Only in certain applications will ppm will be used where very low levels of oxygen may be present and easier to communicate in the ppm scale than the % scale. For example, easier to communicate 10ppm rather than saying 0.001%. 

          Conversion Example

          O2 % value = (O2 ppm / 1,000,000) x 100%

          For example, if we have 5,000 ppm of O2, then we obtain

          O2 % value = 5,000 / 1,000,000) x 100%

          O2% value = 0.5%

          Quick Conversion

          10ppm = 0.001%

          100ppm = 0.01%

          1,000ppm = 0.1%

          10,000ppm =1%

          100,000ppm =10%

          1,000,000ppm =100%

          Final Words

          Oxygen is a critical gas for our survival on planet earth. O2 is used in many applications and selecting the correct oxygen gas detector or oxygen analyzer is important. For oxygen machines and oxygen generators, a oxygen analyzer with an ultrasonic sensor is the go-to choice. In the recent years, the price of these analyzers has reduced and can be purchased today for less than $300.

          About The Author

          Dr. Koz is the President of FORENSICS DETECTORS where the company operates from the scenic Palos Verdes Peninsula in Los Angeles, California. He is a subject matter expert on gas sensor technology, gas detectors, gas meters and gas analyzers. He has been designing, building, manufacturing and testing toxic gas detection systems for over 20 years.

          gas detector expert

          Everyday is a blessing for Dr. Koz. He loves to help customers solve their unique problems. Dr. Koz also loves spending time with his wife and his three children going to the beach, grilling burgers and having a cold beer. 

          Read more about Forensics Detectors here.

          Phone: +1 424-341-3886



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