Best Oxygen Analyzer (for Concentrators)

Oxygen Analyzer, Oxygen Detector -

Best Oxygen Analyzer (for Concentrators)

Oxygen analyzers measure oxygen levels produced by oxygen generators, oxygen concentrators, oxygen systems, and oxygen machines. Typically, these devices combine measurements of oxygen purity concentration (O2), flow (F), and pressure (P). Oxygen analyzers consist of an ultrasonic sensor that detects both oxygen and nitrogen, ranging in price from $300 to $5,000.



  • O2 analyzers can cost as little as $300.
  • Oxygen sensors last for over 5 years.
  • Oxygen is the gas of life and is abundant at 20.9%. Oxygen concentrators can further elevate O2 levels.
  • Oxygen can be displaced and becomes dangerous to life when less than 19.5%.
  • Oxygen can become dangerous at both low and enriched levels - 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 at 20.9%. O2 has many modern uses, as shown below:

  • 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, with a level of 20.9%. This gas helps sustain the majority of life on earth. Without oxygen, our planet would be lifeless.

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

What Does an Oxygen Analyzer Do?

Oxygen analyzers are also known as oxygen detectors, oxygen meters, oxygen monitors, oxygen purity analyzers, and oxygen purity testers. They all refer to a measuring instrument that detects oxygen and provides the user with a quantitative concentration of O2.

An oxygen analyzer tracks the O2 concentration and provides the user with a % or part per million (ppm) reading.

In most cases, O2 analyzers present the user with a % concentration. Some oxygen analyzers have an alarm that warns the user when O2 drops below 19.5%.

How Is Oxygen Gas Detected?

Oxygen is measured in air using O2 gas meters, monitors, and analyzers. Within these devices, there are sensors that interact with oxygen molecules to produce an electronic signal representing the O2 concentration. These sensors range from $10 up to $1,000. 

How Does an Oxygen Analyzer Work?

An oxygen analyzer works by using an ultrasonic sensor to detect O2 concentrations.

These sensors are based on the principle of sound wave speed, or ultrasonics. As sound travels through a gas, it propagates at different speeds and its intensity attenuates to different degrees depending on the composition of the gas. This principle is applicable for other gases beyond oxygen such as nitrogen, hydrogen, nitrous oxide, carbon dioxide, argon, and helium. 

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

In an ultrasonic sensor, there are solid state transducers that last a long time compared to 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. The speed and attenuation is proportional to the oxygen content.

  • Easy to integrate with electronics
  • Immediate ON
  • Long life
  • Long calibration stability
  • Mid-range price
  • More bulky than electrochemical cells



Gas reacts with a working electrode, triggering an electrochemical redox reaction. A current is generated proportional to the oxygen level.

  • 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 and when they are 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 have recommended oxygen gas limits. Some examples are shown in the table below.


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 or concentrated oxygen, it may be too much and lead to hyperoxia, oxygen toxicity, or oxygen poisoning. Oxygen toxicity may damage the lungs, harm cell tissue, cause difficulty breathing, and induce coughing.

What Are the Health Effects of Low Oxygen?

Breathing at low oxygen levels can lead to serious health concerns. Depleted oxygen affects the body and can lead to hypoxia. According to, symptoms of hypoxia include:

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

What Is an Oxygen Analyzer Used For?

There are a plethora of applications that call for the use of an oxygen analyzer. Some of these uses are highlighted below.

  • Veterinary: Oxygen therapy is administered to animals under various situations. An oxygen analyzer is required to ensure the correct amount of O2 is being provided to the animal.
  • Headspace Analysis of Modified Atmosphere Packaging: O2 analyzers are used in many food industries as a quality control check to ensure MAP equipment is operating to specification. Typical requirements include O2 measurement range from 0 to 100%, 0.01% resolution, and a built-in pump. 
  • Equipment Processing & Leakage: Many industrial systems and equipment incorporate an N2 gas supply, where an O2 analyzer and probe is used to monitor leaks. Typical requirements include an O2 measurement range from 0 to 100%, 0.01% resolution, and a built-in pump.
  • Oxygen Concentrators and Oxygen Supply: Therapeutic oxygen must be administered to those that have health disorders. This requires O2 analyzers to detect enhanced oxygen ranging from 21% to 100%. Oxygen is emitted from pressure swing absorption (PSA) oxygen generators.
  • Incubators: Used to grow and store biological samples, incubators require constant CO2 and O2 levels. Analyzers must be able to detect O2 levels from 0% to 20.9% with 0.1% resolution.
  • Combustion: Many combustion processes from household and industrial settings require analysis of oxygen in exhaust gas to ensure the highest combustion efficiency. Analyzers must be able to detect O2 levels from 0% to 20.9% 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 is 20.9% oxygen, bump testing it to pure nitrogen or reduced levels of oxygen is a good check. Another approach is to bump test it to enhanced oxygen. 

If your analyzer has alarms, verify that they are operational. This can be done by spraying the gas onto the sensor to confirm sensor, LED, and buzzer alarm operation. Generally referred to as bump testing, this test  is good practice, especially in personal protection applications where safety is paramount.

Will My Oxygen Analyzer Alarm If I Breathe on It?

If you breathe onto your oxygen detector, the O2 reading will quickly decrease as breath exhalation has depleted oxygen levels of about 17%. Inhalation of oxygen-depleted air (with elevated CO2) has become a controversial issue with the mask mandate.

    What Is the Best Oxygen Analyzer Brand?

    There are many oxygen analyzers on the market. The reputable brands used to detect elevated O2 levels coming from oxygen concentrators include the following:

    How Do I Select an Oxygen Analyzer?

    To select the best oxygen analyzer that serves your purpose, follow this guide. In order to better understand your application and 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 a pump or accreditations?
      • Do I need advanced functions such as battery operation and detection of flow or pressure?
    Based on these answers, you can quickly narrow down a product for your purpose. You may need to compromise on certain features to adjust for your budget.

      How Long Do Oxygen Analyzers Last For?

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

        What Is Oxygen Analyzer Bump Testing?

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

        How Do I Take Care of My Oxygen Analyzer?

        • Store your oxygen analyzer at 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 with no dust or particles.
        • Store it away from any exhaust gas, concentrated vapors, or 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 an oxygen analyzer, there are some important tips to consider. Be smart, read your product manual, and keep these tips in mind:

        • Ensure the oxygen analyzer has been bump tested and validated as operational.
        • When using a personal protection oxygen meter, turn it ON, and keep it on you. Set your alarms as desired.
        • If performing analytical measurements, keep the unit stationary. Ensure humidity and temperature are also tracked and remain as constant as possible.
        • Apply the oxygen source to the analyzer. Make sure the "pressure" of the source is within the acceptable range - we have seen damage caused due to high-pressure situations.
        • Allow the analyzer at least 60 seconds 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 ppm and % Oxygen?

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

          In most cases, % is used because there is a known 20.9% oxygen concentration in the air. Ppm will be used in certain applications where very low levels of oxygen may be present and are easier to communicate in the ppm scale. For example, it is easier to say 1 0ppm than 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

          10 ppm = 0.001%

          100 ppm = 0.01%

          1,000 ppm = 0.1%

          10,000 ppm =1%

          100,000ppm =10%

          1,000,000 ppm =100%

          Final Words

          Oxygen is a critical gas for our survival on Earth. O2 is used in many applications where selecting the correct oxygen analyzer is important. For oxygen machines and oxygen generators, a detector with an ultrasonic sensor is the go-to choice. In the recent years, the price of these devices has dropped 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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