Oxygen Detection

Oxygen (O2) is a colourless gas that makes up 21 percent of Earth's atmosphere. It is one of the life-sustaining elements on Earth and also the most reactive of the non-metallic elements. Oxygen forms compounds by reaction with practically any other element, as well as by reactions that displace elements from their combinations with each other. Its most important compound is water. As a gas, oxygen is clear. But as a liquid, it's pale blue.

About one-half of the earth's crust is made up of chemical compounds containing oxygen, and a fifth of our atmosphere is oxygen gas. Oxygen can be produced from a number of materials, the most common natural method is photo-synthesis, in which plants use sunlight convert carbon dioxide in the air into oxygen. This offsets the respiration process, in which convert oxygen in the air back into carbon dioxide.

The most common commercial method for producing oxygen is the separation of air using either a cryogenic distillation process or a vacuum swing adsorption process. Hydrogen and oxygen can be generated by passing an electric current through water and collecting the two gases as they bubble off. Hydrogen forms at the negative terminal and oxygen at the positive terminal. This method is called electrolysis and produces very pure hydrogen and oxygen.

Gas Specifications

  • Gas Name: Oxygen
  • Formula: O2
  • CAS No.: 782-44-7
  • Density relative to air: 1.10


Accurate oxygen (O2) level measurements are essential in preventing injury in situations where safe levels may be compromised. A most common form of detection is Oxygen depletion. An oxygen gas detector provides a first-level alarm when the oxygen concentration dropped 19.5%. Most people will begin to behave abnormally when the level reaches 17.5%. Exposure to atmospheres containing between 10% and 13% oxygen can bring about unconsciousness very rapidly; death comes very quickly if the oxygen level drops below 6% volume.

Oxygen Enrichment refers to an increased level of oxygen. Oxygen Enrichment may dramatically increase the flammability of any combustible matter. The risk from oxygen enrichment exists where pure oxygen is stored; for example in hospitals and gas manufacturing plants. Very high Oxygen levels over 50% will lead to brain damage.

Selecting an Oxygen detector

There are several options for oxygen detection. An important factor is whether the application is hazardous (or non-hazardous) rated. Another important factor is whether the instrument is used for industrial safety or for other applications (such as fruit ripening). There are Zirconium oxide based sensors which come with a much longer life span, however cannot be used in each and every application.

Before beginning to consider gas detection equipment, a risk assessment should be conducted. Our engineers can help carrying out your risk assessment and select the correct sensor for your application. Contact us for more information.

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