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Oxygen (O2) Gas Detectors

Accurate oxygen (O2) measurements are essential to prevent injuries or deaths in situations with potentially high or low levels of oxygen. O2 gas detectors will typically trigger an alarm when the oxygen level drops below 19.5 percent volume. The most common use of oxygen gas detection is in confined spaces—totally or partially closed areas not designed to be permanently occupied. It is essential to draw an O2 gas sample before entering these spaces and continuously monitor O2 levels after entry.

Oxygen (O2) gas detectors for confined space entry

Characteristics of Oxygen

Oxygen is a gas without color, taste, or smell. While we breathe oxygen in the air, it is generally mixed with nitrogen. Oxygen displacement is a common result of many industrial processes, so it is important to measure oxygen levels and evacuate when the level drops below 19.5% volume, the OSHA-mandated level.

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Effects of Various O2 Levels

Concentration of O2
Resulting Conditions on Humans
23.5% Volume
Maximum "Safe Level"; OSHA.
Oxygen Concentration of air (20.954).
Minimum "Safe Level," OSHA, NIOSH.
Impairment of judgment starts to become evident.
First signs of anoxia appear.
Breathing and pulse rate increase, muscular coordination is slightly impaired.
Emotional upsets, abnormal fatigue upon exertion, disturbed respiration.
Nausea and vomiting, inability to move freely and loss of consciousness may occur.
Convulsive movements and gasping respiration, respiration stops and a few minutes later heart action ceases.

How to Detect Oxygen

 Industrial Scientific provides a range of monitors for O2 detection, including the GasBadge® Pro single-gas detector, the Ventis® Pro5, Ventis® MX4, and MX6 iBrid® multi-gas detectors, and the Radius® BZ1 Area Monitor.

Area Monitor

Radius BZ1

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Multi-Gas Monitor

Ventis Pro5

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Multi-Gas Monitor

Ventis MX4

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Multi-Gas Monitor

MX6 iBrid

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Single-Gas Monitor

GasBadge Pro

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Frequently Asked Questions

What is an oxygen (O2) gas detector?

An oxygen (O2) gas detector is a device that is used to measure the concentration of oxygen (O2) in the air. The O2 detector uses electrochemical based sensors.

The use of an oxygen gas detector, particularly in environments with risk of low or high O2 levels like confined spaces, is essential for maintaining a safe work environment and preventing the risk of injury or death due to oxygen deficiency or enrichment.

At what level should an O2 detector alarm?

Accurate measurement of oxygen levels is crucial in confined spaces as low oxygen concentration is the leading cause of death. Workers must check and continuously monitor the oxygen level before entering such areas. If the oxygen concentration exceeds 23.5%, it becomes too oxygen-rich and may ignite combustible gases.

On the other hand, low oxygen levels below 19.5% of the atmosphere cause nausea, vomiting, and loss of consciousness, impairing judgment and coordination. In case of low oxygen levels, it's essential to identify the gas responsible for the displacement and the reason behind it.

What is O2 deficiency?

When the air we breathe lacks the necessary amount of oxygen to fuel our respiratory systems, it results in oxygen deficiency. The normal concentration of oxygen in the air is around 20.9% by volume, but when it drops below 19.5%, it causes symptoms like dizziness, confusion, rapid heartbeat, and impaired judgment. In severe cases, it can even lead to loss of consciousness, seizures, and death.

Oxygen deficiency can occur in confined spaces like tanks, silos, and tunnels, or in areas with poor ventilation and high-altitude environments where the air pressure and oxygen pressure are low. It's crucial to use appropriate oxygen detection equipment like oxygen gas detectors and follow safety procedures to minimize the risk of oxygen deficiency in the workplace.