Editing Nitrogen (section)

===Oxygen deficiency monitors===
Oxygen deficiency monitors are used to measure levels of oxygen in confined spaces and any place where nitrogen gas or liquid are stored or used. In the event of a nitrogen leak, and a decrease in oxygen to a pre-set alarm level, an oxygen deficiency monitor can be programmed to set off audible and visual alarms, thereby providing notification of the possible impending danger. Most commonly, the oxygen range to alert personnel is when oxygen levels get below 19.5%. OSHA specifies that a hazardous atmosphere may include one where the oxygen concentration is below 19.5% or above 23.5%.<ref>National Institutes of Health. Protocol for Use and Maintenance of Oxygen Monitoring Devices. February 2014, at 1:35 UTC. Available at: https://www.ors.od.nih.gov/sr/dohs/documents/protocoloxygenmonitoring.pdf {{Webarchive|url=https://web.archive.org/web/20201205185802/https://www.ors.od.nih.gov/sr/dohs/documents/protocoloxygenmonitoring.pdf |date=2020-12-05 }}. Accessed June 23, 2020</ref>
Oxygen deficiency monitors can either be fixed, mounted to the wall and hard-wired into the building's power supply or simply plugged into a power outlet, or a portable hand-held or wearable monitor.{{cn|date=April 2025}}