An oxygen concentrator is a machine that utilizes air separation technology to produce oxygen.

The basic working principle of oxygen generators is through Pressure Swing Adsorption (PSA) technology, using air as the raw material without any additives. Once powered on, they adsorb nitrogen and other gases from the air, separating out oxygen of higher purity. This method of oxygen production is a physical process, hence the oxygen generators are also known as physical oxygen generators. Their applications are extensive, particularly in industries such as metallurgy, chemicals, and oil. Germany and France were among the earliest countries to produce oxygen generators, with Germany beginning production in 1903 and France in 1910.