DIN EN 50104:2020 Electrical equipment for the detection and measurement of oxygen - Performance requirements and test methods; German version EN 50104:2019
2020DIN EN 50104:2020 Electrical equipment for the detection and measurement of oxygen - Performance requirements and test methods; German version EN 50104:2019
2011DIN EN 50104:2011 Electrical apparatus for the detection and measurement of oxygen - Performance requirements and test methods; German version EN 50104:2010