Oxygen concentration measuring device

An oxygen concentration measuring device configured for determining an oxygen concentration of a gas in a sample volume containing oxygen, the oxygen concentration measuring device comprising:

• an optical device configured for irradiating the sample volume with a first UV radiation having a first UV radiation intensity, the optical device including a UV light source configured for emitting the first UV radiation, the first UV radiation including at least one wavelength which is close to a spectral absorption line of oxygen;
• a magnetic field generator configured for applying a magnetic field at the sample volume;
• a UV light detector configured for measuring a second UV radiation intensity of a second UV radiation coming from the sample volume;
• an evaluation unit configured for determining the oxygen concentration in the sample volume on the basis of the applied magnetic field and the measured second UV radiation intensity;
• and
• a reference cell which contains oxygen of a reference concentration,
• wherein the evaluation unit is configured for receiving a measured oxygen concentration reference signal indicative of the oxygen concentration in the reference cell, and for determining the oxygen concentration in the sample volume on the basis of the oxygen concentration reference signal.