To this end, we are using commercial optical oxygen detection systems, which enable oxygen detection in both gas and liquid phase, without consumption of oxygen or the maintenance requirements of electrochemical oxygen sensors. Furthermore, it is possible to measure contactless, e.g. through glass, which allows for the easy design of gas tight set-ups. There are multiple vendors offering corresponding optical oxygen measurement systems (e.g. PyroScience, PreSens, OceanOptics).