Monitoring of oxygen concentrations in bioprocesses in real time offers the possibility to learn about the actual metabolic state of the culture and use the information for process optimization. Values like OUR, OTR, RQ or even feeding strategies are essential for process control and optmization. BCP-O2 oxygen analyzers in the simple PA housing have a space saving design and are suitable for small scale stuides (e.g experiments in shake flasks) up to industrial scale processes. Due to the integrated automated temperature and pressure compensation gas cooling, specific valves or pipes are unnecessary. Gas concentrations can be measured directly in the process without expentiture.