Avoiding conditions when electrolytic respirometers fail to function as oxygen chemostats

While the performance of a commercially available electrolytic respirometer was being evaluated, it was discovered that the oxygen concentration in the head space of a respirometric vessel can decrease as the rate of oxygen consumption exceeds the rate of oxygen transfer from the electrolytic cell to the head space. The phenomenon could be corrected by initially filling the holding chamber in the electrolytic cell and in the conduit leading to the vessel head space with oxygen instead of air in order to improve the system response time. A series of experiments was conducted at different initial oxygen concentrations in the head space with and without purging the space in the electrolytic cell and the conduit to observe the above phenomenon and to demonstrate the validity of the proposed procedure