Method of determining the respiration rate of a respiring material in the form of acontinuous process current, as well as a device suitable for such anapplication

Method and device for determining the respiration rate of a respiring material such as active sludge in a continuous process flow before and after holding thereof in a respiration chamber. The oxygen content in the continuous process current is done at a single measurement point. This is done by reversing the incoming and outgoing current of the respiration chamber. Preferably the process flow consists of a mixture of respiring material and waste water to be biologically purified