BOD (Biochemical Oxygen Demand) is an important parameter when measuring for the quality of water bodies and the efficiency of water treatment plants by determining the degradation of carbons. Using the official method of BOD5 the concentration of dissolved oxygen will be measured in diluted samples before and after incubation. When performing the “BOD self-check measurement” in a closed respirometer the absorption of the carbon leads to a gaugeable pressure change. In both cases the samples hav