Biochemical Oxygen Demand (BOD) is an expression for the quantity of oxygen required for biological degradation of organic matter in a waste water sample. BOD measurement is used as a basis for the detection of biologically degradable organic matter in water. The difference between BOD and chemical oxygen demand (COD) is COD additionally registers biologically non-degradable organic matter. BOD measurement is therefore an important measurement of the effects of domestic and industrial waste water on sewage plants and outflow points. Manometric, respirometric BOD measurement using the Oxi700 sensor system is a 6 sample system that allows precise measurements of BOD based on the manometric principle. Manometric respirometers relate oxygen uptake to the change in pressure caused by oxygen consumption while maintaining a constant volume. The integral pressure sensors make it unnecessary to use mercury for pressure measurements.