Air flow measurement is required in aerobic digesters and aeration basins. In digesters, oxygenation allows microbes to decompose complex organic compounds. Concrete aeration basins utilize fine or coarse bubble diffusers to aerate the water. In addition to digesters and aeration basins, air flow monitoring may also include air going to an aerated grit tank, to a flow equalization tank, or to secondary sludge holding tanks.
Aeration blower systems must supply a wide range of airflows with a relatively narrow pressure range under varied conditions. In addition to detecting the presence or absence of air flow, the flow switch should be able to detect low-flow conditions.