Turbine flow meters (HM) are volume counters operating on the Woltmann impeller counter principle. They record the flow rate in the flow-through in a pipe via the average flow velocity. The flow of the medium is directed at the turbine wheel in the axial direction and so rotated. The speed of the freely turning wheel over a wide range is directly proportional to the average flow velocity. Turbine flowmeters are used mainly for applications with lubricating and non-lubricating media. They are especially well suited for the flow rate measurement of low and medium-viscosity liquids such as water, emulsions, glycol mixtures, and light oils. Measuring cryogenic liquids is possible as well. Numerous different process connections are available thanks to the flexible design.