Turbine flowmeters (HM series) are volumetric flowmeters based on the Woltmann impeller counter principle. They detect the flow through the pipe through the average flow rate. The flow profile of the medium is straightened and directed to the turbine, which begins to rotate. The rotational speed of a free-rotating turbine is proportional to the average flow rate. Turbine flow meters are mainly used with lubricating and non-lubricating fluids. They are particularly well suited for low and medium viscosity fluids such as flow measurement of water, emulsions, glycerol mixtures and light oils. Measurement of cryogenic fluids is also possible with turbine flow meters. Due to the innovative design, the meter has no wet seams in contact with the fluid.