A turbine rotor is mounted in a stainless steel housing on two rotor shafts. The material of the bearing is either PTFE or tungsten carbide. That moans even aggressive or slightly abrasive fluids can be measured. The medium passes through the turbine blades, causing the rotor wheel to rotate at a speed proportional to the velocity of the fluid. As each rotor blade passes through the magnetic field generated by the transducer a voltage output is created. A preamplifier converts the sinus wave into a square wave signal.