Fluid entering the flow meter passes through the inlet port of the cylindrically-shaped measurement chamber (1), filling the chamber directly below the diagonally-mounted nutating disc. This action causes the disc to wobble (or nutate) in a counterclockwise direction (2), causing the spindle shaft, located on the ball-shaped pivot, to rotate against the vertical magnetic shaft. This rotating action is transmitted through the magnetic drive assembly to the mechanical register (or pulse register). This measurement chamber actually contains two alternating positive displacement compartments of equal capacity. On each rotational cycle of  the nutating disc, one compartment is being filled (expanding capacity) while the other is discharging fluid (contracting capacity), providing a steady, continuous flow.