Abstract: A device for measuring fluid volume output by a pump includes a meter housing having an inlet and an outlet through which the fluid flows. At least two inter-engaging screw spindles are rotatably mounted within the meter housing and are rotatable in response to fluid flow in an axial direction through the housing. An exciter disc is arranged in the fluid flow in the meter housing and connected to one of the at least two inter-engaging screw spindles for rotation therewith. The exciter disc has at least one substantially planar surface and a plurality of magnets circularly arranged thereon with their fields in an axial direction relative to the exciter disc. The meter housing is configured to form a gap and the exciter disc penetrates the gap, whereby a region of the meter housing is in close proximity to and extends over a portion of the planar surface of the exciter disc.