The invention relates to a method for measuring the volumetric flow (Q) of a fluid in a preferred direction by means of a volume measurement device having an electronic circuit and an incremental encoder, a sensor for detecting a rotational change of angle, preferably designed as two giant magnetoresistance (GMR) sensors in a double measuring bridge, wherein a first sinusoidal signal of the incremental encoder, namely a raw sine signal (S1), and a second sinusoidal signal of the incremental encoder with identical angular frequency ω which is phase-shifted by 90° relative to the first signal (S1), namely a raw cosine signal (S1), are generated, wherein said signals (S1) are preferably initially conditioned (S1+), interpolated/digitized (S2), and said digital signals (S2) are processed and evaluated in an evaluation unit, preferably in a process computer unit having a quadrature encoder counter. The invention further relates to a method for measuring a volumetric flow by means of a quadrature signal, comprising a first signal from a first sensor and a second signal from a second sensor having identical angular frequency ω which are phase-shifted by 90° relative to one another, wherein the quadrature signal serves to determine the flow (Q) of a fluid in a preferred direction by a volume measurement device having an electronic circuit. The invention further relates to a volume measurement device for carrying out a measurement method and to a programmable process computer unit having at least one quadrature encoder interface/quadrature encoder encounter for use in a volume measurement device for measuring a volumetric flow.