Fluid flow measuring device (11, 11', 11"), comprising: a rotatable, magnetic element, wherein the rotatable, magnetic element is positioned in the fluid flow, wherein the rotation of the rotatable, magnetic element depends from the fluid flow, wherein the rotation of the rotatable, magnetic element generates a magnetic field, at least one sensing coil pair having a first sensing coil and a second sensing coil, characterized in that the respective sensing coils (19a, 19b) of the or each sensing coil pair are arranged in such a way that the magnetic field generated by the fluid flow dependent rotation of the rotatable element has a first polarity and a first phase in the region of the respective first sensing coil and a second polarity and a second phase in the region of the respective second sensing coil, wherein said first and second phases and said first and second polarities differ from each other, the respective first sensing coil is positioned at a first circumferential position of the rotatable, magnetic element and the respective second sensing coil is positioned at a second, different circumferential position of the rotatable, magnetic element, an angle between the first circumferential position at which the respective first sensing coil of the or each sensing coil pair is positioned and the second circumferential position at which the respective second sensing coil of the or each sensing coil pair is positioned is 180°±5°, the respective sensing coils (19a, 19b) of the or each sensing coil pair are connected in series to provide a subtraction of their signals thereby eliminating noise caused by a disturbing magnetic field. a rotatable, magnetic element, wherein the rotatable, magnetic element is positioned in the fluid flow, wherein the rotation of the rotatable, magnetic element depends from the fluid flow, wherein the rotation of the rotatable, magnetic element generates a magnetic field, wherein the rotatable, magnetic element is positioned in the fluid flow, wherein the rotation of the rotatable, magnetic element depends from the fluid flow, wherein the rotation of the rotatable, magnetic element generates a magnetic field, at least one sensing coil pair having a first sensing coil and a second sensing coil, characterized in that the respective sensing coils (19a, 19b) of the or each sensing coil pair are arranged in such a way that the magnetic field generated by the fluid flow dependent rotation of the rotatable element has a first polarity and a first phase in the region of the respective first sensing coil and a second polarity and a second phase in the region of the respective second sensing coil, wherein said first and second phases and said first and second polarities differ from each other, the respective first sensing coil is positioned at a first circumferential position of the rotatable, magnetic element and the respective second sensing coil is positioned at a second, different circumferential position of the rotatable, magnetic element, an angle between the first circumferential position at which the respective first sensing coil of the or each sensing coil pair is positioned and the second circumferential position at which the respective second sensing coil of the or each sensing coil pair is positioned is 180°±5°, the respective sensing coils (19a, 19b) of the or each sensing coil pair are connected in series to provide a subtraction of their signals thereby eliminating noise caused by a disturbing magnetic field. the respective sensing coils (19a, 19b) of the or each sensing coil pair are arranged in such a way that the magnetic field generated by the fluid flow dependent rotation of the rotatable element has a first polarity and a first phase in the region of the respective first sensing coil and a second polarity and a second phase in the region of the respective second sensing coil, wherein said first and second phases and said first and second polarities differ from each other, the respective first sensing coil is positioned at a first circumferential position of the rotatable, magnetic element and the respective second sensing coil is positioned at a second, different circumferential position of the rotatable, magnetic element, an angle between the first circumferential position at which the respective first sensing coil of the or each sensing coil pair is positioned and the second circumferential position at which the respective second sensing coil of the or each sensing coil pair is positioned is 180°±5°, the respective sensing coils (19a, 19b) of the or each sensing coil pair are connected in series to provide a subtraction of their signals thereby eliminating noise caused by a disturbing magnetic field.