Fluid flowrate measuring apparatus in which magnet coils, positioned symmetrically about a pipe through which fluid flows, are excited to generate magnetic fields during four periods of an excitation cycle which are additive during the first period of excitation, opposing during the second period of excitation, additive during the third period of excitation in an opposite sense to that during the first period, and opposing during the fourth period of excitation in an opposite sense to that during the second period. Electrodes, which sense fluid flow through the magnetic fields, develop signals representative of fluid flow through the pipe during the four excitation periods and these signals are processed to develop a flowrate measurement signal.