Various flowmeters (10, 70, 80) each have at least one NMR sensor (12, 72, 82) for measuring the various flow parameters of a flowing fluid. The NMR sensor may be used to provide a gradient magnetic field, which provides separate velocities when the fluid is multiphase (FIG. 10). The flowmeters may also be used to measure flow rate directly. The flowmeters may also be used to determine the separate flow fractions of a multiphase fluid.
J. Derwin King; Qingwen Ni; Armando De Los Santos