Method and apparatus for measuring the quantity of a fluid flowing through a pipe by means of nuclear magnetic spin resonance

摘要

A method of measuring the quantity of a flowing fluid through the use of nuclear magnetic spin resonance which includes; passing a fluid containing magnetizable nuclei and having portions of different flow velocities through a pipe of non-magnetic electrically insulating material; applying a direct-current magnetic field to the fluid to align the nuclei spin axes thereof; applying an alternating-current magnetic field to the fluid to synchronize the nuclei; and measuring the resultant nuclear magnetization and the velocity of respective different portions of the fluid with respect to time, the sum of the products of velocity and nuclear magnetization of the portions providing a measure of the quantity of the fluid.