NMR methods for measuring fluid flow rates
AssigneeDomestic/International
InventorsPeter Morris, Terry Moore, Paul Anuzis, Kenneth Astley
Life of this patent
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Abstract
A method for measuring fluid flow rates comprises the steps of: (a) creating a non-oscillating magnetic field of a predetermined strength across a flowing fluid; (b) performing the sub-steps of: (i) exposing the flowing fluid to an oscillating magnetic field pulse orthogonal to the non-oscillating magnetic field to generate an NMR signal, and (ii) detecting the NMR signal from the flowing fluid in the form of a free induction decay; and (c) determining the fluid flow rate from the initial magnitude of the free induction decay.
Claims14
A method for measuring fluid flow rates comprising the steps of:
- (a) creating a non-oscillating magnetic field of a predetermined field strength across a flowing fluid;
- (b) performing the sub-steps of:
- (i) exposing the flowing fluid to an oscillating magnetic field pulse orthogonal to the non-oscillating magnetic field to generate an NMR signal, and
- (ii) detecting the NMR signal from the flowing fluid in the form of a free induction decay;
- (c) measuring the initial magnitude of the free induction decay;
- and
- (d) determining the fluid flow rate from the measured initial magnitude.
A method for measuring fluid flow rates comprising the steps of:
- (a) creating a non-oscillating magnetic field of a predetermined field strength across a flowing fluid;
- (b) performing the sub-steps of:
- (i) exposing the flowing fluid to a first oscillating magnetic field pulse orthogonal to the non-oscillating magnetic field,
- (ii) after a predetermined time delay, τ1, exposing the flowing fluid to a second oscillating magnetic field pulse orthogonal to the non-oscillating magnetic field to generate an NMR signal, and
- (iii) after a further time delay of duration τ1 detecting the NMR signal from the flowing fluid;
- (c) repeating step (b) for each of one or more different predetermined time delays, τ2 . . . τn;
- and
- (d) determining the fluid flow rate from the predetermined time delays (τ1, τ2 . . . τn) and the variation in the detected signals.
A method for measuring fluid flow rates comprising the steps of:
- (a) creating a non-oscillating magnetic field of a predetermined field strength across a flowing fluid;
- (b) repeatedly exposing the flowing fluid to an oscillating magnetic field pulse orthogonal to the non-oscillating magnetic field, a predetermined time delay being imposed between each repetition;
- (c) performing the sub-steps of:
- (i) imposing said predetermined time delay;
- (ii) exposing the flowing fluid to the oscillating magnetic field pulse to generate an NMR signal, and
- (iii) detecting the NMR signal from the flowing fluid;
- (d) repeating steps (b) and (c) for a different predetermined time delay;
- and
- (e) determining the fluid flow rate from the predetermined time delays and the variation in the detected signals.
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Dependencies are inferred from the claim text.