Method and apparatus for detecting a gas leak using nuclear magnetic resonance
AssigneeInterTech Development Company
InventorPeter Davey
Life of this patent
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Abstract
A method and apparatus for measuring a leakage rate for an article using nuclear magnetic resonance includes a source of hyper-polarized gas that is detectable using nuclear magnetic resonance. The hyper-polarized gas is used as a tracer gas. The method for measuring a leakage rate involves injecting hyper-polarized gas into a device under test and determining the leakage rate from the nuclear magnetic resonance measurements of the quantity of gas which passes through the article into a leak test chamber over a given test time period. The hyper-polarized gas is He-3, which is polarized by combining it with an optically pumped vapor of rubidium atoms.
Claims6
A method of determining a leakage rate for an article comprising:
- pressurizing said article with a mixture including some fluid material having a nuclear spin polarization having a value greater than zero;
- collecting any of said fluid material escaping from the article under test in a leak sampling region;
- applying a magnetic field and radio-frequency excitation to the leak sampling region;
- measuring the magnitude of the relaxation resonant frequency for the fluid material;
- and
- determining a leakage rate in response to the measured magnitude of the resonant relaxation frequency for the fluid material.
A method for measuring a leakage rate through an object into a sample region comprising:
- creating a gradient in concentration of a hyper-polarized gaseous species;
- detecting a concentration of the hyper-polarized gaseous species in the sample region;
- and
- determining the leakage of the object in response to the detected concentration of the hyper-polarized gaseous species.
Dependencies are inferred from the claim text.