US3751661A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Engine oil inspection system using x-ray fluorescence
Assignee: RTX Corp
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Filing: 1970-06-10
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Granted: 1973-08-07
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Expires: 1990-06-10
Abstract
Abstract The concentration of metal wear particles in the lubricating oil system of engines such as aircraft gas turbines is continuously monitored by using x-ray fluorescent techniques. A beta excited x-ray source such as promethium-147 is mounted in a novel annular apposition target arrangement, and supplies primary x-rays to circulating engine oil. Depending on the source and target composition, selected metals such as iron in the oil will emit secondary fluorescent radiation which is measured by a lithiumdrifted silicon semiconductor detector. Concentrations of metals as low as 2 parts per million may be detected.
Inventors
- 👤 B Woody
- 👤 L Packer
- 👤 W Bruton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:45
CPC Classifications
G; G01; G01N; G01N23/00; G01N23/22; G01N23/223; G01N2223/00; G01N2223/07; G01N2223/076
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
149 words
Apparatus for measuring the concentration of a metal element in a carrier fluid comprising a source of primary x-ray radiation including a radioactive material of promethium-147 contained on a copper base and having a thin copper target positioned adjacent said radioactive material, said radiation source being arranged in an annular configuration having a centrally located space therein and emitting a high flux of radiation having an energy slightly above the characteristic fluorescent radiation energy of the metal, a container having a wall substantially transparent to x-ray radiation at the wavelength of said primary radiation, means for continuously flowing said carrier fluid through said container so that said fluid forms a thin layer within said container, means for directing said primary radiation toward said transparent wall to intersect said thin fluid layer, and a detector positioned to intercept secondary fluorescent radiation emitted by the metal element in said carrier fluid.
Claim 2
Dependent Claim
23 words
Apparatus as in claim 2 in which the metal element is iron and is contained in a carrier fluid consisting primarily of oil.
Claim 3
Dependent Claim
29 words
Apparatus as in claim 2 in which said copper base is annular and contains a plurality of concentric grooves therein into which said radioactive material is deposited in solution.
Claim 4
Dependent Claim
30 words
Apparatus as in claim 4 in which said annular copper base, said radioactive source and said copper target are positioned in an annular tungsten dish lined with a plastic material.
Claim 5
Dependent Claim
19 words
Apparatus as in claim 2 in which said copper target is deposited on a thin layer of polyimide plastic.
Claim 6
Dependent Claim
27 words
Apparatus as in claim 2 in which said detector is exposed to the secondary radiation which passes through the space in the center of said radiation source.
Claim 7
Dependent Claim
48 words
Apparatus as in clAim 7 and including a source of cobalt-57 positioned adjacent said container so that the radioactive rays emitted therefrom pass through the center of said radiation source and are sensed by said detector, and shutter means positioned between said source of cobalt-57 and said detector.
References Cited (Backward Citations)
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Cited
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Cited
US3526127A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-06 | 1977-02-05 | 1977-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-06 | 1981-02-05 | 1981-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-06 | 1985-02-05 | 1985-08-07 | $7700.00 | Window Closed / Lapsed |