US4448887A
Expired / Lapsed
US
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Method for the particle size independent spectrometric determination of metal particles in lubricating oils and hydraulic fluids
Assignee: United States Department of the Air Force
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Filing: 1982-09-30
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Granted: 1984-05-15
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Expires: 2002-09-30
Abstract
Abstract The degree of wear metal contamination in an oil is determined by treating a sample of the oil with a mixture of HF/HCl/nitric acid, diluting the oil/acid mixture with a solvent mixture consisting of a nonionic surfactant and a diluent, and spectrometrically analyzing the resulting diluted mixture. Severe wear in an oil wetted apparatus may be detected by directly analyzing spectrometrically a sample of the oil and comparing the results of such analysis with the results obtained according to the acid dissolution method described above.
Inventors
- 👤 Robert E. Kauffman
- 👤 Wendell E. Rhine
- 👤 Costandy S. Saba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:24
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/26; G01N33/28; G01N33/2835; G01N33/2858; Y; Y10; Y10T; Y10T436/00; Y10T436/25; Y10T436/25125
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
110 words
A method for determining the degree of wear metal contamination of an oil which comprises the steps of: (a) combining a sample of said oil with an acid mixture consisting of about 8 to 12 weight percent of concentrated HF, about 76 to 84 weight percent of concentrated HCl and about 8 to 12 weight percent of concentrated nitric acid; (b) heating the resulting oil/acid mixture to dissolve wear metal particles; (c) diluting said oil/acid mixture with a solvent mixture consisting of about 20 to 40 parts by weight of a nonionic surfactant and about 60 to 80 parts of a diluent; and (d) spectrometrically analyzing the resulting diluted mixture.
Claim 2
Independent Claim
110 words
A method for determining the degree of wear metal contamination of an oil which comprises the steps of: (a) combining a sample of said oil with an acid mixture consisting of about 8 to 12 weight percent of concentrated HF, about 76 to 84 weight percent of concentrated HCl and about 8 to 12 weight percent of concentrated nitric acid; (b) heating the resulting oil/acid mixture to dissolve wear metal particles; (c) diluting said oil/acid mixture with a solvent mixture consisting of about 20 to 40 parts by weight of a nonionic surfactant and about 60 to 80 parts of a diluent; and (d) spectrometrically analyzing the resulting diluted mixture.
Claim 3
Dependent Claim
28 words
The method of claim 1 wherein said acid mixture consists of about 10 weight percent HF, about 80 weight percent HCl and about 10 weight percent nitric acid.
Claim 4
Dependent Claim
20 words
The method of claim 1 wherein said diluent is selected from the group consisting of kerosene and methyl isobutyl ketone.
Claim 5
Dependent Claim
42 words
The method of claim 1 wherein said surfactant has the general formula RO(CH.sub.2 CH.sub.2 O).sub.n H wherein R is a linear alkyl group having 9 to 11 carbon atoms and n is a number having a value of about 1 to 10.
Claim 6
Dependent Claim
22 words
The method of claim 4 wherein R has an average of 10 carbon atoms and n has an average value of 6.
Claim 7
Dependent Claim
21 words
The method of claim 5 wherein said solvent mixture consists of 35 parts of said surfactant and 65 parts of kerosene.
Claim 8
Dependent Claim
23 words
The method of claim 5 wherein said solvent mixture consists of 25 parts of said surfactant and 75 parts of methyl isobutyl ketone.
Claim 9
Dependent Claim
29 words
The method of claim 1 wherein said oil/acid mixture is heated, with stirring, for about 5 minutes at a temperature in the approximate range of 20° to 70° C.
Claim 10
Dependent Claim
44 words
The method of claim 1 wherein said oil sample is mixed with said acid mixture in a ratio ranging from 4:1 to 6:1 by weight, and the oil/acid mixture is diluted with said solvent mixture in a ratio of at least 1:2, by weight.
Claim 11
Dependent Claim
17 words
The method of claim 9 wherein said oil:acid ratio is 5:1 and said oil/acid:solvent ratio is 1:4.
Claim 12
Independent Claim
145 words
A method for detecting severe wear at an early stage in an oil wetted apparatus which comprises the steps of: (a) obtaining a sample of oil from said apparatus; (b) spectrometrically analyzing a first portion of said sample; (c) treating a second portion of said sample with an acid mixture consisting of about 8 to 12 weight percent concentrated HF, about 76 to 84 weight percent concentrated HCl and about 8 to 12 weight percent concentrated nitric acid; (d) heating the resulting oil/acid mixture to dissolve wear metal particles; (e) diluting said oil/acid mixture with a solvent mixture consisting of about 20 to 40 parts by weight of a nonionic surfactant and about 60 to 80 parts of a diluent; (f) spectrometrically analyzing the resulting diluted mixture; and (g) comparing the results obtained according to step (b) with the results obtained according to step (f).
Claim 13
Independent Claim
145 words
A method for detecting severe wear at an early stage in an oil wetted apparatus which comprises the steps of: (a) obtaining a sample of oil from said apparatus; (b) spectrometrically analyzing a first portion of said sample; (c) treating a second portion of said sample with an acid mixture consisting of about 8 to 12 weight percent concentrated HF, about 76 to 84 weight percent concentrated HCl and about 8 to 12 weight percent concentrated nitric acid; (d) heating the resulting oil/acid mixture to dissolve wear metal particles; (e) diluting said oil/acid mixture with a solvent mixture consisting of about 20 to 40 parts by weight of a nonionic surfactant and about 60 to 80 parts of a diluent; (f) spectrometrically analyzing the resulting diluted mixture; and (g) comparing the results obtained according to step (b) with the results obtained according to step (f).
Claim 14
Dependent Claim
28 words
The method of claim 11 wherein said acid mixture consists of about 10 weight percent HF, about 80 weight percent HCl and about 10 weight percent nitric acid.
Claim 15
Dependent Claim
20 words
The method of claim 11 wherein said diluent is selected from the group consisting of kerosene and methyl isobutyl ketone.
Claim 16
Dependent Claim
42 words
The method of claim 11 wherein said surfactant has the general formula RO(CH.sub.2 CH.sub.2 O).sub.n H wherein R is a linear alkyl group having 9 to 11 carbon atoms and n is a number having a value of about 1 to 10.
Claim 17
Dependent Claim
22 words
The method of claim 14 wherein R has an average of 10 carbon atoms and n has an average value of 6.
Claim 18
Dependent Claim
21 words
The method of claim 15 wherein said solvent mixture consists of 35 parts of said surfactant and 65 parts of kerosene.
Claim 19
Dependent Claim
23 words
The method of claim 15 wherein said solvent mixture consists of 25 parts of said surfactant and 75 parts of methyl isobutyl ketone.
Claim 20
Dependent Claim
29 words
The method of claim 11 wherein said acid/oil mixture is heated, with stirring, for about 5 minutes at a temperature in the approximate range of 20° to 70° C.
Claim 21
Dependent Claim
44 words
The method of claim 11 wherein said second portion is mixed with said acid mixture in a ratio ranging from 4:1 to 6:1, by weight, and the oil/acid mixture is diluted with said solvent mixture in a ratio of at least 1:2, by weight.
Claim 22
Dependent Claim
17 words
The method of claim 19 wherein said oil:acid ratio is 5:1 and said oil/acid:solvent ratio is 1:4.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-05-15 | 1987-11-14 | 1988-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-15 | 1991-11-14 | 1992-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-15 | 1995-11-14 | 1996-05-15 | $7700.00 | Window Closed / Lapsed |