US4686469A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and device for measuring magnetic particles in a fluid
Assignee: TRIBOMETRICS NC BERKELEY CA
•
Filing: 1985-08-12
•
Granted: 1987-08-11
•
Expires: 2005-08-12
Abstract
Abstract A method and device for measuring the amount of magnetic particles in a fluid such as ferrous wear particles in the lubricant of a machine. The particles are entraped by contacting a volume of the fluid with a means to entrap the particles and magnetized by subjecting the entraped particles to a magnetic field. The amount of magnetic particles entraped is measured by measuring the magnetization of the entraped and magnetized particles.
Inventors
- 👤 Robert T. Lewis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:50
CPC Classifications
G; G01; G01N; G01N15/00; G01N15/06; G01N15/0656
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
95 words
A device for measuring the amount of magnetic particles in a flowing fluid comprising: a filter with holes sized to pass the fluid but entrap the particles; a magnet with a magnetic field of sufficient strength to magnetize said particles positioned to have said filter in said magnetic field; a long cylindrical tube located within said filter and having an opening to the outside of said filter, with the axis of said tube perpendicular to the magnetic field of said magnet; and a magnetic field measuring means positioned within said cylindrical tube through said opening.
Claim 2
Independent Claim
95 words
A device for measuring the amount of magnetic particles in a flowing fluid comprising: a filter with holes sized to pass the fluid but entrap the particles; a magnet with a magnetic field of sufficient strength to magnetize said particles positioned to have said filter in said magnetic field; a long cylindrical tube located within said filter and having an opening to the outside of said filter, with the axis of said tube perpendicular to the magnetic field of said magnet; and a magnetic field measuring means positioned within said cylindrical tube through said opening.
Claim 3
Dependent Claim
19 words
The device of claim 1 wherein the major dimension of said holes is between about 0.5 and 200 micrometers.
Claim 4
Dependent Claim
16 words
The device of claim 1 wherein the strength of said magnetic field is at least 0.1T.
Claim 5
Independent Claim
96 words
A method for measuring the amount of magnetic particles in a flowing fluid comprising: flowing said fluid through a filter with holes sized to pass the fluid but entrap the particles; subjecting said filter to the field of a magnet of sufficient strengh to magnetize said particles; and measuring the magnetic field from said magnetized particles with a magnetic field measuring means inserted from the outside of said filter through an opening in a long cylindrical tube located within said filter with the long axis of said tube perpendicular to the magnetic field of said magnet.
Claim 6
Independent Claim
96 words
A method for measuring the amount of magnetic particles in a flowing fluid comprising: flowing said fluid through a filter with holes sized to pass the fluid but entrap the particles; subjecting said filter to the field of a magnet of sufficient strengh to magnetize said particles; and measuring the magnetic field from said magnetized particles with a magnetic field measuring means inserted from the outside of said filter through an opening in a long cylindrical tube located within said filter with the long axis of said tube perpendicular to the magnetic field of said magnet.
References Cited (Backward Citations)
US3432750A
Cited
US3553672A
Cited
US4047814A
Cited
JPS54956A
Cited
US4205904A
Cited
US4176545A
Cited
GB2029580A
Cited
US4219805A
Cited
US4323843A
Cited
DE2931412A1
Cited
US4500839A
Cited
US4492921A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-08-10 | 1991-02-09 | 1991-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-08-10 | 1995-02-09 | 1995-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-08-10 | 1999-02-09 | 1999-08-11 | $7700.00 | Window Closed / Lapsed |