US3763692A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Measuring of fluid density
Assignee: Sarasota Automation Ltd
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Filing: 1972-04-05
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Granted: 1973-10-09
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Expires: 1992-04-05
Abstract
Abstract The density of a fluid is measured employing apparatus including a cylinder immersed in the fluid, together with driving and pickup means operating to resonate the cylinder at its natural frequency as affected by the fluidic medium; the apparatus described has the drive and pick-up coils located external to the resonating cylinder so that they are free of the fluidic medium.
Inventors
- 👤 J Agar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:31
CPC Classifications
G; G01; G01N; G01N9/00; G01N9/002; G01N11/00; G01N11/10; G01N11/16; G01N2009/006
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
186 words
Apparatus for measuring the density of a fluid, said apparatus including a hollow rigid support member of substantial thickness at one section thereof within which with a gap therebetween there is mounted a hollow body having open opposite ends and adapted to have said fluid passing unimpeded straight through its unobstructed interior, external drive means for exciting said body from its exterior to vibrate at a resonant frequency, external detecting means for detecting from the exterior of the hollow body a signal representative of the frequency of said vibrations, the frequency of said signal in operation being dependent substantially only upon the density of said fluid, said external drive means and said external detecting means being disposed in a recess in said section of substantial thickness of the hollow support member thereby isolating said drive and detecting means from said fluid and allowing a portion of said fluid to pass externally around the exterior of said hollow body through said gap and in contact therewith, but out of contact with said external drive means and said external detecting means, and monitoring means for monitoring said signal.
Claim 2
Dependent Claim
186 words
Apparatus for measuring the density of a fluid, said apparatus including a hollow rigid support member of substantial thickness at one section thereof within which with a gap therebetween there is mounted a hollow body having open opposite ends and adapted to have said fluid passing unimpeded straight through its unobstructed interior, external drive means for exciting said body from its exterior to vibrate at a resonant frequency, external detecting means for detecting from the exterior of the hollow body a signal representative of the frequency of said vibrations, the frequency of said signal in operation being dependent substantially only upon the density of said fluid, said external drive means and said external detecting means being disposed in a recess in said section of substantial thickness of the hollow support member thereby isolating said drive and detecting means from said fluid and allowing a portion of said fluid to pass externally around the exterior of said hollow body through said gap and in contact therewith, but out of contact with said external drive means and said external detecting means, and monitoring means for monitoring said signal.
Claim 3
Dependent Claim
12 words
Apparatus as in claim 1 wherein said hollow body is a tube.
Claim 4
Dependent Claim
14 words
Apparatus as in claim 1 wherein said hollow body is of substantially circular cross-section.
Claim 5
Dependent Claim
46 words
Apparatus as in claim 1 wherein said hollow body is provided at each end thereof with flanges so as to render said body substantially dumb-bell shaped, whereby to allow said body to be clamped at said flanges without affecting the frequency of oscillation of the body.
Claim 6
Dependent Claim
23 words
Apparatus as in claim 4 wherein said flanges are provided with apertures through which said fluid may pass externally around said hollow body.
Claim 7
Dependent Claim
112 words
Apparatus as in claim 1 wherein both said external drive means and said external detecting means are electomagnetic coil means located around the exterior of said hollow body and disposed to substantially prevent the flux paths thereof from overlapping each other and which flux paths are caused to repectively extend into the exterior of said hollow body over only a small region thereof relative to the circumference of said body to reduce cross-coupling between the said external drive means and the said external detecting means, the electromagnetic coil means being 90* out of phase with each other and being arranged in planes at right angles to the axis of said hollow body.
Claim 8
Dependent Claim
27 words
Apparatus as in claim 1 wherein said external drive means and said external detecting means are respectively constituted by electro-acoustic transducers for vibrating the said hollow body.
Claim 9
Dependent Claim
47 words
Apparatus as in claim 1 wherein said external drive means and said external detector means are capacitor plates, the exterior of said hollow body constituting the other plate for the drive capacitor and for the detector capacitor for the electrostatic excitation of vibrations in said hollow body.
Claim 10
Dependent Claim
48 words
Apparatus as in claim 1 wherein there is provided a locating pin for connecting said support member to the said hollow body such that removal and replacement of said body may be effected without re-adjusting the relative positions of the said hollow body and the said support member.
Claim 11
Dependent Claim
28 words
Apparatus as in claim 1 wherein a core is provided within the interior of the hollow body so as to reduce the cross-sectional area of fluid flow therewithin.
Claim 12
Dependent Claim
32 words
Apparatus as in claim 1 wherein said support member is provided with an end portion engageable with an adaptor mounted on a handle for use of the apparatus in relatively inaccessible locations.
Claim 13
Dependent Claim
30 words
Apparatus as in claim 1 wherein said support member is a rigid casing surrounding said hollow body along at least the major part of the length of said hollow body.
Claim 14
Dependent Claim
24 words
Apparatus as in claim 1 wherein filter means are provided for filtering the fluid prior to its passing in contact with said hollow body.
Claim 15
Dependent Claim
174 words
Apparatus for measuring the density of a fluid, comprising a hollow rigid tubular support member through which said fluid is adapted to flow, a hollow tubular body positioned within said support member, said tubular body having an unobstructed interior and open opposite ends permitting substantially unimpeded flow of fluid therethrough, means mounting said tubular support member, said mounting means permitting flow of said fluid within said support member and exteriorly of said tubular body so that said fluid is in contact with and flows across the inner and outer surfaces of said tubular body, external drive means for exciting said tubular body from its exterior to vibrate at a resonant frequency, external detecting means for detecting from the exterior of said tubular body a signal representative of the frequency of said vibrations, the frequency of said signal being dependent upon the density of said fluid, means mounting said drive means and said detecting means at spaced locations exteriorly on said support member and isolated from said fluid, and monitoring means for monitoring said signal.
Claim 16
Dependent Claim
174 words
Apparatus for measuring the density of a fluid, comprising a hollow rigid tubular support member through which said fluid is adapted to flow, a hollow tubular body positioned within said support member, said tubular body having an unobstructed interior and open opposite ends permitting substantially unimpeded flow of fluid therethrough, means mounting said tubular support member, said mounting means permitting flow of said fluid within said support member and exteriorly of said tubular body so that said fluid is in contact with and flows across the inner and outer surfaces of said tubular body, external drive means for exciting said tubular body from its exterior to vibrate at a resonant frequency, external detecting means for detecting from the exterior of said tubular body a signal representative of the frequency of said vibrations, the frequency of said signal being dependent upon the density of said fluid, means mounting said drive means and said detecting means at spaced locations exteriorly on said support member and isolated from said fluid, and monitoring means for monitoring said signal.
Claim 17
Dependent Claim
70 words
Apparatus as in claim 14 in which said tubular support member has a section thereof of generally cylindrical form and said hollow body is of generally cylindrical form mounted within said cylindrical section of said support member and spaced uniformly from the inner walls of said support member, and wherein said drive means and said detecting means are mounted on the exterior of the cylindrical section of said support member.
References Cited (Backward Citations)
US3516283A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-08 | 1977-04-09 | 1977-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-08 | 1981-04-09 | 1981-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-08 | 1985-04-09 | 1985-10-09 | $7700.00 | Window Closed / Lapsed |