US3846631A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gamma ray differential density probe
Assignee: Applied Inventions Corp
•
Filing: 1972-03-13
•
Granted: 1974-11-05
•
Expires: 1992-03-13
Abstract
Abstract A gamma ray density probe and method utilizing a pair of alternately operated gamma ray sources, and a pair of gamma ray detectors, said density probe being able to measure differentially the density at a predetermined distance from the probe, independent of the geometry of the sample and of the geometry and the chemical composition of interfering materials by computing the product of the ratio and the inverse ratio of two counting rates.
Inventors
- 👤 P Kehler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:25
CPC Classifications
G; G01; G01V; G01V5/00; G01V5/04; G01V5/08; G01V5/14; G01V5/02; G01V5/12
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
445 words
A gamma ray density probe utilizing a first collimated gamma ray source, a second collimated gamma ray source, a first collimated gamma ray detector and a second collimated gamma ray detector, wherein said first and said second collimated gamma ray sources are located on two parallel planes placed at a distance from each other, with said first gamma ray source emitting gamma rays into a sample to be measured along at least one trajectory within the first of said two parallel planes and said second collimated gamma ray source emitting gamma rays into said sample along at least one trajectory within the second of said two parallel planes, with some of the gamma rays emitted by said first collimated gamma ray source being scattered under a geometrically predetermined scattering angle towards said second collimated gamma ray detector at a first location in said sample and along at least one trajectory that is intersecting said second of said two parallel planes at a second location in said sample, with some of the gamma rays emitted by said second collimated gamma ray source being scattered under said geometrically predetermined angle towards said first collimated gamma ray detector at a third location in said sample and along at least one trajectory that is intersecting said first of said two parallel planes at a fourth location in said sample, with some of the gamma rays emitted by said first collimated gamma ray source being scattered under said geometrically predetermined scattering angle towards said first collimated gamma ray detector at said fourth location in said sample and with some of the gamma rays emitted by said second collimated gamma ray source being scattered under said geometrically predetermined scattering angle towards said second collimated gamma ray detector at said second location in said sample, wherein a ratio is computed by dividing the counting rate of said first collimated gamma ray detector which is caused by gamma rays scattered from said fourth location by the counting rate of said second collimated gamma ray detector which is caused by gamma rays scattered from said first location, wherein an inverse ratio is computed by dividing the counting rate of said second collimated gamma ray detector which is caused by gamma rays scattered from said second location by the counting rate of said first collimated gamma ray detector which is caused by gamma rays scattered from said third location, and wherein a product of said ratio and said inverse ratio is formed and displayed in a manner that allows interpretation of this product in terms of the average density of that volume of said sample that is located between said four locations in said sample.
Claim 2
Dependent Claim
445 words
A gamma ray density probe utilizing a first collimated gamma ray source, a second collimated gamma ray source, a first collimated gamma ray detector and a second collimated gamma ray detector, wherein said first and said second collimated gamma ray sources are located on two parallel planes placed at a distance from each other, with said first gamma ray source emitting gamma rays into a sample to be measured along at least one trajectory within the first of said two parallel planes and said second collimated gamma ray source emitting gamma rays into said sample along at least one trajectory within the second of said two parallel planes, with some of the gamma rays emitted by said first collimated gamma ray source being scattered under a geometrically predetermined scattering angle towards said second collimated gamma ray detector at a first location in said sample and along at least one trajectory that is intersecting said second of said two parallel planes at a second location in said sample, with some of the gamma rays emitted by said second collimated gamma ray source being scattered under said geometrically predetermined angle towards said first collimated gamma ray detector at a third location in said sample and along at least one trajectory that is intersecting said first of said two parallel planes at a fourth location in said sample, with some of the gamma rays emitted by said first collimated gamma ray source being scattered under said geometrically predetermined scattering angle towards said first collimated gamma ray detector at said fourth location in said sample and with some of the gamma rays emitted by said second collimated gamma ray source being scattered under said geometrically predetermined scattering angle towards said second collimated gamma ray detector at said second location in said sample, wherein a ratio is computed by dividing the counting rate of said first collimated gamma ray detector which is caused by gamma rays scattered from said fourth location by the counting rate of said second collimated gamma ray detector which is caused by gamma rays scattered from said first location, wherein an inverse ratio is computed by dividing the counting rate of said second collimated gamma ray detector which is caused by gamma rays scattered from said second location by the counting rate of said first collimated gamma ray detector which is caused by gamma rays scattered from said third location, and wherein a product of said ratio and said inverse ratio is formed and displayed in a manner that allows interpretation of this product in terms of the average density of that volume of said sample that is located between said four locations in said sample.
Claim 3
Dependent Claim
410 words
A gamma ray density probe utilizing two collimated gamma ray sources and two collimated gamma ray detectors, wherein the first and second collimated gamma ray detectors are located in two parallel planes placed at a distance from each other, with said first collimated gamma ray detector receiving scattered radiation from a sample to be measured along at least one trajectory within the first parallel plane and said second collimated gamma ray detector receiving scattered radiation from said sample along at least one trajectory within the second parallel plane, wherein some of the gamma rays emitted from the second collimated gamma ray source along at least one trajectory are scattered towards said first collimated gammA ray detector at a first location in said sample under a geometrically predetermined angle and along trajectories that pass through a fourth location in said sample, wherein some of the gamma rays emitted from said second collimated gamma ray source along at least one trajectory are scattered towards the second gamma ray detector at a second location in said sample, wherein some of the gamma rays emitted from the first collimated gamma ray source along at least one trajectory are scattered towards said second collimated gamma ray detector at a third location in said sample under the same said geometrically predetermined angle and along trajectories that pass through said second location in said sample, wherein some of the gamma rays emitted from said first collimated gamma ray source along at least one trajectory are scattered towards said first collimated gamma ray detector at said fourth location in said sample, wherein a ratio is computed by dividing the counting rate of said first collimated gamma ray detector which is caused by gamma rays scattered from said fourth location by the counting rate of said second collimated gamma ray detector which is caused by gamma rays scattered from said third location, wherein an inverse ratio is computed by dividing the counting rate of said second collimated gamma ray detector which is caused by gamma rays scattered from said second locations by the counting rate of said first collimated gamma ray detector which is caused by gamma rays scattered from said first location, and wherein a product of said ratio and said inverse ratio is formed and displayed in a manner that allows interpretation of this product in terms of the average density of that volume of said sample that is located between said four locations in said sample.
Claim 4
Dependent Claim
410 words
A gamma ray density probe utilizing two collimated gamma ray sources and two collimated gamma ray detectors, wherein the first and second collimated gamma ray detectors are located in two parallel planes placed at a distance from each other, with said first collimated gamma ray detector receiving scattered radiation from a sample to be measured along at least one trajectory within the first parallel plane and said second collimated gamma ray detector receiving scattered radiation from said sample along at least one trajectory within the second parallel plane, wherein some of the gamma rays emitted from the second collimated gamma ray source along at least one trajectory are scattered towards said first collimated gammA ray detector at a first location in said sample under a geometrically predetermined angle and along trajectories that pass through a fourth location in said sample, wherein some of the gamma rays emitted from said second collimated gamma ray source along at least one trajectory are scattered towards the second gamma ray detector at a second location in said sample, wherein some of the gamma rays emitted from the first collimated gamma ray source along at least one trajectory are scattered towards said second collimated gamma ray detector at a third location in said sample under the same said geometrically predetermined angle and along trajectories that pass through said second location in said sample, wherein some of the gamma rays emitted from said first collimated gamma ray source along at least one trajectory are scattered towards said first collimated gamma ray detector at said fourth location in said sample, wherein a ratio is computed by dividing the counting rate of said first collimated gamma ray detector which is caused by gamma rays scattered from said fourth location by the counting rate of said second collimated gamma ray detector which is caused by gamma rays scattered from said third location, wherein an inverse ratio is computed by dividing the counting rate of said second collimated gamma ray detector which is caused by gamma rays scattered from said second locations by the counting rate of said first collimated gamma ray detector which is caused by gamma rays scattered from said first location, and wherein a product of said ratio and said inverse ratio is formed and displayed in a manner that allows interpretation of this product in terms of the average density of that volume of said sample that is located between said four locations in said sample.
Claim 5
Independent Claim
139 words
A method for determining the density of a sample from the product of the ratio and the inverse ratio of the counting rates of a first collimated gamma ray detector and a second collimated gamma ray detector, said ratio being derived by dividing the counting rate of said first collimated gamma ray detector by the counting rate of said second collimated gamma ray detector during a time when a first collimated gamma ray source is and a second collimated gamma ray source is not irradiating said sample, and said inverse ratio being derived by dividing the counting rate of said second collimated gamma ray detector by the counting rate of said first collimated gamma ray detector during a time when said second collimated gamma ray source is and said first collimated gamma ray source is not irradiating said sample.
Claim 6
Independent Claim
139 words
A method for determining the density of a sample from the product of the ratio and the inverse ratio of the counting rates of a first collimated gamma ray detector and a second collimated gamma ray detector, said ratio being derived by dividing the counting rate of said first collimated gamma ray detector by the counting rate of said second collimated gamma ray detector during a time when a first collimated gamma ray source is and a second collimated gamma ray source is not irradiating said sample, and said inverse ratio being derived by dividing the counting rate of said second collimated gamma ray detector by the counting rate of said first collimated gamma ray detector during a time when said second collimated gamma ray source is and said first collimated gamma ray source is not irradiating said sample.
Claim 7
Dependent Claim
153 words
The method for determining the density of a sample according to claim 3, wherein the collimator of said first collimated gamma ray detector allows only that singly scattered gamma radiation to enter said first collimated gamma ray detector which has been emitted by said first collimated gamma ray source or said second collimated gamma ray source into said sample and is scattered at geometrically predetermined locations and under geometrically predetermined scattering angles toward said first collimated gamma ray detector, and wherein the collimator of said second collimated gamma ray detector allows only that singly scattered gamma radiation to enter said second collimated gamma ray detector which has been emitted by said first collimated gamma ray source or said second collimated gamma ray source into said sample and is scattered from within said sample toward said second collimated gamma ray detector at geometrically predetermined locations and under the same said geometrically predetermined scattering angle.
Claim 8
Dependent Claim
197 words
The method for determining the density of a sample according to claim 4, wherein said first collimated gamma ray detector and said second collimated gamma ray detector are feeding pulses to energy discriminators, said energy discriminators allowing passage of signals that are due to gamma rays that are scattered only once and under said geometrically predetermined scatteRing angle, and discriminating against gamma rays that are scattered more than once or that are scattered once but at locations different from said geometrically predetermined locations in said sample, wherein only the signals passed by said energy discriminators are contributing to said counting rate of said first collimated gamma ray detector and said counting rate of said second collimated gamma ray detector, said counting rates of said first and said second collimated gamma ray detectors being used for the computation of said ratio and said inverse ratio, and wherein said product of said ratio and said inverse ratio are independent of the presence of any interfering materials that may be positioned between said sample and said first collimated gamma ray source, said second collimated gamma ray source, said first collimated gamma ray detector or said second collimated gamma ray detector.
Claim 9
Dependent Claim
76 words
An oil well density logging tool according to claim 1, wherein said first collimated gamma ray detector, said second collimated gamma ray detector, said first collimated gamma ray source and said second collimated gamma ray source are located within one elongated cylindrical housing and on one common line, said common line being perpendicular to said two parallel planes on which said first collimated gamma ray source and said second collimated gamma ray source are respectively located.
Claim 10
Dependent Claim
76 words
An oil well density logging tool according to claim 2, wherein said first collimated gamma ray detector, said second collimated gamma ray detector, said first collimated gamma ray source and said second collimated gamma ray source are located within one elongated cylindrical housing and on one common line, said common line being perpendicular to said two parallel planes on which said first collimated gamma ray detector and said second collimated gamma ray detector are respectively located.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-04 | 1978-05-06 | 1978-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-04 | 1982-05-06 | 1982-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-04 | 1986-05-06 | 1986-11-05 | $7700.00 | Window Closed / Lapsed |