US3626183A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radioisotope analytical instrument for cement analysis of concrete
Assignee: United States Atomic Energy Commission
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Filing: 1970-07-15
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Granted: 1971-12-07
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Expires: 1990-07-15
Abstract
Abstract A portable radioisotope instrument has been developed for field cement analysis yielding an accuracy of 1 to 2 percent cement in wet concrete. The instrument consists essentially of a cylindrical depth probe unit in which a pair of gamma -ray sources of different energy and a detector are arranged in coaxial alignment and the output of the detector is coupled to a portable scaler. The detector is shielded from the source so that only the gamma -backscattered radiation is detected and through proper calibration of the device as to the aggregate type the operator can radially analyze a wet mix by inserting the probe into the mix and measure the two radiation intensities with reference to the proper calibration curve to determine the cement content.
Inventors
- 👤 Peter Francis Berry
- 👤 James D Hall
- 👤 Tomihiko Furuta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:58
CPC Classifications
G; G01; G01N; G01N23/00; G01N23/20; G01N23/203
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
43 words
The device as set forth in claim 1 wherein said depth probe housing is a cylindrical-shaped housing having a removable conical-shaped end portion adjacent the position of said second source and a handle portion extending from the opposite end of said cylindrical housing.
Claim 2
Dependent Claim
32 words
The device as set forth in claim 2 wherein said radiation detector means is a scintillation-type detector including a photomultiplier tube having an output connected to the input of said counting means.
Claim 3
Dependent Claim
20 words
The device as set forth in claim 3 wherein said first and second radioisotope sources are conical-shaped gamma ray sources.
Claim 4
Dependent Claim
22 words
The device as set forth in claim 4 wherein said first radioisotope source is americium-241 and said second radioisotope source is cobalt-57.
Claim 5
Dependent Claim
48 words
The device as set forth in claim 5 wherein said first source is mounted at a distance of approximately 5 cm. along said axis from said scintillator and said second source is positionable within a range of from 8 to 15 cm. from said detector along said axis.
Claim 6
Dependent Claim
33 words
The device as set forth in claim 6 wherein said means for positionably mounting said second source includes a position indicating means sealably enclosed within said removable end portion of said probe housing.
Claim 7
Dependent Claim
73 words
The device as set forth in claim 7 wherein said means for counting said backscattered radiation events includes an amplifier having an input and an output, said input being connected to the output of said photomultiplier tube, and a single channel pulse height analyzer having an input and a first output corresponding to events generated by said second radioisotope source and a second output corresponding to events generated by said first radioisotope source.
Claim 8
Dependent Claim
92 words
The device as set forth in claim 8 wherein said means for storing said counted events includes first and second scalers connected to receive said first and second outputs of said pulse height analyzer, respectively, a first gating means coupling said first and second outputs of said analyzer to said first and second scalers, respectively, a timer connected to said gating means for controlling the passage of counted events to said scalers, a count register, and a second gating means for selectively passing the counts stored in said scalers to said register.
Claim 9
Dependent Claim
27 words
The device as set forth in claim 9 further including means for correlating the registered counts with the quantity of cement in the concrete matrix being analyzed.
References Cited (Backward Citations)
US3452201A
Cited
US3529151A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-06 | 1975-06-07 | 1975-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-06 | 1979-06-07 | 1979-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-06 | 1983-06-07 | 1983-12-07 | $7700.00 | Window Closed / Lapsed |