US3924133A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for measuring density of substances by penetrating rays
Assignee: Siemens AG
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Filing: 1971-08-10
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Granted: 1975-12-02
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Expires: 1991-08-10
Abstract
Abstract A device for measuring density of substances of living objects without damaging them by penetrating rays, has as the ray source an X-ray device with a ray measuring device located behind the object being measured. The ray measuring device produces electrical values corresponding to the measured ray intensity values. The invention is particularly characterized by a switching device used for switching to a higher value and in rhythmical sequence the high voltage applied to the X-ray tube and having a low value which, however, is clearly above the Kabsorption edge of the body substance. There is also an actuating device synchronized by the switch-over frequency which weakens the ray intensity during the application of the high voltage value in such manner that for two voltage values behind an average object intensity values are present corresponding to the linear measuring range of the ray measuring device. The ray measuring device integrates for a certain constant time period the crest range of electrical values measuring during each time period when the X-ray tube was switched on and forms a quotient from the two values.
Inventors
- 👤 Karl-Hanz Reiss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:11
CPC Classifications
A; A61; A61B; A61B6/00; A61B6/40; A61B6/405; A61B6/02; A61B6/03; A61B6/032; A61B6/44; A61B6/4476; A61B6/48; A61B6/482; G; G01; G01N; G01N23/00; G01N23/02; G01N23/04; G01N23/043
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
193 words
A device for measuring density of substances of living objects, comprising an X-ray tube device adapted to project Xrays upon an object, a ray measuring device adapted to be located behind the object and producing electrical values corresponding to ray intensity values, a generator supplying the X-ray tube with high voltage, a switching device connected with said X-ray tube device and with said ray measuring device and switching a low value of the high voltage which, however, is clearly above the K-absorption edge of the object body, in rhythmical sequence to a higher value, and an actuating device connected with said Xray tube device and with said ray measuring device and synchronized by the switching frequency to lower the ray intensity during the application of the high voltage value in such manner that for two voltage values behind an average object intensity values are present corresponding to the linear measuring range of said ray measuring device, said ray measuring device integrating for a certain constant time period the crest range of electrical values measured during each time period when the X-ray tube was switched on and forming a quotient from the two values.
Claim 2
Independent Claim
193 words
A device for measuring density of substances of living objects, comprising an X-ray tube device adapted to project Xrays upon an object, a ray measuring device adapted to be located behind the object and producing electrical values corresponding to ray intensity values, a generator supplying the X-ray tube with high voltage, a switching device connected with said X-ray tube device and with said ray measuring device and switching a low value of the high voltage which, however, is clearly above the K-absorption edge of the object body, in rhythmical sequence to a higher value, and an actuating device connected with said Xray tube device and with said ray measuring device and synchronized by the switching frequency to lower the ray intensity during the application of the high voltage value in such manner that for two voltage values behind an average object intensity values are present corresponding to the linear measuring range of said ray measuring device, said ray measuring device integrating for a certain constant time period the crest range of electrical values measured during each time period when the X-ray tube was switched on and forming a quotient from the two values.
Claim 3
Dependent Claim
41 words
A device in accordance with claim 1, wherein the switching takes place synchronously in such manner that the lower voltage is effective during a half wave of the line frequency and the higher voltage is effective during the following half wave.
Claim 4
Dependent Claim
56 words
A device in accordance with claim 1, comprising an additional generator connected with said switching device and producing additional high voltage corresponding to the half voltage difference between the high and low voltage values and supplied to the voltage average value produced by the first-mentioned generator additively during one switching and subtractively during the other switching.
Claim 5
Dependent Claim
54 words
A device in accordance with claim 1, comprising a transporting device connected with said X-ray tube device for lowering the ray intensity, said transporting device comprising a ray filter and means introducing said ray filter into the X-rays between the X-ray tube and the object being examined while the high voltage value is applied.
Claim 6
Dependent Claim
25 words
A device in accordance with claim 1, wherein the low voltage value is substantially 75 kV and the high voltage value is substantially 150 kV.
Claim 7
Dependent Claim
26 words
A device in accordance with claim 1, wherein said ray measuring device comprises a ray receiver consisting of a camera tube of an X-ray television unit.
References Cited (Backward Citations)
US2962594A
Cited
US3546461A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-01 | 1979-06-02 | 1979-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-01 | 1983-06-02 | 1983-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-01 | 1987-06-02 | 1987-12-02 | $7700.00 | Window Closed / Lapsed |