US4350889A
Expired / Lapsed
US
⏱️ 0.0 years remaining
X-Ray fluorescent analysis with matrix compensation
Assignee: International Paper Co
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Filing: 1980-09-17
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Granted: 1982-09-21
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Expires: 2000-09-17
Abstract
Abstract A new X-ray fluorescence method for testing a sample having two essentially parallel planar faces that provides full matrix effect compensation is disclosed. The intensities of the transmitted and fluorescent beams of photons are measured by X-ray detectors, and the X-ray source and the two detectors are operated so that ##EQU1## where Φ is the angle of the primary beam to one face of the sample, Ψ is the angle of the fluorescent beam to either face of the sample, E 1 is the energy of the photons of the primary beam, and E 2 is the characteristic electron orbital transition energy for the element of interest. From the ratio of the two intensities the mean average concentration of the element is calculated directly without iterative or other complex procedures.
Inventors
- 👤 Khaim Lisnyansky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:31
CPC Classifications
G; G01; G01N; G01N23/00; G01N23/22; G01N23/223; G01N2223/00; G01N2223/07; G01N2223/076
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
154 words
An X-ray fluorescence method for determining the mean average concentration of an element in a sample having essentially parallel planar first and second faces in the region being tested, said method comprising: (a) aiming a beam of primary photons of a predetermined energy E 1 at the first face of the sample such that the beam is at angle Φ to the first face; (b) aiming a first X-ray detector at the second face of the sample to detect the transmitted beam of photons of energy E 1 ; (c) aiming a second X-ray detector at the sample at angle Ψ to either face of the sample to detect the beam of characteristic secondary fluorescent photons of energy E 2 emitted by the particular element of interest in response to the irradiation by the beam of primary photons wherein ##EQU4## (d) utilizing the intensities of the transmitted and fluorescent beams to determine said concentration.
Claim 2
Dependent Claim
154 words
An X-ray fluorescence method for determining the mean average concentration of an element in a sample having essentially parallel planar first and second faces in the region being tested, said method comprising: (a) aiming a beam of primary photons of a predetermined energy E 1 at the first face of the sample such that the beam is at angle Φ to the first face; (b) aiming a first X-ray detector at the second face of the sample to detect the transmitted beam of photons of energy E 1 ; (c) aiming a second X-ray detector at the sample at angle Ψ to either face of the sample to detect the beam of characteristic secondary fluorescent photons of energy E 2 emitted by the particular element of interest in response to the irradiation by the beam of primary photons wherein ##EQU4## (d) utilizing the intensities of the transmitted and fluorescent beams to determine said concentration.
Claim 3
Dependent Claim
26 words
The method of claim 1 wherein the sample is paper, a polymeric film, a textile, a sheet of rubber, a metal foil, or a plant leaf.
Claim 4
Dependent Claim
20 words
The method of claim 1 wherein the sample is paper and the element of interest is calcium, barium, or titanium.
Claim 5
Dependent Claim
10 words
The method of claim 1 wherein Ψ is 90 degrees.
Claim 6
Dependent Claim
42 words
The method of claim 1 wherein the second detector is aimed at the point of intersection of the line of the beam of primary photons with an imaginary plane parallel to and half-way between the first and second faces of the sample.
Claim 7
Dependent Claim
10 words
The method of claim 5 wherein Ψ is 90 degrees.
Claim 8
Dependent Claim
26 words
The method of claim 6 wherein the sample is paper, a polymeric film, a textile, a sheet of rubber, a metal foil, or a plant leaf.
Claim 9
Dependent Claim
20 words
The method of claim 6 wherein the sample is paper and the element of interest is calcium, barium, or titanium.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-09-20 | 1986-03-22 | 1986-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-09-20 | 1990-03-22 | 1990-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-09-20 | 1994-03-22 | 1994-09-21 | $7700.00 | Window Closed / Lapsed |