US3688110A - Photographic emulsion silver gage - Google Patents
Photographic emulsion silver gage Download PDFInfo
- Publication number
- US3688110A US3688110A US38929A US3688110DA US3688110A US 3688110 A US3688110 A US 3688110A US 38929 A US38929 A US 38929A US 3688110D A US3688110D A US 3688110DA US 3688110 A US3688110 A US 3688110A
- Authority
- US
- United States
- Prior art keywords
- film
- radiation
- silver
- photographic film
- source
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 title claims abstract description 46
- 229910052709 silver Inorganic materials 0.000 title claims abstract description 46
- 239000004332 silver Substances 0.000 title claims abstract description 46
- 239000000839 emulsion Substances 0.000 title abstract description 22
- 230000005855 radiation Effects 0.000 claims abstract description 38
- LXQXZNRPTYVCNG-YPZZEJLDSA-N americium-241 Chemical compound [241Am] LXQXZNRPTYVCNG-YPZZEJLDSA-N 0.000 claims abstract description 5
- 238000005259 measurement Methods 0.000 claims description 3
- 230000001154 acute effect Effects 0.000 claims description 2
- 238000004458 analytical method Methods 0.000 abstract description 3
- 239000000470 constituent Substances 0.000 abstract description 2
- 238000004846 x-ray emission Methods 0.000 abstract 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 8
- 239000000047 product Substances 0.000 description 5
- 239000002131 composite material Substances 0.000 description 4
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- FVAUCKIRQBBSSJ-UHFFFAOYSA-M sodium iodide Chemical compound [Na+].[I-] FVAUCKIRQBBSSJ-UHFFFAOYSA-M 0.000 description 3
- 238000006073 displacement reaction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000005670 electromagnetic radiation Effects 0.000 description 2
- 238000007689 inspection Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- WKBOTKDWSSQWDR-UHFFFAOYSA-N Bromine atom Chemical compound [Br] WKBOTKDWSSQWDR-UHFFFAOYSA-N 0.000 description 1
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- 235000013290 Sagittaria latifolia Nutrition 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 229910052787 antimony Inorganic materials 0.000 description 1
- WATWJIUSRGPENY-UHFFFAOYSA-N antimony atom Chemical compound [Sb] WATWJIUSRGPENY-UHFFFAOYSA-N 0.000 description 1
- 229910052790 beryllium Inorganic materials 0.000 description 1
- ATBAMAFKBVZNFJ-UHFFFAOYSA-N beryllium atom Chemical compound [Be] ATBAMAFKBVZNFJ-UHFFFAOYSA-N 0.000 description 1
- GDTBXPJZTBHREO-UHFFFAOYSA-N bromine Substances BrBr GDTBXPJZTBHREO-UHFFFAOYSA-N 0.000 description 1
- 229910052794 bromium Inorganic materials 0.000 description 1
- 239000002775 capsule Substances 0.000 description 1
- 235000015246 common arrowhead Nutrition 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 230000005251 gamma ray Effects 0.000 description 1
- 229910052736 halogen Inorganic materials 0.000 description 1
- 150000002367 halogens Chemical class 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000001151 other effect Effects 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 238000003908 quality control method Methods 0.000 description 1
- 235000009518 sodium iodide Nutrition 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
- G01N23/22—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material
- G01N23/223—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material by irradiating the sample with X-rays or gamma-rays and by measuring X-ray fluorescence
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2223/00—Investigating materials by wave or particle radiation
- G01N2223/07—Investigating materials by wave or particle radiation secondary emission
- G01N2223/076—X-ray fluorescence
Definitions
- ABSTRACT Apparatus measuring the silver content in photographic film emulsion utilizing an Americium-24l radioisotope source causing fluorescent Xray emissions from the emulsion silver, and electronic pulse height analysis with compensation for radiation attributable to other constituents of the film than silver.
- this invention comprises apparatus for measuring the silver content in the silver emulsion coating of photographic film comprising an Americium-24l radioisotope source, means directing the radiation from the source at close range and at a composite angle reducing scatter with respect to photographic film to be tested, detector means generating electrical signals responsive to electromagnetic radiation (photons) received from the film in the energy region (A), displaying the 24.9 Kev maximum, primarily characteristic of silver fluorescence but inclusive also of some scatter contributed by other components of the film, and also in the energy region (B), displaying the 59.6 Kev maxima, constituting scatter contributed by all components in the film, and electronic pulse height analyzer means receiving the output of the detector means determining the silver content of the photographic film as a function of the
- FIG. 1 is a cross-sectional partially schematic view of reference channel intensity for the apparatus of FIGS.
- FIGS. 6A and 6B are recorder read-outs for the same specimen of commercial X-ray film wherein FIG. 6A is that of the wet emulsion product whereas FIG. 6B is that of the dry emulsion product.
- Photographic film is, of course, radiation-sensitive and it is paramount that inspection radiation not expose or fog the product.
- different radiation sources give different film radiation outputs, scatter or other effects for the different components of the coated film which interfere with accurate silver gauging and sources, in the number of two, three, or four individual sources 10 of, e.g., 50 millicurie strength Americium- 241 each, disposed at equi-radial distances and equiangular spacings from the longitudinal axis of detector 11 in order to distribute the radiation incident on the photographic film uniformly over a large area such that the radiation intensity per unit area of film will be small for each photon detected.
- a source disposition insures more representative readings.
- the construction can conveniently embody a unitary head design, indicated generally at 15, wherein sources 10 are supported on the ends of radial spokes 15a, only two of which are detailed in FIG. 1.
- Sources 10 are disposed close to the plane 12 of photographic film travel at a distance, typically, of 1.70 inches directed inwardly and collimated at an acute angle of radiation incidence a with the film, preferably of about 45, in order to reduce radiation scatter to a minimum. Since sources 10 have an appreciable transverse width, it will be understood that radiation from given points of each source impinge on the photographic film at a great variety of angles. Nevertheless, with the film-detector ll angle substantially normal, it has been found that the composite angle of radiation impinging on the film with the source axis-film angle a about 45 and source-to-film distance approximately equal to film-to-detector distance measured along an angle of reflection equaling a, is such as to reduce scatter to a practical minimum. The signal-to-noise ratio reduction occasioned by such scatter has not hitherto been viewed as an important factor contributing to inaccuracy in radiation gaging; however, I have found it very desirable to minimize scatter insofar as practicable.
- detector 11 is also relatively critical, as is shown by FIG. 2.
- the optimum detector-to-film spacing for maximum radiation intensity preservation is approximately 1.25 inches, although dispositions in the range of 1 5/32 to l 11/32 inches can be tolerated without changing the average reading by more than $0.5 per cent.
- the difference between these limiting values is three-sixteenths inch, equal to 194 mils.
- Conventional film support devices are capable of supporting running films with lateral film displacements not exceeding about :50 mils, so that lateral film displacement constitutes no obstacle to overall measurement precision.
- Americium-241 is a unique source for the purposes contemplated, since it emits 26.4 Kev gamma rays which are nearly ideal for producing silver fluorescence. In addition, it also emits 59.6 Kev gamma rays, which are less ideal in energy but greater in number per unit time and, so, also useful for producing fluorescent X-rays. As hereinbefore mentioned, 50 millicurie sources 10 are suitable, these preferably being backed with compacted antimony powder in order to convert some of the 59.6 Kev gamma rays normally lost into useful 30 Kev X-rays.
- the sources 10 are preferably doubly encapsulated, with each capsule sealed with a 5 mil stainless steel window 10a.
- Gauging head 15 is fabricated from stainless steel and is, as hereinbefore described, designed to provide approximately collimation between the sources and detector 1 l in order to minimize radiation scatter.
- the radiation-exposed areas on the film are non-overlapping ellipses with axes of approximately 1 inch and 1.5 inches.
- Detector 11 can be a 2 inches diameter thin cleaved crystal of sodium iodide optically coupled to a low noise photomultiplier tube and hermetically sealed in an aluminum container provided with a window disposed toward the film 12 fabricated from 5 mil beryllium foil.
- Detector 11 is optically coupled to a low noise photomultiplier tube (not detailed) and the voltage pulse output of the latter is supplied via electrical connection 16 as input to preamplifier 19 (FIG. 3) which, in turn, feeds its output to amplifier 20.
- Amplifier 20 supplies voltage pulse signals to two separate channels, the lowermost of which, as seen in FIG. 3, is the silver channel and the uppermost of which is the reference channel.
- the silver channel comprises a conventional pulse height analyzer 21 and a conventional ratemeter 22 set to count and display the photons in the energy region arbitrarily denoted (A), FIG. 4, which is primarily characteristic of silver, the peak of which is at approximately 24.9 Kev.
- the reference channel comprises a conventional pulse height analyzer 23, incorporating means for dynamic feedback stabilization applicable to the gauging head voltage source 24, together with its ratemeter 25.
- the reference channel is reserved to the display of photons in the energy region arbitrarily denoted (B), FIG. 4, the peak of which is at 59.6 Kev, including the scatter contributed by silver.
- ratemeters 22 and 25 are passed to difference amplifier 26, and the voltage output of the latter is supplied to the silver content recorder 27.
- the apparatus described lacks discrimination as regards particular mono-energetic inputs, the existing situation being that shown generally in FIG. 4.
- curve D is the test spectrum for X-ray film coated with dried silver-containing emulsion over the energy range of 80 Kev
- the curve of intensity variation plotted on the ordinate axis displays three separate peaks.
- the second for silver fluorescence, primarily, but with some contribution from radiation scattered by underlying film base and emulsion materials is at about 24.9 Kev
- the third, for radiation scattered from film base and emulsion materials primarily is at about 59.6 Kev.
- the identical film base free of all emulsion, is tested under identical conditions, it displays two energy peaks, one being at about 26.4 Kev, whereas the other is at 59.6 Kev, as shown approximately by plot E, FIG. 4, which peaks are due to scattering of the Americium 241 radiation by the base film.
- the first of the latter peaks intrudes on the silver content characteristic radiation (A).
- the silver intensity value of curve D must be compensated for the contribution of scatter if silver is to be determined with accuracy.
- FIG. 5 The graphical proof of equivalence of water to film base is shown in FIG. 5, wherein the variation of silver channel intensity, as ordinate, is shown versus reference channel intensity as abscissa, drawn by a conventional X Y plotter.
- Apparatus for measuring the silver content in the silver emulsion coating of photographic film comprising, in combination, an Americium-24l radioisotope source, means directing the radiation from said source at close range and at a composite angle reducing scatter with respect to photographic film to be tested, detector means generating electrical signals responsive to electromagnetic radiation received from said film in the energy region (A), displaying the 24.9 Kev maximum, primarily characteristic of silver fluorescence but inclusive also of some scatter contributed by other components of said film, and also in the energy region (B), displaying the 59.6 Kev maxima, constituting scatter contributed by all components in said fihn, and electronic pulse height analyzer means receiving the output of said detector means determining the silver content of said photographic film as a function of the difference between the total of said (A) radiation measured and a preselected quantity of said (B) radiation substantially equivalent to the fraction of said (A) radiation measured attributable to scatter from other components of said photographic film than said silver content.
- said electronic pulse height analyzer means comprises individual pulse height analyzers with associated ratemeters reserved to measurement of said (A) radiation and said (B) radiation individually, adjusting means regulative of the output signal from the (B) radiation measuring one of said associated ratemeters, a diflerence amplifier receiving
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- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Analysing Materials By The Use Of Radiation (AREA)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US3892970A | 1970-05-20 | 1970-05-20 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3688110A true US3688110A (en) | 1972-08-29 |
Family
ID=21902714
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US38929A Expired - Lifetime US3688110A (en) | 1970-05-20 | 1970-05-20 | Photographic emulsion silver gage |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US3688110A (de) |
| DE (1) | DE2125051A1 (de) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4573181A (en) * | 1982-01-12 | 1986-02-25 | Elementanalys Almen & Gronberg Ab | X-Ray fluorescence analyzers |
| US5657363A (en) * | 1995-10-10 | 1997-08-12 | Advanced Micro Devices, Inc. | Method and apparatus for determining the thickness and elemental composition of a thin film using radioisotopic X-ray fluorescence (RXRF) |
| US6005915A (en) * | 1997-11-07 | 1999-12-21 | Advanced Micro Devices, Inc. | Apparatus and method for measuring the roughness of a target material surface based upon the scattering of incident X-ray photons |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4748647A (en) * | 1985-08-12 | 1988-05-31 | General Electric Company | Fuel tube barrier gauge |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2449066A (en) * | 1946-07-19 | 1948-09-14 | Friedman Herbert | Analysis by fluorescent X-ray excitation |
| US2675482A (en) * | 1952-03-25 | 1954-04-13 | Isotope Products Ltd | Method and apparatus for measuring material thickness |
| US2897367A (en) * | 1956-04-25 | 1959-07-28 | Applied Res Lab Inc | Spectroscopy |
| US2928944A (en) * | 1954-08-04 | 1960-03-15 | Research Corp | Apparatus for x-ray fluorescence analysis |
| US2947871A (en) * | 1955-08-01 | 1960-08-02 | Friedman Herbert | Apparatus for determining the composition and thickness of thin layers |
| BE598814A (fr) * | 1960-01-04 | 1961-05-02 | Ilford Ltd | Procédé et appareil pour déterminer la teneur en argent |
| GB960373A (en) * | 1959-09-15 | 1964-06-10 | Commissariat Energie Atomique | X-ray analysis with a source of beta rays |
-
1970
- 1970-05-20 US US38929A patent/US3688110A/en not_active Expired - Lifetime
-
1971
- 1971-05-19 DE DE19712125051 patent/DE2125051A1/de active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2449066A (en) * | 1946-07-19 | 1948-09-14 | Friedman Herbert | Analysis by fluorescent X-ray excitation |
| US2675482A (en) * | 1952-03-25 | 1954-04-13 | Isotope Products Ltd | Method and apparatus for measuring material thickness |
| US2928944A (en) * | 1954-08-04 | 1960-03-15 | Research Corp | Apparatus for x-ray fluorescence analysis |
| US2947871A (en) * | 1955-08-01 | 1960-08-02 | Friedman Herbert | Apparatus for determining the composition and thickness of thin layers |
| US2897367A (en) * | 1956-04-25 | 1959-07-28 | Applied Res Lab Inc | Spectroscopy |
| GB960373A (en) * | 1959-09-15 | 1964-06-10 | Commissariat Energie Atomique | X-ray analysis with a source of beta rays |
| BE598814A (fr) * | 1960-01-04 | 1961-05-02 | Ilford Ltd | Procédé et appareil pour déterminer la teneur en argent |
| GB920356A (en) * | 1960-01-04 | 1963-03-06 | Ilford Ltd | Improvements in or relating to method and apparatus for determining silver content |
Non-Patent Citations (1)
| Title |
|---|
| Alloy Analysis and Coating Weight Determination Using Gamma-Ray Excited Souces by J.A. Hope et al From International Journal of Applied Radiation and Isotopes, Vol. 16, 1965, pgs. 9 14. * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4573181A (en) * | 1982-01-12 | 1986-02-25 | Elementanalys Almen & Gronberg Ab | X-Ray fluorescence analyzers |
| US5657363A (en) * | 1995-10-10 | 1997-08-12 | Advanced Micro Devices, Inc. | Method and apparatus for determining the thickness and elemental composition of a thin film using radioisotopic X-ray fluorescence (RXRF) |
| US6005915A (en) * | 1997-11-07 | 1999-12-21 | Advanced Micro Devices, Inc. | Apparatus and method for measuring the roughness of a target material surface based upon the scattering of incident X-ray photons |
Also Published As
| Publication number | Publication date |
|---|---|
| DE2125051A1 (de) | 1971-12-02 |
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