US3735126A
Expired / Lapsed
US
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Method and apparatus for testing rock coal dust
Assignee: Reuter Stokes Electronic Components Inc
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Filing: 1971-01-08
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Granted: 1973-05-22
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Expires: 1991-01-08
Abstract
Abstract A method and apparatus for determining the percentage incombustibles in a rock coal dust mixture by irradiating a sample of rock coal dust with gamma radiation from a collimated source spaced from the sample and measuring the backscattered radiation at an area behind the source. The sample of rock coal dust has a depth of about 2 inches to the entering gamma rays in order to minimize any changes in the count rate due to sample depth and density. Time is measured for detection of a predetermined number of radiation counts as a measurement of the percentage of incombustibles. The apparatus includes a source of radiation collimated by a lead holder to irradiate a sample of the mixture of rock coal dust. The lead holder is centered on a detector''s area of sensitivity to give significant count rates with relatively small sources of radiation.
Inventors
- 👤 K Casper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:35
CPC Classifications
G; G01; G01N; G01N23/00; G01N23/20; G01N23/203
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
138 words
An apparatus for quantitatively determining the composition of a sample of a mixture having more than one substance comprising: a radiation detector means having an area of sensitivity; means for supporting a sample of the mixture spaced from the radiation detector means, the area of sensitivity facing the supporting means; means for emanating radiation from between the area of sensitivity and the sample, the means for emanating radiation appropriately directing radiation toward the sample so that the radiation, detector means senses primarily only backscatter radiation from the source; and means for counting the backscatter radiation operatively connected to the radiation detector means as a measure of one of the substanceS of the mixture, said means for counting including means for inverting the count rate as a measurement of the percentage of one of the substances of the composition.
Claim 2
Independent Claim
138 words
An apparatus for quantitatively determining the composition of a sample of a mixture having more than one substance comprising: a radiation detector means having an area of sensitivity; means for supporting a sample of the mixture spaced from the radiation detector means, the area of sensitivity facing the supporting means; means for emanating radiation from between the area of sensitivity and the sample, the means for emanating radiation appropriately directing radiation toward the sample so that the radiation, detector means senses primarily only backscatter radiation from the source; and means for counting the backscatter radiation operatively connected to the radiation detector means as a measure of one of the substanceS of the mixture, said means for counting including means for inverting the count rate as a measurement of the percentage of one of the substances of the composition.
Claim 3
Dependent Claim
23 words
The apparatus of claim 1 wherein the source means is substantially adjacent to but spaced from the area of sensitivity of the detector.
Claim 4
Dependent Claim
17 words
The apparatus of claim 2 wherein the source means is substantially centered on the area of sensitivity.
Claim 5
Dependent Claim
39 words
The apparatus of claim 3 wherein the source means is collimated by and sets in a recess in a lead holder in order to yield a bulk density minimum, said recess facing the sample which is rock coal dust.
Claim 6
Dependent Claim
25 words
The apparatus of claim 4 wherein the means for emanating radiation sits in the recess about 0.100 inches below the top of the lead holder.
Claim 7
Dependent Claim
32 words
The apparatus of claim 4 wherein the spacing of the source means, sample and detector means are arranged in order to reduce variations in the count rate due to density and humidity.
Claim 8
Dependent Claim
40 words
The apparatus of claim 6 wherein the distance between the source and sample is about 2 mm to 7.5 mm and the distance between the sample and area of sensitivity of the detector is about 10 mm to 15 mm.
Claim 9
Independent Claim
109 words
A method of quantitatively determining the composition of a sample having more than one substance comprising: irradiating the sample having an appropriate thickness to give accurate tests with radiation from a source spaced from the sample; deflecting radiation with the sample; detecting the deflected radiation in a given area with a radiation detector at a distance from the sample, the distances between the source, sample and detector being such that density and humidity in different samples do not cause a significant deviation in the amount of deflected radiation; measuring the reciprocal of the count rate as a measurement of the percentage of one of the substances of the composition.
Claim 10
Independent Claim
109 words
A method of quantitatively determining the composition of a sample having more than one substance comprising: irradiating the sample having an appropriate thickness to give accurate tests with radiation from a source spaced from the sample; deflecting radiation with the sample; detecting the deflected radiation in a given area with a radiation detector at a distance from the sample, the distances between the source, sample and detector being such that density and humidity in different samples do not cause a significant deviation in the amount of deflected radiation; measuring the reciprocal of the count rate as a measurement of the percentage of one of the substances of the composition.
Claim 11
Dependent Claim
35 words
The method of claim 8 wherein the sample is rock coal dust and the measuring of the reciprocal of the count rate is done by measuring the time necessary to reach a predetermined radiation count.
Claim 12
Dependent Claim
26 words
The method of claim 9 wherein the detecting of the radiation is done from a position on the opposite side of the source from the sample.
Claim 13
Dependent Claim
24 words
The method of claim 10 wherein the sample is about 2 inches thick to reduce differences in the count rate due to sample thickness.
Claim 14
Dependent Claim
36 words
The method of claim 11 wherein the radiation of the sample is done from the source located in the center of the detection area in order that the deflected radiation has a small angle of reflection.
Claim 15
Dependent Claim
40 words
The method of claim 12 wherein the distance of the source to the sample is a range of about 2 mm to 7.5 mm and the distance from the sample to the detector is about 10 mm to 15 mm.
Claim 16
Dependent Claim
21 words
The method of claim 13 wherein the radiation is directed by collimator to the sample and not to the detector directly.
Claim 17
Dependent Claim
98 words
The process of determining the percentage of incombustibles in rock coal dust comprising: radiating a sample of rock coal dust with gamma radiation from a radiation source spaced from the sample, the sample presenting a thickness of about 2 inches to the entering gamma rays in order to minimize any changes from thickness of the material; deflecting the gamma radiation with the sample; detecting the deflected gamma radiation entering the area centered about and behind the radiation source; measuring the time for detecting of a predetermined number of radiation counts as a measurement of the percentage of incombustibles.
Claim 18
Dependent Claim
98 words
The process of determining the percentage of incombustibles in rock coal dust comprising: radiating a sample of rock coal dust with gamma radiation from a radiation source spaced from the sample, the sample presenting a thickness of about 2 inches to the entering gamma rays in order to minimize any changes from thickness of the material; deflecting the gamma radiation with the sample; detecting the deflected gamma radiation entering the area centered about and behind the radiation source; measuring the time for detecting of a predetermined number of radiation counts as a measurement of the percentage of incombustibles.
Claim 19
Dependent Claim
22 words
The method of claim 15 wherein the process of claim 8 is a Amercium 241 having a strength of about 170 microcuries.
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) | 1976-05-21 | 1976-11-20 | 1977-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-21 | 1980-11-20 | 1981-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-21 | 1984-11-20 | 1985-05-22 | $7700.00 | Window Closed / Lapsed |