US3794843A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gauge for determining the percentage by weight of moisture contained in a bulk material transported on a moving conveyor
Assignee: Ohmart Corp
•
Filing: 1972-12-29
•
Granted: 1974-02-26
•
Expires: 1992-12-29
Abstract
Abstract A moisture gauge including a radiation source for irradiating with fast neutrons and gamma radiation a bulk substance having moisture contained therein, a detector responsive to gamma radiation which has interacted with a predetermined fractional cross-sectional area of the bulk substance to produce a first electrical signal correlated to the total weight of the bulk substance including contained moisture, and a detector which is responsive to slow neutrons generated by the interaction of fast neutrons and hydrogen atoms of the contained moisture in said predetermined fractional cross-sectional area to produce a second electrical signal correlated to the weight of the moisture contained in the bulk substance. An electrical circuit divides the moisture weight signal and total weight signal to provide an output correlated to the percent by weight of moisture contained in the bulk material. An alternative embodiment of the invention is disclosed which is particularly adapted to provide accurate measurements of the weight percentage moisture of bulk substances containing a relatively high degree of moisture and/or other bulk substances, such as iron or sodium chloride, having a relatively large thermal neutron reaction cross-section. This embodiment includes a first detector responsive to gamma radiation which has been transmitted through a predetermined fractional cross-sectional area of the bulk substance to produce a first electrical signal correlated to the total weight of the bulk substance, including contained moisture, and a second detector which responds to fast neutrons transmitted through the bulk substance in the predetermined fractional cross-sectional area to produce a second electrical signal correlated to the weight of the moisture contained in the bulk substance. These signals are then mathematically processed to provide an output correlated to the percentage by weight of moisture contained in the bulk material, which output is highly accurate notwithstanding the fact that the bulk substance has relatively high moisture content and/or contains material having a relatively large thermal neutron reaction cross-section.
Inventors
- 👤 Y Chen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 03:25
CPC Classifications
G; G01; G01N; G01N23/00; G01N23/02; G01N23/06; G01N23/09; G01N23/12
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
157 words
A gauge for determining the weight percentage moisture in a bulk substance transported in a longitudinal direction on a moving conveyor, which bulk material has a relatively large thermal neutron reaction cross-section, said gauge comprising: a source of fast neutrons for directing fast neutrons into said bulk substance transported thereby, a source of gamma radiation for directing gamma radiation into said bulk substance transported thereby, a detector for detecting fast neutrons transmitted through a first cross-sectional area of said bulk substance and producing a first electrical signal correlated thereto, and for detecting gamma radiation emanating from a second cross-sectional area of the bulk substance and producing a second electrical signal correlated thereto, and a signal processing circuit for processing said first and second signals to produce an output correlated to the weight percentage moisture in said bulk substance, which is substantially free of errors due to the relatively large thermal neutron reaction cross-section of said bulk substance.
Claim 2
Dependent Claim
157 words
A gauge for determining the weight percentage moisture in a bulk substance transported in a longitudinal direction on a moving conveyor, which bulk material has a relatively large thermal neutron reaction cross-section, said gauge comprising: a source of fast neutrons for directing fast neutrons into said bulk substance transported thereby, a source of gamma radiation for directing gamma radiation into said bulk substance transported thereby, a detector for detecting fast neutrons transmitted through a first cross-sectional area of said bulk substance and producing a first electrical signal correlated thereto, and for detecting gamma radiation emanating from a second cross-sectional area of the bulk substance and producing a second electrical signal correlated thereto, and a signal processing circuit for processing said first and second signals to produce an output correlated to the weight percentage moisture in said bulk substance, which is substantially free of errors due to the relatively large thermal neutron reaction cross-section of said bulk substance.
Claim 3
Dependent Claim
218 words
A gauge for determining the weight percentage moisture in a bulk substance transported in a longitudinal direction on a moving hydrogenous conveyor having a width perpendicular to the direction of conveyor movement, said bulk substance having a relatively large thermal neutron reaction cross-section, said gauge comprising: a source of fast neutrons for directing fast neutrons through substantially less than the entire width of said hydrogenous belt and bulk substance transported thereby, a source of gamma radiation for directing gamma radiation through substantially less than the entire width of said hydrogenous belt and bulk substance transported thereby, the energy of said fast neutrons and the belt width irradiated being selected to irradiate a cross-sectional area of said bulk substance substantially equal in cross-sectional area to the cross-sectional area of said bulk material irradiated by said gamma source, a detector for detecting fast neutrons transmitted through said bulk material and producing a first electrical signal correlated thereto, and for detecting gamma radiation transmitted through said bulk material and generating a second electrical signal correlated thereto, and a signal processing circuit for processing said first and second signals to produce an output related to the weight percentage moisture in said bulk substance, which is substantially free of errors due to the relatively large thermal neutron reaction cross-section of said bulk substance.
Claim 4
Dependent Claim
218 words
A gauge for determining the weight percentage moisture in a bulk substance transported in a longitudinal direction on a moving hydrogenous conveyor having a width perpendicular to the direction of conveyor movement, said bulk substance having a relatively large thermal neutron reaction cross-section, said gauge comprising: a source of fast neutrons for directing fast neutrons through substantially less than the entire width of said hydrogenous belt and bulk substance transported thereby, a source of gamma radiation for directing gamma radiation through substantially less than the entire width of said hydrogenous belt and bulk substance transported thereby, the energy of said fast neutrons and the belt width irradiated being selected to irradiate a cross-sectional area of said bulk substance substantially equal in cross-sectional area to the cross-sectional area of said bulk material irradiated by said gamma source, a detector for detecting fast neutrons transmitted through said bulk material and producing a first electrical signal correlated thereto, and for detecting gamma radiation transmitted through said bulk material and generating a second electrical signal correlated thereto, and a signal processing circuit for processing said first and second signals to produce an output related to the weight percentage moisture in said bulk substance, which is substantially free of errors due to the relatively large thermal neutron reaction cross-section of said bulk substance.
Claim 5
Dependent Claim
194 words
A gauge for determining the weight percentage moisture in a bulk substance transported on a longitudinal direction on a moving hydrogenous conveyor having a width perpendicular to the direction of conveyor movement, said bulk substance having a relatively large thermal neutron scatter cross-section, said gauge comprising: a source of fast neutrons for directing fast neutrons through said belt and bulk substance transported thereby, a source of gamma radiation for directing gamma radiation through said belt and bulk substance transported thereby, a detector for detecting fast neutrons transmitted through a first cross-sectional area of said bulk substance and producing a first electrical signal correlated thereto, and for detecting gamma radiation emanating from a second cross-sectional area of said bulk substance and producing a second electrical signal correlated thereto, said first and second cross-sectional areas being substantially equal and being substantially less than the entire cross-sectional area of said bulk substance, and a signal processing circuit for processing said first and second signals to produce an output related to the weight percentage moisture in said bulk substance, which is substantially free of errors due to the relatively large thermal neutron scatter cross-section of said bulk substance.
Claim 6
Dependent Claim
194 words
A gauge for determining the weight percentage moisture in a bulk substance transported on a longitudinal direction on a moving hydrogenous conveyor having a width perpendicular to the direction of conveyor movement, said bulk substance having a relatively large thermal neutron scatter cross-section, said gauge comprising: a source of fast neutrons for directing fast neutrons through said belt and bulk substance transported thereby, a source of gamma radiation for directing gamma radiation through said belt and bulk substance transported thereby, a detector for detecting fast neutrons transmitted through a first cross-sectional area of said bulk substance and producing a first electrical signal correlated thereto, and for detecting gamma radiation emanating from a second cross-sectional area of said bulk substance and producing a second electrical signal correlated thereto, said first and second cross-sectional areas being substantially equal and being substantially less than the entire cross-sectional area of said bulk substance, and a signal processing circuit for processing said first and second signals to produce an output related to the weight percentage moisture in said bulk substance, which is substantially free of errors due to the relatively large thermal neutron scatter cross-section of said bulk substance.
Claim 7
Dependent Claim
96 words
The gauge of claim 1 wherein said gamma detector is elongated and disposed transversely relative to said belt, and wherein said fast neutron detector is elongated and disposed transversely of said belt, and wherein said fast neutron detector includes a slow neutron detecting tube, a slow neutron blocking filter between said tube and said belt for selectively passing fast neutrons, and a fast neutron thermalizing material between said tube and said filter to thermalize fast neutrons transmitted through said bulk substance from said fast neutron source to facilitate detection thereof by said slow neutron detecting tube.
Claim 8
Dependent Claim
60 words
The gauge of claim 5 wherein said slow neutron detecting tube is between said belt and said gamma detector, and further including a gamma transmitting and fast neutron reflecting material between said slow neutron detecting tube and said gamma detector for reflecting fast neutrons to said thermalizing material to increase the fast neutron detection efficiency of said fast neutron detector.
Claim 9
Independent Claim
128 words
A method of detecting weight percent moisture in a bulk substance having a relatively large thermal neutron reaction cross-section comprising the steps of: transporting said bulk substance on a conveyor, irradiating said bulk substance with gamma radiation, transmitting fast neutrons through said bulk substance, detecting fast neutrons transmitted through said bulk substance to produce a first electrical signal correlated to the moisture content of said bulk substance, detecting gamma radiation emanating from said bulk substance to produce a second electrical signal correlated to the total weight of said bulk substance, and mathematically processing said signals to produce an output correlated to the weight percentage moisture of said bulk substance which is substantially free of errors due to the relatively large thermal neutron reaction cross-section of said bulk substance.
Claim 10
Independent Claim
128 words
A method of detecting weight percent moisture in a bulk substance having a relatively large thermal neutron reaction cross-section comprising the steps of: transporting said bulk substance on a conveyor, irradiating said bulk substance with gamma radiation, transmitting fast neutrons through said bulk substance, detecting fast neutrons transmitted through said bulk substance to produce a first electrical signal correlated to the moisture content of said bulk substance, detecting gamma radiation emanating from said bulk substance to produce a second electrical signal correlated to the total weight of said bulk substance, and mathematically processing said signals to produce an output correlated to the weight percentage moisture of said bulk substance which is substantially free of errors due to the relatively large thermal neutron reaction cross-section of said bulk substance.
Claim 11
Dependent Claim
29 words
The method of claim 6 wherein said bulk material has a thermal neutron reaction cross-section approximately equivalent to 5-7 inches of wood chips at 50 percent by weight moisture.
Claim 12
Dependent Claim
29 words
The method of claim 6 wherein said bulk material has a thermal neutron reaction cross-section approximately equivalent to 4-5 inches of sinter mix at 15 percent by weight moisture.
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) | 1977-02-25 | 1977-08-27 | 1978-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-25 | 1981-08-27 | 1982-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-25 | 1985-08-27 | 1986-02-26 | $7700.00 | Window Closed / Lapsed |