Standardization system for a digital radiation gauge

Claim 2

In a nucleonic material measuring system of the type that has means for establishing a nucleonic radiaTion path including a nucleonic source and detector unit, wherein the material moves through said path during a measuring time and then causes an output from the detector of pulses having rates of recurrence indicating weight per unit area of the moving material and wherein said material and source detector unit are relatively movable away from each other during a standardizing time so that none of said material is in said radiation path and said detector then provides an output of pulses having a standardizing pulse rate dependent on various factors including the amount of source decay and foreign matter between the source and detector, the improvement comprising: means operative during said standardizing time for counting said detector output pulses for a predetermined interval to provide a standardized digital count signal, and means operative during successive time periods for directly combining said digital count signal and said detector output pulses during said measuring time to provide a standardized indication of the measure of said material during each such period.

Claim 3

A system as in claim 1 and further including means for regulating the length of said successive time periods inversely in accordance with said standardized digital count signal.

Claim 4

A system as in claim 2 wherein said combining means includes second counting means responsive both to said digital count signal directly and to said output pulses during said measuring time, said means for regulating the length of the successive time periods including: gating means for resetting said second counting means at the end of each said time period, and means operative on said digital count signal for converting same to an inverted analog signal for controlling the said gating means as to the length of said successive time periods.

Claim 5

A system as in claim 2 wherein said combining means includes second counting means operative directly on said digital count signal and said detector outputs during a measuring time, and wherein said means for regulating the length of the successive time periods includes digital means operating on said digital count signal to start and stop said second counting means at intervals determined by the count represented by the digital counting signal.

Claim 6

A system as in claim 4 wherein said digital means includes; means for generating clock pulses third counting means for combining said digital count signal and said clock pulse, and counter control means for stopping said second and third counting means when the latter counts the number of clock pulses represented by said digital count signal and for thereafter restarting said second and third counting means.

Claim 7

In a nucleonic material measuring system of the type that has means for establishing a nucleonic radiation path including a nucleonic source and detector unit, wherein the material moves through said path during a measuring time and then causes an output from the detector of pulses having rates of recurrence indicating weight per unit area of the moving material and wherein said material and source detector unit are relatively movable away from each other during a standardizing time so that none of said material is in said radiation path and said detector then provides an output of pulses having a standardizing pulse rate dependent on various factors including the amount of source decay and foreign matter between the source and detector, the improvement comprising: means operative during said standardizing time for counting said detector output pulses for predetermined interval to provide a standardized digital count signal, and means for directly combining said digital count signal and said detector output pulses during a measuring time to provide a standardized indication of the measure of said material.

Claim 8

In a nucleonic material measuring system of the type that has means for establishing a nucleonic radiation path including a nucleonic source and detector unit, wherein the material moves through said path during a measuring time and then causes an output from the detector of pulses having rates of recurrence indicating weight per unit area of the moving material and wherein said material and source detector unit are relatively movable away from each other during a standardizing time so that none of said material is in said radiation path and said detector then provides an output of pulses having a standardizing pulse rate dependent on various factors including the amount of source decay and foreign matter between the source and detector, the improvement comprising: means operative during said standardizing time for counting said detector output pulses for predetermined interval to provide a standardized digital count signal, and means for directly combining said digital count signal and said detector output pulses during a measuring time to provide a standardized indication of the measure of said material.

Claim 9

A system as in claim 6 wherein said combining means includes a down counter which is set at a count represented by said digital count signal and which counts doWn the detector output pulses during measuring times to provide said standardized indication of the material measured.

Claim 10

In a nucleonic material measuring system of the type that has means for establishing a nucleonic radiation path including a nucleonic source and detector unit, wherein the material moves through said path to be measured and then causes an output from the detector of pulses having rates of recurrence indicating weight per unit area of the moving material and wherein said material and source detector unit are relatively movable away from each other during a standardizing time so that none of said material is in said radiation path and said detector then provides an output of pulses having a standardizing pulse rate dependent on various factors including the amount of source decay and foreign matter between the source and detector, the improvement comprising: means operative during said standardizing time for counting said detector output pulses for a predetermined interval to provide a standardized digital count signal, second counting means operative during successive time periods for counting the said detector output pulses during said measuring time, and means for modifying the length of said successive time periods inversely in accordance with said standardized digital count signal to provide from said second counting means a standardized indication of the measure of said material during each such time period, said modifying means including a digital-to-analog converter responsive only to said standardized digital count signal for producing an analog signal directly proportional thereto for controlling the length of said time periods.

Claim 11

In a nucleonic material measuring system of the type that has means for establishing a nucleonic radiation path including a nucleonic source and detector unit, wherein the material moves through said path to be measured and then causes an output from the detector of pulses having rates of recurrence indicating weight per unit area of the moving material and wherein said material and source detector unit are relatively movable away from each other during a standardizing time so that none of said material is in said radiation path and said detector then provides an output of pulses having a standardizing pulse rate dependent on various factors including the amount of source decay and foreign matter between the source and detector, the improvement comprising: means operative during said standardizing time for counting said detector output pulses for a predetermined interval to provide a standardized digital count signal, second counting means operative during successive time periods for counting the said detector output pulses during said measuring time, and means for modifying the length of said successive time periods inversely in accordance with said standardized digital count signal to provide from said second counting means a standardized indication of the measure of said material during each such time period, said modifying means including a digital-to-analog converter responsive only to said standardized digital count signal for producing an analog signal directly proportional thereto for controlling the length of said time periods.

Claim 12

In a nucleonic material measuring system of the type that has means for establishing a nucleonic radiation path including a nucleonic source and detector unit, wherein the material moves through said path to be measured and then causes an output from the detector of pulses having rates or recurrence indicating weight per unit area of the moving material and wherein said material and source detector unit are relatively movable away from each other during a standardizing time so that none of said material is in said radiation path and said detector then provides an output of pulses having a standardizing pulse rate dependent on various factors including the amount of source decay and foreign matter between the source and detector, the improvement comprising: means operative during said standardizing time for counting said detector output pulses for a predetermined interval to provide a standardized digital count signal, digital-analog conversion means responsive only to said standardized digital count for changing said digital count signal to a corresponding analog signal directly proportional thereto, second counting means, means for generating reference pulses, gating means for respectively resetting said second counting means at the end of successive time periods, said second counting means being operative during each of said successive time periods for combining said reference pulses and the detector output pulses during said measuring time, and means coupling said directly proportional analog signal from said conversion means to at least one of said generating and gating means to cause the said second counting means to provide a standardized indication of the measure of said material during each of the said successive time periods.

Claim 13

In a nucleonic material measuring system of the type that has means for establishing a nucleonic radiation path including a nucleonic source and detector unit, wherein the material moves through said path to be measured and then causes an output from the detector of pulses having rates or recurrence indicating weight per unit area of the moving material and wherein said material and source detector unit are relatively movable away from each other during a standardizing time so that none of said material is in said radiation path and said detector then provides an output of pulses having a standardizing pulse rate dependent on various factors including the amount of source decay and foreign matter between the source and detector, the improvement comprising: means operative during said standardizing time for counting said detector output pulses for a predetermined interval to provide a standardized digital count signal, digital-analog conversion means responsive only to said standardized digital count for changing said digital count signal to a corresponding analog signal directly proportional thereto, second counting means, means for generating reference pulses, gating means for respectively resetting said second counting means at the end of successive time periods, said second counting means being operative during each of said successive time periods for combining said reference pulses and the detector output pulses during said measuring time, and means coupling said directly proportional analog signal from said conversion means to at least one of said generating and gating means to cause the said second counting means to provide a standardized indication of the measure of said material during each of the said successive time periods.

Claim 14

A system as in claim 9 wherein said conversion means is coupled to both said generating means and gating means to cause the said reference pulses to be directly proportional to said standardized digital count signal and to cause the successive time periods effected by said gating means to be inversely proportional to that digital count signal.

Claim 15

A nucleonics radiation gauge comprising a source and radiation pulse detector whose measurement of a single physical variable depends upon the average count raTe of radiation pulses measured at said detector, said nucleonics radiation gauge further comprising: down counting means for counting output pulses from the radiation detector down from a preset count for a predetermined counting period, and means for modifying said preset count in accordance with changes in the radiation pulse rate caused by extraneous changes in variables other than the measured variable for causing the totalized count of pulses for each counting period to be at least substantially equal to the total pulses determined for a given value of the measured variable at the time of original radiation gauge calibration.

Claim 16

A nucleonics radiation gauge comprising a source and radiation pulse detector whose measurement of a single physical variable depends upon the average count raTe of radiation pulses measured at said detector, said nucleonics radiation gauge further comprising: down counting means for counting output pulses from the radiation detector down from a preset count for a predetermined counting period, and means for modifying said preset count in accordance with changes in the radiation pulse rate caused by extraneous changes in variables other than the measured variable for causing the totalized count of pulses for each counting period to be at least substantially equal to the total pulses determined for a given value of the measured variable at the time of original radiation gauge calibration.

Claim 17

A nucleonic device for measuring the density and/or the thickness of material, comprising: means for providing a nucleonic radiation path including a radiation source and a radiation detector, means for causing said material to be in said path during measurement thereof and out of said path at other times, means for counting down from a preset count a total of pulses related to the radiation reaching the detector from the material during each predetermined counting period, and means for modifying the count down in accordance with the detected radiation when the material is out of the path to cause the resulting count to be substantially the same each counting period for a given measurement of said material regardless of the amount of radiation then detected, the detected radiation being dependent on various factors including the amount of source decay and the amount of foreign matter between the source and the detector.

Claim 18

A nucleonic device for measuring the density and/or the thickness of material, comprising: means for providing a nucleonic radiation path including a radiation source and a radiation detector, means for causing said material to be in said path during measurement thereof and out of said path at other times, means for counting down from a preset count a total of pulses related to the radiation reaching the detector from the material during each predetermined counting period, and means for modifying the count down in accordance with the detected radiation when the material is out of the path to cause the resulting count to be substantially the same each counting period for a given measurement of said material regardless of the amount of radiation then detected, the detected radiation being dependent on various factors including the amount of source decay and the amount of foreign matter between the source and the detector.

Claim 19

A device according to claim 12 wherein said modifying means is effective to modify said count down by modifying the said preset count in accordance with changes in the radiation detected at a later time while the material is out of the path.

Claim 20

A device according to claim 13 in which the time of said counting period is also varied by said modifying means to modify the said count down.

Claim 21

In a nucleonic measuring system in which a property such as thickness or density of a material is measured by subjecting the measured material to radiation from a nucleonic radiation source and by detecting the resulting radiation received at a radiation pulse detector after said radiation has interacted with the said measured material, said material being removable from said source and detector at predetermined times in order to determine the radiation received at said detector for the condition in which the measured material no longer interacts with the radiation and in which the detected radiation pulse rate depends only on nonmaterial factors such as foreign material between the source and detector and the source strength existing at a given time, means operative during successive counting periods for counting pulses issuing from the radiation pulse detector down from a preset count so as to provide an output reading of the measured characteristic in terms of the number of pulses received by the detector during each counting period, and means for determining the required length of said counting periods and for changing the said length thereof in accordance with said radiation received when said measured material no longer interacts therewith and in such a manner that the remaining count in said counting means at the end of each counting period is substantially equal to the count therein for a respective value of measured characteristic determined during the original calibration of the measuring system.

Claim 22

In a nucleonic measuring system in which a property such as thickness or density of a material is measured by subjecting the measured material to radiation from a nucleonic radiation source and by detecting the resulting radiation received at a radiation pulse detector after said radiation has interacted with the said measured material, said material being removable from said source and detector at predetermined times in order to determine the radiation received at said detector for the condition in which the measured material no longer interacts with the radiation and in which the detected radiation pulse rate depends only on nonmaterial factors such as foreign material between the source and detector and the source strength existing at a given time, means operative during successive counting periods for counting pulses issuing from the radiation pulse detector down from a preset count so as to provide an output reading of the measured characteristic in terms of the number of pulses received by the detector during each counting period, and means for determining the required length of said counting periods and for changing the said length thereof in accordance with said radiation received when said measured material no longer interacts therewith and in such a manner that the remaining count in said counting means at the end of each counting period is substantially equal to the count therein for a respective value of measured characteristic determined during the original calibration of the measuring system.

Claim 23

Apparatus as in claim 15 wherein the said means for determining the necessary length of said counting periods includes time gating means for periodically resetting the preset count in said counting means and means for increasing the length of the said counting periods as the detected radiation pulse rate decreases due to nonmaterial characteristics such as foreign material between the source and detector, changes in source strength, and changes in efficieNcy of the radiation pulse detector.

Claim 24

A nucleonic material measuring system of the type comprising means for establishing a nucleonic radiation path including a nucleonic source and detector unit, wherein the material moves through said path during a measuring time and then causes an output from the detector of pulses having rates of recurrence indicating weight per unit area of the moving material and wherein said material and source detector unit are relatively movable away from each other during a standardizing time so that none of said material is in said radiation path and said detector then provides an output of pulses having a standardizing pulse rate dependent on various factors including the amount of source decay and foreign matter between the source and detector, the improvement comprising: means operative for counting said detector output pulses for a predetermined interval within said standardizing time to derive an indication of a standardized digital count and for directly combining said digital count with said detector output pulses during said measuring time to provide a standardized indication of the measure of said material.

Claim 25

A nucleonic material measuring system of the type comprising means for establishing a nucleonic radiation path including a nucleonic source and detector unit, wherein the material moves through said path during a measuring time and then causes an output from the detector of pulses having rates of recurrence indicating weight per unit area of the moving material and wherein said material and source detector unit are relatively movable away from each other during a standardizing time so that none of said material is in said radiation path and said detector then provides an output of pulses having a standardizing pulse rate dependent on various factors including the amount of source decay and foreign matter between the source and detector, the improvement comprising: means operative for counting said detector output pulses for a predetermined interval within said standardizing time to derive an indication of a standardized digital count and for directly combining said digital count with said detector output pulses during said measuring time to provide a standardized indication of the measure of said material.