JPS61175553A - Measurement for density of material - Google Patents
Measurement for density of materialInfo
- Publication number
- JPS61175553A JPS61175553A JP60015468A JP1546885A JPS61175553A JP S61175553 A JPS61175553 A JP S61175553A JP 60015468 A JP60015468 A JP 60015468A JP 1546885 A JP1546885 A JP 1546885A JP S61175553 A JPS61175553 A JP S61175553A
- Authority
- JP
- Japan
- Prior art keywords
- photon absorption
- density
- measured
- absorption coefficient
- substance
- 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.)
- Pending
Links
- 238000005259 measurement Methods 0.000 title claims description 14
- 239000000463 material Substances 0.000 title abstract description 11
- 238000010521 absorption reaction Methods 0.000 claims abstract description 39
- 230000005540 biological transmission Effects 0.000 claims abstract description 3
- 239000000126 substance Substances 0.000 claims description 34
- 238000000034 method Methods 0.000 claims description 10
- 238000002591 computed tomography Methods 0.000 claims description 2
- 238000001739 density measurement Methods 0.000 description 4
- 230000005855 radiation Effects 0.000 description 2
- 230000001419 dependent effect Effects 0.000 description 1
- 230000001066 destructive effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005251 gamma ray Effects 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 238000003325 tomography Methods 0.000 description 1
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
- G01N23/02—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 transmitting the radiation through the material
- G01N23/04—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 transmitting the radiation through the material and forming images of the material
- G01N23/046—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 transmitting the radiation through the material and forming images of the material using tomography, e.g. computed tomography [CT]
-
- 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
- G01N2223/40—Imaging
- G01N2223/419—Imaging computed tomograph
Landscapes
- Health & Medical Sciences (AREA)
- Engineering & Computer Science (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Pulmonology (AREA)
- Radiology & Medical Imaging (AREA)
- Theoretical Computer Science (AREA)
- Physics & Mathematics (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)
- Apparatus For Radiation Diagnosis (AREA)
Abstract
Description
【発明の詳細な説明】
〔発明の技術分野〕
本発明は非破壊で物質の密度を測定する密度測定法に係
り、特に不均質物質の密度を高精度で測定することがで
きる物質の密度測定法に関する。[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a density measurement method for non-destructively measuring the density of a substance, and particularly to a density measurement method of a substance that can measure the density of a heterogeneous substance with high precision. Regarding the law.
従来物質の密度を測定する場合には、測定対象物の重８
と体積とを測定し、これらの測定データに基づいて密度
算出するのが一般的である。Conventionally, when measuring the density of a substance, the weight of the object to be measured is 8
It is common to measure the volume and the density and calculate the density based on these measurement data.
しかし、このような従来の密度測定法においては、重り
測定時に測定対象物が単体で存在しな（プればならず、
また体積測定時には測定対象物の外殻が明確に現われて
いる必要があるため、測定対象物が容器、特に不透明な
容器に収納されている場合には、非破壊で密度測定する
ことが困難である。However, in such conventional density measurement methods, the object to be measured does not exist alone when measuring the weight.
In addition, when measuring volume, the outer shell of the object to be measured must be clearly visible, so if the object to be measured is stored in a container, especially an opaque container, it is difficult to measure density non-destructively. be.
なお、最近では測定対象物の全体に亘って放射線を照射
し、測定対象物透過後の放射線強度を測定して、その測
定対象物の体積を求める方法が考えられている。このよ
うな方法を利用ずれば測定対象物が不透明な容器に収納
された状態でも、ずなわち、非破壊状態でもその測定対
象物の体積を求めることができる。したがって、容器収
納前の測定対象物の重量を予め知ることができる場合に
は、非破壊で測定対免物全体の平均密度を測定すること
が可能である。Recently, a method has been considered in which the volume of the object is determined by irradiating the entire object with radiation and measuring the intensity of the radiation after passing through the object. By using such a method, the volume of the object to be measured can be determined even when the object is housed in an opaque container, that is, even in a non-destructive state. Therefore, if the weight of the object to be measured before being stored in the container can be known in advance, it is possible to non-destructively measure the average density of the entire object to be measured.
ところで、近時各種の分野で物質の高精度の密度測定が
要望されている。すなわち、測定対象物に不均質物質が
内在していたり、測定対象物の密度が位置によって異な
っている場合において、その特定の物質の密度のみを正
確に求めようとする場合等である。Incidentally, there has recently been a demand for highly accurate density measurement of substances in various fields. That is, when the object to be measured contains a heterogeneous substance or the density of the object to be measured differs depending on the position, it is necessary to accurately determine the density of only that particular substance.
前記従来の測定方法では、少なくとも全体の宙吊と体積
とを測定することが前提条件となっており、その測定対
象物仝休の平均密度を算出するようにしているため、そ
の測定対Φ物を構成する特定の物質のみを抽出して密度
測定を行なうこ、とはできないものである。In the conventional measurement method described above, it is a prerequisite to measure at least the overall suspension and volume, and the average density of the object to be measured is calculated. It is not possible to extract and measure the density of only the specific substances that make up the material.
〔発明の目的］
本発明はこのような事情に鑑みてなされたもので、測定
対象物が容器に収納されたり、その測定対象物の内部に
不均質箇所がある場合でも、非破壊でその測定対象物の
特定の物質の密度測定を高精度で行なうことができる物
質の密度測定法を提供することを目的とづる。[Object of the Invention] The present invention has been made in view of the above circumstances, and it is possible to measure the object non-destructively even when the object to be measured is stored in a container or there are non-uniform parts inside the object. The purpose of this invention is to provide a method for measuring the density of a substance that can measure the density of a specific substance in an object with high accuracy.
上記の目的を達成するために、本発明に係る物質の密度
測定法では、外部光子源を有する透過型コンピュータ断
層囮影装首により測定対象物の任意断層面における光子
吸収係数の２次元分布測定を行ない、その測定データに
基づいて各光子吸収係数の頻度分布を調べ、その頻度分
布から測定対象物の光子吸収係数近傍の一群の係数中の
最大頻度の光子吸収係数値を選定し、その測定対象物の
光子吸収係数と密度との関係式を用いて選定された光子
吸収係数値からその測定対象物の密度を求めることを特
徴としている。In order to achieve the above object, the method for measuring the density of a substance according to the present invention measures the two-dimensional distribution of photon absorption coefficients on an arbitrary tomographic plane of a measurement object using a transmission-type computerized tomography decoy head equipped with an external photon source. , examine the frequency distribution of each photon absorption coefficient based on the measurement data, select the photon absorption coefficient value with the highest frequency among a group of coefficients near the photon absorption coefficient of the measurement object from the frequency distribution, and measure it. The method is characterized in that the density of the object to be measured is determined from the photon absorption coefficient value selected using the relational expression between the photon absorption coefficient and the density of the object.
（発明の実施例〕 以下、本発明の一実施例を図面を参照して説明する。(Embodiments of the invention) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.
第１図は測定対象物を模式的に示すものである。FIG. 1 schematically shows the object to be measured.
容器１に収納された物質２の内部に不均質な物質（例え
ば空気あるいは異物）３が混在している。A heterogeneous substance 3 (for example, air or foreign matter) is mixed inside a substance 2 housed in a container 1.
このような測定対象物に対し、外部光子源を有寸る透過
型コンピュータ断層Ｉｆυ影装置により、任意断層面に
おける光子吸収係数の２次元分布測定を行なう。使用す
る光子は例えばγ線である。また、γ線の走査数は９０
Ｘ９０と１゛る。そして、これにより得られた測定デー
タに基づいて光子吸収係数の頻度分布を調べる。For such a measurement object, a two-dimensional distribution of photon absorption coefficients on an arbitrary tomographic plane is measured using a transmission type computer tomography Ifυ imager equipped with an external photon source. The photons used are, for example, gamma rays. In addition, the number of gamma ray scans is 90
There is one with X90. Then, the frequency distribution of photon absorption coefficients is investigated based on the measurement data obtained thereby.
第２図はこのようにして求めた光子吸収係数の頻度分布
をグラフ化したものである。図において横軸は光子吸収
係数（相対値）を示し、縦軸は頻度を示ず。図から明ら
かなように、測定対象である物質２の光子吸収係数相対
値がほぼ１５０近傍で最大となるピーク状の分布が表わ
れている。FIG. 2 is a graph of the frequency distribution of photon absorption coefficients obtained in this manner. In the figure, the horizontal axis shows the photon absorption coefficient (relative value), and the vertical axis does not show the frequency. As is clear from the figure, a peak-like distribution appears in which the relative value of the photon absorption coefficient of the substance 2 to be measured reaches a maximum near approximately 150.
そこで、この最大頻度の光子吸収係数値を物質２の光子
吸収係数として設定し、下記の光子吸収係数と密度との
関係式を用いて物質２の密度を求める。Therefore, this maximum frequency photon absorption coefficient value is set as the photon absorption coefficient of substance 2, and the density of substance 2 is determined using the following relational expression between photon absorption coefficient and density.
すなわち、上記のようにして求められた光子吸収係数は
線吸収係数であり、これをμとおくと、μは一般に次式
で表わされる。That is, the photon absorption coefficient determined as described above is a linear absorption coefficient, and when this is denoted by μ, μ is generally expressed by the following equation.
値であるが、その値は物質成分が変化してもそれほど変
化しない。また測定対象物の内容物の組成の成分がある
程度既知であれば、十分良いＶ；度で理論的に評価可能
である。However, the value does not change much even if the material components change. Further, if the composition of the contents of the object to be measured is known to some extent, it can be theoretically evaluated with a sufficiently good V; degree.
そこで、前記測定データにより最大光子吸収係数μが知
られていることから、上記式を変換してによりρを求め
れば物質２の密度を得ることかできる。Therefore, since the maximum photon absorption coefficient μ is known from the measurement data, the density of the substance 2 can be obtained by converting the above equation and calculating ρ.
以上のように光子吸収係数は、測定対象物境界外の物質
（例えば空気）、容器、求める物質、その物質中に含ま
れる不均質物質（例えば空気、異物）に対応する吸収係
数値を示しているため、頻度分布を作成すると、それら
の吸収係数値を中心とする一定の分布形状が求められる
。そこで、求める物質の光子吸収係数近傍における最大
頻度の光子吸収係数を測定データにより得ればその値が
物質の光子吸収係数となるので、その光子吸収係数に密
度との関係式を用いて、その求める物質の密度を知るこ
とができるのである。As described above, the photon absorption coefficient indicates the absorption coefficient value corresponding to a substance outside the boundary of the measurement object (e.g. air), a container, the substance to be measured, and a heterogeneous substance contained in the substance (e.g. air, foreign matter). Therefore, when a frequency distribution is created, a certain distribution shape centered around these absorption coefficient values is obtained. Therefore, if the photon absorption coefficient with the highest frequency in the vicinity of the photon absorption coefficient of the desired substance is obtained from measurement data, that value becomes the photon absorption coefficient of the substance. This allows us to know the density of the desired substance.
したがって、最大頻度の光子吸収係数を求めることによ
り、測定対象物中に存在する不均質物質の光子吸収係数
を分離して、その彩管を受けることなく、求める物質の
光子吸収係数を高精度で測定し、その結果特定の物質の
みの密度を非破壊で、かつ高精度で測定することができ
る。Therefore, by determining the photon absorption coefficient of the maximum frequency, the photon absorption coefficient of the heterogeneous material present in the object to be measured can be separated, and the photon absorption coefficient of the desired material can be determined with high precision without receiving the chromatic tube. As a result, the density of only a specific substance can be measured non-destructively and with high precision.
なお、前記実施例では、測定対象とする物質を単一の物
質２について実施した場合を沃明したが、本発明によれ
ば、求める物質が２以上ある場合でも（れぞれの密度を
測定する場合について適用することができる。In the above embodiment, the measurement was performed on a single substance 2, but according to the present invention, even when there are two or more substances to be measured (the density of each substance can be measured) It can be applied in cases where
以上のように、本発明に係る物質の密度測定法によれば
、測定対象物の重はまたは体積等を測定する必要なく、
密度を光子吸収係数の関数によって表現することができ
るので、測定対象物の外形状態にとられれることなく、
非破壊で、しかも不均質物質が含まれているようなもの
であっても、特定の物質の密度のみについても測定が高
精度で確実に行なえるようになる。As described above, according to the method for measuring the density of substances according to the present invention, there is no need to measure the weight or volume of the object to be measured.
Since the density can be expressed as a function of the photon absorption coefficient, it is not dependent on the external shape of the object to be measured.
The density of a specific substance can be measured non-destructively and reliably with high precision, even if it contains heterogeneous substances.
第１図は本発明の一実施例を示す測定対象物の模式図、
第２図は光子吸収係数の預度分布を示すグラフである。
１・・・容器、２・・・測定用の物質、３・・・不均質
物質。FIG. 1 is a schematic diagram of an object to be measured showing an embodiment of the present invention;
FIG. 2 is a graph showing the distribution of photon absorption coefficients. 1... Container, 2... Substance for measurement, 3... Heterogeneous substance.
Claims (1)
より測定対象物の任意断層面における光子吸収係数の２
次元分布測定を行ない、その測定データに基づいて各光
子吸収係数の頻度分布を調べ、その頻度分布から測定対
象物の光子吸収係数近傍の一群の係数中の最大頻度の光
子吸収係数値を選定し、その測定対象物の光子吸収係数
と密度との関係式を用いて選定した光子吸収係数値から
その測定対象物の密度を求めることを特徴とする物質の
密度測定法。2 of the photon absorption coefficient in an arbitrary tomographic plane of the measurement object using a transmission computed tomography system with an external photon source.
Measure the dimensional distribution, examine the frequency distribution of each photon absorption coefficient based on the measured data, and select the photon absorption coefficient value with the highest frequency among a group of coefficients near the photon absorption coefficient of the measurement target from the frequency distribution. A method for measuring the density of a substance, characterized in that the density of the object to be measured is determined from a photon absorption coefficient value selected using a relational expression between the photon absorption coefficient and the density of the object to be measured.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60015468A JPS61175553A (en) | 1985-01-31 | 1985-01-31 | Measurement for density of material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60015468A JPS61175553A (en) | 1985-01-31 | 1985-01-31 | Measurement for density of material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS61175553A true JPS61175553A (en) | 1986-08-07 |
Family
ID=11889628
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60015468A Pending JPS61175553A (en) | 1985-01-31 | 1985-01-31 | Measurement for density of material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61175553A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4864593A (en) * | 1987-11-24 | 1989-09-05 | North American Philips Corporation | Method of measuring plasma densities and temperatures |
| JP2006084467A (en) * | 2004-09-14 | 2006-03-30 | Hitachi Ltd | Method and apparatus for implementing computed tomography |
| WO2019077857A1 (en) * | 2017-10-20 | 2019-04-25 | 国立大学法人千葉大学 | Tomography apparatus |
| WO2020217979A1 (en) * | 2019-04-24 | 2020-10-29 | 国立大学法人千葉大学 | Reflection-type tomography device |
-
1985
- 1985-01-31 JP JP60015468A patent/JPS61175553A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4864593A (en) * | 1987-11-24 | 1989-09-05 | North American Philips Corporation | Method of measuring plasma densities and temperatures |
| JP2006084467A (en) * | 2004-09-14 | 2006-03-30 | Hitachi Ltd | Method and apparatus for implementing computed tomography |
| JP4732843B2 (en) * | 2004-09-14 | 2011-07-27 | 株式会社日立製作所 | Method and apparatus for performing computed tomography |
| WO2019077857A1 (en) * | 2017-10-20 | 2019-04-25 | 国立大学法人千葉大学 | Tomography apparatus |
| JPWO2019077857A1 (en) * | 2017-10-20 | 2020-11-05 | 国立大学法人千葉大学 | Computed tomography equipment |
| WO2020217979A1 (en) * | 2019-04-24 | 2020-10-29 | 国立大学法人千葉大学 | Reflection-type tomography device |
| JP2020180816A (en) * | 2019-04-24 | 2020-11-05 | 国立大学法人千葉大学 | Reflection type tomographic apparatus |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR102075828B1 (en) | X-ray unit, data processing unit and data processing method | |
| KR102252847B1 (en) | X-ray device, X-ray inspection method, data processing device, data processing method, and computer program | |
| US7813470B2 (en) | Three-dimensional contents determination method using transmitted x-ray | |
| CN106466188B (en) | System and method for emission tomography quantification | |
| US7697657B2 (en) | System and method of density and effective atomic number imaging | |
| JPH01202685A (en) | Measurement of x rays energy | |
| CN106353828B (en) | The method and apparatus that checked property body weight is estimated in safe examination system | |
| US4766319A (en) | Portable nuclear moisture-density gauge with low activity nuclear sources | |
| JPS6282942A (en) | Phantom for inspecting quality of bone and ct scanner and scanning method utilizing the same | |
| US20060034418A1 (en) | Tomography appliance, and method for a tomography appliance | |
| US5959300A (en) | Attenuation correction in a medical imaging system using computed path lengths and attenuation values of a model attenuation medium | |
| US9330493B2 (en) | Method for generating a 3D representation of an object | |
| JPS61175553A (en) | Measurement for density of material | |
| CN108065950A (en) | A kind of radiological imaging method and its system | |
| CA1164580A (en) | Compton scatter diagnostic apparatus for determining structures in a body | |
| WO1992006636A1 (en) | Three-dimensional tomographic system | |
| CN112603347A (en) | Novel CT dose die body and detection method thereof | |
| JPH08304309A (en) | Method for forming distribution diagram for radiation dose of material body after correction for attenuation caused by material body thereof | |
| Rapaport et al. | Application of gamma ray computed tomography to nondestructive testing | |
| JPS6170444A (en) | Concentration analyzing method in electron ray micro-analysis instrument | |
| CN214434256U (en) | Novel CT dose die body | |
| Scanavini et al. | Computed tomography | |
| SU989952A1 (en) | Method of nondestructive quality control of articles | |
| JPH039011Y2 (en) | ||
| JPH01153141A (en) | Method for taking monochromatic x-ray image |