WO1981001198A1 - Device allowing the detection in solids,liquids or gases,of the metal particles included,the location thereof and the determination of their size - Google Patents

Device allowing the detection in solids,liquids or gases,of the metal particles included,the location thereof and the determination of their size Download PDF

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Publication number
WO1981001198A1
WO1981001198A1 PCT/FR1980/000057 FR8000057W WO8101198A1 WO 1981001198 A1 WO1981001198 A1 WO 1981001198A1 FR 8000057 W FR8000057 W FR 8000057W WO 8101198 A1 WO8101198 A1 WO 8101198A1
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WO
WIPO (PCT)
Prior art keywords
transmitter
receiver
size
detection
location
Prior art date
Application number
PCT/FR1980/000057
Other languages
French (fr)
Inventor
J Clausin
Original Assignee
J Clausin
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by J Clausin filed Critical J Clausin
Priority to BR8008878A priority Critical patent/BR8008878A/en
Publication of WO1981001198A1 publication Critical patent/WO1981001198A1/en
Priority to DK275081A priority patent/DK275081A/en

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V3/00—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation
    • G01V3/08—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices
    • G01V3/10—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices using induction coils
    • G01V3/104—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices using induction coils using several coupled or uncoupled coils
    • G01V3/105—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices using induction coils using several coupled or uncoupled coils forming directly coupled primary and secondary coils or loops
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/72—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables

Definitions

  • Device for detecting liquids or gases in solids including metallic particles, locating them and determining their size.
  • the present invention relates to metal particle detectors included in bodies that are not very conductive of electricity, for example, metal inclusions that can be contained in wooden logs and the presence of which is very damaging to saws, or weapons hidden by people frequenting public places or luxury goods stores.
  • this detection is carried out by measuring the variation in impedance of a flat cylindrical coil crossed in its middle by the object or the person to be checked, and excited by sinusoidal alternating current.
  • the device according to the invention in addition to the detection of electrically conductive or magnetic objects, locates them and indicates their size. It is also not sensitive to radio interference.
  • the device, object of the invention comprises two detection units each consisting of a flat quadrangular coil, radiating an electromagnetic field of well-defined frequency, and called later emitting rement, in the axis of which is placed a collector coil of the emitted magnetic field provided or not with a ferromagnetic focusing core and whose axis is simultaneously perpendicular to the emitting axis and parallel to the direction of movement of the object, and later called receiver.
  • the receiver In the absence of any body conducting electricity or magnetic permeability different from that of vacuum, the receiver does not receive any magnetic flux, so there appears no voltage across its terminals.
  • the device according to the invention has the advantage of providing a computable signal, the morphology of which depends on the distance separating the object from the plane of the transmitter and its electromagnetic mass.
  • a digital computer of known technology therefore provides these two pieces of information, distance to the plane of the transmitter and size.
  • a second identical unit using a different frequency to avoid the influence of mutual parasitic radiation, is arranged similarly on the path of the object, but angularly offset by 90o. It therefore provides the elements for determining the distance Z from the object to the transmitter and the electromagnetic size.
  • the size of the object, its position in the plane XOZ, and in the direction of the displacement Y is known the size of the object, its position in the plane XOZ, and in the direction of the displacement Y.
  • FIGS 1,2 and 3 attached illustrate by way of example an embodiment of the device according to the present invention.
  • the device comprises two transmitters 1 and 2 and two receivers 3 and 4, joined by two frames 5 and 6.
  • the two receivers have an electromagnetic shielding 7 and 8 open in order to overcome electrical radiation and well-known antenna effects.
  • the signals are then filtered and amplified by the filter 9 and the amplifier 10.
  • a zero compensation device (11) cancels the last parasitic voltages from the radiation of the fixed bodies located around the units and a synchronous demodulator 12 controlled by a synchronous sinusoidal voltage and followed by a DC amplifier 13 delivers the output signal.
  • FIG. 4 shows the signals obtained by the device according to the invention for a determined and non-limiting geometrical configuration.
  • the signal 14 comprises two bumps 15 and 16 whose temporal position relative to zero is characteristic of the distance separating the object from the plane of the transmitter. This position is independent of particle size. On the other hand, the amplitude 17 is characteristic of the object.
  • the device according to the invention can be used in all cases where it is necessary OR useful to know the position of metallic objects or more generally electrically or magnetic conductors.
  • the first is to detect metallic particles in wooden logs.
  • the three-dimensional location thus allows the maximum valuation of the National Park; a not described marking device is associated with the computer.
  • the second consists in detecting the weapons held by people frequenting public places: the knowledge of the position of the weapon on the individual allows the security agents to intervene discreetly and without risks.

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  • Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Remote Sensing (AREA)
  • Chemical & Material Sciences (AREA)
  • Electrochemistry (AREA)
  • Biochemistry (AREA)
  • Geology (AREA)
  • Geophysics (AREA)
  • Environmental & Geological Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electromagnetism (AREA)
  • Health & Medical Sciences (AREA)
  • Analytical Chemistry (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Geophysics And Detection Of Objects (AREA)
  • Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
  • Investigating Or Analysing Materials By The Use Of Chemical Reactions (AREA)
  • Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)

Abstract

It comprises an induction coil (1) radiating an alternating magnetic field and a sensor (3) associated to an amplifier (10) and a synchroneous demodulator (12) controlled by a signal proportional to the current passing through the induction coil. The device may be used for detecting metal bodies in timbers, food products, luggage and on persons attending public places and transports.

Description

Dispositif permettant de détecter dans des solides des liquides ou des gaz, les particules métalliques incluses, de les localiser et d'en déterminer la taille.Device for detecting liquids or gases in solids, including metallic particles, locating them and determining their size.
La présente invention concerne les détecteurs de particules métalliques incluses dans des corps peu conducteurs de l'électricité, par exemple, les inclusions métalliques que peuvent contenir les grumes de bois et dont la présence est fort dommageable pour les scies, ou les armes cachées par des personnes fréquentant les lieux publics ou les magasins de produits de luxe.The present invention relates to metal particle detectors included in bodies that are not very conductive of electricity, for example, metal inclusions that can be contained in wooden logs and the presence of which is very damaging to saws, or weapons hidden by people frequenting public places or luxury goods stores.
Actuellement, cette détection s'effectue par une mesure de la variation d'impédance d'une bobine cy- lindrique plate traversée en son milieu par l'objet ou la personne à contrôler, et excitée en courant alternatif sinusoidal.Currently, this detection is carried out by measuring the variation in impedance of a flat cylindrical coil crossed in its middle by the object or the person to be checked, and excited by sinusoidal alternating current.
Cette disposition présente cependant l'inconvénient de ne pas permettre ni la localisation de l'objet, ni sa taille. De plus elle est très sensible aux parasites radioélectriques provoquant ainsi des fausses détections.However, this arrangement has the disadvantage of not allowing the location of the object or its size. In addition, it is very sensitive to radio interference, thus causing false detections.
Le dispositif selon l'invention, en plus de la détection des objets conducteurs de l'électricité ou magné- tiques, les localise et en indique la taille. Il est in aussi\sensible aux parasites radioélectriques.The device according to the invention, in addition to the detection of electrically conductive or magnetic objects, locates them and indicates their size. It is also not sensitive to radio interference.
Le dispositif, objet de l'invention comporte deux unités de détection chacune constituée d'une bobine qua- drangulaire plate, rayonnant un champ électromagné- tique de fréquence bien définie, et appelée ultérieu- rement émetteur, dans l'axe de laquelle se trouve placée une bobine collectrice du champ magnétique émis munie ou non d'un aoyau ferromagnétique de focalisation et dont l'axe est simultanément perpendiculaire à l' axe émetteur et parallèle au sens de déplacement de l'objet, et appelée ultérieurement récepteur.The device, object of the invention comprises two detection units each consisting of a flat quadrangular coil, radiating an electromagnetic field of well-defined frequency, and called later emitting rement, in the axis of which is placed a collector coil of the emitted magnetic field provided or not with a ferromagnetic focusing core and whose axis is simultaneously perpendicular to the emitting axis and parallel to the direction of movement of the object, and later called receiver.
En l'absence de tout corps conducteur de l'électricité ou de perméabilité magnétique différente de celle du vide, le récepteur ne reçoit aucun flux magnétique donc il n'apparaît aucune tension à ses bornes.In the absence of any body conducting electricity or magnetic permeability different from that of vacuum, the receiver does not receive any magnetic flux, so there appears no voltage across its terminals.
Inversement, lorsqu'un objet présentant les qualités ci-dessus se déplace parallèlement à l'axe du récepteur dans la zone comprise entre ce dernier et l'émetteur, il apparaît à ses bornes une tension sinusoïdale qui croît puis s'annule lorsque l'objet se trouve situé dans le plan de symétrie de l'émetteur perpendiculaire à l'axe du récepteur, puis croît de nouveau et s'annule lorsque l'objet s'éloigne. La phase de la tension change lorsque l'objet passe dans le plan de symétrie de l'émetteur» Un dispositif de démodulation synchrone connu convertit cette tension alternative en un signal continu de polarités différentes dépendantes de la position de l'objet par rapport au plan de symétrie.Conversely, when an object having the above qualities moves parallel to the axis of the receiver in the area between the latter and the transmitter, it appears at its terminals a sinusoidal voltage which increases and then vanishes when the object is located in the plane of symmetry of the transmitter perpendicular to the axis of the receiver, then grows again and is canceled when the object moves away. The phase of the voltage changes when the object passes in the plane of symmetry of the transmitter "A known synchronous demodulation device converts this alternating voltage into a continuous signal of different polarities depending on the position of the object relative to the plane of symmetry.
Le dispositif selon l'invention a l'avantage de four-nir un signal calculable dont la morphologie dépend de la distance séparant l'objet du plan de l'émetteur et de sa masse électromagnétique. Un calculateur numérique de technologie connue fournit donc ces deux informations, distance au plan de l'émetteur et taille. Selon l'invention, une deuxième unité identique, utilisant une fréquence différente pour éviter l'influence des rayonnements parasites mutuels, est disposée de manière semblable sur le parcours de l'objet, mais décalée angulairement de 90º. Elle fournit donc les éléments de détermination de la distance Z de l'objet à l'émetteur et de la taille électromagnétique. Ainsi est connue la taille de l' objet, sa position dans le plan XOZ, et dans la direc-tion du déplacement Y.The device according to the invention has the advantage of providing a computable signal, the morphology of which depends on the distance separating the object from the plane of the transmitter and its electromagnetic mass. A digital computer of known technology therefore provides these two pieces of information, distance to the plane of the transmitter and size. According to the invention, a second identical unit, using a different frequency to avoid the influence of mutual parasitic radiation, is arranged similarly on the path of the object, but angularly offset by 90º. It therefore provides the elements for determining the distance Z from the object to the transmitter and the electromagnetic size. Thus is known the size of the object, its position in the plane XOZ, and in the direction of the displacement Y.
Enfin, l'adoption de deux capteurs permet de supprimer les erreurs dues aux parasites électromagnétiques, car ils apparaissent simultanément sur les deux capteurs, alors que les signatures des objets sont toujours décalées dans leur chronologie.Finally, the adoption of two sensors makes it possible to eliminate the errors due to electromagnetic parasites, because they appear simultaneously on the two sensors, while the signatures of the objects are always shifted in their chronology.
Les figures 1,2 et 3 annexées illustrent à titre d'exemple un mode de réalisation du dispositif conforme à la présente invention.Figures 1,2 and 3 attached illustrate by way of example an embodiment of the device according to the present invention.
Tel qu'il est représenté, le dispositif comporte deux émetteurs 1 et 2 et deux récepteurs 3 et 4, réunis par deux bâtis 5 et 6.As shown, the device comprises two transmitters 1 and 2 and two receivers 3 and 4, joined by two frames 5 and 6.
Les deux récepteurs comportent un blindage électromagnétique 7 et 8 ouvert afin de s'affranchir du rayonnement électrique et des effets d'antenne bien connus. Les signaux sont ensuite filtrés et amplifiés par le filtre 9 et l'amplificateur 10. Un dispositif de compensation de zéro (11), annule les dernières tensions parasites issues des rayonnements des corps fixes situés aux alentours des unités et un démodulateur synchrone 12 commandé par une tension sinusoïdale synchrone et suivi d'un amplificateur à courant continu 13 délivre le signal de sortie.The two receivers have an electromagnetic shielding 7 and 8 open in order to overcome electrical radiation and well-known antenna effects. The signals are then filtered and amplified by the filter 9 and the amplifier 10. A zero compensation device (11) cancels the last parasitic voltages from the radiation of the fixed bodies located around the units and a synchronous demodulator 12 controlled by a synchronous sinusoidal voltage and followed by a DC amplifier 13 delivers the output signal.
La figure 4 montre les signaux obtenus par le dispositif selon l'invention pour une configuration géomé- trique déterminée et non limitative.FIG. 4 shows the signals obtained by the device according to the invention for a determined and non-limiting geometrical configuration.
Le signal 14 comporte deux bosses 15 et 16 dont la position temporelle par rapport au zéro est caractéristique de la distance séparant l'objet du plan de l'émetteur. Cette position esrt indépendante de la taille de la particule. Par contre, l'amplitude 17 est caractéristique de l'objet.The signal 14 comprises two bumps 15 and 16 whose temporal position relative to zero is characteristic of the distance separating the object from the plane of the transmitter. This position is independent of particle size. On the other hand, the amplitude 17 is characteristic of the object.
Le dispositif selon l'invention peut être utilisé dans tous les cas où il est nécessaire OU utile de connaître la position d'objets métalliques ou plus généralement conducteurs de l'électricité ou magnétiques.The device according to the invention can be used in all cases where it is necessary OR useful to know the position of metallic objects or more generally electrically or magnetic conductors.
Deux applications particulièrement intéressantes peuvent être énumérées sans limitations:Two particularly interesting applications can be listed without limitations:
La première consiste à détecter les particules métalliques dans les grumes de bois. Le repérage tridimensionnel permet ainsi la valorisation maximale du Parc National; un dispositif de marquage non décrit est associé au calculateur.The first is to detect metallic particles in wooden logs. The three-dimensional location thus allows the maximum valuation of the National Park; a not described marking device is associated with the computer.
La seconde consiste à détecter les armes détenues par des personnes fréquentant les lieux publics: la connaissance de la position de l'arme sur l'individu permet aux préposés à la Sécurité d'intervenir discrètement et sans risques. The second consists in detecting the weapons held by people frequenting public places: the knowledge of the position of the weapon on the individual allows the security agents to intervene discreetly and without risks.

Claims

REVENDICATIONS
1 Dispositif permettant de détecter des particules métalliques comportant une à deux unités constituées chacune d'un émetteur et d'un récepteur à ondes électromagnétiques. 2 Dispositif selon revendication 1 caractérisé par le fait que la détection de la taille et de la position selon deux axes est assurée par la forme géométrique de l'émetteur et du récepteur et leur position respective. 3 Dispositif selon revendication 1 caractérisé par le fait que l'émetteur est constitué d'une bobine de fil quadrangulaire de dimension très supérieure aux dimensions de l'objet à détecter. 4 Dispositif selon revendication 1 caractérisé par le fait que le récepteur est constitué d'une petite bobine de fil munie d'un noyau électromagnétique d'axe perpendiculaire à l'axe de l'émetteur. 5 Dispositif selon revendication 1 caractérisé par le fait que le signal est démodulé par un démodulateur synchrone. 6 Dispositif selon revendication 1 caractérisé par le fait que les tensions résiduelles sont compensées par un circuit. électronique de correction. 7 Dispositif selon revendication 1 caractérisé par le fait que la réunion de deux unités constituées chacune d'un émetteur et d'un récepteur, calées perpendicu - lairement l'une par rapport à l'autre, fournit le repérage de l'objet dans les trois dimensions de l'espace. 8 Dispositif selon revendication 1 caractérisé par le fait que la disposition selon revendication 7 élimine toutes les erreurs dues aux parasites industriels élec- tromagnétiques. 1 Device for detecting metal particles comprising one to two units each consisting of an emitter and a receiver of electromagnetic waves. 2 Device according to claim 1 characterized in that the detection of the size and the position along two axes is ensured by the geometric shape of the transmitter and the receiver and their respective position. 3 Device according to claim 1 characterized in that the transmitter consists of a coil of quadrangular wire of dimension much greater than the dimensions of the object to be detected. 4 Device according to claim 1 characterized in that the receiver consists of a small coil of wire provided with an electromagnetic core with an axis perpendicular to the axis of the transmitter. 5 Device according to claim 1 characterized in that the signal is demodulated by a synchronous demodulator. 6 Device according to claim 1 characterized in that the residual voltages are compensated by a circuit. electronic correction. 7 Device according to claim 1 characterized in that the meeting of two units each consisting of a transmitter and a receiver, calibrated perpendicularly - relative to each other, provides the location of the object in the three dimensions of space. 8 Device according to claim 1 characterized in that the arrangement according to claim 7 eliminates all errors due to industrial electromagnetic interference.
PCT/FR1980/000057 1979-10-22 1980-04-11 Device allowing the detection in solids,liquids or gases,of the metal particles included,the location thereof and the determination of their size WO1981001198A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
BR8008878A BR8008878A (en) 1979-10-22 1980-04-11 DEVICE THAT ALLOWS TO DETECT INSIDE OF SOLIDS, LIQUIDS OR GASES THE PRESENCE OF METALLIC PARTICLES, LOCATES THEM AND DETERMINES ITS SIZE
DK275081A DK275081A (en) 1979-10-22 1981-06-22 DEVICE FOR DETECTING LOCATION AND FACON DETERMINATION OF 7ETAL PARTICLES CONTAINED IN SOLID LIQUID OR GASFUL SUBSTANCES

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR7926116A FR2468133A1 (en) 1979-10-22 1979-10-22 DEVICE FOR DETECTING INCLUDED METAL PARTICLES IN SOLIDS, LIQUIDS OR GASES, AND LOCATING AND DETERMINING THE SIZE THEREOF
FR7926116 1979-10-22

Publications (1)

Publication Number Publication Date
WO1981001198A1 true WO1981001198A1 (en) 1981-04-30

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PCT/FR1980/000057 WO1981001198A1 (en) 1979-10-22 1980-04-11 Device allowing the detection in solids,liquids or gases,of the metal particles included,the location thereof and the determination of their size

Country Status (8)

Country Link
EP (1) EP0038326A1 (en)
JP (1) JPS56501382A (en)
BR (1) BR8008878A (en)
DK (1) DK275081A (en)
ES (1) ES510409A0 (en)
FR (1) FR2468133A1 (en)
NO (1) NO812076L (en)
WO (1) WO1981001198A1 (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2158240A (en) * 1984-04-26 1985-11-06 Standard Telephones Cables Ltd A null-balanced proximity sensor
GB2166865A (en) * 1984-10-05 1986-05-14 Truetzschler & Co Device and method for detecting foreign bodies in bales of textile fibre
EP0308073A2 (en) * 1987-08-25 1989-03-22 Anritsu Corporation System for detecting stray metal in articles
WO1990012316A1 (en) * 1989-03-30 1990-10-18 Cintex Limited Product monitoring
FR2692365A1 (en) * 1992-06-15 1993-12-17 Clausin Jacques Moving ferromagnetic object locating and size evaluating device - uses three magnetometers disposed in a triangle with a fourth at a distance feeding a neural network.

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2111094A5 (en) * 1970-10-08 1972-06-02 Westinghouse Electric Corp
US3765007A (en) * 1969-07-11 1973-10-09 Minnesota Mining & Mfg Method and apparatus for detecting at a distance the status and identity of objects
FR2362455A1 (en) * 1976-08-18 1978-03-17 Knogo Corp METHOD AND APPARATUS INTENDED TO ACCENTUATE THE RESPONSE SIGNALS OF A DETERMINED HARMONIC IN AN ARTICLE DETECTION DEVICE

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3765007A (en) * 1969-07-11 1973-10-09 Minnesota Mining & Mfg Method and apparatus for detecting at a distance the status and identity of objects
FR2111094A5 (en) * 1970-10-08 1972-06-02 Westinghouse Electric Corp
FR2362455A1 (en) * 1976-08-18 1978-03-17 Knogo Corp METHOD AND APPARATUS INTENDED TO ACCENTUATE THE RESPONSE SIGNALS OF A DETERMINED HARMONIC IN AN ARTICLE DETECTION DEVICE

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2158240A (en) * 1984-04-26 1985-11-06 Standard Telephones Cables Ltd A null-balanced proximity sensor
GB2166865A (en) * 1984-10-05 1986-05-14 Truetzschler & Co Device and method for detecting foreign bodies in bales of textile fibre
EP0308073A2 (en) * 1987-08-25 1989-03-22 Anritsu Corporation System for detecting stray metal in articles
EP0308073A3 (en) * 1987-08-25 1990-03-07 Anritsu Corporation System for detecting stray metal in articles
WO1990012316A1 (en) * 1989-03-30 1990-10-18 Cintex Limited Product monitoring
US5304927A (en) * 1989-03-30 1994-04-19 Cintex Limited Method and apparatus for monitoring a series of products
FR2692365A1 (en) * 1992-06-15 1993-12-17 Clausin Jacques Moving ferromagnetic object locating and size evaluating device - uses three magnetometers disposed in a triangle with a fourth at a distance feeding a neural network.

Also Published As

Publication number Publication date
FR2468133A1 (en) 1981-04-30
BR8008878A (en) 1981-08-25
ES8304323A3 (en) 1983-02-01
ES510409A0 (en) 1983-02-01
EP0038326A1 (en) 1981-10-28
DK275081A (en) 1981-06-22
JPS56501382A (en) 1981-09-24
FR2468133B1 (en) 1984-05-25
NO812076L (en) 1981-06-18

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