WO2002025318A1 - Detecteur de metal - Google Patents

Detecteur de metal Download PDF

Info

Publication number
WO2002025318A1
WO2002025318A1 PCT/GB2001/004223 GB0104223W WO0225318A1 WO 2002025318 A1 WO2002025318 A1 WO 2002025318A1 GB 0104223 W GB0104223 W GB 0104223W WO 0225318 A1 WO0225318 A1 WO 0225318A1
Authority
WO
WIPO (PCT)
Prior art keywords
signal
coil
frequencies
output signals
coil output
Prior art date
Application number
PCT/GB2001/004223
Other languages
English (en)
Inventor
Trevor Smith
Original Assignee
Safeline Limited
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 Safeline Limited filed Critical Safeline Limited
Priority to AU2001290074A priority Critical patent/AU2001290074A1/en
Publication of WO2002025318A1 publication Critical patent/WO2002025318A1/fr

Links

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

Definitions

  • the present invention relates to an apparatus and method for
  • foodstuffs and the like comprises two receiver coils disposed coaxially with,
  • the receiver coils are connected so that the voltage induced in one coil is
  • substantially non-conductive material for example a foodstuff.
  • the minimum metal particle size detectable is as
  • the vibration signal two components, a vibration signal and a product signal.
  • the product signal is caused
  • the background signal is
  • the vibration signal generally corresponds to reactive interaction with the
  • a metal particle depends on the size and other characteristics of the particle.
  • vibration and product signal can be determined. The larger of these can then be eliminated.
  • phase discrimination can render
  • the present invention has been made in consideration of these
  • the invention also reduces the risk
  • vibration signal generally remains substantially constant with frequency.
  • the product signal can be eliminated.
  • output signals comprises a means for synchronously detecting two or more
  • the apparatus further preferably comprises means for scaling and/or
  • the means for detecting two or more coil output signals preferably
  • a preamplifier for amplifying the signal induced
  • the digital signal processing means is preferably
  • the digital signal processor preferably
  • Figure 1 is a schematic view of the coil arrangement of apparatus
  • Figure 2 is a schematic block circuit diagram of apparatus according to the invention.
  • the coils are wound on a former (not shown) and housed in an enclosure
  • the enclosure includes an aperture around which the coils
  • These means comprise a synthesiser 3 for generating a signal having two or more
  • excitation coil 1 to produce alternating magnetic fields at two or more
  • the field produced by the excitation coil 1 induces a voltage in the
  • receiver coils 2 The receiver coils 2 are connected in series opposition and
  • the coil signal is fed to a wide band preamplifier 5, preferably
  • the output of the preamplifier 5 is
  • the digital signal processor 6 comprises means for digitizing the coil
  • the digital signal processor 6 is arranged to simultaneously
  • Each signal will typically
  • First the digital signal processor scales and/or phase rotates one of
  • the two signals are the same magnitude and phase as that of the other signal.
  • the two signals are the same magnitude and phase as that of the other signal.
  • the resultant signal can then be subjected to phase discrimination in
  • the scaling factor and/or phase rotation angle required is stored in an
  • a plurality of such values or combination of values may be
  • the excitation coil 1 is usually not frequency dependent.
  • product signal is to be eliminated by subtraction it is necessary to determine
  • the digital signal processor 6 is also connected to the output of the
  • excitation coil 1 driving amplifier 4 which supplies a reference signal to
  • the power amplifier output 4 will appear at the pre-amplifier output 5, but
  • the synthesizer 3 is also connected to the pre-amplifier 5, to provide
  • the synthesizer 3 can be used to provide a signal to be
  • ADC analogue to digital convertor
  • the coils may go out of balance for a number of reasons, including
  • the signal causes the synthesiser to generate a corrective signal, transmitted
  • Typical carrier frequencies might be 100 and 800 KHz or 1O and 300
  • the dynamic ra ge of the ADC might be about 100dB and the power

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Remote Sensing (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Electromagnetism (AREA)
  • Environmental & Geological Engineering (AREA)
  • Geology (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Geophysics (AREA)
  • Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)

Abstract

La présente invention concerne un appareil qui permet de détecter des matières magnétiques et électroconductrices, lequel appareil comprend : un moyen qui permet d'attaquer (3,4) une bobine d'excitation (1) à l'aide d'un courant alternatif à au moins deux fréquences simultanées ; un moyen qui permet de détecter (5,6) au moins deux signaux de sortie de bobine (2) de fréquences différentes à partir d'un signal de sortie comprenant au moins deux fréquences ; et un moyen qui permet de soustraire (6) un signal détecté de l'autre. L'appareil de l'invention permet d'éliminer de façon améliorée les signaux de fond des signaux de sortie de bobine et il permet par conséquent de détecter des particules plus petites de matières magnétiques ou électroconductrices. L'appareil peut comprendre un moyen qui permet la mise à l'échelle et/ou la rotation de phase d'un signal de sortie de bobine détecté.
PCT/GB2001/004223 2000-09-22 2001-09-21 Detecteur de metal WO2002025318A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU2001290074A AU2001290074A1 (en) 2000-09-22 2001-09-21 Metal detector

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB0023303A GB0023303D0 (en) 2000-09-22 2000-09-22 Metal detector
GB0023303.1 2000-09-22

Publications (1)

Publication Number Publication Date
WO2002025318A1 true WO2002025318A1 (fr) 2002-03-28

Family

ID=9899959

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB2001/004223 WO2002025318A1 (fr) 2000-09-22 2001-09-21 Detecteur de metal

Country Status (3)

Country Link
AU (1) AU2001290074A1 (fr)
GB (1) GB0023303D0 (fr)
WO (1) WO2002025318A1 (fr)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006021045A1 (fr) * 2004-08-26 2006-03-02 Minelab Electronics Pty Limited Procede et dispositif de detection de metaux par traitement de signaux numeriques
AU2005276953B2 (en) * 2004-08-26 2010-06-10 Minelab Electronics Pty Limited Method and apparatus for metal detection employing digital signal processing
US20120179394A1 (en) * 2005-02-16 2012-07-12 Clive Francis Kittel Metal Detector
EP2562565A1 (fr) 2011-08-24 2013-02-27 Mettler-Toledo Safeline Limited Appareil de détection de métaux
EP2570824A1 (fr) 2011-09-19 2013-03-20 Mettler-Toledo Safeline Limited Procédé de fonctionnement d'un appareil de détection de métal et appareil
GB2499239A (en) * 2012-02-10 2013-08-14 Illinois Tool Works Automatically balancing the detector coil system in a metal detector
WO2013119741A1 (fr) 2012-02-10 2013-08-15 Illinois Tool Works Inc. Détecteur de métaux
US9018935B2 (en) 2011-09-19 2015-04-28 Mettler-Toledo Safeline Limited Method for operating a metal detection apparatus and apparatus
EP3260889A1 (fr) 2016-06-22 2017-12-27 Mettler-Toledo Safeline Limited Appareil de détection de métaux
EP3693763A1 (fr) 2015-12-23 2020-08-12 Illinois Tool Works, Inc. Détecteur de métal

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4563645A (en) * 1981-02-09 1986-01-07 Goring Kerr Limited Inductively balanced oscillatory coil current for metal detection
EP0780704A2 (fr) * 1995-12-21 1997-06-25 White's Electronics, Inc. Procédé et dispositif à plusieurs fréquences pour l'identification des objets métalliques dans un arrière-plan
EP0949514A2 (fr) * 1998-04-07 1999-10-13 Ishida Co., Ltd. Détecteur de matière étrangère et système de détection de matière étrangère

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4563645A (en) * 1981-02-09 1986-01-07 Goring Kerr Limited Inductively balanced oscillatory coil current for metal detection
EP0780704A2 (fr) * 1995-12-21 1997-06-25 White's Electronics, Inc. Procédé et dispositif à plusieurs fréquences pour l'identification des objets métalliques dans un arrière-plan
EP0949514A2 (fr) * 1998-04-07 1999-10-13 Ishida Co., Ltd. Détecteur de matière étrangère et système de détection de matière étrangère

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
"CONTROLE QUALITE LES DETECTEURS INDUSTRIELS DE METAUX", MESURES REGULATION AUTOMATISME, CFE. PARIS, FR, no. 689, 1 November 1996 (1996-11-01), pages 111 - 113,115-119, XP000679699, ISSN: 0755-219X *
BRIGHTON M ET AL: "CALCULATION OF OPTIMUM SPACING FOR A THREE COIL AXIALLY SYMMETRIC METAL DETECTOR", ELECTRONICS LETTERS, IEE STEVENAGE, GB, vol. 29, no. 10, 13 May 1993 (1993-05-13), pages 838 - 839, XP000367628, ISSN: 0013-5194 *

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1782100A1 (fr) * 2004-08-26 2007-05-09 Minelab Electronics Pty Limited Procede et dispositif de detection de metaux par traitement de signaux numeriques
US7432715B2 (en) 2004-08-26 2008-10-07 Minelab Electronics Pty Limited Method and apparatus for metal detection employing digital signal processing
AU2005276953B2 (en) * 2004-08-26 2010-06-10 Minelab Electronics Pty Limited Method and apparatus for metal detection employing digital signal processing
AU2005276953C1 (en) * 2004-08-26 2010-10-21 Minelab Electronics Pty Limited Method and apparatus for metal detection employing digital signal processing
EP1782100A4 (fr) * 2004-08-26 2012-01-04 Minelab Electronics Pty Ltd Procede et dispositif de detection de metaux par traitement de signaux numeriques
WO2006021045A1 (fr) * 2004-08-26 2006-03-02 Minelab Electronics Pty Limited Procede et dispositif de detection de metaux par traitement de signaux numeriques
US20120179394A1 (en) * 2005-02-16 2012-07-12 Clive Francis Kittel Metal Detector
US8473235B2 (en) * 2005-02-16 2013-06-25 Illinois Tool Works Inc. Metal detector
US8841903B2 (en) 2011-08-24 2014-09-23 Mettler-Toledo Safeline Limited Metal detection apparatus
EP2562565A1 (fr) 2011-08-24 2013-02-27 Mettler-Toledo Safeline Limited Appareil de détection de métaux
EP2570824A1 (fr) 2011-09-19 2013-03-20 Mettler-Toledo Safeline Limited Procédé de fonctionnement d'un appareil de détection de métal et appareil
US9018935B2 (en) 2011-09-19 2015-04-28 Mettler-Toledo Safeline Limited Method for operating a metal detection apparatus and apparatus
GB2499239A (en) * 2012-02-10 2013-08-14 Illinois Tool Works Automatically balancing the detector coil system in a metal detector
GB2499239B (en) * 2012-02-10 2014-02-12 Illinois Tool Works Metal detector
WO2013119741A1 (fr) 2012-02-10 2013-08-15 Illinois Tool Works Inc. Détecteur de métaux
EP3287815A1 (fr) 2012-02-10 2018-02-28 Illinois Tool Works Inc. Détecteur de métaux
US10215875B2 (en) 2012-02-10 2019-02-26 Illinois Tool Works Inc. Metal detector
EP3693763A1 (fr) 2015-12-23 2020-08-12 Illinois Tool Works, Inc. Détecteur de métal
EP3260889A1 (fr) 2016-06-22 2017-12-27 Mettler-Toledo Safeline Limited Appareil de détection de métaux
US10605946B2 (en) 2016-06-22 2020-03-31 Mettler-Toledo Safeline Ltd. Metal detection apparatus

Also Published As

Publication number Publication date
GB0023303D0 (en) 2000-11-08
AU2001290074A1 (en) 2002-04-02

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