CA924779A - Multiple frequency magnetic field technique for differentiating between classes of metal objects - Google Patents

Multiple frequency magnetic field technique for differentiating between classes of metal objects

Info

Publication number
CA924779A
CA924779A CA121521A CA121521A CA924779A CA 924779 A CA924779 A CA 924779A CA 121521 A CA121521 A CA 121521A CA 121521 A CA121521 A CA 121521A CA 924779 A CA924779 A CA 924779A
Authority
CA
Canada
Prior art keywords
differentiating
classes
magnetic field
frequency magnetic
multiple frequency
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.)
Expired
Application number
CA121521A
Other languages
English (en)
Other versions
CA121521S (en
Inventor
George T. Mallick, Jr.
C. Miller Robert
Walter J. Carr, Jr.
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
CBS Corp
Original Assignee
Westinghouse Electric Corp
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 Westinghouse Electric Corp filed Critical Westinghouse Electric Corp
Application granted granted Critical
Publication of CA924779A publication Critical patent/CA924779A/en
Expired legal-status Critical Current

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
    • 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

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)
  • Geophysics And Detection Of Objects (AREA)
  • Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
CA121521A 1970-10-08 1971-08-27 Multiple frequency magnetic field technique for differentiating between classes of metal objects Expired CA924779A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US7918070A 1970-10-08 1970-10-08

Publications (1)

Publication Number Publication Date
CA924779A true CA924779A (en) 1973-04-17

Family

ID=22148930

Family Applications (1)

Application Number Title Priority Date Filing Date
CA121521A Expired CA924779A (en) 1970-10-08 1971-08-27 Multiple frequency magnetic field technique for differentiating between classes of metal objects

Country Status (7)

Country Link
US (1) US3686564A (fr)
JP (1) JPS5117426B1 (fr)
CA (1) CA924779A (fr)
DE (1) DE2149371A1 (fr)
FR (1) FR2111094A5 (fr)
GB (1) GB1350273A (fr)
IL (1) IL37351A (fr)

Families Citing this family (60)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3938125A (en) * 1974-02-20 1976-02-10 Minnesota Mining And Manufacturing Company Antipilferage system and marker therefor
US4063230A (en) * 1975-06-12 1977-12-13 The Magnavox Company Balanced field theft detection system
JPS5233411A (en) * 1975-09-10 1977-03-14 Nippon C Ee T Bui Kk Automatic equalizing system in a wire broadcast equipment
JPS5233412A (en) * 1975-09-10 1977-03-14 Nippon C Ee T Bui Kk Remaining equalizing system in a wire broadcast equipment
US4263551A (en) * 1975-10-16 1981-04-21 Georgetown University Method and apparatus for identifying conductive objects by monitoring the true resistive component of impedance change in a coil system caused by the object
US3986104A (en) * 1976-01-19 1976-10-12 Robert F. Gardiner Dual frequency metal detector system
DE2715106C2 (de) * 1977-04-04 1982-05-27 Siemens AG, 1000 Berlin und 8000 München Vorrichtung zur Messung des Ortes, der Lage und/oder der Orts- bzw. Lageänderung eines starren Körpers im Raum
US4128803A (en) * 1977-04-29 1978-12-05 Pni, Inc. Metal detector system with ground effect rejection
NL7708012A (nl) * 1977-07-19 1979-01-23 Nedap Nv Detectiestelsel.
GB1603578A (en) * 1978-08-25 1981-11-25 Univ Georgetown System and method for identifying samples having conductive properties
BE871580A (fr) * 1978-10-26 1979-02-15 Janssen Lambert Systeme electromagnetique de detection
US4250451A (en) * 1978-12-28 1981-02-10 Cordless Power Corporation Magnetic induction imaging system
US4303879A (en) * 1979-01-29 1981-12-01 Garrett Electronics Metal detector circuit with mode selection and automatic tuning
US4334192A (en) * 1979-01-29 1982-06-08 Garrett Electronics Metal detector circuit having automatic tuning with multiple rates
FR2468133A1 (fr) * 1979-10-22 1981-04-30 Clausin Jacques Dispositif permettant de detecter dans les solides, des liquides ou des gaz les particules metalliques incluses, de les localiser et d'en determiner la taille
US4493039A (en) * 1980-05-06 1985-01-08 President And Directors Of Georgetown University Apparatus and method for image reproduction of materials using their magnetic and electric properties
FR2510764A1 (fr) * 1981-07-30 1983-02-04 Franquet Leon Dispositif de detection d'objets metalliques, tels que des armes a feu, et sas d'acces de locaux equipes de tels dispositifs
SE430545B (sv) * 1982-04-01 1983-11-21 Asea Ab Anordning for detektering av metallforemal i ett materialflode
US4641092A (en) * 1982-07-08 1987-02-03 Sumitomo Metal Industries, Ltd. Rotary probe apparatus for detecting flaws in a test object
US4709213A (en) * 1982-07-23 1987-11-24 Garrett Electronics, Inc. Metal detector having digital signal processing
FR2547659B1 (fr) * 1983-06-20 1985-11-22 Clausin Jacques Detecteurs d'objets metalliques indiquant : la distance, la taille et la matiere
FR2552888B1 (fr) * 1983-09-30 1986-02-28 Electroniques Meca Et Dispositif electronique pour la detection d'objets au moins en partie metalliques, a l'interieur d'un volume determine
US4818936A (en) * 1985-02-15 1989-04-04 The Broken Hill Proprietary Company Limited Method and apparatus for identifying and classifying steels
DE3530082A1 (de) * 1985-08-22 1987-02-26 Micro Epsilon Messtechnik Verfahren zum beruehrungslosen vermessen elektrisch leitfaehiger objekte und vorrichtung zur durchfuehrung des verfahrens
EP0261142A1 (fr) * 1986-02-04 1988-03-30 Minelab Electronic Industries Ltd. Detection de metal dans des supports conducteurs utilisant un signal a double frequence
DE3714009A1 (de) * 1987-04-27 1988-11-10 Hauni Werke Koerber & Co Kg Metalldetektor
US4814690A (en) * 1987-10-02 1989-03-21 Massachusetts Institute Of Technology Apparatus and methods for measuring permittivity in materials
USRE36986E (en) * 1987-10-02 2000-12-12 Massachusetts Institute Of Technology Apparatus and methods for measuring permeability and conductivity in materials using multiple wavenumber magnetic interrogations
US4821023A (en) * 1988-01-07 1989-04-11 Del Norte Technology, Inc. Walk-through metal detector
ES2006048A6 (es) * 1988-01-15 1989-04-01 Gosalbez Gosalbez Fco Jose Sistema detector de materiales magneticos.
FR2626680A1 (fr) * 1988-02-02 1989-08-04 Bousquet Alain Dispositif destine a deceler et signaler la presence de masses metalliques dans un espace aux dimensions determinees
FI84208C (fi) * 1989-01-31 1991-10-25 Outokumpu Oy Foerfarande foer detektering av metallfoeremaol.
US5130653A (en) * 1990-08-17 1992-07-14 Coors Brewing Company Apparatus for detecting surface flaws in cylindrical articles
US5432444A (en) * 1990-10-23 1995-07-11 Kaisei Engineer Co., Ltd. Inspection device having coaxial induction and exciting coils forming a unitary coil unit
EP0543648A1 (fr) * 1991-11-21 1993-05-26 Kaisei Engineer Co., Ltd. Appareil et méthode pour l'inspection à l'induction électromagnétique
US5506506A (en) * 1992-01-14 1996-04-09 Halcro Nominees Pty Ltd. Metal detector for detecting and discriminating between ferrous and non-ferrous targets in ground
US5721489A (en) * 1995-10-06 1998-02-24 Garrett Electronics, Inc. Metal detector method for identifying target size
US5642050A (en) * 1995-12-21 1997-06-24 White's Electronics, Inc. Plural frequency method and system for identifying metal objects in a background environment using a target model
US5654638A (en) * 1995-12-21 1997-08-05 White's Electronics, Inc. Plural Frequency method and system for identifying metal objects in a background environment
US5900816A (en) * 1997-06-18 1999-05-04 Weaver; Jon Neal Anti-shoplifting security system utilizing a modulated transmitter signal
AU4070697A (en) * 1996-08-16 1998-03-06 Jon Neal Weaver Anti-shoplifting security system
US5969528A (en) * 1998-01-22 1999-10-19 Garrett Electronics, Inc. Dual field metal detector
US5994897A (en) * 1998-02-12 1999-11-30 Thermo Sentron, Inc. Frequency optimizing metal detector
IT1310277B1 (it) * 1999-07-27 2002-02-11 Clarbruno Vedruccio Analizzatore elettromagnetico di anisotropia in sistemi chimiciorganizzati.
US6172499B1 (en) * 1999-10-29 2001-01-09 Ascension Technology Corporation Eddy current error-reduced AC magnetic position measurement system
US6724191B1 (en) * 2000-05-09 2004-04-20 Admiralty Corporation Systems and methods useful for detecting presence and/or location of various materials
AU2002365033A1 (en) * 2001-10-25 2003-06-17 The Johns Hopkins University Wide area metal detection (wamd) system and method for security screening crowds
EP1332719A1 (fr) * 2002-01-23 2003-08-06 Roke Manor Research Limited Méthode et dispositif pour detecter de fragments de métal entre des patients
US6879161B2 (en) * 2002-02-11 2005-04-12 White's Electronics, Inc. Method and apparatus for distinguishing metal objects employing multiple frequency interrogation
US6911823B2 (en) * 2002-02-11 2005-06-28 White's Electronics, Inc. Metal detector employing static discrimination
US7649356B2 (en) 2002-12-18 2010-01-19 White's Electronics, Inc. Pulse induction metal detector having high energy efficiency and sensitivity
US7126323B1 (en) 2003-07-25 2006-10-24 Admiralty Corporation Systems and methods for synchronous detection of signals
DE102004014572B4 (de) 2004-03-25 2023-06-07 Cewe Stiftung & Co. Kgaa Prüfanordnung und Prüfverfahren für Inhaltsprüfung von Fototaschen
US20060241396A1 (en) * 2005-02-10 2006-10-26 Fabian Carl E Multi-modal detection of surgical sponges and implements
US8729902B1 (en) 2009-10-05 2014-05-20 White's Electronics, Inc. Metal detector analysis and display methods
EP2439560B1 (fr) * 2010-10-07 2013-05-29 Mettler-Toledo Safeline Limited Procédé de fonctionnement d'un système de détection de métaux et système de détection de métaux
CN105849593A (zh) * 2013-10-04 2016-08-10 无线电探测有限公司 验证电子标记定位器的操作
CN105842741B (zh) * 2016-03-23 2017-12-05 成都恒高科技有限公司 一种金属探测装置以及方法
US11409017B2 (en) 2018-06-20 2022-08-09 Eriez Manufacturing Co. Metal detector coil configuration to eliminate orientation effect
CN111812733B (zh) * 2020-07-21 2023-05-12 上海太易检测技术有限公司 一种多频金检机信息处理方法及装置

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA798999A (en) * 1968-11-12 W. Van Rooyen Daniel Tramp metal detector
US3012190A (en) * 1946-03-06 1961-12-05 Electro Mechanical Res Inc Multiple frequency alternating current network
US2929984A (en) * 1956-01-12 1960-03-22 Canadian Airborne Geophysics L Method and apparatus for qualitative electromagnetic surveying
US3500373A (en) * 1966-05-06 1970-03-10 Nat Bank Of North America The Method and apparatus for article theft detection

Also Published As

Publication number Publication date
JPS5117426B1 (en) 1976-06-02
IL37351A (en) 1974-09-10
JPS478243A (en) 1972-04-28
GB1350273A (en) 1974-04-18
US3686564A (en) 1972-08-22
FR2111094A5 (fr) 1972-06-02
IL37351A0 (en) 1971-12-29
DE2149371A1 (de) 1972-06-08

Similar Documents

Publication Publication Date Title
CA924779A (en) Multiple frequency magnetic field technique for differentiating between classes of metal objects
CA1001256A (en) Static magnetic field metal detector
CA948078A (en) Method of making a magnetic powder
CA934990A (en) Magnetic alloy
CA926367A (en) Separation of magnetizable particles
CA896722A (en) Method of electromagnetic prospecting
CA1011817A (en) Method of magnetic testing of metal articles
CA948245A (en) Magnetic switches and method for making same
IT993180B (it) Processo ed apparecchiatura per il controllo magnetico di billette ferromagnetiche
CA659989A (en) Electromagnetic pulse method of ore detection
CA736437A (en) Method of hard facing metallic articles
CA705853A (en) Process for the manufacture of magnetic tapes
CA842750A (en) Thermoset articles and method of forming
CA1009704A (fr) Procede de prospection electromagnetique a plusieurs largeurs d'impulsions
CA847823A (en) Method of making fluorescent magnetic particles
CA834098A (en) Method of forming magnetic ferrite films
CA711401A (en) Method of magnetic recording
CA775234A (en) Method and means for obtaining high magnetic fields
CA797207A (en) Method of improving magnetic characteristics
CA942886A (en) Magnetic card and method of making and magnetizing the same
CA723578A (en) Method of making metallic powders
CA851920A (en) Method of manufacturing pole-pieces for magnetic heads
CA706011A (en) Magnet body for electromagnetic clutches especially of the stationary body type
CA854019A (en) Apparatus for the magnetic separation of fine parts
CA782626A (en) Method of processing ferrous metals