FR2291495A1 - Foucault pulse metal detector - has coil surrounding ferrite core initially attracted by permanent magnet - Google Patents

Foucault pulse metal detector - has coil surrounding ferrite core initially attracted by permanent magnet

Info

Publication number
FR2291495A1
FR2291495A1 FR7437868A FR7437868A FR2291495A1 FR 2291495 A1 FR2291495 A1 FR 2291495A1 FR 7437868 A FR7437868 A FR 7437868A FR 7437868 A FR7437868 A FR 7437868A FR 2291495 A1 FR2291495 A1 FR 2291495A1
Authority
FR
France
Prior art keywords
ferrite core
foucault
permanent magnet
coil
detector
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.)
Granted
Application number
FR7437868A
Other languages
French (fr)
Other versions
FR2291495B1 (en
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.)
Plessey Handel und Investments AG
Original Assignee
Plessey Handel und Investments AG
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 Plessey Handel und Investments AG filed Critical Plessey Handel und Investments AG
Priority to FR7437868A priority Critical patent/FR2291495A1/en
Publication of FR2291495A1 publication Critical patent/FR2291495A1/en
Application granted granted Critical
Publication of FR2291495B1 publication Critical patent/FR2291495B1/fr
Granted 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
    • 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

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Remote Sensing (AREA)
  • Environmental & Geological Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • Geology (AREA)
  • Geophysics (AREA)
  • Electromagnetism (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)

Abstract

A metal detector working on the principle of pulsed Foucault currents has a detector coil with ferrite core which has been submitted to a magnetic field from a permanent magnet or an electromagnetic field. The ferrite core is in the form of a long bar and is placed in a coil to which direct current is applied to produce 1000 ampere turns in one sense. The current is then reversed. This makes the coil insensitive to the earthhs magnetic field. When the detector is used a pulsed current is applied to a coil which produces Foucault currents in nearby metal, the currents inducing current in the detector.
FR7437868A 1974-11-18 1974-11-18 Foucault pulse metal detector - has coil surrounding ferrite core initially attracted by permanent magnet Granted FR2291495A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
FR7437868A FR2291495A1 (en) 1974-11-18 1974-11-18 Foucault pulse metal detector - has coil surrounding ferrite core initially attracted by permanent magnet

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7437868A FR2291495A1 (en) 1974-11-18 1974-11-18 Foucault pulse metal detector - has coil surrounding ferrite core initially attracted by permanent magnet

Publications (2)

Publication Number Publication Date
FR2291495A1 true FR2291495A1 (en) 1976-06-11
FR2291495B1 FR2291495B1 (en) 1978-11-24

Family

ID=9145007

Family Applications (1)

Application Number Title Priority Date Filing Date
FR7437868A Granted FR2291495A1 (en) 1974-11-18 1974-11-18 Foucault pulse metal detector - has coil surrounding ferrite core initially attracted by permanent magnet

Country Status (1)

Country Link
FR (1) FR2291495A1 (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1264300A (en) * 1969-04-18 1972-02-16

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1264300A (en) * 1969-04-18 1972-02-16

Also Published As

Publication number Publication date
FR2291495B1 (en) 1978-11-24

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Legal Events

Date Code Title Description
TP Transmission of property
TP Transmission of property
ST Notification of lapse