SE9801106L - Apparatus and method for detecting metal objects - Google Patents

Apparatus and method for detecting metal objects

Info

Publication number
SE9801106L
SE9801106L SE9801106A SE9801106A SE9801106L SE 9801106 L SE9801106 L SE 9801106L SE 9801106 A SE9801106 A SE 9801106A SE 9801106 A SE9801106 A SE 9801106A SE 9801106 L SE9801106 L SE 9801106L
Authority
SE
Sweden
Prior art keywords
signal
point
metal objects
voltage signal
resulting
Prior art date
Application number
SE9801106A
Other languages
Swedish (sv)
Other versions
SE521941C2 (en
SE9801106D0 (en
Inventor
Anders Eidenvall
Original Assignee
Abb Ab
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 Abb Ab filed Critical Abb Ab
Priority to SE9801106A priority Critical patent/SE521941C2/en
Publication of SE9801106D0 publication Critical patent/SE9801106D0/en
Publication of SE9801106L publication Critical patent/SE9801106L/en
Publication of SE521941C2 publication Critical patent/SE521941C2/en

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

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)

Abstract

At a point on the path of a first voltage signal used to warn of a metal object towards the unit used to signal the warning, this first signal is detected and a second voltage signal with an opposite character to the first signal is sent to a point along the first signal path upstream from the point where the first signal is detected. A summation is made at this upstream point between the first and second signals and the resulting 0-signal is sent via the first signal detection point to the warning unit. Metal objects passing through a measuring coil (8) cause a change in magnetic field, resulting in a corresponding detection voltage signal being generated to alert the presence of the object. Low frequency signals caused by disturbance are ignored and only those signals with frequencies typical for metal objects are analysed. An Independent claim is also included for the detection device.
SE9801106A 1998-03-31 1998-03-31 Detecting metal objects using coil to monitor changes in magnetic field SE521941C2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
SE9801106A SE521941C2 (en) 1998-03-31 1998-03-31 Detecting metal objects using coil to monitor changes in magnetic field

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE9801106A SE521941C2 (en) 1998-03-31 1998-03-31 Detecting metal objects using coil to monitor changes in magnetic field

Publications (3)

Publication Number Publication Date
SE9801106D0 SE9801106D0 (en) 1998-03-31
SE9801106L true SE9801106L (en) 1999-10-01
SE521941C2 SE521941C2 (en) 2003-12-23

Family

ID=20410787

Family Applications (1)

Application Number Title Priority Date Filing Date
SE9801106A SE521941C2 (en) 1998-03-31 1998-03-31 Detecting metal objects using coil to monitor changes in magnetic field

Country Status (1)

Country Link
SE (1) SE521941C2 (en)

Also Published As

Publication number Publication date
SE521941C2 (en) 2003-12-23
SE9801106D0 (en) 1998-03-31

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