JPS5784349A - Eddy current type flaw detection system - Google Patents

Eddy current type flaw detection system

Info

Publication number
JPS5784349A
JPS5784349A JP15961680A JP15961680A JPS5784349A JP S5784349 A JPS5784349 A JP S5784349A JP 15961680 A JP15961680 A JP 15961680A JP 15961680 A JP15961680 A JP 15961680A JP S5784349 A JPS5784349 A JP S5784349A
Authority
JP
Japan
Prior art keywords
signal
detection
processing section
signal processing
phase
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.)
Pending
Application number
JP15961680A
Other languages
Japanese (ja)
Inventor
Seiichi Watanabe
Takao Sugimoto
Hiroshi Kawase
Toshiyuki Koike
Masaaki Nakajima
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.)
Hitachi Ltd
Nippon Steel Corp
Original Assignee
Hitachi Ltd
Nippon Steel 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 Hitachi Ltd, Nippon Steel Corp filed Critical Hitachi Ltd
Priority to JP15961680A priority Critical patent/JPS5784349A/en
Publication of JPS5784349A publication Critical patent/JPS5784349A/en
Pending legal-status Critical Current

Links

Classifications

    • 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
    • G01N27/82—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws
    • G01N27/90—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws using eddy currents
    • G01N27/9046—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws using eddy currents by analysing electrical signals

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)

Abstract

PURPOSE:To improve S/N with a broader dynamic range of a flaw signal by removing an offset signal proper to a detector section in the course to a signal processing section employing a feed back signal from a phase discrimination output before the flaw detecting operation. CONSTITUTION:A detection mechanism 2 is excited based on an AC signal of an oscillator 1 and a detection signal is outputted to a detection coil of the detection mechanism 2. The detection signal is transmitted to a signal processing section 4 provided in an aromatic balance circuit passing through an amplifier 3. The amplitude signal the same in the phase component as the outpt of an oscillator 1 is discriminated with a phase detector section 42 of a signal processing section 4 and that in the phase component shifted by 90 deg. with a 90 deg. phase detector section 43. These signals are fed back to an adder 5 provided between the detection mechanism 2 and the amplifier 3 and the signal (coil residual signal) proper to the detection coil is removed from input signals to the signal processing section 4.
JP15961680A 1980-11-14 1980-11-14 Eddy current type flaw detection system Pending JPS5784349A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP15961680A JPS5784349A (en) 1980-11-14 1980-11-14 Eddy current type flaw detection system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP15961680A JPS5784349A (en) 1980-11-14 1980-11-14 Eddy current type flaw detection system

Publications (1)

Publication Number Publication Date
JPS5784349A true JPS5784349A (en) 1982-05-26

Family

ID=15697602

Family Applications (1)

Application Number Title Priority Date Filing Date
JP15961680A Pending JPS5784349A (en) 1980-11-14 1980-11-14 Eddy current type flaw detection system

Country Status (1)

Country Link
JP (1) JPS5784349A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0135204A2 (en) * 1983-06-15 1985-03-27 CISE- Centro Informazioni Studi Esperienze S.p.A. Measuring device for surface and subsurface defects in metal bodies above the Curie temperature

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS53122477A (en) * 1977-03-31 1978-10-25 Shimadzu Corp End control system of auto balance circuit in eddy current flaw detector

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS53122477A (en) * 1977-03-31 1978-10-25 Shimadzu Corp End control system of auto balance circuit in eddy current flaw detector

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0135204A2 (en) * 1983-06-15 1985-03-27 CISE- Centro Informazioni Studi Esperienze S.p.A. Measuring device for surface and subsurface defects in metal bodies above the Curie temperature
EP0135204A3 (en) * 1983-06-15 1988-09-21 CISE- Centro Informazioni Studi Esperienze S.p.A. Measuring device for surface and subsurface defects in metal bodies above the curie temperature

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