JPS5794645A - Eddy-current flaw detector - Google Patents

Eddy-current flaw detector

Info

Publication number
JPS5794645A
JPS5794645A JP17096980A JP17096980A JPS5794645A JP S5794645 A JPS5794645 A JP S5794645A JP 17096980 A JP17096980 A JP 17096980A JP 17096980 A JP17096980 A JP 17096980A JP S5794645 A JPS5794645 A JP S5794645A
Authority
JP
Japan
Prior art keywords
frequency
flaw
eddy
oscillator
depth
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
JP17096980A
Other languages
Japanese (ja)
Inventor
Masaaki Nakajima
Hiroshi Kawase
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
Original Assignee
Hitachi Ltd
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 filed Critical Hitachi Ltd
Priority to JP17096980A priority Critical patent/JPS5794645A/en
Publication of JPS5794645A publication Critical patent/JPS5794645A/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 detect the depth of a flaw in accordance with the relative magnitude of these signals, by multiplexing the frequency of an eddy-current generated in a steel plate to fetch a detection signal having the same frequency at every energizing frequency by generating a beat frequency. CONSTITUTION:For instance, when the frequency of an oscillator 1 and the frequency of the second oscillator 23 are set to 100kHz and 95kHz, resectively, the frequency which has passed through an LPF22 becomes 5kHz. A flaw signal component contained in this intermediate frequency is extracted by phase detecting circuits 5, 6 of X and Y, and a flaw signal is obtained. As for the flaw signal, it is necessary to change the energizing frequency depending on depth of a flaw, a quality of material and a surface state of the material, but a low constant frequency is obtained as an output of a multiplier 21 by myltiplying 2 frequencies which are slightly differnent.
JP17096980A 1980-12-05 1980-12-05 Eddy-current flaw detector Pending JPS5794645A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP17096980A JPS5794645A (en) 1980-12-05 1980-12-05 Eddy-current flaw detector

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP17096980A JPS5794645A (en) 1980-12-05 1980-12-05 Eddy-current flaw detector

Publications (1)

Publication Number Publication Date
JPS5794645A true JPS5794645A (en) 1982-06-12

Family

ID=15914715

Family Applications (1)

Application Number Title Priority Date Filing Date
JP17096980A Pending JPS5794645A (en) 1980-12-05 1980-12-05 Eddy-current flaw detector

Country Status (1)

Country Link
JP (1) JPS5794645A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5848848A (en) * 1981-09-17 1983-03-22 Nisshin Steel Co Ltd Eddy current test equipment

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS53140088A (en) * 1977-05-13 1978-12-06 Mitsubishi Heavy Ind Ltd Flaw detection using eddy current

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS53140088A (en) * 1977-05-13 1978-12-06 Mitsubishi Heavy Ind Ltd Flaw detection using eddy current

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5848848A (en) * 1981-09-17 1983-03-22 Nisshin Steel Co Ltd Eddy current test equipment

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