Title:
FILM THICKNESS MEASURING DEVICE OF SURFACE OF CONDUCTIVE MATERIAL
Document Type and Number:
Japanese Patent JPH05223559
Kind Code:
A
Abstract:
PURPOSE:To achieve a highly accurate measurement of film thickness by converting the difference between an electrical signal for detecting leak current according to eddy current type and that for detecting distance optically to a coating film thickness. CONSTITUTION:A magnetic flux which is generated from a detection coil 12 of an eddy current displacement detector 10 generates eddy current at a conductive object to be detected and then converts impedance of the coil 12 to an electrical signal Lg corresponding to the distance between the coil 12 and a conductive material. Then, laser beam is cast to the object to be inspected from a laser diode 22 of a laser displacement detector 20. The irradiating light is reflected on the surface of a coating material which is coated on the object to be inspected and forms an image on a light position detection element 26. The element 26 generates an electrical signal Ls at a level corresponding to the image-forming position, which corresponds to the distance to the surface of the coating material. Then, by obtaining a difference (Lg-Ls) of an electrical signal corresponding to the detection distance, a coating film thickness can be detected.
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Inventors:
MOTOMURA MASAKI
TOKUDA ATSUHIRO
TOKUDA ATSUHIRO
Application Number:
JP2847192A
Publication Date:
August 31, 1993
Filing Date:
February 14, 1992
Export Citation:
Assignee:
NIPPON STEEL CORP
International Classes:
B22D11/06; G01B7/06; G01B11/06; G01B21/08; (IPC1-7): B22D11/06; G01B7/06; G01B11/06; G01B21/08
Attorney, Agent or Firm:
Nobuoki Sugi