The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 18, 1989
Filed:
Feb. 11, 1987
Shoji Nasu, Kobe, JP;
Yoshiro Nishimoto, Higashiosaka, JP;
Hiroaki Yasukuni, Kobe, JP;
Masayoshi Iwasaki, Miki, JP;
Kabushiki Kaisha Kobe Seiko Sho, Kobe, JP;
Abstract
A signal processing method in an electromagnetic induction test. A test object is subjected to an electromagnetic induction by use of N (N.gtoreq.1) kinds of test frequencies to obtain M (M.ltoreq.2N) kinds of phase detection outputs corresponding to respective states of the test object. The phase detection outputs are then sampled at a plurality of measuring points so that there exists n (n<M) kinds of disturbance factors of which a portion contribute to the electromagnetic induction test. The phase detection outputs have a variance greater than a variance of a target parameter of the test object and contribute to the electromagnetic induction test. A first coordinate axis Z, is determined in a direction in which a variance of a distribution of the group of the measuring points comes to be a maximum in an M-dimensional space formed with the coordinate axes associated with the M kinds of the phase detection outputs. The remaining coordinate axes are likewise determined. Based on the coordinate of each of the measuring points viewed from the coordinate axis Z.sub.n+1, a measuring is effected to determine a presence or an absence of a defect, a physical quantity, and a geometric quantity on a surface of the test object.