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:
Sep. 02, 1997
Filed:
Oct. 18, 1995
Yoshiaki Nagashima, Hitachi, JP;
Kenichi Fujiwara, Hitachi, JP;
Masao Sato, Kitaibaraki, JP;
Fuminobu Takahashi, Hitachinaka, JP;
Masahiro Koike, Hitachi, JP;
Hajime Umehara, Hitachinaka, JP;
Yoshihiro Michiguchi, Ibaraki-ken, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi Nuclear Engineering Co., Ltd., Hitachi, JP;
Abstract
Ultrasonic waves from a transmit device are transmitted to an object subject to measurement. A surface reflected wave propagated in a contact medium and reflected at the surface of a tube and bottom surface reflected waves passing through an oxidation layer on the tube and reflected at the inner surface of the tube are convened into electric signals. A feature extracting part 5, in consideration of a correlation relationship of energy with respect to the frequency of a received signal, based on the received signal of ultrasonic waves converted to electric signals, extracts a signal feature data determined beforehand which has a strong correlation relationship with the thickness of a measured part. Based on the extracted signal feature data, a thickness conversion part references a relationship storage part which has stored therein beforehand a function that shows a relationship between the signal feature data and the thickness of the oxidation layer, and obtains the thickness of the oxidation layer.