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:
Nov. 05, 2002
Filed:
Oct. 31, 2000
Yasuharu Chuman, Nagasaki, JP;
Masafumi Yamauchi, Nagasaki, JP;
Nobuhiko Nishimura, Nagasaki, JP;
Masahiro Umata, Nagasaki, JP;
Mitsubishi Heavy Industries, Ltd., Tokyo, JP;
Abstract
A method and apparatus for monitoring crack inside piping suitable for high temperature environment including an electrode attachment process for attaching a pair of heat resistant current input-output electrodes to an outer circumferential surface of the piping such that the crack is positioned between electrodes. Measuring intra-crack potential difference by a pair of heat resistant potential difference measuring electrodes attached to outer circumferential surface of the piping and placed between the input output electrodes by supplying alternating current between the input-output electrodes. Crack length is calculated from the measured electric potential difference after correcting the intra-crack electric potential difference as a function pipe temperature and pressure by an intra-crack electrode potential difference correction process.