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:
Jan. 08, 1991
Filed:
Jun. 09, 1989
Yuji Matoba, Tokyo, JP;
Toshio Koshihara, Tokyo, JP;
NKK Corporation, Tokyo, JP;
Abstract
A method for detecting a thinned out portion on the inner surface or the outer surface of a pipe, comprising heating or cooling a pipe to be tested from the outer surface or the inner surface thereof so that a difference in temperature is produced between two portions of the outer surface or the inner surface of the pipe corresponding to a thinned out portion and a normal portion of the inner surface or the outer surface of the pipe; shooting the outer surface or the inner surface of the pipe by means of a thermal imaging system to obtain a thermal image of the difference in temperature; and then calculating a differential value of a temperature distribution of the thermal image of the difference in temperature on a line passing the highest temperature point or the lowest temperature point in the thermal image of the difference in temperature. Then, two points of inflection are determined on both sides of the highest temperature point or the lowest temperature point of the temperature distribution for the thinned out portion, on the basis of the differential value of the temperature distribution; and then an extent of the thinned out portion is detected on the basis of a distance between the two points of inflection of the temperature distribution.