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:
Jul. 12, 1994
Filed:
Feb. 12, 1993
Didier Desruelles, Gresy-sur-Isere, FR;
Abstract
The duplex tube (1) comprises a tubular core (2) and a cladding or covering layer (3) made from an alloy, the base metal of which is identical to the base metal of the alloy constituting the tubular core (2). Ultrasonic waves at normal incidence are emitted into the thickness of the covering (3) and of the core (2) of the tube (1), the ultrasonic waves reflected by the inner and outer surfaces of the tube, by its interface (4) and by any flaws in cohesion at the interface (4) are collected, the propagation times of the ultrasonic waves in the thickness of the tube (1) are measured, the amplitude and the shape of the reflected waves is determined, the tube (1), from its outer surface, is subjected to a magnetic induction created by a multi-frequency sinusoidal current, measurements of the phase and/or amplitude of the currents induced in the tube (1) are made, the thickness of the covering layer (3) is deduced therefrom, the total thickness of the tube (1) is calculated from the measurements of the propagation times of the ultrasonic waves and of the thickness of the covering layer (3), and the cohesion of the tube at its interface (4) is determined by analyzing the amplitude and the shape of the ultrasonic waves reflected by the interface (4) or transmitted by the covering layer (3).