Patent · US Active

Method for nondestructive testing of pipes for surface flaws

US7783432B2 · kind B2 · utility

5Cited by

3References

8Claims

0Family size

Assignee

V & M DEUTSCHLAND GMBH · DE

Inventors

Thomas Orth · Bad Hersfeld, DE
Stefan Nitsche · Seelow, DE
Till Schmitte · Bochum, DE

Key dates

Filing date	Jul 28, 2006
Grant date	Aug 24, 2010
Priority date	—
Expiry date	Jul 28, 2026

Classification

Technology area (CPC G)Physics
CPC primaryG01N27/82
WIPO fieldMeasurement
WIPO sectorInstruments

Abstract

A method for nondestructive testing of the pipes for detecting surface flaws using magnetic leakage flux is disclosed. With of the method, flaws can be detected and analyzed in near-real-time while the pipe is produced. The data obtained with inductive coils, Hall sensors or GMR sensors are digitized, the digital data are buffered in a first memory, and a subset of the digital data are copied into a second memory. The copied data are transformed with a wavelet transformation and the resulting wavelet coefficients are filtered and/or modified. In an alternative embodiment, the digital data can be continuously supplied to a routine for wavelet transformation, which is performed using cascaded digital signal processing routines. The evaluated variable is compared with a reference value, wherein a determined flaw-based signal can be unambiguously associated with the position of the flaw.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.