Magnetic flux leakage (MFL) is - concerning the detection of surface-near and surface-braking defects - the most commonly used method in inspecting steel pipelines after production and in service. In this paper, we attempt to use a new method based on MFL to inspect pipeline heads. We introduce the idea of a generalized characterization of the leading pipeline (in the joining region) in order to define a reference signal of a flaw, and discuss the method of separating the MFL signal of a superimposed defect near pipeline heads. The difference between reference MFL signals and artificial flaw MFL signals can be extracted properly by using the methodology of correlation canceling. The processor H represents a linear filtering operation and the vectors x and y are blocks of signal samples. Correlation canceling can contribute to reduce or even to eliminate undetectable region in the model. The obtained higher inspection speed and lower inspection preparation time required make the MFL inspection to an attractive candidate for replacement magnetic of the particle inspection in some areas.
Correlation canceling principle used in pipeline head inspection
Korrelationsaufhebungsprinzip bei der Prüfung von Pipelineköpfen
NDT&E International ; 39 , 4 ; 253-257
2006
5 Seiten, 7 Bilder, 1 Tabelle, 5 Quellen
Aufsatz (Zeitschrift)
Englisch
British Library Conference Proceedings | 1993
|Method And Apparatus for Noise Canceling Based on Partial Correlation Function
Europäisches Patentamt | 2023
|