信号位相を利用したECT信号からのき裂指示の抽出
Extraction of crack indications from ECT signals by using signal phase characteristics
著者:
山本 敏弘 Toshihiro YAMAMOTO 八島 建樹 Kenji YASHIMA 高木 敏行 Toshiyuki TAKAGI 内一 哲哉 Tetsuya UCHIMOTO
発刊日:
公開日:
crack detectioneddy current testingmulti-coil probenoise reduction
概要
This paper shows phase characteristics of crack indications obtained with a multi-coil ECT probe, and proposes a method to reduce noise and extract crack indications from the detection signals of this multi-coil ECT p robe based on these phase characteristics. Because this multi-coil ECT probe performs two kinds of scanning patterns: U-scan and T-scan, and obtains two sets of signal distributions for one scanning area simultaneousl y, the proposed method uses a two-stage process that includes so-called a main filter and a sub filter. While the main filter uses the phase information of the same scanning pattern by which the target signals are obt ained, the sub filter uses the phase information of the other scanning pattern for the target signals. Using these two filters imposes more strict conditions on extracting crack indications so as to reduce more noise.
