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FMC/TFM Technique for Defect Characterisation

The TFM technique is not affected by the beam size; the algorithm creates a virtual focus on every pixel of the image.

FMC/TFM Technique for Defect Characterisation

Defect characterisation has always been a challenge for ultrasonic inspection techniques. Phased array has greatly enhanced the interpretation compared to conventional UT. However, some defects are still easily misinterpreted such as cracks with slag or lack of penetration depending on the geometry of the root.

The weld inspection field is vast and regulated by many standards. Most of them have different criteria according to the defect nature. For example, the ASME standard would allow defects under a certain dimension but will automatically reject cracks and lack of fusion. A proper characterisation may save money and increase public safety at the same time.

For now, the FMC/TMF technique is not regulated by standards which makes it difficult to apply on a day-to-day basis. The Sonatest solution offers a multiscan approach based on the Veo3 inspection instrument. This solution allows the user to keep using his rejection criteria for a weld inspection and, when in doubt about the nature of the defect, generate a high-resolution image with the FMC/TFM technique for a better assessment.

  FMC-TFM Technique for Defect Charecterisation  (358.6KB)

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