![]() ZOI is located in the near surface zone, in the front of the wedge only. Double V weld with centred lack of fusion.None surface-breaking defect and vertical.It solves thickness reading applications underneath the probe volume. The red rectangles represent the ZOIs.įor contact probes or flat wedges. The following table provides concrete examples concerning the main propagation modes. Thus, it is easy to determine if a mode is more likely to detect a defect on the backwall or on the surface of the part. Like the response of a mode based on the defect’s orientation, the energy level of a given area relative to the probe is also predictive. Anticipate the level of ultrasonic energy depending on the defect’s location.By relying on Figure 2, you can choose the appropriate mode according to the likely defect in the part.įigure 2: The double, triple and quadruple modes will generally respond better to defects having a 45, 180 and 270-degree orientation, respectively. Identify the nature and likely orientation of the defects to be detected.įor example, during an angle inspection, the reconstruction algorithm for TT, TTT and TT-TT modes is predictive of the amplitude response as a function of a defect’s orientation.For example, there may be a mode that works very well for inspecting the left side of the weld but that is not suitable for the right side. In fact, the sound path relative to the defect’s orientation will not be the same depending on the positioning of the probe. It is essential to know the relative position of the probe as a function of the ZOI. Identify the places likely to have discontinuities within the part inspected.Here are some tips for finding your way around: Nevertheless, there are various TFM propagation modes that can be difficult for the inspection to rely on. In fact, a good understanding and knowledge of ultrasound physic enables an informed user to accurately predict their TFM inspection results. The fact remains that the amplitude response of a defect as a function of a precise propagation mode remains easily predictive. There are simulation software programs that can predict the amplitude response according to a defect’s orientation based on the propagation mode. How to Properly Choose the Propagation Mode In other words, the propagation mode will not be the same if it is necessary to inspect a part suitable for delamination compared to a single V weld configuration. The quality of the image reconstructed in TFM is based on the choice of the right propagation mode, the defect’s orientation and the instrument’s configuration such as the Zone of Interest (ZOI), speed and thickness. Multi-scan acquisition representing the PA- TT- TTT-TTTT views. Therefore, if the propagation mode is not adequate with respect to the defect’s orientation, the amplitude response can greatly compromise its detectability, as demonstrated in Figure 1:įigure 1: Typical representation of sensitivity as a function of the different propagation modes for image reconstruction. The TFM, compared to phased array ultrasonic testing (PAUT), has many advantages: better resolution (which makes it easier to distinguish two reflectors close to each other), a focused image at all points and increased sensitivity depending on the mode selected and the orientation of the defects. The Challenges of Choosing the Right Propagation Mode ![]() Incorrect parameterization or an inappropriate choice of propagation mode can cause distortion in the reconstructed image or an incorrect location of the defect. The latter must assume the sound path, the type of propagation wave and their respective speeds in order to reconstruct the image as it should. The Total Focusing Method (TFM) technique involves reconstructing an image based on an A-scan matrix from the Full Matrix Capture (FMC). What Is Propagation Mode in Total Focusing Method (TFM)? A poor selection of propagation mode can seriously compromise the quality of the inspection. The TFM technique is a new, emerging technique that is still misunderstood by many people today. Understanding Propagation Mode in Total Focusing Method (TFM) ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |