Comparison in detect the defects sizing using conventional ultrasonic testing and phased array ultrasonic testing (PAUT) / Nur Umairah Md Nor

This project gives a review for the comparison of Conventional Ultrasonic Testing and Phase
Array Ultrasonic Testing methods in detecting and sizing defects in V-butt joint welds. The
instrument used in this project is Omniscan MX2 for both techniques. For the probe, the
criteria of selection for Phased Array technique are frequency and the number of elements.
Normally, the frequency is 5 MHz and the number of element used 32 elements. For
Conventional technique, the addition of criteria is the angle used, which. is the angle set to
60°. The test samples used in this project are PL14960, PL14962 and PL14971. The types of
these samples are V-butt weld plate and each sample has different type of artificial defect that
are central line crack, slag inclusion and lack of side wall fusion (LOSWF). The results were
evaluated based on the value of percentage error. This study proved that the percentage error
for the slag inclusion using conventional techniques is 20% while using phased array
technique is 36%. For LOSWF, the percentage error using conventional technique is 7.14%
while using phased array technique is 17.9%. For central line crack, percentage error using
conventional is 6.67%, while using phased array is 3.33%. It was proven that for slag
inclusion and LOSWF, conventional technique provides a better sizing result compared with
phased array technique. However for central line crack, phased array gives a better result
compared with conventional. This may be influenced by the thickness of the plate and the
way the inspector interpreted the data.