Abstract:
Service Inspection for checking defects in material shall be implemented after work pieces have
been used. It is very important and necessary to check the material after being painted in order to
reduce working time and work processes since paint would not have to be removed and recoated
after testing. This research is to study the theory of sound wave transmission through media, the
mathematical relationship between variables coating thicknesses and the velocity and echo height of
sound waves were raised. It is to discover the possibilities of high frequency sound waves
application for material inspection after painted. The high frequency sound waves are probe
frequency, velocity, acoustic impendence, transmission, refection, echo height and sound
attenuation. It was divided into two frequency sound waves of 2.25 MHz and 5.0 MHz of
longitudinal waves. The high frequency sound wave will be transmitted through material with five
difference coating thicknesses which are unpainted material, coated material with 100 micron, 250
micron, 325 micron and 475 micron. The results of velocity, echo height and sizes of defect related
to all coating thicknesses have been recorded. Furthermore, it is finding that the thickness of paint
layer does not affect the transmission of velocity of high frequency sound wave; on the other hand,
the thickness of paint layer affected the amplitude (echo height).