Ultrasonic testing (UT) is considered one of the modern technologies that would allow checking engineering constructions and solid materials and detecting internal defects while keeping the structures intact and undamaged. Ultrasound uses acoustic waves to spread through the material to test and detect any irregularities. Such irregularities are discontinuities (type and location), material grain structure, thickness, internal corrosion, etc. Ultrasonic testing can be used on a wide variety of plastics, composites, ceramics and metals but cannot be used on wood and paper products. Other limitations include the shape of the material, its surface, its orientation during testing, and the device must be able to test the material with ease. This new technology is known as non-destructive testing (NDT) because the waves penetrate the material without damaging the original structure. The UT device would consist of a receiver, a transducer, and a monitor where the transducer would generate high-frequency sound waves that would propagate through the material being tested; these sound waves are generated at levels beyond human hearing ability. Waves pass through it and when faced with a discontinuity, part of the wave is reflected and then converted into an electrical signal where the monitor can display the result. Ultrasound is based on acoustics focused on the unidirectional movement of atoms which in turn generates a mechanical wave that will be homogeneous everywhere. The wave frequencies used are generally high, meaning the wavelengths are much shorter and more responsive, so changes in the media in the material can be easily detected. UT detects defects in the material, defects that can cause...... paper medium ......solutions/introduction-ultrasound/introduction-material-analysis/ >2010. "Frequently Asked Questions About Ultrasound Testing". Olympus. April 15, 2010 Berke, M. 2000. “Nondestructive Testing of Materials with Ultrasonics.” NDT.net. April 15, 2010 < http://www.ndt.net/article/v05n09/berke/berke1.htm#0 >"Introduction to Ultrasonic Testing." NDT Resource Center. April 15, 2010 < http://www.ndt-ed.org/EducationResources/CommunityCollege/Ultrasonics/cc_ut_index.htm > Singha, Rajib . 2010. “Ultrasonic Testing – Ultrasonic Inspection Equipment.” Buzzle.com. April 15, 2010 Tietz, May, Dietz, Bühling, 1997. “Ultrasonic Testing of Green Ceramic Materials.” NDT.net. April 15, 2010