Description

Theoretical considerations and experimental references are introduced to show that the science of supersonics is not so much a matter of the inaudible sounds themselves as essentially of their practical applications in the new "mechanical high-frequency techniques" these lie predomin- antly in liquids and solids. Apart from underwater communications, one of the oldest fields of application for ultrasonics is the testing of materials for flaws. This technique has been considerably developed in recent years. Fully automatic testing devices for coarse and fine pressed steel, metal strip, tubes, round sections and wire are shown, and their mechanism explained. An important place in industry today is taken by high-frequency cleaning. It is now possible to clean inaccessible machine parts without any manual intervention: the cleaning of machine interiors is also possible, since high-frequency vibrations can to a large extent penetrate machine walls. Ways of ensuring the best possible sound wave permeability are being discussed. It is further demonstrated that even indismantled parts can be satisfactorily cleaned in ultrasonically charged baths, a fact which is of great importance for all re-assembly work.