Ultrasound

Description

Acoustic frequencies that occur outside the range of the human ear, i.e. above 20,000 Hz. Ultrasonic vibrations are made with small transducers that change electrical energy into resonating mechanical motion. A wide range of frequencies are used depending on the application. High intensity waves are used for cleaning, emulsification, friction welding, and sonar detection. Low-amplitude waves are used for security systems (burglar alarms, etc.) and material testing. Ultrasonic vibrations are used to nondestructively characterize physical properties of materials, such as porosity, water retention, and density and also to detect defects like cracks, unbondings, delaminations, voids, porosities, interfaces of two components in objects (generally metallic ones). See Ultrasonic testing

Synonyms and Related Terms

ultrason (Fr.); Ultraschall (Deut.); ultrasonic; supersound; ultrasonography

Resources and Citations

• Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993

• Matt Roberts, Don Etherington, Bookbinding and the Conservation of Books: a Dictionary of Descriptive Terminology, U.S. Government Printing Office, Washington DC, 1982

• Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976

• Art and Architecture Thesaurus Online, http://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000

• Website: www.hants.org.uk/museums/ofr/cmeth_t.html