scanning electron microscope

noun
1.
a device in which the specimen is examined point by point directly in a moving electron beam, and electrons reflected by the specimen are used to form a magnified, three-dimensional image on a television screen.
Abbreviation: SEM.
Origin
1950-55
British Dictionary definitions for scanning electron microscope

scanning electron microscope

noun
1.
a type of electron microscope that produces a three-dimensional image
scanning electron microscope in Medicine

scanning electron microscope n.
Abbr. SEM
An electron microscope that forms a three-dimensional image on a cathode-ray tube by moving a beam of focused electrons across an object and reading both the electrons scattered by the object and the secondary electrons produced by it.

scanning electron microscope in Science
scanning electron microscope
  (skān'ĭng)   
An electron microscope that moves a narrowly focused beam of electrons across an object and detects the patterns made by the electrons scattered by the object and the electrons knocked loose from the object. From these patterns a three-dimensional image of the object is created.