clappergappawpawUrban and Civil

Nov 16, 2013 (4 years and 5 months ago)


Electron Microscopes are scientific
instruments that use a beam of highly
energetic electrons to examine objects
on a very fine scale.

Transmission Electron Microscope
: A
beam of electrons is passed through the
specimen. Electrons that pass through
are used to expose film. Areas of the
specimen that scatter electrons appear
dark. False coloring enhances the

As the light passes through the film, it
interacts with the film & specific areas

Light pass through unobstructed, other
areas absorb light and doesn’t let it pass

The light that does go through is hits the
lenses found on the other side

The resulting image is projected onto a

Scanning Electron Microscope
: An
electron beam is scanned across the
surface of the specimen, and electrons
are knocked off the surface. Thus, the
surface topography of the specimen
determines the contrast and the content
of the image. False coloring enhances
the image.

A beam of electrons is produced at the
top of the microscope by an electron

The electron beam follows a vertical
path through the microscope, which is
held within a vacuum.

The beam travels through
electromagnetic fields and lenses

Which focus the beam down toward the

Once the beam hits the sample,

Detectors collect these X
rays, back
scattered electrons, and secondary

Convert them into a signal that is sent to
a screen similar to a television screen.

This produces the final image.

Organelles of a grain of tobacco

Polio Virus

Gills of a fish

Normal Circulating Human Blood