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INTRODUCTION:
It is a one type of electron microscopy.
Transmission electron microscopy (TEM) is a technique used to observe the
features of very small specimens. The technology uses an accelerated beam of
electrons, which passes through a very thin specimen to enable a scientist the
observe features such as structure and morphology.
The technology was first developed by German scientists Max Knoll and Ernst
Ruska in 1931 and has evolved over the years to become a common technique
that is used globally in science and engineering to look at micro and nanoparticles.
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It has three main parts. They are,
1. An Electron gun
2.The condenser system
3.Image producing system
4.Image recording system
PARTS OF TEM
Transmission Electron Microscope
Electron gun
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1. Electron gun- To produce the electrons.
2. Image producing system- Its made up of the objective lens, a movable stage
or holding the specimen, intermediate and projector lenses. They function by
focusing the passing electrons through the specimen forming a highly
magnified image.
3. Image recording system-Its made up of the fluorescent screen used to view
and to focus on the image. They also have a digital camera that permanently
records the images captured after viewing.
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APPLICATION:
1.It can be used in various industries from medical research where it is employed to investigate
viruses and bacteria, for example, to forensic science, gemology and materials science.
2.To visualize and study cell structures of bacteria, viruses, and fungi
3.To view bacteria flagella and plasmids
4.To view the shapes and sizes of microbial cell organelles
5.To study and differentiate between plant and animal cells.
6.Its also used in nanotechnology to study nanoparticles such as ZnO nanoparticles
7.It is used to detect and identify fractures, damaged micro particles which further enable repair
mechanisms of the particles.
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ADVANTAGES:
1.It has a very powerful magnification of about 2 million times that of the Light microscope.
2.It can be used for a variety of applications ranging from basic Biology to Nanotechnology, to
education and industrial uses.
3.It can be used to acquire vast information on compounds and their structures.
4.It produces very efficient, high-quality images with high clarity.
5.It can produce permanent images.
6.It is easy to train and use the Transmission Electron Microscope.
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DISADVANTAGES:
1.Very expensive to purchase.
2. They are very big to handle.
3.They are laborious to maintain.
4.It requires a constant inflow of voltage to operate.
5.The preparation of specimens to be viewed under the TEM is very tedious.
6.It requires a constant inflow of voltage to operate.