There are two categories of microscopes based on the principle on which magnification is achieved, Light microscopes and Electron microscopes (EM). In Light or optical microscopes, magnification is obtained by a system of optical lenses using light waves. Electron microscope (EM) uses beams of electrons to produce images. In overall design, EM is similar to light microscopes with some differences (Refer: Electron Microscope vs Light Microscope)
Watch our Video: 10 Types of Microscope
Electron microscope was designed by Knoll and Ruska of Germany in 1932. There are two types of electron microscopes: TEM (Transmission Electron Microscope) and SEM (Scanning Electron Microscope)
Scanning Electron Microscope (SEM)
|
Transmission Electron Microscope (TEM)
|
Used to produce excellent images of the surfaces of cells and small organisms. Excellent for studying surface morphology of the organisms, cells or any suitable material under study
|
Used to study the ultra structure of the cell and its components. It can see objects as small as a protein molecule or even at nano level. Provides details about internal composition of cells or any suitable material under study
|
Electron beam scans over the surface of the sample
|
Electron beam pass through the sample
|
Based on scattered electrons or produces images by detecting secondary electrons which are emitted from the surface due to excitation by the primary electron beam
|
Based on transmitted electrons or produces images by detecting primary electrons transmitted from the sample
|
Comparatively low resolution than TEM; Resolution: 2nm(Average), 0.2nm (Special)
|
High Resolution; Resolution: 10 nm (Average), 0.5nm (Special)
|
Depth of field: High
|
Depth of field: Moderate
|
Magnifying power: 100,000X
|
Magnifying power: 5,000,000X
|
Specimen contrast: by electron adsorption
|
By electron scattering
|
Produces three-dimensional black and white images
|
Produces two-dimensional black and white images
|
Preparation technique: easy
|
Skilled, very thin sample is required
|
Preparation thickness: variable
|
Very thin
|
Specimen mounting: Aluminium stubs
|
Thin films on copper grids
|
Field of view: Large
|
Limited
|
Similarities between SEM and TEM
|
|
· Type of object : Non living
|
|
· Source of radiation: Electron
|
|
· Medium: High vacuum
|
|
· Nature of lenses: one electrostsastic and a few electromagnetic lenses
|
|
· Magnification Adjustment: Current in the projector lens coil
|
|
· Focusing: Current in the objective lens coil
|
|
Image credit:1) http://remf.dartmouth.edu/imagesindex.html 2) https://www.paldat.org/pub/Tilia_platyphyllos/109978
|
Download free Parts of Microscope Worksheet at our TPT store
Thank you so much:)
Wonderful it's so good
ردحذفnice piece of information
ردحذفReally good information
ردحذفawesome.....
ردحذفawesome.....
ردحذفBased on the table, it looks like the SEM has higher resolution than the TEM. Otherwise, this is an awesome comparison!
ردحذفReally helpful table - concise and informative, thanks!!
ردحذفGood information but resolution of Sem is 10 nm normally and not of TEM .TEM has higher resolution so it is normally 0.2nm.
ردحذفIt is very useful
ردحذفI liked the most this one.Very clear and neat.well done u are amazing
ردحذفResolution figures don't make sense?! How is 2nm lower resolution than 10nm? Other than being numerically smaller, I would have thought it is greater resolution because it has a greater ability to *resolve* details.
ردحذفUseful piece of information. Thank you.
ردحذفwow - pete heitmeyer
ردحذفthank you very much. This is short, neat, and easy to understand
ردحذفthank you very much. This is short, neat, and easy to understand
ردحذفvery helpful...thankyou
ردحذفThank you, the write was very helpful
ردحذفThe article was practical
ردحذفإرسال تعليق
We Love to hear from U :) Leave us a Comment to improve this site
Thanks for Visiting.....