There are 2 categories of microscopes based on the regulation on which magnification is achieved, Light microscopes in addition to Electron microscopes (EM). In Light or optical microscopes, magnification is obtained yesteryear a arrangement of optical lenses using low-cal waves. Electron microscope (EM) uses beams of electrons to attain images. In overall design, EM is like to low-cal microscopes amongst roughly differences (Refer: Electron Microscope vs Light Microscope)
Electron microscope was designed yesteryear Knoll in addition to Ruska of Deutschland inwards 1932. There are 2 types of electron microscopes: TEM (Transmission Electron Microscope) in addition to SEM (Scanning Electron Microscope)
Scanning Electron Microscope (SEM) vs Transmission Electron Microscope (TEM)
Scanning Electron Microscope (SEM) | Transmission Electron Microscope (TEM) |
Used to attain fantabulous images of the surfaces of cells in addition to pocket-size organisms. Excellent for studying surface morphology of the organisms, cells or whatever suitable cloth nether study | Used to report the ultra construction of the jail cellphone in addition to its components. It tin run into objects equally pocket-size equally a poly peptide molecule or fifty-fifty at nano level. Provides details almost internal composition of cells or whatever suitable cloth nether study |
Electron beam scans over the surface of the sample | Electron beam top through the sample |
Based on scattered electrons or produces images yesteryear detecting secondary electrons which are emitted from the surface due to excitation yesteryear the master copy electron beam | Based on transmitted electrons or produces images yesteryear detecting master copy electrons transmitted from the sample |
Comparatively depression resolution than TEM; Resolution: 2nm(Average), 0.2nm (Special) | High Resolution; Resolution: x nm (Average), 0.5nm (Special) |
Depth of field: High | Depth of field: Moderate |
Magnifying power: 100,000X | Magnifying power: 5,000,000X |
Specimen contrast: yesteryear electron adsorption | By electron scattering |
Produces three-dimensional dark in addition to white images | Produces two-dimensional dark in addition to white images |
Preparation technique: easy | Skilled, real sparse sample is required |
Preparation thickness: variable | Very thin |
Specimen mounting: Aluminium stubs | Thin films on copper grids |
Field of view: Large | Limited |
Similarities betwixt SEM in addition to TEM | |
· Type of object : Non living | |
· Source of radiation: Electron | |
· Medium: High vacuum | |
· Nature of lenses: ane electrostsastic in addition to a few electromagnetic lenses | |
· Magnification Adjustment: Current inwards the projector lens coil | |
· Focusing: Current inwards the objective lens coil | |
Image credit:1) http://remf.dartmouth.edu/imagesindex.html 2) https://www.paldat.org/pub/Tilia_platyphyllos/109978 | |
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