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Microscopic Measurement
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Microscopic Measurement of Size
Most people use put a transparent plastic ruler under microscope to perform this task. Actually, the microscope itself provides pretty accurate measurements ranging from 0.2 - 10 mm. Based on optical physics, the diameter of the field of view can be reliably derived by a simple formula:
Diameter of the field of view (mm) = F / M, where F is the number of field of view (FOV) of the eyepiece, and M is the magnification (mag.) of the objective.
For example: Diameter of the field of view (mm) = 20 / 40 = 0.50, where 20 is the field number of eyepiece, and 40 = objective mag.
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Eyepiece |
Objective (Mag.) |
Diameter of field of view ( = F / M) mm |
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|
2 x |
10 |
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4 x |
5.0 |
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10 x |
2.0 |
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20 x |
1.0 |
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40 x |
0.50 |
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100 x |
0.20 |
Most modern microscopes have eyepieces with the number of field of view at 20 or 22. The diameters of the field of view are listed:
|
F number |
2 x = |
4 x = |
10 x = |
20 x = |
40 x = |
60 x = |
100 x = |
|
20 |
10 mm |
5.0 mm |
2.0 mm |
1.0 mm |
0.5 mm |
0.33 mm |
0.2 mm |
|
22 |
11 mm |
5.5 mm |
2.2 mm |
1.1 mm |
0.55 mm |
0.36 mm |
0.2.2 mm |
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Microscopic Measurement of Area of Field (Click the section headings (in blue) to expand or collapse the content)
Calculate the Percentage (%) of Cells
Count with Full-field
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