1. Measurement with the Microscope

2. Key Terms Field of View (FOV)
The diameter of circular image seen through a microscope.
Usually measured in micrometers (μm)
White Blood Cells seen through a microscope
FOV

3. …Key Terms
Fit Number
The number of times a specimen will fit across the field of view. i.e. 2, 4, 3.5.
What is the fit number of the white blood cell shown below…?

4. …Key Terms
…Fit Number
This cell will fit across the field of view approximately 5.3 times.
Fit number is 5.3

5. …Key Terms Scaled Magnification (SM)
Scaled magnification refers to how much bigger your drawing is than the actual image
If the actual image is 0.2 mm and your drawing is 20 mm, then SM = 100X
SM is NOT the same as ‘magnification’.

6. Formulas Don’t forget to use the same units within the same formula!
How to calculate an unknown Field of view (FOV)
Determine FOV on low power as instructed by your teacher
Unknown FOV size = known FOV on low power X magnification on low power
magnification at unknown FOV
How to estimate the size of a specimen in a field of view
size of specimen (in µm) = field size (in µm)
“fit number”
How to determine the scaled magnification
scaled magnification = diagram size (mm)
actual size (mm)
Don’t forget to use the same units within the same formula!