The Compound Microscope

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The Compound Microscope
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Parts of Compound Microscope
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Parts / Functions

• 1.Ocular Eyepiece structure you look through to
  examine the specimen contains a lens with a
  magnification of 10x.
• 2.Revolving Nosepiece moves the desired
  objective (lens) into place.
• 3.Objectives are the 3 lenses
• low or scanning power 4x
• medium power 10x
• high power 40x

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• 4.Arm supports the ocular eyepiece, revolving
  nosepiece, objectives.
• 5.Stage Clip holds the slide with the specimen
  in place.
• 6.Stage supports the slide and moves up or
  down.
• 7.Diaphragm controls the amount of light that
  passes through the specimen.

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• 8. Illuminator light source.
• 9.Coarse Focus Adjustment Knob used only under
  low power it moves the stage a great distance to
  bring the specimen into focus.
• 10.Fine Focus Adjustment Knob can be
  used under any objective moves the stage a small
  distance to fine tune the image.

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• 11. Base supports the microscope.
• 12. On / Off Switch

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Magnification
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TOTAL MAGNIFICATION

• Powers of the eyepiece (10X) multiplied by
  objective lenses determine total magnification.

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Field of View

• Field of View (FV) is the illuminated circle that
  you see when looking through the ocular eyepiece.
  
• If we know the diameter of the FV then we can
  estimate the size of our microorganisms.

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Field of View

• With our microscopes the diameter of the FV under
  low power is 4 mm
• FV is measured in micrometers or microns.
• 1 mm 1000 microns
• Therefore, our FV under low power is 4000 microns
  

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Questions

• Read pages 25-26, 171, 1070-1071 and answer the
• following questions below
• (A) Compare light (compound) microscopes to
• electron microscopes.
• (B) Compare and contrast
• Transmission Electron Microscopes (TEM)
  
• Scanning Electron Microscopes (SEM)
• (C) Explain how to prepare a wet mount slide

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TEM
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SEM