Compound Microscope
Physics Project
How it works:
The microscope pictured above is referred to as a compound light microscope.
The term light refers to the method by which light transmits the image to your
eye. Compound deals with the microscope having more than one lens.
Microscope is the combination of two words; "micro" meaning small and "scope"
meaning view.
Early microscopes, like Leeuwenhoek's,
were called simple because they only had
one lens. Simple scopes work like
magnifying glasses that you have seen
and/or used. These early microscopes
had limitations to the amount of
magnification no matter how they were
constructed.
The creation of the compound microscope
by the Janssen’s helped to advance the
field of microbiology light years ahead of
where it had been only just a few years
earlier. The Janssen’s added a second
lens to magnify the image of the primary
(or first) lens.
Eyepiece Lens: the lens at the top that you look through. They are usually 10X
or 15X power.
Tube: Connects the eyepiece to the objective lenses
Arm: Supports the tube and connects it to the base
Base: The bottom of the microscope,
used for support
Illuminator: A steady light source (110
volts) used in place of a mirror. If your
microscope has a mirror, it is used to
reflect light from an external light source
up through the bottom of the stage.
Stage: The flat platform where you place
your slides. Stage clips hold the slides in
place. If your microscope has a
mechanical stage, you will be able to move
the slide around by turning two
knobs. One moves it left and right; the
other moves it up and down.
Revolving Nosepiece or Turret: This is the part that holds two or more
objective lenses and can be rotated to easily change power.
Objective Lenses: Usually you will find 3 or 4 objective lenses on a
microscope. They almost always consist of 4X, 10X, 40X and 100X
powers. When coupled with a 10X (most common) eyepiece lens, we get total
magnifications of 40X (4X times 10X), 100X, 400X and 1000X. To have good
resolution at 1000X, you will need a relatively sophisticated microscope with an
Abbe condenser
Rack Stop: This is an adjustment that determines how close the objective lens
can get to the slide. It is set at the factory and keeps students from cranking the
high power objective lens down into the slide and breaking things. You would
only need to adjust this if you were using very thin slides and you weren't able to
focus on the specimen at high power
Magnifying Objects/ Focusing Image:
When viewing a slide through the microscope make sure that the stage is all
the way down and the 4X-scanning objective is locked into place.
Place the slide that you want to view over the aperture and gently move the
stage clips over top of the slide to hold it into place.
Beginning with the 4X objective, looking through the eyepiece making sure to
keep both eyes open (if you have trouble cover one eye with your hand)
slowly move the stage upward using the coarse adjustment knob until the
image becomes clear. This is the only time in the process that you will need
to use the coarse adjustment knob. The microscopes that you will be using
are par focal, meaning that the image does not need to be radically focused
when changing the magnification.
To magnify the image to the next level rotates the nosepiece to the 10X
objective. While looking through the eyepiece focus the image into view using
only the fine adjustment knob, this should only take a slight turn of the fine
adjustment knob to complete this task.
To magnify the image to the next level rotates the nosepiece to the 40X
objective. While looking through the eyepiece focus the image into view using
only the fine adjustment knob, this should only take a slight turn of the fine
adjustment knob to complete this task.
Total Magnification:
To figure the total magnification of an
image that you are viewing through
the microscope is really quite simple.
To get the total magnifications takes
the power of the objective (4X, 10X,
40x) and multiply by the power of the
eyepiece, usually 10X.
Videos Of Compound Microscope:
Parts of a compound microscope
https://www.youtube.com/watch?v=9nUseN_E-l0
How to Use a Compound Microscope
https://www.youtube.com/watch?v=j5GuVIzDgrE&feature=related
How to Correctly Use a Microscope
https://www.youtube.com/watch?v=jP9HtcAvGDk&feature=related
Websites That We Search:
http://www.microscope-microscope.org/basic/microscope-parts.htm
http://www.cas.muohio.edu/mbi-ws/microscopes/compoundscope.html#how
http://www.cas.muohio.edu/mbi-ws/microscopes/Magnification.html