Miscellaneous Operations; Oil-Immersion Observation - Nikon eclipse e100 Instructions Manual

Miscellaneous Operations

Oil-Immersion Observation

The "Oil" mark on the side of an objective indicates that it is an oil-immersion type objective. (The
oil-immersion objective also has a black band around the barrel end.) An oil-immersion objective
is used with the immersion oil applied between the front of the objective and the coverglass. For
an oil-immersion objective with a numerical aperture of 1.0 or more, use of an oil-immersion type
condenser is required to take full advantage of its performance. An oil-immersion type condenser,
like an oil-immersion type objective, needs immersion oil to be applied between the front of the
condenser and the coverglass.
The abbe condenser included in the bright viewfield set can be used for oil immersion observation.
Example of Oil-Immersion
Condenser:
Move the specimen toward the back and
lower the condenser slightly. Add a drop
of oil on the front of the condenser from
the long hole on the stage. Bring the
specimen back over the condenser and
slowly raise the condenser.
Objective:
Rotate the revolving nosepiece to move
the objective out of position. Add a drop
of oil to the specimen. Slowly rotate the
revolving nosepiece to bring the objective
back into position.
Eliminate Air Bubbles
Make sure that air bubbles are not trapped during oil application. Air bubbles degrade the
image. To see if any air bubbles are trapped in the oil, remove one eyepiece and fully open the
aperture diaphragm. Look into the eyepiece tube and check the objective pupil (a bright round
part). If you cannot see it well, replace one of the eyepieces with the centering telescope
(optional) and look through the eyepieces of the centering telescope while rotating the eyepiece
part of the centering telescope.
Do any of the following to eliminate air bubbles:
• Rotate the revolving nosepiece to move the objective back and forth.
• Gently move the condenser vertical motion lever to move the condenser up and down.
• Add another drop of oil.
• Wipe off the oil and apply again.
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