Chapter 5 Miscellaneous Operations; Oil-Immersion Observation - Nikon ECLIPSE E200 MV Series Instruction Manual

5
Miscellaneous Operations

Oil-Immersion Observation

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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. The condenser has an oil receptacle around its front lens.
● 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 (and field diaphragm, if the microscope has the field 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 adapter and the centering telescope (both
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 once or twice.
• Gently rotate the condenser focus knob to move the condenser up and down.
• Add another drop of oil.
• Wipe off the oil and apply again.
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