Use Of Oil Immersion Objective - Optika Italy B-810 Serie Manuel D'instructions

9.13 Use of oil immersion objective

1. Focus the specimen with a low power objective.
2. Lower the stage (remembering to lock the coarse
upper limit lever).
3. Put a drop of oil (provided) on the area of the
specimen to be observed. (Fig. 20)
• Make sure that there are no oil bubbles. Air
bubbles in the oil damage the image quality.
• To check for bubbles: remove an eyepiece, fully
open the aperture diaphragm and observe the
objective exit pupil. (The pupil must be round and
bright).
• To remove the bubbles, gently move the
nosepiece to the right and left to move the
immersion objective a few times and allow the air
bubbles to move.
4. Insert immersion objective.
5. Return the stage to the upper focusing point and
obtain an optimal focus using the fine focus knob.
6. After use, gently remove the oil with a soft paper
towel or a lightly moistened optic paper with a
mixture of ethyl ether (70%) and absolute ethyl
alcohol (30%).
• The immersion oil, if not immediately cleaned,
could crystallize creating a glass-like layer. In
this situation the observation of the specimen
would be difficult if not impossible due to the
presence of an additional thickness on the
objective.
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Fig. 20