Use Of Oil Immersion Objective; Use Of Alc System; Use Of The Polarizer (Optional) - Optica B-380 Serie Manual De Instrucciones

9.10 Use of oil immersion objective

1. Focus the specimen with a low power objective.
2. Lower the stage.
3. Put a drop of oil (provided) on the area of the
specimen to be observed. (Fig. 21)
• Make sure that there are no oil bubbles. Air
bubbles in the oil damage the image quality.
• To check for bubbles: remove an eyepiece, ful-
ly open the aperture diaphragm and observe the
objective exit pupil. (The pupil must be circular
and bright).
• To remove the bubbles, gently move the nose-
piece 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 speci-
men would be difficult (even not impossible)
due to the presence of an additional thickness
on the objective.

9.11 Use of ALC system

1. Adjust the desired brightness through the eyepie-
ces using the light intensity dial (chapter 9.1).
2. Press the ALC button ① to store this setting (Fig.
22). The light on the microscope will turn off for
some seconds, then will turn on again; ALC but-
ton will light up in blue showing that ALC system
is active.
• The settings could not be working when the
light intensity is too low or too high. This is
not a defect.
3. Now the system will automatically adapt the
brightness to the eyepieces when an objective is
changed, when the aperture diaphragm is used
or when another specimen is placed on the sta-
ge.
4. Pressing the ALC button again, the ALC system
will be disabled.
• When ALC system is active the light intensity
dial is not active.

9.12 Use of the polarizer (optional)

1. Remove the specimen from the stage.
2. Looking inside the eyepieces, rotate the polarizer
until the darkest position is achieved.
3. Once the dark is achieved ("extinction" or "Cros-
sed Nicol" position) it is possible to begin the
observation.
①
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Fig. 21
Fig. 22