9.15 Use of oil immersion objective
1. Focus the specimen with a low power objective.
2. Lower the stage (remember to lock the coarse
upper limit knob).
3. Put a drop of oil (provided) on the area of the spe-
cimen to be observed. (Fig. 38)
•
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 round and
bright).
•
To remove the bubbles, gently move the nose-
piece to the right and to the left to move the im-
mersion objective a few times and allow the air
bubbles to move away.
4. Insert immersion objective in the light path.
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 pa-
per towel or a lightly moistened optic paper with a
mixture of ethyl ether (70%) and absolute alcohol
(30%).
•
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 if not impossible due to
the presence of an additional thickness on the
objective.
9.16 Use of ALC system (optional)
1. Adjust the desired brightness through the eyepie-
ces using the light intensity dial (chapter 9.3).
2. Press the MEM key ① to store this setting (Fig.
39). The light on the microscope will turn off for
some seconds, the will turn on again.
•
The settings could not be working when the
light intensity is too low or too high. This is
not a defect.
3. The LED ② of the AUTO key ③ will light up to
show that the system is now active.
4. 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 stage.
5. Pressing the AUTO key, the ALC system will be
disabled, but keeping in memory the setting of the
illumination previously achieved.
6. Pressing the AUTO key again the setting is re-
called.
•
When ALC system is active, the light intensity
dial is not active.
•
To store a new setting, repeat step 1 and 2.
This will overwrite the old setting and will sto-
re a new one.
①
Page 24
Fig. 38
②
③
Fig. 39