Adjust The Interpupillary Distance; Diopter Adjustment; Use Of Oil Immersion Objective - Optika B-190TB Serie Manual De Instrucciones

8.5

Adjust the interpupillary distance

Except models B-191 / B-191S
Hold the right and left parts of the observation head
using both hands and adjust the interpupillary dis-
tance by turning the two parts until one circle of light
can be seen. (Fig. 17)
• The graduation on the interpupillary distance in-
dicator ①, pointed by the spot "." on the eyepiece
holder, shows the distance between the opera-
tor's eyes.
The range of the interpupillary distance is 48- 75 mm.
8.6

Diopter adjustment

Except models B-191 / B-191S
1. Look into the right eyepiece with your right eye
only, and focus on the specimen.
2. Look into the left eyepiece with your left eye only.
If the image is not sharp, use the dioptric adjust-
ment ring ② to compensate. (Fig. 18)
• The adjustment range is ±5 diopter. The num-
ber indicated on the adjustment ring gradua-
tion should correspond to the operator's di-
optric correction.
8.7

Use of oil immersion objective

B-191 / B-192 / B-193 /B-190TB
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. 19)
• 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 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 pa-
per 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.
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