Optika B-810 Series, Инструкция по эксплуатации

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Page 11
Centering the condenser (Fig.13)
1. Place the specimen on the stage, insert
10x objective into the light path and
focus.
2. Insert the front lens of the swing-out
condenser
①
.
3. Rotate the field diaphragm ring
②
in the
direction showed by the arrow, to fully
close the diaphragm.
4. Rotate the condenser height adjustment
knob
③
to focus the edges of the
diaphragm.
5. Rotate the two centering screws
④
to
bring the bright spot in the center of the
field of view.
6. Gradually open the diaphragm. The
condenser is centered when the
diaphragm image is symmetrical to the
field of view.
7. In normal use, open the diaphragm until
it circoscribes the field of view.
Effects of the field diaphragm
Field diaphragm adjusts the illuminated area
to obtain a high contrast image.
Set the diaphragm according to the objective
in use until it circoscribes the field of view,
in order to eliminate unnecessary light to
eyepieces.
Aperture diaphragm (Fig. 13-14)
• The Numerical Aperture (N.A.) value of
the aperture diaphragm affects the image
contrast. Increasing or reducing this value
one can vary resolution, contrast and
depth of focus of the image.
• With low contrast specimens set the
numerical aperture value
①
(printed on
the condenser ring) to about 70%-80% of
the objective’s N.A. If necessary, remove
on eyepiece and, looking into empty
sleeve, adjust the condenser’s ring in
order to obtain an image like the one in
fig. 15.
Example: with objective PLAN 40x /
0,65 set the scale to 0.65 x 0.8 = 0,52
CENTERING THE CONDENSER
①
③
④
②
Fig.13
Fig.14
Fig.15
①
IMAGE OF
APERTURE
DIAPHRAGM
FIELD OF VIEW
30-20%
70-80%
Uso del condensatore