14
A12.0910
3-9 Center the Condenser
(1) Rotate the condenser up-down knob
①
to raise it to
the highest position. (See Fig. 21)
(2) Rotate the spanner
②
to move the front lens into
light path.
★
Move the front lens of condenser into light path
when the objective is beyond 20X.
(3) Move the 20X objective into light path and focus
the specimen.
(4) Rotate the field diaphragm adjustment ring
③
to put
the field diaphragm to the smallest position, then the
image of field diaphragm can be observed through
eyepiece.
(5) Rotate the condenser up-down knob to adjust the
image to the clearest.
(6) Adjust the condenser center adjusting screw
④
to
put the image to the center of the field of view.
(7) Open the field diaphragm gradually. If the image is
in the center all the time and inscribed to the field of
view, it shows condenser has been centered correctly.
(See Fig. 22)
(8) In actual use, you can enlarge the field diaphragm a
bit and make the image circumscribed to the field of
view.
3-10 Adjust the Field Diaphragm
By limiting the diameter of light entering the condenser,
the field diaphragm can prevent other light and
strengthen the image contrast. When the image is just
on the edge of the field of view, the objective can
perform best and obtain the clearest image.
Rotate the field diaphragm adjustment ring
③
in
clockwise, to enlarge the field diaphragm; otherwise, to
decrease it in counterclockwise. (See Fig. 21)
Fig.22
图
17
Fig.21
Fig.23
