10
A12.1095
3-8 Adjusting the condenser
（
Fig.8
、
9
）
The condenser and the objective are coaxial. It
has been adjusted before leaving factory, so the
user needn’t to adjust them by self
The highest position of the condenser has been
adjusted before leaving factory, so the user
needn’t to adjust them by self
Turn the condenser focus knob
①
to move the
condenser up and down. Raise the condenser when
using the high magnification objective, and
descend it when using the low magnification one.
Centering the Condenser
：
1.
Adjust the condenser focus knob
①
to the
highest position.
2.
Focus the specimen with 10× objective.
3.
Rotate field iris diaphragm ring
④
until the
image of field iris diaphragm can be observed.
4.
Adjust the condenser focusing knob
①
to
focus the image of field iris diaphragm.
5.
Rotate the centering screw
③
by Allen wrench
to center the field iris diaphragm.
6.
Gradually open the field iris diaphragm until
the image of the field iris diaphragm inscribed
with the field of viewing. That means the
condenser is centred correctly.
7.
Slightly increase the field iris diaphragm in
reality operation to make the image circumscribed
with the field.
Adjusting Aperture Iris Diaphragm
The aperture iris diaphragm is designed for the
adjustment of the numerical aperture, not for the
brightness. Generally, setting the aperture iris
diaphragm to 70- 80% of the N.A. of the objective
in use will provide an image with good contrast. If
you want to observe the image of the aperture iris
diaphragm, remove one eyepiece and look
through the tube. You will see
a dark circle
encroaching on
the bottom of the tube.
Adjusting the Field Iris Diaphragm
When using, turn the ring
④
to reduce the field iris
diaphragm, look into the field, if the diaphragm
image is faintness, and do the follow steps: first,
turn the condenser focus knob, shift the condenser
holder to the position where the observed image of
the field of view is sharp; then open the field
diaphragm, let the image full of the field of view,
reduce the mixed light, improving the quality of
the image.
①
②
③
Fig.8
④
Fig.9
