Olympus BHTU Руководство по эксплуатации - Страница 14
Просмотреть онлайн или скачать pdf Руководство по эксплуатации для Микроскоп Olympus BHTU. Olympus BHTU 22 страницы. Reverse nosepiece
Также для Olympus BHTU: Полная разборка, очистка и сборка (19 страниц)
Печатать страницуD.
Condenser Adjustment
®
Fig. 14
Fig. 15
1.
Condenser Centration
1) Stop down the field iris diaphragm with
knurled ring
CD
by rotating in the direc-
tion of the arrow. (Fig. 14)
2) Use the condenser height adjustment
knob
®
to move the condenser up and
down until an image of the field dia-
phragm can be seen clearly in the eye-
pieces. The rotation of the knob in the
direction of the arrow lowers the con-
denser.
Field iris
diaphragm image
Field of view
3) Bring the field iris diaphragm image into the center of the field of view with the two con-
denser centering knobs
®.
(Fig. 14)
4) Widen the diameter of the iris diaphragm progressively. If the polygonal image of the iris
diaphragm becomes inscribed in the field it means that the field diaphragm is centered.
(Fig. 15)
Field Iris Diaphragm
I
•
The field iris diaphragm controls the diameter of the ray bundle impining on the speci-
men surface and therefore, by stopping down the field diaphragm until it is slightly
larger than the field of view, it can reduce stray light, which in turn increases image defi-
nition and contrast.
70-80%
20 - 30","
Fig. 16
Opening of the
aperture diaphragm
Objective exit pupil
Aperture Iris Diaphragm
I
•
In order to achieve opTimum objective performance, the opening of the aperture iris
diaphragm should be matched to the numerical aperture of the objective in use. It is
often preferable, however, to stop down the aperture diaphragm slightly more than in-
dicated by the objective N.A. This will result in better image contrast, increased depth of
focus and a flatter field.
•
After completing focus adjustment, re-
move one of the eyepieces from the ob-
servation tube and look into the empty
eyepiece tube.
As you stop down the
aperture iris diaphragm, the image of the
iris diaphragm can be seen in the object-
ive pupil.
Adjust the opening of the
diaphragm to match the N.A. of the ob-
jective in use. If the specimen is low in
contrast, it is recommended to stop down
to
70% - 80%
of the objective N.A. (Fig.
161
13