-12-
MT-50
Series
3-9
Adjust the Aperture Diaphragm
1. The aperture diaphragm decides the numerical
aperture of the illumination. Only when the N.A.
of illumination is matching with the N.A. of the
objective, it can obtain better resolution and
contrast, and also increase the depth of field.
2. As the contrast is usually low, rotate the
diaphragm adjust ring
③
to make the arrowhead
pointed to the related magnification position on
condenser base
④
, namely, to adjust the N.A. of
illumination to 70%-80% of the N.A. of objective.
The eyepiece can be taken off when it’s necessary
to observe from the tube.
Adjust the ring
③
until see the figure as shown in
Fig. 18, to adjust the proportion (see Fig. 18&19,
①
is the image of aperture diaphragm,
②
is the
edge of objective).
3-10
Use the Oil Objective (100X)
1. Use objective 4X to focus the specimen.
2. Place a drop of oil
①
on the specimen (see Fig.
20).
3. Rotate the nosepiece counterclockwise and
rotate the oil objective (100X) to the light path.
Then use the fine focusing knob to focus.
★
Make sure there is no air bubble in the oil
for fear affect the image.
A. Move the eyepiece to examine the air bubble.
Open the aperture diaphragm and field diaphragm
fully and observe the edge of the objective from
the tube (It seems round and light).
B. Rotate nosepiece slightly and swing the oil
objective for some times to remove the air bubble.
4. After using, wipe the front lens with a tissue
moistened with a small amount of 3:7 mixture of
alcohol and ether or with dimethylbenzene. Wipe
oil on the specimen.
★
Don‟t put another objective to the light path
before the oil is wiped to avoid wetting the dry
objective.
★
Too much dimethylbenzene would dissolve
the lens‟s stickiness.
Fig. 19
Fig. 20
Fig. 18
