3. Place the microscopic specimen slide on the stage, making sure that the cover slip is raised.
Lift the specimen holder clips (5) pressing downwards on the lower part, and slide the
specimen slide under the clips. Release pressure so that the slide is firmly held in place.
4. Make sure that the sample on the slide is in the optical path.
5. While looking through the eyepiece (1), turn the coarse focus knob until the sample is in
focus.
6. Readjust the focus with the fine focus knob (13) until the image appears sharp.
C. Adjusting the aperture of the diaphragm.
The diaphragm (8) should not be used to regulate the light intensity. Its function is to obtain a
high resolution of the specimen and to provide contrast in the image. Smaller apertures will
deliver higher contrast to image, although closing the aperture too much will reduce
resolution. The best way to obtain the correct aperture of the diaphragm is to experiment.
Suggested apertures for each objective are as follows:
OBJECTIVE
APERTURE OF IRIS
4X
From fully closed to 1/8 open.
10X
From 1/8 to 1/4
40X
From 1/4 to 1/2
100X (optional)
From 1/2 to 3/4
D. Changing magnification.
1. Position the objective 10X (4) in the optical path.
2. This microscope has already been parfocalised, although it is possible that small differences
exist between the objectives. It may then be necessary to adjust the focus slightly with the
fine focus knob (13).
3. When changing to the 40X and 100X objectives (optional), it must be done with great care,
ensuring that the objectives do not cause damage to the front lens.
4. In order to obtain maximum resolution of the 100X (optional), it is necessary to apply
immersion oil between the cover slip of the slide and the front lens of the objective.
a. Only a very small amount of immersion oil is needed, a drop should be enough.
b. If air bubbles appear they can be removed by gently rotating the nosepiece back
and forth.
c. After viewing, all parts that have come into contact with the oil must be cleaned
using a soft cotton cloth, lightly dampened with Xylene. If the 100X objective is not
cleaned, the oil will dry, and it will not be possible to see through it; permanent
damage could also occur.
NB. Immersion oil must ONLY be used with the 100X objective, as it is the only one
specially prepared for it. If any other objective comes into contact with the oil, it must
be cleaned immediately.
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