6. USEFUL ADVICES
The head of all models of microscopes serie 137 is rotary, then is is advisable the obser-
vation through the frontal part of the plate, since it makes easy the approach to the mechan-
ical controls.
When you use the immersion objective you have to take into account the following points
To use the numerical aperture of the immersion objective, both the objective and the pre-
paration will be immersed in oil, then you have to follow this process:
- focus the preparation with a low magnifying objective (4x).
- put a drop of immersion oil in the cover glass.
rotate the nosepiece and place the immersion objective, adjust the focus with the micro-
metric control.
You should avoid the appearance of bubbles in the oil film, since it produces a deteriora-
Picture 6
tension adjustment ring that is placed next to the right macrometric control of the microsco-
pe (Pic.6). However, you must avoid to loosen it excessively since this could produce the fall
of the plate together with the problems of focusing accuracy.
Picture 7
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tion in the resulting image.
It is advisable to dry the frontal lens after each observa-
tion. Never use a yellow duster!! It is better to dry it with a
special paper for the cleaning of glasses or with a piece of
linen cloth. The objective must not be immersed in any kind
of liquid, since it can bring about the release of the lens.
Depending on the observant the tension of the macrome-
tic focal controls can be modified, since it is provided with a
There is also a device for the control of the focal limit. All
models of this serie are provided with a ring that avoids that
the plate raises beyond a point, that can be determined once
the sample has been focussed, and this fact can avoid possible
accidental collisions during the observation (pic. 7). This
mechanism also allows the possibility of getting a quick focu-
sing, acelerating the observation process when you are wor-
king with different samples.
Instruction manual 50137XXX
Version 1 January-00